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名词解释prototroph原养型是能够在基本培养基（只含有无机盐类、碳源、水等基本营养成分的培养基）上生长的细菌。
auxotroph辅养型是一种细菌，通过突变失去了合成一至多种有机化合物的能力，在基本培养基上不能生长。
F+ cell F+细胞是作为部分染色体的供体的细胞。
F－细胞是接受供体染色体材料，并将它与它自己的染色体重组的细胞。
Hfr细胞（高频率重组细胞）带有一个整合的F因子的细胞叫高频率重组细胞。
plasmid质粒（F因子）是自主存在在细菌细胞质中的F因子，是双链的环状DNA. competence感受态细菌细胞能够吸收整合DNA的一种特殊状态接合conjugation遗传物质从供体转移到受体的过程性导sexduction指接合时由F’因子所携带的外源DNA转移到细菌染色体的过程。
转化transformation指某些细菌（或其他生物）通过其细胞膜摄取周围供体的DNA片段，并将此外源DNA片段通过重组整合到自己染色体组的过程。
普遍性转导generalized transduction转导噬菌体可以转移细菌染色体组的任何不同部分的转导。
特殊性转导specialized transduction指一些温和性噬菌体只能转导细菌染色体基因组的某些基因。
基因型频率genotype frequency在一个群体内某特定基因型所占的比例基因频率gene frequency在一个群体内特定基因座某一等位基因占该基因座等位基因总数的比例。
群体遗传漂变genetic drift在一个小样本内由于抽样误差造成的群体基因频率的随机波动现象。
改变群体基因型的因素：自然选择、突变、迁移、遗传漂变、非随机交配。
杂合优势的显性假说dominance hypothesis杂交亲本的有利性状大都由显性基因控制，不利性状大都由隐性基因控制。
通过杂交，使双亲的显性基因全部集中在杂种里，杂种优势是由于双亲的有利显性基因全部集中在杂种里所引起的互补作用的结果。
体外哺乳动物细胞基因突变试验的英语Gene mutation is a crucial process in the evolution of species, as it introduces genetic diversity and drives adaptation to changing environments. In the field of molecular biology, researchers often conduct gene mutation experiments on mammalian cells to study the effects of specific genetic changes on cellular function. One commonly used method for studying gene mutations in mammalian cells is the in vitro mammalian cell gene mutation assay.The in vitro mammalian cell gene mutation assay is a widely accepted and standardized test for assessing the mutagenic potential of chemicals and other substances. This assay is based on the principle that mutations in specific genes can lead to changesin cellular phenotype, such as altered growth characteristics or resistance to certain toxins. By exposing mammalian cells to a test substance and then monitoring for genetic changes, researchers can determine the mutagenic potential of the substance in question.To conduct an in vitro mammalian cell gene mutation assay, researchers typically start by selecting a suitable mammalian cell line for the experiment. Commonly used cell lines include Chinese hamster ovary (CHO) cells, L5178Y mouse lymphoma cells, and TK6 human lymphoblastoid cells. These cell lines are chosen for their sensitivity to genetic changes and their ability to accurately reflect the mutagenic potential of test substances.Once a cell line has been selected, researchers expose the cells to varying concentrations of the test substance and incubate them for a specified period of time. During this incubation period, the cells are allowed to replicate and divide, giving them the opportunity to accumulate genetic mutations. After the incubation period, researchers can assess the presence of gene mutations by performing molecular analyses, such as polymerase chain reaction (PCR) or DNA sequencing.The results of an in vitro mammalian cell gene mutation assay can provide valuable information about the potential mutagenic effects of a test substance. If the test substance induces a significant increase in the frequency of gene mutations in the treated cellscompared to untreated controls, it may be considered mutagenic. This information is important for assessing the safety of chemicals and other substances, as mutagenic compounds have the potential to cause genetic damage and increase the risk of cancer.In conclusion, the in vitro mammalian cell gene mutation assay is a powerful tool for studying the mutagenic potential of chemicals and other substances. By exposing mammalian cells to test substances and monitoring for genetic changes, researchers can gain valuable insights into the effects of specific genetic mutations on cellular function. This assay plays a crucial role in assessing the safety of chemicals and informing regulatory decisions to protect human health and the environment.。
鳞茎球根植物的遗传转化英文回答：Genetic transformation of bulbous plants is a technique that allows for the introduction of foreign genes into the genome of these plants. This process involves the transfer of desired genes into the cells of the plant, which are then integrated into the plant's DNA. This genetic modification can result in a variety of traits, such as enhanced disease resistance, improved yield, or altered flower color.One example of genetic transformation in bulbous plants is the introduction of a gene for insect resistance in lilies. By inserting a gene from the bacteria Bacillus thuringiensis (Bt), which produces a toxin lethal tocertain insects, lilies can become resistant to pests such as aphids or thrips. This transformation can significantly reduce the need for chemical pesticides, making the plant more environmentally friendly.Another example is the modification of flower color in tulips. Through genetic transformation, scientists havebeen able to introduce genes responsible for the production of pigments such as anthocyanins or carotenoids. This has allowed for the creation of tulips with unique and vibrant colors that are not naturally found in these plants. These genetically modified tulips have become popular in the horticultural industry due to their aesthetic appeal.Genetic transformation in bulbous plants can beachieved through various methods, including Agrobacterium-mediated transformation and biolistic (gene gun) transformation. Agrobacterium-mediated transformation involves the use of a soil bacterium called Agrobacterium tumefaciens, which naturally transfers DNA into plant cells. This bacterium is genetically engineered to carry the desired gene and then introduced to the plant tissue. The bacterium transfers the gene into the plant cells,resulting in genetic transformation.Biolistic transformation, on the other hand, involvesthe use of a gene gun to deliver DNA-coated particles into the plant cells. The gene gun shoots tiny gold or tungsten particles coated with the desired gene into the plant tissue. The particles penetrate the cell walls and deliver the foreign DNA into the plant cells, leading to genetic transformation.In both methods, the transformed plant cells are then cultured in a laboratory to encourage their growth into whole plants. Once the plants have grown, they are screened for the presence of the desired trait, such as insect resistance or altered flower color. This screening process involves various molecular techniques, such as PCR or gene expression analysis, to confirm the successful integration of the foreign gene into the plant's genome.Overall, genetic transformation of bulbous plantsoffers a powerful tool for improving their traits and characteristics. It allows for the introduction of desired genes that can confer benefits such as pest resistance, enhanced color, or increased yield. This technology has the potential to revolutionize the horticultural industry bycreating novel and improved varieties of bulbous plants.中文回答：鳞茎球根植物的遗传转化是一种将外源基因引入这些植物基因组的技术。
acrocentric chromosome近端着丝粒染色体acute intermittent porphyria急性间隙性卟啉症additive gene累加基因adenylate deaminase，ADA腺苷脱氨酶affected pedigree member，APM患病家系成员法affected sib-pair，ASP患病同胞对法agammaglobulinemia丙种球蛋白血症albinism白化病alkaptonuria尿黑酸尿症Allele-specific oligonucleotide，ASO等位基因特异性寡核苷酸Alu family Alu家族An International System for Human Cytogenetics Nomenclature，ISCN人类细胞遗传学命名的国际体制anaphase lag染色体分裂后期延滞anencephalus无脑畸胎aneupliod非整倍体anticipation遗传早现antisense technology反义技术association关联assortative mating选型婚配atrial septal defect，ASD房间隔缺损autoimmune disease，AID自身免疫性疾病autosomal disease常染色体病autosomal dominant inheritance，AD常染色体显性遗传autosomal dominantly inherited chronic progressive external ophthalmoplegia，AD-CPEO慢性进行性外眼肌麻痹autosomal inheritance常染色体遗传average inbreeding coefficient平均近婚系数autosomal recessive inheritance，AR常染色体隐性遗传autosome常染色体Bbalanced translocation carrier染色体平衡易位携带者base substitution碱基替换biological fitness生物适合度biometric model fitting生物统计模型拟合birth defect出生缺陷brachydactyly短指（趾）症breakage断裂bronchial asthma支气管哮喘carrier携带者centi-Morgan，cM厘摩centric fusion着丝粒融合centromere着丝粒chromatid染色单体chromatin染色质chromosomal disorder染色体病chromosomal polymorphism染色体多态性chromosomal rearrangement染色体重排chromosome染色体chromosome aberration染色体畸变chromosome banding染色体显带chromosome lose染色体丢失chromosome set染色体组chronic progressive external ophthalmoplegia，CPEO慢性进行性眼外肌瘫痪clinical genetics临床遗传学co-segregation共分离codominance共显性codon密码子coefficient of relationship亲缘系数comparative genomics比较基因组学complete penetrance完全外显complex disease复杂疾病congenital adrenal hyperplasia先天性肾上腺皮质增生症congenital glucose-galactose malabsorption先天性葡萄糖、半乳糖吸收不良症congenital malformation先天畸形consanguinous mating近亲婚配cri du chat syndrome猫叫综合征cysticfibrosis，CF囊性纤维样变cystinuria胱氨酸尿症Ddelayed dominance延迟显性deletion缺失derivation chromosome衍生染色体diabetes mellitus，DM糖尿病diandry双雄受精dicentric chromosome双着丝粒染色体digyny双雌受精diploid二倍体Down Syndrome，DS Down综合征Down syndrome cell adhesion molecule，DSCAM DS细胞黏附分子Down syndrome critical region，DCR DS关键区Duchenne muscular dystrophy，DMD Duchenne型肌营养不良症duplication重复dynamic mutation动态突变EEdward syndrome Edward综合征Ehlers-Danlos Ehlers-Danlos综合征endomitosis核内有丝分裂endoreduplication核内复制euchromatin常染色质eugenics优生学euphanics优形学euploid整倍体eupsychics优心学euthenics优境学expanded familial genetic counseling扩大的家庭遗传咨询expressivity表现度Ffetal alcohol syndrome胎儿酒精综合征frame-shift mutation移码突变functional cloning功能克隆functional genomics功能基因组学familiar hypercholesterolemia家族性高胆固醇血症Ggain-of-function mutation功能加强突变galactosemia半乳糖血症gene基因gene augmentation基因增强gene correction基因修正gene expression基因表达gene mutation基因突变gene replacement基因替代gene therapy基因治疗genetic code遗传密码genetic counseling遗传咨询genetic disease遗传病genetic heterogeneity遗传异质性genetic imprinting遗传印记genetic map遗传图genetic medicine遗传医学genetic shift随机遗传漂变genome基因组genomic imprinting基因组印记glucose-6-phosphate dehydrogenase deficiency，G6PD葡糖-6-磷酸脱氢酶缺乏症glycogen storage disease，GSD糖原贮积症GT-AG rule GT-AG法则Hhaploid单倍体haplotype单倍型healthy birth健康生殖hemizygote半合子hemoglobinopathy血红蛋白疾病hemolytic disease of the newborn新生儿溶血症hemophilia A血友病Ahereditary chorea遗传性舞蹈病hereditary enzymopathy遗传性酶病heritability遗传度heterochromatin异染色质heteromorphism异形性heteroplasmy异质性histo-blood group组织血型homoplasmy同质性housekeeping protein持家蛋白human genetics人类遗传学human genome diversity project，HGDP人类基因组多样性计划human genome project，HGP人类基因组计划human leucocyte antigen，HLA人类白细胞抗原human prion diseases人类朊蛋白病Huntington’s chorea Huntington舞蹈病hydramnios羊水过多hyperdiploid超二倍体hypodiploid亚二倍体Iimmunodeficiency免疫缺陷inborn errors of metabolism先天性代谢缺陷inbreeding coefficient近婚系数incomplete penetrance不完全外显induced aberration诱发畸变induced mutaion诱发突变industrial genomics工业基因组学inherited disorders of col1age胶原蛋白病insertion插入interstitial deletion中间缺失intrauterine diagnosis宫内诊断inversion倒位irregular dominance不规则显性isochromosome等臂染色体Kkaryotype核型karyotype analysis核型分析Kearns-Sayre syndrome，KSS Kearns-Sayre综合征Klinefelter syndrome Klinefelter综合征KpnⅠfamily KpnⅠ家族Llandmark界标Leber hereditary optic neuropathy，LHON Leber遗传性视神经病Leigh sysdrom，LS Leigh综合征Lesch-Nyhan syndrome Lesch-Nyhan综合征liability易患性length-based heteroplasmy长度异质性linkage map连锁图loss-of-function mutation功能丢失的突变luxury protein奢侈蛋白Mmajor gene主基因major histocompatibility complex，MHC主要组织相容性复合体maternal inheritance母系遗传medical genetics医学遗传学metacentric chromosome中着丝粒染色体minor gene微效基因missense mutation错义突变mitochondrial disease线粒体病mitochondrial DNA，mtDNA线粒体DNAmitochondria1 encephalomyopathies，ME线粒体脑肌病mitochondrial encephalomyopathy with lactic acidosis，and stroke-like episodes，MELAS线粒体脑肌病合并乳酸血症及卒中样发作molecular diagnosis分子诊断molecular disease分子病monogenic disorder基因遗传病monosomy单体型morbid genomics疾病基因组学mucopolysaccharidosis，MPS粘多糖贮积症multifactorial disorder多因子病multifactorial inheritance，MF多因子遗传mutagen诱变剂mutant protein突变蛋白mutation突变mutation load突变负荷myeloschisis脊髓裂myoclonic epilepsy and ragged red fibers，MERRF伴有破碎红纤维的肌阵挛癫痫Nneonatal screening新生儿筛查neurogenic muscle weakness,ataxia,and retinitis pigmentosa，NARP神经源性肌软弱、共济失调并发色素性视网膜炎non-disjunction不分离non-sense mutation无义突变novel property mutation新特征突变nuclear DNA，nDNA核DNAnullosomy缺体型OOnline Mendelian Inheritance in Man在线《人类孟德尔遗传》osteogenesis imperfecta成骨不全Pparacentric inversion臂内倒位parental imprinting亲代印记Parkinson disease，PD帕金森病path analysis通径分析Patau syndrome Patau综合征pedigree analysis系谱分析法penetrance外显率pericentric inversion臂间倒位peudogene拟基因pharmacogenomics药物基因组学phenocopy拟表型phenylketonuria，PKU苯丙酮尿症physical map物理图plasma protein disease血浆蛋白病pleiotropy基因的多效性point mutation点突变polygenic disorder多基因遗传病polygenic inheritance多基因遗传polyploid多倍体polysomy多体型positional cloning位置克隆post-translational isozyme翻译后同工酶prenatal diagnosis产前诊断proband先证者proteomics蛋白质组学pseudodiploid假二倍体Qqualitative character质量性状quantitative character数量性状quantitative trait loci，QTL数量性状位点Rreceptor disease受体病reciprocal translocation相互易位recurrence risk再发风险率rejoin重接restriction fragment length polymorphism，RFLP限制性片段长度多态性reunion愈合或重合rheumatoid authritis，RA类风湿性关节炎ring chromosome环状染色体Robertsonian translocation罗伯逊易位Ssame sense mutation同义突变schizophrenia，SZ精神分裂症segregation load分离负荷selection coefficient选择系数sequence-based heteroplasmy序列异质性sequence map序列图severe combined immunodeficiency，SCID严重联合免疫缺陷病sex chromatin性染色质sex chromosome性染色体sex chromosome disease性染色体病sex-conditioned inheritance从性遗传sex-determining region Y，SRY Y性别决定区域sex-limited inheritance限性遗传short tandem repeat，STR短串联重复sick1e cel1 anemia镰状细胞贫血single gene disorder单基因遗传病single nucleotide polymorphism，SNP单核苷酸多态性single-strand conformation polymorphism，SSCP单链构象多态性small deletion syndrome微小缺失综合征somatic cell genetic disorder体细胞遗传病somatic mutation体细胞突变spina difida脊柱裂spina bifida occulta隐性脊柱裂spontaneous aberration自发畸变spontaneous mutation自发突变static mutation静态突变structural equation modeling结构等式模型structural genomics结构基因组学submetacentric chromosome亚中着丝粒染色体susceptibility易感性Ttandemly repeatd genes串联重复基因telocentric chromosome端着丝粒染色体telomere端粒teratogen致畸因子terminal deletion末端缺失terminator codon mutation终止密码突变testis-determining factor，TDF睾丸决定因子tetralogy of Fallot法乐氏四联症tetraploid四倍体tha1assemia地中海贫血tissue-specific protein组织特异性蛋白translocation易位transcription map转录图transition转换transmission disequilibrium test，TDT传递不平衡检验法transvertion颠换3trinucleotide repeat amplification脱氧三核苷酸重复扩增trinucleotide repeat expansion diseases，TREDs三核苷酸重复扩增疾病triplet code三联体密码trisomy三体型Turner syndromeTurner综合征Vvariable number of tandem repeats，VNTR可变数目串联重复ventricular septal defect，VSD室间隔缺损vitamin D-resistant rickets抗维生素D佝偻病XX chromatin X染色质X inactivation X染色体失活X-linked dominant inheritance，XD X伴性显性遗传X-linked inheritanceX伴性遗传X-linded recessive inheritance，XR X连锁隐性遗传xeroderma pigmentosum，XP着色性干皮病YY chromatin Y染色质Y-linked inheritance Y连锁遗传。
Eternal youth could be one step closer following the successful transformation1 of old human cells into young ones.随着科学家成功地将人体衰老细胞转换成年轻的细胞，人类距离青春永驻的梦想将更近一步。
The process increases the length of the 'telomeres', which are the protective caps on the end of chromosomes2 that impact ageing and disease.Researchers in the US say the technique could extend human life and provide new hope for battling diseases that arise from old age.Telomeres - often described as being like the plastic caps on the end of shoelaces –help keep DNA3 healthy.These protective end caps become shorter with each DNA replication, and eventually are no longer able to protect DNA from sustaining damage and mutations, causing people to age.In young people, telomeres are about 8,000-10,000 organic molecules4, or nucleotides, long.'Now we have found a way to lengthen5 human telomeres by as much as 1,000 nucleotides, turning back the internal clock in these cells by the equivalent of many years of human life,' said Helen Blau of Stanford University.To make the discovery, researchers used modified messenger RNA to extend the telomeres.RNA carries instructions from genes6 in the DNA to the cell's protein-making factories.The RNA used in this experiment contained the coding sequence for TERT - the active component7 of a naturally occurring enzyme8 called telomerase.When the cells are treated, they behave as if they are younger and multiply quickly rather than dying.'One day it may be possible to target muscle stem cells in a patient with Duchenne muscular dystrophy, for example, to extend their telomeres,' said Dr Blau.'There are also implications for treating conditions of aging, such as diabetes9 and heart disease.'This has really opened the doors to consider all types of potential uses of this therapy.'The researchers also hope that the method will be able to allow scientists to generate large numbers of cells that could someday lead to an effective anti-aging drug.词汇解析：1 transformationn.变化；改造；转变参考例句：Going to college brought about a dramatic transformation in her outlook.上大学使她的观念发生了巨大的变化。
中英文对照的分子育种相关名词3'untranslated region (3'UTR) 3'非翻译区5'untranslated region (5; UTR) 5'非翻译区A chromosome A 染色体AATAAA 多腺苷酸化信号aberration 崎变abiogenesis 非生源说accessory chromosome 副染色体accessory nucleus 副核accessory protein 辅助蛋白accident variance 偶然变异Ac-Ds system Ac-Ds 系统acentric chromosome 无着丝粒染色体acentric fragment 无着丝粒片段acentric ring 无着丝粒环achromatin 非染色质acquired character 获得性状acrocentric chromosome 近端着丝粒染色体acrosyndesis 端部联会activating transcription factor 转录激活因子activator 激活剂activator element 激活单元activator protein( AP)激活蛋白activator-dissociation system Ac-Ds 激活解离系统active chromatin 活性染色质active site 活性部位adaptation 适应adaptive peak 适应顶峰adaptive surface 适应面addition 附加物addition haploid 附加单倍体addition line 附加系additive effect 加性效应additive gene 加性基因additive genetic variance 加性遗传方差additive recombination 插人重组additive resistance 累加抗性adenosine 腺昔adenosine diphosphate (ADP )腺昔二鱗酸adenosine triphosphate( ATP)腺昔三憐酸adjacent segregation 相邻分离A-form DNA A 型DNAakinetic chromosome 无着丝粒染色体akinetic fragment 无着丝粒片断alien addition monosomic 外源单体生物alien chromosome substitution 外源染色体代换alien species 外源种alien-addition cell hybrid 异源附加细胞杂种alkylating agent 焼化剂allele 等位基因allele center 等位基因中心allele linkage analysis 等位基因连锁分析allele specific oligonucleotide(ASO)等位基因特异的寡核苷酸allelic complement 等位（基因）互补allelic diversity 等位（基因）多样化allelic exclusion 等位基因排斥allelic inactivation 等位（基因）失活allelic interaction 等位（基因）彼此作用allelic recombination 等位（基因）重组allelic replacement 等位（基因）置换allelic series 等位（基因）系列allelic variation 等位（基因）变异allelism 等位性allelotype 等位（基因）型allohaploid 异源单倍体allopatric speciation 异域种alloploidy 异源倍性allopolyhaploid 异源多倍单倍体allopolyploid 异源多倍体allosyndesis 异源联会allotetraploid 异源四倍体alloheteroploid 异源异倍体alternation of generation 世代交替alternative transcription 可变转录alternative transcription initiation 可变转录起始Alu repetitive sequence, Alu family Alu 重复序列，Alu 家族ambiguous codon 多义密码子ambisense genome 双义基因组ambisense RNA 双义RNAaminoacyl-tRNA binding site氨酰基tRNA接合位点aminoacyl-tRNA synthetase 氨酰基tRNA连接酶amixis 无融合amorph 无效等位基因amphipolyploid 双多倍体amplicon 扩增子amplification 扩增amplification primer 扩增引物analysis of variance 方差分析anaphase (割裂）后期anaphase bridge (割裂）后期桥anchor cell 锚状细胞androgamete 雄配子aneuhaploid 非整倍单倍体aneuploid 非整倍体animal genetics 动物遗传学annealing 复性antibody 抗体anticoding strand 反编码链anticodon 反密码子anticodon arm 反密码子臂anticodon loop 反密码子环antiparallel 反向平行antirepressor 抗阻抑物antisense RNA 反义RNAantisense strand 反义链apogamogony 无融合结实apogamy 无配子生殖apomixis 无融合生殖arm ratio (染色体)臂比artificial gene人工基因artificial selection 人工选择asexual hybridization 无性杂交asexual propagation 无性繁殖asexual reproduction 无性生殖assortative mating 选型交配asynapsis 不联会asynaptic gene 不联会基因atavism 返祖atelocentric chromosome 非端着丝粒染色体attached X chromosome 并连X 染色体attachment site 附着位点attenuation 衰减attenuator 衰减子autarchic gene 自效基因auto-alloploid 同源异源体autoallopolyploid 同源异源多倍体autobivalent 同源二阶染色体auto-diploid 同源二倍体；自体融合二倍体autodiploidization 同源二倍化autoduplication 自体复制autogenesis自然发生autogenomatic 同源染色体组autoheteroploidy 同源异倍性autonomous transposable element 自主转座单元autonomously replicating sequence(ARS)自主复制序列autoparthenogenesis 自发单性生殖autopolyhaploid 同源多倍单倍体autopolyploid 同源多倍体autoradiogram 放射自显影图autosyndetic pairing 同源配对autotetraploid 同源四倍体autozygote 同合子auxotroph 营养缺陷体B chromosome B 染色体B1，first backcross generation 回交第一代B2，second backcross generation 回交第二代back mutation 答复突变backcross 回交backcross hybrid 回交杂种backcross parent 回交亲本backcross ratio 回交比率background genotype 背景基因型bacterial artification chromosome( BAC )细菌人工染色体Bacterial genetics 细菌遗传学Bacteriophage 噬菌体balanced lethal 平衡致死balanced lethal gene 平衡致死基因balanced linkage 平衡连锁balanced load 平稳负荷balanced polymorphism 平衡多态现象balanced rearrangements 平稳重组balanced tertiary trisomic 平稳三级三体balanced translocation 平稳异位balancing selection 平稳选择band analysis 谱带分析banding pattern (染色体)带型basal transcription apparatus 基础转录装置base analog 碱基类似物base analogue 类減基base content 减基含量base exchange 碱基交换base pairing mistake 碱基配对错误base pairing rules 碱基配对法则base substitution 减基置换base transition 减基转换base transversion 减基颠换base-pair region 碱基配对区base-pair substitution 碱基配对替换basic number of chromosome 染色体基数behavioral genetics 行为遗传学behavioral isolation 行为隔离bidirectional replication 双向复制bimodal distribution 双峰散布binary fission 二割裂binding protein 结合蛋白binding site 结合部位binucleate phase 双核期biochemical genetics 生化遗传学biochemical mutant 生化突变体biochemical polymorphism 生化多态性bioethics 生物伦理学biogenesis 生源说bioinformatics 生物信息学biological diversity 生物多样性biometrical genetics 生物统计遗传学（简称生统遗传学) bisexual reproduction 两性生殖bisexuality 两性现象bivalent 二价体blending inheritance 混合遗传blot transfer apparatus 印迹转移装置blotting membrane 印迹膜bottle neck effect 瓶颈效应branch migration 分支迁移breed variety 品种breeding 育种，培育;繁衍，生育breeding by crossing 杂交育种法breeding by separation 分隔育种法breeding coefficient 繁衍率breeding habit 繁殖习性breeding migration 生殖回游，繁衍回游breeding period 生殖期breeding place 繁衍地breeding population 繁殖种群breeding potential繁衍能力，育种潜能breeding range 繁衍幅度breeding season 繁衍季节breeding size 繁衍个体数breeding system 繁衍系统breeding true 纯育breeding value 育种值broad heritability 广义遗传率bulk selection 集团选择C0，acentric 无着丝粒的Cl,monocentric 单着丝粒C2, dicentric双着丝粒的C3,tricentric 三着丝粒的candidate gene 候选基因candidate-gene approach 候选基因法Canpbenmodel坎贝尔模型carytype染色体组型，核型catabolite activator protein 分解活化蛋白catabolite repression 分解代谢产物阻遏catastrophism 灾变说cell clone 细胞克隆cell cycle 细胞周期cell determination 细胞决定cell division 细胞割裂cell division cycle gene(CDC gene) 细胞割裂周期基因ceU division lag细胞割裂延迟cell fate 细胞命运cell fusion 细胞融合cell genetics 细胞的遗传学cell hybridization 细胞杂交cell sorter细胞分类器cell strain 细胞株cell-cell communication 细胞间通信center of variation 变异中心centimorgan(cM) 厘摩central dogma 中心法则central tendency 集中趋势centromere DNA 着丝粒DNAcentromere interference 着丝粒干扰centromere 着丝粒centromeric exchange ( CME)着丝粒互换centromeric inactivation 着丝粒失活centromeric sequence( CEN sequence)中心粒序列character divergence 性状趋异chemical genetics 化学遗传学chemigenomics 化学基因组学chiasma centralization 交叉中化chiasma terminalization 交叉端化chimera异源嵌合体Chi-square (x2) test 卡方检验chondriogene 线粒体基因chorionic villus sampling 绒毛膜取样chromatid abemition染色单体畸变chromatid break染色单体断裂chromatid bridge 染色单体桥chromatid interchange 染色单体互换chromatid interference 染色单体干涉chromatid segregation 染色单体分离chromatid tetrad 四分染色单体chromatid translocation 染色单体异位chromatin agglutination 染色质凝聚chromosomal aberration 染色体崎变chromosomal assignment 染色体定位chromosomal banding 染色体显带chromosomal disorder 染色体病chromosomal elimination 染色体消减chromosomal inheritance 染色体遗传chromosomal interference 染色体干扰chromosomal location 染色体定位chromosomal locus 染色体位点chromosomal mutation 染色体突变chromosomal pattern 染色体型chromosomal polymorphism 染色体多态性chromosomal rearrangement 染色体质量排chromosomal reproduction 染色体增殖chromosomal RNA 染色体RNA chromosomal shift 染色体变迁，染色体移位chromosome aberration 染色体畸变chromosome arm 染色体臂chromosome association 染色体联合chromosome banding pattern 染色体带型chromosome behavior 染色体动态chromosome blotting 染色体印迹chromosome breakage 染色体断裂chromosome bridge 染色体桥chromosome coiling 染色体螺旋chromosome condensation 染色体浓缩chromosome constriction 染色体缢痕chromosome cycle 染色体周期chromosome damage 染色体损伤chromosome deletion 染色体缺失chromosome disjunction 染色体分离chromosome doubling 染色体加倍chromosome duplication 染色体复制chromosome elimination染色体丢失chromosome engineering 染色体工程chromosome evolution 染色体进化chromosome exchange 染色体互换chromosome fusion 染色体融合chromosome gap 染色体间隙chromosome hopping 染色体跳移chromosome interchange 染色体互换chromosome interference 染色体干与chromosome jumping 染色体跳查chromosome knob 染色体结chromosome loop 染色体环chromosome lose染色体丢失chromosome map 染色体图chromosome mapping 染色体作图chromosome matrix 染色体基质chromosome mutation染色体突变chromosome non-disjunction染色体不分离chromosome paring染色体配对chromosome polymorphism 染色体多态性chromosome puff染色体疏松chromosome rearrangement染色体质量排chromosome reduplication 染色体再加倍chromosome repeat染色体质量叠chromosome scaffold 染色体支架chromosome segregation 染色体分离chromosome set 染色体组chromosome stickiness染色体粘性chromosome theory of heredity 染色体遗传学说chromosome theory of inheritance 染色体遗传学说chromosome thread 染色体丝chromosome walking 染色体步查chromosome-mediated gene transfer 染色体中介基因转移chromosomology 染色体学CIB method CIB法;性连锁致死突变显现频率检测法circular DNA 环林DNAcis conformation 顺式构象cis dominance 顺式显性cis-heterogenote顺式杂基因子cis-regulatory element 顺式调剂兀件cis-trans test 顺反考试cladogram 进化树cloning vector 克隆载体C-meiosis C减数割裂C-metaphase C 中期C-mitosis C有丝割裂code degeneracy 密码简并coding capacity编码容量coding ratio 密码比coding recognition site 密码识别位置coding region 编码区coding sequence 编码序列coding site 编码位置coding strand 密码链coding triplet 编码三联体codominance 共显性codon bias 密码子偏倚codon type 密码子型coefficient of consanguinity 近亲系数coefficient of genetic determination 遗传决定系数coefficient of hybridity 杂种系数coefficient of inbreeding 近交系数coefficient of migration 迁移系数coefficient of relationship 亲缘系数coefficient of variability 变异系数coevolution 协同进化coinducer 协诱导物cold sensitive mutant 冷灵敏突变体colineartiy 共线性combining ability 配合力comparative genomics 比较基因组学competence 感受态competent cell感受态细胞competing groups 竞争类群competition advantage 竞争优势competitive exclusion principle 竞争排斥原理complementary DNA (cDNA)互补DNA complementary gene 互补基因complementation test 互补考试complete linkage 完全连锁complete selection 完全选择complotype 补体单元型composite transposon 复合转座子conditional gene 条件基因conditional lethal 条件致死conditional mutation 条件突变consanguinity 近亲consensus sequence 共有序列conservative transposition 保守转座constitutive heterochromatin 组成型染色质continuous variation 持续变异convergent evolution 趋同进化cooperativity 协同性coordinately controlled genes 协同操纵基因core promoter element 核心启动子core sequence 核心序列co-repressor协阻抑物correlation coefficient相关系数cosegregation 共分离cosuppression 共抑制cotranfection 共转染cotranscript共转录物cotranscriptional processing共转录进程cotransduction 共转导cotransformation 共转化cotranslational secrection 共翻译分泌counterselection 反选择coupling phase 互引相covalently closed circular DNA(cccDNA)共价闭合环状DNA covariation 相关变异criss-cross inheritance 交叉遗传cross 杂交crossability 杂交性crossbred 杂种cross-campatibility 杂交亲和性cioss-infertility 杂交不育性crossing over 互换crossing-over map 互换图crossing-over value 互换值crossover products 互换产物crossover rates 互换率crossover reducer 互换抑制因子crossover suppressor 互换抑制因子crossover unit 互换单位crossover value 值crossover-type gamete 互换型配子C-value paradox C 值悖论cybrid 胞质杂种cyclin 细胞周期蛋白cytidme 胞苷cytochimera 细胞嵌合体cytogenetics 细胞遗传学cytohet 胞质杂合子cytologic 细胞学的cytological map 细胞学图cytoplasm细胞质cytoplasmic genome 胞质基因组cytoplasmic heredity 细胞质遗传cytqplasmic incompatibility 细胞质不亲和性cytoplasmic inheritance 细胞质遗传cytoplasmic male sterility 细胞质雄性不育cytoplasmic mutation 细胞质突变cytofdasmic segregation 细胞质分离cytoskeleton 细胞骨架Darwin 达尔文Darwinian fitness 达尔文适合度Darwinism 达尔文学说daughter cell 子细胞daughter chromatid 子染色体daughter chromosome 子染色体deformylase 去甲酰酶degenerate code 简并密码degenerate primer 简并引物degenerate sequence 简并序列degenerated codon 简并密码子degeneration 退化degree of dominance 显性度delayed inheritance 延迟遗传deletant 缺失体deletion 缺失deletion loop 缺失环deletion mapping 缺失作图deletion mutation 缺失突变denatured DNA 变性DNA denatured protein 变性蛋白denaturing gel 变性胶denaturing gel electrophoresis 变性凝胶电泳denaturing gradient polyacrylamide gel 变性聚丙稀酰胺凝胶density gradient centrifugation 密度梯度离心density gradient separation 密度梯度分离deoxyribonucleic acid-dependent DNA polymerase 依托于DNA的DNA聚合酶derived line 衍生系derived type 衍生类型developmental genetics 发育遗传学developmental pathway 发育途径dicentric bridge 双粒染色体桥dicentric chromosome 双着丝粒染色体differential staining technique 显带技术differentiation center 分化中心dihaploid 双单倍体,dihybrid 双因子杂种dihybrid cross 双因子杂交dimorphism 二态性diploidization 二倍化diploidize 二倍化diploidized haploid 二倍化的单倍体direct cross 正交direct repeat 同向重复（序列）direct selection 正选择directed mutagenesis 正向突变discontinuous variation 不持续变异distant hybrid 远缘杂种distant hybridization 远缘杂交diversity center 多样性中心diversity curve 多样性曲线diversity gene ( D gene) D 基因diversity indices 多样性指数diversity of species 种的多样性diversity region ( D region) D 区；多变区DNA alkylation DNA 烧化DNA amplification DNA 扩增DNA amplification in vitro DNA 体外扩增DNA amplification polymorphism DNA 扩增多态性DNA breakage DNA 断裂DNA database DNA 数据库DNA degradation DNA 降解DNA denaturation DNA 变性DNA detection DNA 检测DNA distortion DNA 变形DNA duplex DNA 双链体DNA duplicase DNA 复合酶DNA element DNA 单元DNA evolution DNA 进化DNA fingerprint DNA 指纹DNA fingerprinting DNA 指纹分析DNA homology DNA 同源性DNA hybridization DNA 杂交DNA jumping technique DNA 跳查技术DNA melting DNA 解链DNA methylation DNA 甲基化DNA modification DNA 修饰DNA modification restriction system DNA 修饰限制系统DNA nicking DNA 切口形成DNA oxidation DNA 氧化DNA packaging DNA 包装DNA pairing DNA 配对DNA pitch DNA 螺距DNA polymorphism DNA 多态性DNA probe DNA 探针DNA puff DNA 泡DNA purification DNA 纯化DNA recombination DNA 重组DNA redundant 多余DNADNA repair DNA 修复DNA replication DNA 复制DNA replication enhancer DNA 复制增强子DNA replication origin DNA 复制起点DNA replication site DNA 复制点DNA sealase DNA 连接酶DNA sequence analysis DNA 序列分析DNA sizing gene DNA大小决定基因DNA strand exchange DNA 链互换DNA strand separation DNA 链分离DNA strand transfer protein DNA 链转移蛋白DNA template DNA 模板DNA thermal cycler DNA 热循环仪DNA topoisomerase DNA 拓扑异构酶DNA transcript DNA 转录物DNA transposon DNA 转座子DNA twist DNA 扭曲DNA typing DNA 分型DNA untwisting DNA 解旋DNA unwinding enzyme DNA 解旋酶DNA unwinding protein DNA 解旋蛋白DNA-agar technique DNA 琼脂技术DNAase I footprinting DNA 酶I 足迹法DNAase-free reagent 无DNA 酶试剂DNA-binding domain DNA 结合域DNA-binding motif DNA 结合基序DNA-binding protein DNA 结合蛋白DNA-polymerase DNA 聚合酶DNA-protein complex DNA -蛋白质复合体DNA-protein interaction DNA _ 蛋白质彼此作用DNA-restriction enzyme DNA 限制酶DNA-RNA hybrid DNA-RNA 杂交体DNase-free 不含DNA 酶的dominance 显性dominance type 优势型dominance variance 显性方差dominant allele 显性等位基因dominant effect 显性效应dominant gene 显性基因dominant gene mutation 显'性基因突变dominant lethal 显性致死dominant phenotype 显性表型donor DNA 供体DNAdonor organism 供体生物dosage compensation 剂量补偿作用dotting blotting 点溃法double crossing over 双互换double fertilization 汉受精duplicate genes 重复基因duplication 重复duplicon 重复子dyad 二分体dynamic selection 动态选择ecological genetics 生态遗传学ecological isolation 生态隔离ecological niche 生态小境ectopic expression 异位表达ectopic integration 异位整合effective population size 有效群体大小embryoid 胚状体embryonic stem cells( ES cells)胚胎干细胞endocrine signal 内分泌信号endogamy 近亲繁殖endomitosis 核内有丝割裂endonuclease 内切核酸酶endopolyploidy 核内多倍体environment 环境environmental variance 环境方差environmental variation 环境变异epigenesis 后成说epigenetic inheritance 后生遗传epigenetically silenced 后生沉默episome 附加体epistasis 上位性epistatic dominance 超显性epistatic gene 上位基因equal segregation 均等分离equational division 均等割裂equilibrium population 平衡群体Expressed Sequence T ag(EST)表达序列标签euchromatin 常染色质euchromatin常染色质eugenics 优生学euhaploid 整单倍体eukaryote 真核生物eukaryotic chromosome 真核染色体eukaryotic cell 真核细胞eukaryotic organism 真核生物eukaryotic vector 真核载体euphenics 优型学euploid 整倍体evolutional load 进化负荷evolutionary divergence 进化趋异evolutionary genetics 进化遗传学evolutionaiy rate 进化速率excision repair 切除修复exconjugant 接合后体excretion vector 分泌型载体exit site 萌生点exogenote 外基因子exogenous gene 外源基因exonuclease 外切核酸酶expression cloning 表达克隆expression library 表达文库expression mutation 表达突变expression plasmid 表达质粒expression product 表达产物expression screening 表达挑选extinguisher loci 消失基因座，灭绝基因座extirpated species 绝迹种extrachromosomal inheritance 染色体外遗传extra-chromosome 超数染色体，额外染色体extranuclear inheritance 核外遗传F1 generation F1代，子一代F2 generation F2 代，子二代facultative heterochromatin 兼性异染色质familial trait 家族性状family selection 家系选择feedback suppression 反馈抑制female gamete 雌配子fertility factor 致育因子filial generation 子代fingerprint 指纹finite population 有限群体first division segregation 第一次分裂分离first division segregation pattern 第一次割裂分离模式flanking sequence 侧翼序列flow cytometry 流式细胞仪fluorescence in situ hybridization ( FISH )荧光原位杂交fluorescent primer 荧光引物fluorescent probe 荧光探针formyl methionine (fMet)甲酰甲硫氨酸foot printing 足迹法foreign DNA 外源DNAforward genetics 正向遗传学forward mutation 正向突变forward primer 正向引物founder effect 成立者效应four strand double crossing over 四线双交换full-sib 全同胞functional genomics 功能基因组学functional RNA 功能RNAgain-of-function mutation 功能获得性突变gamete 配子gametic 配子的gametic incompatibility 配子不亲和性gametic lethal 配子致死gametic linkage 配子连锁gametic meiosis 配子减数分裂gametic ratio 配子分离比gametoclonal variation 配子无性系变异gametophyte 配子体G-band G带；中期染色体带GC box GC 框GC tailing GC 加尾gel electrophoresis 凝胶电泳gemetic sterility 配子不育gene activation 基因激活gene activity 基因活性gene amplification 基因扩增gene analysis 基因分析gene arrangement 基因排列gene balance 基因平稳gene basis 基因基础gene batteries 基因群gene block 基因区段gene carrier 基因携带者gene center theory 基因中心学说gene cluster 基因簇gene combination 基因重组gene complex 基因复合体gene content 基因含量gene conversion 基因转换gene distribution 基因散布gene diversity 基因多样性gene dosage 基因剂量gene dosage compensation 基因剂量补偿gene dosage effect 基因剂量效应gene duplication 基因重复gene element 基因元件gene exchange 基因交流gene expression 基因表达gene expression system 基因表达系统gene family 基因家族gene fixation 基因固定gene flow 基因流gene frequency 基因频率gene fusion 基因融合gene inactivation 基因失活gene inoculation 基因接种gene interaction 基因相互作用gene isolation 基因分离gene knockout 基因敲除gene knock-out 基因失效法gene linkage 基因连锁gene localization 基因定位gene location 基因位置gene locus 基因位点gene magnification 基因扩增gene manipulation 基因操作gene map 基因图谱gene mapping 基因作图gene multiplication 基因重复gene mutation 基因突变gene mutation rate 基因突变频率gene order 基因顺序gene organization 基因组构gene pool 基因库gene position effect 基因位置效应gene probe 基因探针gene product 基因产物gene rearrangement 某因重排gene reassortment 基因从头配对gene replication 基因复制gene repression 基因抑制gene resortment 基因重配gene silencing 基因沉默gene splicing 基因剪接gene string 基因线gene structure 基因结构gene substitute 基因置换gene substitution 基因置换gene suppression 基因抑制gene synthesis 基因合成gene tagged 基因标签gene tagging 基因标签gene targeting 基因导向，基因寻靶gene transfer 基因转移gene transfer agent 基因传递因子gene transfer vector 基因转移载体gene transposition 基因转座genealogical classification 系谱分类genera 属general transcription factor ( GTF )通用转录因子generalized transduction 普遍性转导generation 世代generative cell 生殖细胞generative reproduction 有性繁衍generic coefficient 种属系数generic cross 属间杂交generic name 属名genes in common 一起基因gene-specific transcription factor 基因特异性转录因子genetic ablation 基因缺损genetic advance 遗传进度genetic algebra 遗传代数genetic analysis 遗传分析genetic background 遗传背景genetic balance 遗传平稳genetic block 遗传性阻碍genetic compensation 遗传补偿genetic complementation 遗传互补genetic composition 遗传组成genetic continuity 遗传连续性genetic control 遗传控制genetic covariance 遗传协方差genetic cross 杂交genetic database 遗传数据库genetic death 遗传性死亡genetic deficiency 遗传缺损genetic deformity 基因变型genetic determinant 遗传决定因子genetic dimorphism 遗传二型现象genetic distance 遗传距离genetic divergence 遗传趋异genetic diversity 遗传多样性genetic dominance 遗传优势genetic donor 基因供体genetic drift 遗传漂变genetic element遗传因子，遗传成份genetic engineering 遗传工程genetic equilibrium 遗传平衡genetic erosion 遗传冲洗，遗传蚀变genetic expression 遗传表达genetic extinction 遗传灭绝genetic facilitation 遗传增进作用genetic factor 遗传因子genetic feedback 遗传反馈genetic fingerprint 遗传指纹genetic fingerprinting 遗传指纹分析genetic fitness 遗传适合度genetic flexibility 遗传可塑性genetic gain 遗传获得量genetic heterogeneity 遗传异质性genetic homology 遗传同源genetic immunity 遗传免疫genetic imprinting 遗传印记genetic inertia 遗传惰性genetic information 遗传信息genetic inoculation 基因接种genetic instability 遗传不稳定性genetic continuity 遗传连续性genetic control 遗传控制genetic covariance 遗传协方差genetic cross 杂交genetic database 遗传数据库genetic death 遗传性死亡genetic deficiency 遗传缺损genetic deformity 基因变型genetic determinant 遗传决定因子genetic dimorphism 遗传二型现象genetic distance 遗传距离genetic divergence 遗传趋异genetic diversity 遗传多样性genetic dominance 遗传优势genetic donor 基因供体genetic drift 遗传漂变genetic element遗传因子，遗传成份genetic engineering 遗传工程genetic equilibrium 遗传平衡genetic erosion 遗传冲洗，遗传蚀变genetic expression 遗传表达genetic extinction 遗传灭绝genetic facilitation 遗传增进作用genetic factor 遗传因子genetic feedback 遗传反馈genetic fingerprint 遗传指纹genetic fingerprinting 遗传指纹分析genetic fitness 遗传适合度genetic flexibility 遗传可塑性genetic gain 遗传获得量genetic heterogeneity 遗传异质性genetic homology 遗传同源genetic immunity 遗传免疫genetic imprinting 遗传印记genetic inertia 遗传惰性genetic information 遗传信息genetic inoculation 基因接种genetic instability 遗传不稳定性genetic interaction 遗传彼此作用genetic isolating factor 遗传隔离因子genetic isolation 遗传隔离genetic knock-out experiment 基因失效试验genetic linkage 遗传连锁genetic linkage map 遗传连锁图谱genetic load 遗传负荷genetic manipulation 遗传操作genetic map 遗传图谱genetic mapping 遗传作图genetic marker 遗传标记genetic masking 基因组掩饰genetic material 遗传物质genetic mobilization 遗传转移genetic modification 遗传修饰genetic module 遗传组件genetic nomenclature 遗传命名法genetic parameter 遗传参数genetic polarity 遗传极性genetic polymorphism 遗传多样性genetic population 遗传群体genetic potential 遗传潜力genetic process 遗传进程genetic property 遗传特'性genetic ratio 遗传比genetic reactivation 遗传复活genetic reassortment 遗传重排genetic recipient 基因受体genetic recombination 遗传重组genetic regulation 遗传调剂genetic relationship 亲缘关系genetic repair mechanism 遗传修复机制genetic replication 遗传复制genetic risk 遗传危险性genetic screening 遗传筛查genetic segregation 遗传分离genetic selection 遗传选择genetic sex 遗传性别genetic shift 遗传漂移genetic stability 遗传稳定性genetic sterility 遗传性不育genetic strain 遗传品系genetic suppression 遗传抑制genetic switch 遗传开关genetic system 遗传体系genetic transcription 遗传转录genetic transformation 遗传转换genetic translation 遗传翻译genetic transmission 遗传传递genetic typing 遗传分型genetic unit 遗传单位genetic value 遗传值genetic variability 遗传变异性genetic variance 遗传方差genetic vulnerability 遗传易损性genetic“hot spot” 遗传“热点”genetical marker 遗传标记genetical non-disjunction 遗传不分离genetical population 遗传群体genetically heterogeneous 遗传异质的genetically modified organism 基因修饰生物genetics correction 遗传修正genetics of resistance 抗性遗传genetype 基因型genic balance 基因平稳genome allopolyploid基因组异质多倍体genome amplification 基因组扩增genome evolution 基因组进化genome mapping 基因组作图genome project 基因组计划genome rearrangement 基因组重排genome sequencing 基因组测序genomic exclusion 基因组排斥genomic fingerprinting 基因组指纹分析genomic footprinting 基因组足迹分析genomic imprinting 基因组印记genomic instability 基因组不稳固性genomic library 基因组文库genomic walking 基因组步查genotypic frequency 基因型频率genotypic ratio 基因型比值genotypic value 基因型值genotypic variance 基因型方差geographic speciation 地理型新种形成geographical isolation 地理隔离geographical polymorphism 地理多态现象germ layer 胚层germ line 种系germ nucleus 生殖核germ plasm 种质germinal mutation 生殖细胞突变germ-line gene therapy 种系基因医治giant chromosome 巨型染色体global homology 整体同源性global region 全局调剂子globular protein 球蛋白group selection 集团选择growth factor 生长因子GT-AG rule mRNA剪接识别信号规那么gynandromorphy 雌雄嵌合体hairpin loop 发夹环hairpin structure 发夹结构half life 半寿期half sib mating 半同胞交配haplogenotypic 单倍基因型的haploid 单倍体haploidization 单倍体化haplotype 单元型hapostatic gene 下位基因Hardy-Weinberg equilibrium 哈迪-温伯格平稳heat shock gene 热激基因heat sock protein 热激蛋白heavy chain 重链helical structure 螺旋结构。
GENETIC TRANSFORMATION OF PERENNIAL TROPICAL FRUITSMIGUEL A.GO´MEZ-LIM 1*ANDRICHARD E.LITZ 21CINVESTAV Unidad Irapuato,Km.9.6Carretera Irapuato-Leo´n,Apartado Postal 629,Irapuato GTO 36500,Mexico 2Tropical Research and Education Center,University of Florida,Homestead,Florida 33031(Received 17September 2003;accepted 10February 2004;editor E.C.Pua)SummaryGenetic transformation provides the means for modifying single horticultural traits in perennial plant cultivars without altering their phenotype.This capability is particularly valuable for perennial plants and tree species in which development of new cultivars is often hampered by their long generation time,high levels of heterozygosity,nucellar embryony,etc.Most of these conditions apply to many tropical and subtropical fruit crops.Targeting specific gene traits is predicated upon the ability to regenerate elite selections of what are generally trees from cell and tissue cultures.The integrity of the clone would thereby remain unchanged except for the altered trait.This review provides an overview of the genetic transformation of perennial tropical and subtropical fruit crops,i.e.,citrus (Citrus spp.),banana and plantain (Musa groups AAA,AAB,ABB,etc.),mango (Mangifera indica L.),pineapple (Ananas comosus L.),avocado (Persea americana Mill.),passion fruit (Passiflora edulis L.),longan (Dimocarpus longan Lour.),and litchi (Litchi chinensis Sonn.).Key words:avocado;banana;genetic transformation;mango;tropical fruits.IntroductionTropical fruits are important in the diet of people in less-developed countries,and are increasingly important as exports from many of these countries.Conventional breeding of perennial tropical fruit cultivars has been limited by their long juvenile period (up to 20years),low fertility,high levels of heterozygosity,various levels of ploidy,polyembryony,complex intraspecific incompat-ibility relationships,and severe inbreeding depression.Plant breeders often do not have access to adequate genetic diversity within local germplasm collections.Genetic diversity within many tropical fruit crop species is unexplored,and most cultivars are either seedlings from uncontrolled pollinations or dooryard selections.The production of many tropical fruit crops is based on a rather limited number of cultivars,which are poorly characterized for genetic traits.Biotechnologies that could increase the efficiency of tropical fruit crop improvement are essential to generate improved cultivars with novel traits.For example,genetic mapping could provide breeders with the tools to make rapid progress in crop improvement.Functional genomics could provide insights into genetic regulation of plant function and novel means for isolating genes for manipulation in transgenic plants.Older biotechnologies,including somatic hybridization,in vitro mutation induction and selection,etc.,have rarely been applied to these tropical fruit species for crop improvement.These tools have only begun to be employed for many tree crops,and work with tropical crops lags far behind that with herbaceous species.Of the nearly 6000field releases of transgenicplants in the USA from 1987to 2000,less than 1%(approximately 40)were fruit trees (/biotech).Genetic Transformation of Tropical TreesThe difficulty in regenerating many tree species from elite or mature phase selections is one of the most serious obstacles for applying gene transfer technologies to these plants.In addition,few genotypes of a particular species have been transformed and,in many instances,these genotypes are not commercially important.Evaluating the performance of transgenic fruit tree cultivars requires approximately 12years or until fruiting and flowering have been observed,depending on the species.Thus,molecular breeding represents a highly efficient approach for developing improved,perennial tropical fruit cultivars.The following discussion of tropical fruit crops outlines some of the research in progress,and is not meant to be an exhaustive review.Citrus (Various Citrus )Citrus species are the most widely grown fruit,and world production exceeds 102600000Mt (FAOSTAT,2004).Breeding imperatives have focused on rootstock and scion cultivar improvement.Rootstocks should be tolerant of biotic and abiotic stresses associated with roots,show good graft-compatibility with scions,show polyembryony,and support good yields.Scion breeding has attempted to retain the characteristics of existing superior selections but with improved fruit quality,yield,disease resistance,earlier or later maturing fruit,etc.Breeding goals of fruit for processing and for fresh consumption are different.Application *Author to whom correspondence should be addressed:Email mgomez@ira.cinvestav.mxIn Vitro Cell.Dev.Biol.—Plant 40:442–449,September–October 2004DOI:10.1079/IVP2004547q 2004Society for In Vitro Biology 1054-5476/04$18.00+0.00442of biotechnology to citrus has recently been reviewed by Moore et al. (2004).Genetic transformation studies involving citrus have been based upon organogenic and embryogenic regeneration pathways. Induction of citrus embryogenic cultures was described by Maheshwari and Rangaswamy(1958),and many later studies defined the optimum conditions for maintenance of embryogenic cultures and somatic embryo development(Kochba and Spiegel-Roy,1977a,b).The earliest citrus transformation experiments involved direct uptake of DNA into embryogenic protoplasts (Kobayashi and Uchimiya,1989;Vardi et al.,1990;Niedz et al., 1995).Particle bombardment was used to transform embryogenic suspension cultures of‘Page’tangelo(Yao et al.,1996),and Hidaka et al.(1990)described Agrobacterium tumefaciens-mediated transformation of embryogenic cultures.Cervera et al.(2000) characterized70transgenic Carrizo citrange plants and observed altered ploidy level,T-DNA rearrangements,and low uidA expression,possibly due to multiple inserts or transgene silencing. The current protocol has involved the transformation of cells in seedling stem pieces and regeneration of shoots from organogenic cultures.Moore et al.(1992,1993)transformed Citrus with A.tumefaciens EHA101containing pMON9793with npt II and uidA,and transformation of Poncirus trifoliata,trifoliate orange, using a similar technique was reported by Kaneyoshi et al.(1994). The recovery of transformed grapefruit plants has been described using A.tumefaciens strain EHA101with pGA482GG(Luth and Moore,1999)and strain C58C1with pBin35SGUS(Yang et al., 2000),both containing npt II and uid A.Pen˜a et al.(1995a,b) reported efficient transformation of Poncirus£sweet orange hybrid Carrizo citrange and sweet orange‘Pineapple’from internodal stem segments inoculated with A.tumefaciens strain EHA105with 35SGUSINT.In order to overcome poor rooting of transformed shoots,they were micrografted onto Troyer citrange.Bond and Roose(1998)transformed epicotyl segments of‘Washington’navel orange using A.tumefaciens strain C58C1with p35SGUSINT. Transgenic key lime was recovered by Pen˜a et al.(1997)using A.tumefaciens strain EHA105with p35SGUSINT.The procedure required co-culture of stem pieces on feeder plates consisting of tomato cells on medium containing high auxin levels.The regenerated shoots were micrografted onto Troyer citrange seedlings.Yu et al.(2002)refined Agrobacterium-based transform-ation,and utilized epicotyl segments that were cut in half longitudinally to increase the wounded area of the explants.Ghorbel et al.(1999)transformed three citrus types using this procedure with A.tumefaciens strain EHA105(pBin19-sgfp),which contains a gene for greenfluorescent protein(GFP).Recovery of transformed citrus in the mature phase has been reported.Cervera et al.(1998)partially rejuvenated mature sweet orange by grafting buds onto seedling rootstock.Internodal stem pieces were inoculated with A.tumefaciens strain EHA105with p35SGUSINT,and then co-cultivated on tomato cell culture feeder plates.Some of the transformed regenerantsflowered,and fruit were produced after14mo.In another study,Carrizo citrange was transformed to express the Arabidopsis LEAFY(LFY)or the APETALA1(AP1)genes,which promotefloral initiation(Pen˜a et al., 2001).The regenerants displayed an abnormal phenotype,but plants expressing AP1had fertileflowers and bore fruit in thefirst year. Perez-Molphe-Balch and Ochoa-Alejo(1998)reported trans-formation of Mexican lime following inoculation of stem segments with a wild strain of A.rhizogenes containing a binary vector plasmid pESC4that contained nptII and uid A.Shoots were regenerated directly or from the hairy roots.Genetic transformation of Citrus has focused on enhancing disease resistance and improving fruit quality.Several groups have transformed citrus with the CTV-CP gene(Gutierrez-E.et al.,1997; Dominguez et al.,2000;Ghorbel et al.,2000)or with an untranslatable version of this gene(Yang et al.,2000).Cervera et al. (2000)transformed Carrizo citrange with the yeast gene HAL2, which seems to be implicated in salt tolerance.Yang et al.(2000) also transformed grapefruit with the Galanthus nivalis agglutinin gene,an insecticidal gene.A gene for a pathogenesis-related(PR) protein from tomato(PR-5)has been expressed in transgenic sweet orange,and regenerants showed increased tolerance to Phy-tophthora citrophthora(Fagoaga et al.,2001).Banana(Musa groups AAA,ABB,AAB,etc.)Bananas and plantains together are a major staple food crop of the tropics and the dessert banana is a valuable export commodity. The annual production of banana and plantain is approximately 69000000Mt(FAOSTAT,2004),and is exceeded among fruit only by Citrus.Most of the producers grow the crop(s)on a small scale for domestic consumption.Fusarium oxysporum Schlecht f.sp.cubense(E.F.Smith)Snyd and Hans(Panama disease or wilt)and Mycosphaerellafijiensis Morelet(black Sigatoka)have spread rapidly throughout the major production areas during the past generation.Despite the importance of banana and plantain for food security,conventional breeding has been ineffective for addressing these and other production problems because all important Musa cultivars are sterile triploids.World production is based upon very few cultivars that have been vegetatively propagated for centuries;somatic mutations have provided the only genetic variability.The genome size is approximately873Mb or six times that of Arabidopsis thaliana (Arumuganathan and Earle,1991).Genetic transformation of Musa has focused on disease resistance and the control of fruit ripening,particularly of the‘Cavendish’type of cultivars.Genetic transformation of Musa has been reviewed by Smith et al.(2004a),and can be achieved in several ways,most of which are based on manipulation of embryogenic cultures. Embryogenic cultures are usually induced from immature male (Shii et al.,1992;Escalant et al.,1994)and femaleflowers(Grapin et al.,2000).Cote et al.(1996)and Dhed’a et al.(1991)optimized conditions for maintenance and somatic embryo development from suspension cultures.May et al.(1995)wounded the meristems of in vitro plantlets by microprojectile bombardment followed by co-cultivation with A. tumefaciens(LBA4404strain).Although transformed plants were regenerated,this procedure has not been widely utilized because of low transformation rates and chimeras.Other successful transform-ation procedures have involved direct DNA uptake into protoplasts by electroporation(Sagi et al.,1994)and particle bombardment of embryogenic cultures(Sagi et al.,1995;Becker et al.,2000).The most commonly used procedure has involved Agrobacterium-mediated transformation of embryogenic suspension cultures. Ganapathi et al.(2001)infected embryogenic suspension cultures of‘Rasthali’(ABB)with A.tumefaciens strain EHA105,andTRANSFORMATION OF TROPICAL FRUITS443transformed plants were regenerated;this procedure has now been adopted by other groups.Embryogenic cultures have been transformed with genes for resistance to banana bunchy top virus(BBTV)and banana bract mosaic virus(BBrMV)(Becker et al.,2000),i.e.,genes important or essential for BBTV replication and a gene encoding the BBrMV-CP. Several banana genes have been cloned(Clendennen and May, 1997;Medina-Suarez et al.,1997),including some coding for defense proteins(Clendennen et al.,1997),which should be useful for addressing disease problems.Banana has been transformed with genes encoding antimicrobial peptides,and extracts from leaves of transformed plants strongly suppress growth of Mycosphaerella fijiensis(black Sigatoka)(Sagi et al.,1998).Musa has been transformed with genes coding for plant defensins(Broekaert et al., 1995;Remy et al.,1998).Bananas have also been suggested as an appropriate vehicle for edible vaccines(Mor et al.,1998)and bananas containing malaria epitopes have been generated and are currently infield evaluation(Y.J.Pen˜a-Ramirez and M.A Go´mez-Lim,unpublished results).In otherfield trials of transgenic banana, delayed fruit ripening has been obtained using sense suppression of genes involved in ethylene biosynthesis(Balint-Kurti et al.,2001). Transformation of bananas has also facilitated the testing of novel promoters such as the constitutive banana actin1promoter (Hermann et al.,2001),and promoters derived from the BBTV DNA-1to25,which are expressed mainly in vascular tissue (Dugdale et al.,2001).Mango(Mangifera indica L.)Mango is one of the most important tropical crops,with world production of approximately26million Mt(FAOSTAT,2004), which is exceeded only by Citrus,Musa(bananas and plantains), table grapes,and apples.The species consists of two ecogeographic races that can be distinguished on the basis of their seed type,i.e., monoembryonic/subtropical and polyembryonic/tropical(Mukher-jee,1998).The rapid growth of the mango industry that has occurred in the past25years has largely been based upon modern selections of monoembryonic mangoes,i.e.,‘Haden’,‘Keitt’,‘Kent’, and‘Tommy Atkins’,which were identified from(uncontrolled) openly pollinated seedlings in Florida,and now form the basis for the international trade of fresh fruit.Mango production in the humid tropics is often based upon polyembryonic selections that originated in South-East Asia,e.g.,‘Carabao’,‘Cambodiana’,‘Nam doc Mai’,‘Manila’,etc.With very few exceptions,mango cultivars have not emerged from breeding programs(Iyer and Degani,1998).Mango breeding has not had a high priority,because it has been very difficult to achieve breeding objectives in an expeditious manner.The mango has a7-year juvenile period and the time required to evaluate seedling trees can be up to12years.The species is an allotetraploid (2n¼4x¼40)(Mukherjee,1950)with a genome size about three times that of A.thaliana(439Mb)(Arumuganathan and Earle, 1991).The frequency of fruit set has been estimated to be approximately0.001%(Mathews and Litz,1992),which is too low to permit manual,controlled pollinations.Genetic transformation of mango has been based upon embryogenic cultures derived from the nucellus of young fruit (Litz et al.,1982;Litz,1984).DeWald et al.(1989a,b)and Litz et al. (1993)optimized the conditions for induction,maintenance,maturation,and germination.Genetic transformation of mango has recently been reviewed by Litz and Gomez-Lim(2002).Mathews et al.(1992,1993)transformed embryogenic cultures of‘Hindi’and of a‘Keitt’zygotic embryo-derived embryogenic line,respectively. These two studies utilized different disarmed,engineered strains of A.tumefaciens:strain C58C1containing the plasmid pGV 3850::1103with nptII(Mathews et al.,1993)and strain A208 containing the plasmid pTiT37-SE::pMON9749with uidA and nptII (Mathews et al.,1992)under the control of the CaMV35S promoter. Transgenic‘Keitt’plants were regenerated.Genetic transformation of mango has involved a two-step selection(Mathews et al.,1992). Only a single breeding objective of mango has been addressed using genetic transformation,i.e.,control of fruit ripening.Two cDNA clones,mango1-aminocyclopropane-1-carboxylate(ACC) synthase and ACC oxidase,have been identified(Go´mez Lim, 1993),and a cDNA for mango alternate oxidase has been isolated (Cruz Hernandez and Go´mez Lim,1995).Cruz-Hernandez et al. (1997)transformed‘Hindi’utilizing A.tumefaciens strain LBA4404 containing pBI121with nptII,uidA,and each of the following: mango ACC oxidase,ACC synthase and ACC alternative oxidase cloned in the antisense orientation and under the control of the35S constitutive promoter.Since mango is a climacteric fruit, regeneration of plants in which ethylene production in mature fruit is inhibited could resolve the problem of premature ripening (jelly seed)and major post-harvest losses due to spoilage.The feasibility for genetic manipulation of mango will allow the manipulation of fruit quality,the alteration of tree architecture, greater resistance to insect pests and diseases and the generation of parthenocarpic mango fruit(Yao et al.,2001).Some of these goals are being pursued in the laboratories of the authors.Pineapple(Ananas comosus L.)Pineapple world production is.14700000Mt annually(FAO-STAT,2004),and30%of the crop is exported either as fresh fruit or as processed products.Pineapple is native to South America and its center of origin is in the Orinoco and Rio Negro River basins.It has a diploid number of2n¼2x¼50(Brown et al.,1997),although triploid,tetraploid,and heteroploid cultivars exist(Collins,1960). The main objective of cultivar development is improvement of the processing cultivar‘Smooth Cayenne’,specifically with respect to nematode resistance,pineapple mealybug wilt virus resistance, resistance to fungal diseases(Espinosa et al.,2002),flowering,fruit ripening control,and blackheart resistance(Botella et al.,2000; Graham et al.,2000;Rohrbach et al.,2000).Although pineapple is a major fruit crop,there have been few molecular genetic studies, and very few genes been isolated.Much of the work involving genetic transformation of pineapple is proprietary,and has not been published.The current status of pinapple biotechnology has been reviewed by Smith et al.(2004b).Pineapple has been transformed by microprojectile bombardment and by co-cultivation with A.tumefaciens.Nan et al.(1996)used microprojectile bombardment to transform embryogenic suspension cultures and obtained low-frequency transformation.Firoozabady and Gutterson(1998)and Isidron et al.(1998)recovered transformed plants from embryogenic cultures using A.tumefaciens. Graham et al.(2000)transformed‘Smooth Cayenne’leaf bases using A.tumefaciens,and recovered transformed plants from organogenic cultures.Espinosa et al.(2002)transformed morphogenic callus of444GO´MEZ-LIM AND LITZ‘Smooth Cayenne’with Agrobacterium strains AT2260and LBA4404and regenerated plants.Maize ubiquitin and CaMV35S promoters have been shown to function well in various pineapple tissues(Firoozabady and Gutterson,1998;Graham et al.,2000). The breeding objectives of pineapple that have been addressed using genetic transformation include disease resistance,control of fruit ripening,and control of blackheart disorder.Espinosa et al. (2002)described a complete protocol for transformation of pineapple with PR genes using A.tumefaciens containing constructs pHCA58and pHCG59,respectively.Plasmid pHCA58contained a class I bean chitinase gene under the control of a hybrid OCS-CaMV35S-rice actin I promoter(pA5)and tobacco ap24gene with the CaMV35S promoter.The plasmid pHCG59contained the chitinase gene under the control of the hybrid pA5promoter and a class I tobacco b-1,3-glucanase gene with the CaMV35S promoter. Plants were regenerated.Although pineapple fruits are non-climacteric,both ethylene biosynthetic genes are up-regulated in theflesh of pineapple fruits during ripening(Cazzonelli et al.,1998,1999).An ACC synthase gene that may be involved infloral initiation has been cloned (Botella et al.,2000),and its silencing in pineapple could suppress flowering until it is induced artificially.This might facilitate synchronization of fruiting and ripening,and enable mechanized harvesting.Transformed pineapple plants containing genetic constructs to inactivate this gene as well as the ripening-related ACC synthase are underfield evaluation(Botella et al.,2000). Blackheart is a fruit defect caused by exposure of pineapples to temperatures,208C,which stimulates polyphenol oxidase(PPO) activity.Stewart et al.(2001)cloned a PPO gene from pineapple fruits under conditions that produce blackheart.The PPO gene has been silenced in transformed plants and transgenic plants are under field evaluation.Avocado(Persea americana Mill.)World production of avocados is.2800000Mt(FAOSTAT, 2004),and Mexico accounts for approximately35%of the total production.The international trade in fresh avocado fruit is very important,and Chile and Mexico are the leading exporters.The species is genetically heterozygous with a7–8-year juvenile period and high rates offlower abscision and immature fruit drop.There are three races or subspecies of avocado:Mexican(subtropical), Guatemalan(highland tropical),and West Indian(lowland tropical). The chromosome number is2n¼2x¼24(Garcia,1975)and the size of the genome is about six times that of A.thaliana and similar to that of banana(883Mb)(Arumuganathan and Earle,1991). Major breeding objectives include resistance to Phytophthora root rot(PRR)caused by Phytophthora cinnamomi Rands.in rootstock cultivars,control of tree size,extended shelf-life of fruit, and development of a replacement for‘Hass’with many of the best qualities of this cultivar.Avocado breeding programs in various countries have been moderately successful,although cultivars have been derived from uncontrolled open pollinations.There are no genetic barriers among the avocado subspecies/races,and many cultivars are hybrids involving two or more subspecies.‘Hass’and ‘Fuerte’,which dominate world trade,are Guatemalan£Mexican hybrids.Genetic transformation of avocado has been reviewed recently (Litz and Witjaksono,2002;Litz et al.,2004c).Zygotic embryos (Pliego-Alfaro and Murashige,1988;Raviv et al.,1997;Witjaksono and Litz,1999a,b)and the nucellus(maternal)(Witjaksono et al., 1999)have been used for induction of embryogenic cultures. Conditions for optimizing growth of embryogenic cultures in suspension,somatic embryo development,and plant recovery have been defined(Witjaksono and Litz,1999a,b).Genetic transform-ation of avocado has been based upon highly embryogenic suspensions(Witjaksono and Litz,1999a,b).In thefirst report,Cruz-Hernandez et al.(1998)utilized a two-step selection procedure,involving incubation of the putative transformed tissue in increasing concentrations of kanamycin.This study utilized A.tumefaciens strain LBA4044with binary vector pBI121containing nptII and uidA under the control of the35S CaMV promoter.Transformation of somatic embryos was confirmed; however,plants were not regenerated.The breeding objectives of avocado that have been addressed using genetic transformation include disease resistance and control of fruit ripening.In order to address some of the disease-related problems of avocado,embryogenic cultures have been transformed with various genes for PR-related proteins(Litz and co-workers).(1) Embryogenic cultures have been infected with A.tumefaciens strain EHA101harboring pHGAFP which contains the antifungal protein gene(AFP)together with uidA,the gene for resistance to hygromycin and the CaMV35s promoter.(2)Glucanase and chitinase have been cloned in pGPTV,together with uidA,bar (Basta resistance),and the CaMV35S promoter(Witjaksono, S.Raharjo,M.A.Go´mez-Lim and R.E.Litz,unpublished data). Transformed plants with the AFP gene have been regenerated,and are currently in greenhouse trials.In addition,a complex transformed somatic hybrid consisting of‘Fuerte’with b-1,3-glucanase,chitinase,bar,and uidAþ‘Hass’with AFP,nptII,and uidA was selected on medium containing Basta and kanamycin sulfate,and plants(tetraploid)have been regenerated(S.Raharjo, Witjaksono,M.A.Go´mez-Lim and R.E.Litz,unpublished data). The regenerants will be screened as potential rootstocks. Avocado has also been transformed to extend the shelf-life of avocado fruit,and to extend the on-the-tree storage of mature fruit. Avocado fruit are climacteric.Fruit of Mexican,Guatemalan,and Guatemalan£Mexican types do not ripen on the tree,and can be stored in this way for a few months(Whiley,1992).Tropical avocado fruit ripen on the tree,and have a poor shelf-life. Embryogenic cultures have been genetically transformed using A. tumefaciens strain EHA101with pAG4092harboring SAM hydrolase,a gene that blocks ethylene biosynthesis,in a construct containing nptII and under the control of an avocado fruit-specific cellulase promoter(Efendi,2003).Plants have been regenerated. Longan(Dimocarpus longan Lour.)and Litchi(Litchi chinensis Sonn.)The litchi and longan originated in South-East Asia and southern China.The leading litchi-producing countries are China,Taiwan, India,Madagascar,and Thailand(Menzel,1992),and significant production also occurs in South Africa,Australia,and the USA. Longan is important in Thailand,China,Taiwan,Australia,and the USA.Neither longan nor litchi has benefited from conventional breeding.There is little genetic diversity within germplasm collections of these species(Menzel,1992;Ding et al.,2001). The chromosome number of longan is2n¼2x¼30(Choo andTRANSFORMATION OF TROPICAL FRUITS445Ketsa,1992),and that of litchi is2n¼2x¼28,30,or32(Menzel, 1992).Trees are very heterozygous,and are vegetatively propagated.Litchi and longan have not become major crops because of their relatively brief harvest period and the rapid decline of fruit quality and appearance after harvesting.The fruit are non-climacteric. Some of the important cultivars are very susceptible to anthracnose caused by Colletotrichum gloeosporioides Penz.,and chemical control is becoming unsustainable.Litchi and longan trees are irregular bearers,and high yields and regular bearing are necessary in order to exploit the potential of local and international markets. In China,the most valued litchi and longan fruit have small aborted seeds,known as‘chicken tongues’,a trait that is cultivar-related. Longan and litchi biotechnology have been reviewed recently(Litz et al.,2004a,b).Somatic embryogenesis has been described from mature tissue of elite cultivars of longan(Litz,1988)and from zygotic embryos of litchi(Zhou et al.,1996;Yu and Chen,1997;Yu et al.,2000)and longan(Lai et al.,1998,2000).Conditions for optimizing maintenance of embryogenic suspension cultures(Lai et al.,1995; Yu and Chen,1998)and for somatic embryo development have been described.Zheng et al.(2001)transformed somatic embryos derived from longan zygotic embryos by inoculating them with the R1601 wild strain of A.rhizogenes.Secondary somatic embryos were induced from the hairy roots and transformed plants were recovered. Embryogenic litchi cultures derived from zygotic embryos have been genetically transformed with the antifungal protein gene (Witjaksono and R. E.Litz,unpublished data).Cultures were infected with A.tumefaciens strain LBA4404containing pBI121 with nptII,uidA,and the antifungal protein gene,with the CaMV 35S promoter.Although transformed somatic embryos were recovered,plants have not been regenerated.A major objective of longan and litchi transformation is the recovery of parthenocarpic fruit(Yao et al.,2001);however,a de novo regeneration pathway for litchi from elite selections mustfirst be defined.Passionfruit(Passiflora edulis and lis Sims f.flavicarpa Deg.) Passion vines are vigorous,wood-stemmed,tendril climbers,with a90-d juvenile period.Passion fruit is grown commercially throughout the tropics and subtropics.Brazil is the leading producer of the yellow passion fruit,lis Sims f.flavicarpa Deg.,and 35%of Brazilian production is processed.The main commercial species and horticultural hybrids of passion fruit are2n¼2x¼18. Breeding programs have focused on lis,the purple passion fruit,and lisflavicarpa,the yellow form.The main breeding objectives include:(1)improved yield,(2)fruit quality,and(3) disease resistance.The most important diseases include Brown spot (Alternaria spp.),Phytophthora blight(Phytophthora ssp.),Fusar-ium wilt(Fusarium oxysporium f.passiflorae),Xanthomonas campestris pv.passiflorae,and passionfruitwoodiness virus(PWV). De novo regeneration of passionfruit has been by the organogenic pathway from explants derived from anogenesis can occur either from callus(Mourad-Agha and Dexheimer,1979; Kantharajah and Dodd,1990;Monteiro et al.,2000)or directly from the explant(Kawata et al.,1995;Faria and Segura,1997;Otahola, 2000).Plant regeneration without a callus phase has been optimized for lisflavicarpa.The application of biotechnology to passion fruit has been reviewed by Vieira and Carneiro(2004).Transformation of lis mediated by A.tumefaciens has been reported(Silva,1998;Hall et al.,2000).Agrobacterium tumefaciens strain1065,carrying uidA and nptII,has been used to infect leaf and root segments.Manders et al.(1994)utilized A.tumefaciens strain GV3111SE with pMON200that contains nptII,and obtained transformed plants.Stable transformation of passion fruit with nptII and uidA has also been described by Silva(1998),who used the LBA4404strain.The primary breeding objectives that are being addressed using genetic transformation include resistance to bacterial and virus diseases.Particle bombardment has been used to transfer the bactericide attacinA gene driven by the35S–35S promoter to yellow passion fruit(Vieira et al.,2002),with the objective of resistance to X.campestris pv.passiflorae.Braz(1999)transformed passion fruit with a sequence derived from the replicase and capsid protein(cp)genes isolated from PWV.Preliminary results suggest that this strategy can be used to control this virus disease.ConclusionsGenetic transformation of perennial tropical fruits has generally depended on embryogenic systems,and therefore regenerants of the woody species,i.e.,mango,avocado,longan,litchi,citrus,etc.,must pass through a period of juvenility before they can be properly evaluated.The two alternatives that have been utilized to overcome this limitation include:(1)invigorating plant material through grafting of mature buds onto juvenile stock plants(Cervera et al., 1998)and(2)constitutive expression of either the LEAFY or APETALA1genes from A.thaliana to shorten the juvenile phase and promote precociousflowering(Pen˜a et al.,2001).Both of these innovations could stimulate more transformation attempts with these species.The major hindrances that have stymied genetic transformation studies with tropical/subtropical fruit,however,concern lack of regeneration protocols for elite(mature phase)selections,e.g.,litchi and many tropical/subtropical fruit and nut species not included in this review,and the relative absence of molecular studies involving species other than citrus and bananas.The latter reflects the state of the science in many developing countries where these fruit crops are grown on a large scale and the relative severity of production and post-harvest problems of the crop.Biotechnology studies involving fruit crops everywhere are generally underfunded,and national and international agencies should perhaps consider more support for research with these plants.AcknowledgmentsM.A.G.-L.gratefully acknowledgesfinancial support from CONACYT.This paper is Florida Agricultural Experiment Station Journal Series no.R-10211.ReferencesArumuganathan,K.;Earle,E.D.Nuclear DNA content of some important plant species.Plant Mol.Biol.Rep.9:208–218;1991.Balint-Kurti,P.;Firoozabady,E.;Moy,Y.;Mercier,R.;Fong,R.;Wong,L.;Gutterson,N.Better bananas–the biotech musa10:vi;2001.Becker,D.K.;Dugdale,B.;Smith,M.K.;Harding,R.M.;Dale,J.L.Genetic transformation of Cavendish banana(Musa spp.AAA group)cv.446GO´MEZ-LIM AND LITZ。
