RFLP ANALYSIS OF PHYLOGENETIC-RELATIONSHIPS AND GENETIC-VARIATION IN THE GENUS LYCOPERSICON
RFLP ANALYSIS OF PHYLOGENETIC-RELATIONSHIPS AND GENETIC-VARIATION IN THE GENUS LYCOPERSICON
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DOI：
10.1007/bf00226743
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发表时间：
1990-01-01
影响因子：
5.4
通讯作者：
TANKSLEY, SD
中科院分区：
文献类型：
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作者：
MILLER, JC;TANKSLEY, SD
40个单拷贝，已知染色体位置的核探针被用来检查限制性片段长度多态性在番茄属番茄。探针来自三个文库：一个cDNA文库和两个基因组文库-一个基因组文库用EcoRI制备，另一个用Pst I制备。用五种不同的限制性内切酶切割代表八个物种的156株植物的总DNA，并在198种探针-酶组合中进行评分。从限制性内切酶图谱和共有带的比例计算了种质（居群）和种间的遗传距离。属于同一物种的加入大部分聚集在一起，证实了它们目前的分类。然而，一个山加入，归类为L。秘鲁变种humifusum（LA 2150）与L. peruvianum，它可能有资格作为一个单独的物种L。esculentum和L. pimpinellifolium是分化最不明显的，可能反映了渗入杂交，已知在近代历史上已被人类促进。从cDNA与基因组克隆构建的树状图在其一般的物种分组中几乎是相同的。树状图揭示了该属中的两个主要二分法：一个对应于交配行为[自交亲和（SC）与自交不亲和（SI）物种]，另一个对应于果实颜色（红色与绿色果实物种）。与加入之间的多样性的比例低得多SC物种，表明这些物种内的大部分多样性存在于种群之间，而不是种群内。总体而言，SI物种的遗传变异量远远超过SC物种。该结果通过以下事实来例证：在SI物种之一的单个加入物内可以发现更多的遗传变异（例如，L. peruvianum）比任何一种SC物种（例如，L. esculentum或L. pimpinellifolium）。从这项研究的结果进行了讨论有关种质的收集/利用，并在番茄育种和遗传学的RFLPs的使用。
Forty single-copy, nuclear probes of known chromosomal position were used to examine restriction fragment length polymorphism in the tomato genus Lycopersion. The probes were from three libraries: one cDNA, and two genomic libraries-one genomic made with EcoRI and the other with PstI. Total DNA from 156 plants representing eight species was cut with five different restriction enzymes and scored in 198 probe-enzyme combinations. Genetic distances between accessions (populations) and species were calculated from the resultant restriction patterns and proportion of shared bands. Accessions belonging to the same species largely clustered together, confirming their current classification. However, one mountain accession, classified as L. peruvianum var. humifusum (LA2150), was sufficiently distinct from the other accessions of L. peruvianum that it may qualify as a separate species L. esculentum and L. pimpinellifolium were the least clearly differentiated, possibly reflecting introgressive hybridization, known to have been promoted by man in recent history. Dendrograms constructed from cDNA versus genomic clones were nearly identical in their general grouping of species. The dendrograms revealed two major dichotomies in the genus: one corresponding to mating behavior [self-compatible (SC) versus self-incompatible (SI) species] and the other corresponding to fruit color (red versus green-fruited species). The ratio of within- versus between-accession diversity was much lower for SC species, indicating that most of the diversity within these species exists between populations, rather than within populations. Overall, the amount of genetic variation in the SI species far exceeded that found in SC species. This result is exemplified by the fact that more genetic variation could be found within a single accession of one of the SI species (e.g., L. peruvianum) than among all accessions tested of any one of the SC species (e.g., L. esculentum or L. pimpinellifolium). Results from this study are discussed in relation to germ plasm collection/utilization and with regard to the use of RFLPs in tomato breeding and genetics.