ALLOZYME EVIDENCE FOR THE ORIGIN AND DIVERSIFICATION OF GOSSYPIUM-BARBADENSE L
ALLOZYME EVIDENCE FOR THE ORIGIN AND DIVERSIFICATION OF GOSSYPIUM-BARBADENSE L
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DOI：
10.1007/bf00226164
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发表时间：
1990-01-01
影响因子：
5.4
通讯作者：
WENDEL, JF
中科院分区：
文献类型：
--
作者：
PERCY, RG;WENDEL, JF
海岛棉 (Gossypium barbadense L.) 是一种具有重要商业价值的棉花品种，原产于南美热带地区，目前在世界许多地区种植。该物种形态多样，包括各种野生（或野生）、共生、地方品种和高度改良的商业品种。我们对代表 G. barbadense 多样性谱的 153 个种质进行了等位酶分析，以确定该物种的地理起源、驯化后的扩散模式，并揭示种内关系。海岛 G. barbadense 的遗传变异水平中等。在评分的 59 个基因座中，24 个是多态性的，每个基因座的平均等位基因数为 1.69，平均泛杂合度为 0.062。主成分分析揭示了种质在地理上聚集成六个相对离散的区域。这些区域中许多位点的基因频率存在显着异质性，平均 GST 为 0.272。南美洲西北部的遗传变异性最大；我们认为该地区是该物种的祖先家园。数据表明，从该地区进入阿根廷-巴拉圭以及安第斯山脉以东的南美洲东部和北部有不同的扩散途径。加勒比岛屿和中美洲的形式似乎源自后者。这些扩散途径符合形态学证据和历史记录。与基于地理邻近性的预期相反，太平洋岛屿品种与来自南美洲东部的品种最接近。先进的栽培种群似乎主要源自西安第斯材料，但也含有基因渗入的陆地棉种质。在商业种群以及来自阿根廷-巴拉圭和各个太平洋岛屿的材料中，基因渗入相对较高（占种质的 22%-50%），但在中美洲和加勒比地区的材料中，基因渗入明显较低或不存在，因为这两个物种的共生形式和商业形式是同域的。
Gossypium barbadense L. is a commercially important cotton species of tropical South American origin presently grown in many regions of the world. The species is morphologically diverse, consisting of a wide range of wild (or feral), commensal, landrace, and highly improved commercial forms. We performed allozyme analysis on 153 accessions representing the spectrum of G. barbadense diversity to ascertain the geographic origin of the species, its patterns of diffusion subsequent to domestication, and to reveal infraspecific relationships. Levels of genetic variation in G. barbadense are moderate. Of 59 loci scored, 24 were polymorphic, with a mean number of alleles per locus of 1.69 and an average panmictic heterozygosity of 0.062. Principal component analysis revealed geographic clustering of accessions into six relatively discrete regions. Gene frequencies at many loci are significantly heterogeneous among these regions, with an average GST of 0.272. Northwestern South America contains the greatest genetic variability; we suggest that this region is the ancestral home of the species. The data indicate separate diffusion pathways from this region into Argentina-Paraguay and into eastern and northern South America east of the Andes. Caribbean Island and Central American forms appear to be derived from the latter. These diffusion pathways are in accordance with morphological evidence and historical record. In contrast to expectations based on geographic proximity, Pacific Island forms have their closest affinity to accessions from eastern South America. Advanced cultivated stocks seem largely derived from western Andean material, but also contain introgressed G. hirsutum germ plasm. Introgression was relatively high (22%-50% of accessions) in commercial stocks and in forms from Argentina-Paraguay and various Pacific Islands, but was conspicuously low or absent in material from Central America and the Caribbean, where commensal and commercial forms of both species are sympatric.