Isozyme Polymorphism and Genetic Differentiation in Natural Populations of a New Tetraploid Species Avena agadiriana, from Morocco
Isozyme Polymorphism and Genetic Differentiation in Natural Populations of a New Tetraploid Species Avena agadiriana, from Morocco
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摩洛哥四倍体新种燕麦的同工酶多态性和自然群体遗传分化
DOI：
10.1007/s10722-005-2248-y
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发表时间：
2005
影响因子：
2
通讯作者：
J. M. Leggett
中科院分区：
文献类型：
--
作者：
T. Morikawa;J. M. Leggett
从摩洛哥大西洋沿岸的五个种群中采集了一个新的野生四倍体燕麦 Avena agadiriana Baum et Fedak。研究了六种酶系统的变异，并计算了等位基因频率、多态性位点百分比、每个位点的等位基因数量、观察到的和预期的杂合性以及无偏遗传距离。对代表 11 个多态性位点的表型频率进行评分。多态位点的平均百分比为 46.25，每个位点的平均等位基因数为 1.502，平均预期杂合度为 0.1526。在 M60 和 M71 的后代中发现了两个由异型杂交产生的杂合子。 M71 群体具有其他群体中不存在的特殊等位基因 Est-4A。该物种的大部分遗传多样性存在于种群之间，而种群内则很少存在。种群间地理距离和遗传距离呈正相关，相关系数为0.7031。聚类分析显示两个明显分化的组：M71 和 M74 以及其余组。前一类似乎适应了人造栖息地，例如路边或桉树种植园，而后者则适应了独特的干燥沙质栖息地。为了在该物种中产生广泛的种内变异，改良的交配系统是必不可少的。
A new wild tetraploid oat Avena agadiriana Baum et Fedak was collected from the five populations along the Atlantic coast in Morocco. Variations in six enzyme systems were surveyed and allele frequency, percentage of polymorphic loci, number of alleles per locus, observed and expected heterozygosities, and unbiased genetic distance were calculated. Phenotypic frequencies were scored representing 11 polymorphic loci. The mean percentage of polymorphic loci was 46.25, the mean number of alleles per locus was 1.502, and the mean expected heterozygosity was 0.1526. Two heterozygotes resulting from outcrosses were found in the progeny from M60 and M71. The population of M71 had peculiar alleles Est-4A not present in the other populations. Most of the genetic diversity of this species was between populations with little existing within populations. Geographic and genetic distances between populations were positively correlated with each other and the correlation coefficient was 0.7031. Cluster analysis showed two strongly differentiated groups were apparent, M71 and M74, and the remainder. The former group appears to be adapted to man-made habitat, such as road side or eucalyptus plantation, and the latter to a distinct dry, sandy habitat. To make wide intra-specific variation in this species, the modified mating system would be indispensable.