大豆Soja亚属内种子大小的遗传差异及半野生类型分类归属

Soja亚属包括野生、半野生和栽培大豆三种类型,其中半野生型变异丰富,与野生和栽培大豆形态重叠。然而半野生大豆是属于野生种内还是栽培种的变异类型还存在争议。本研究使用421份包括两组野生大豆百粒重类型、三组半野生大豆百粒重类型和小粒秣食豆类型大豆地方品种对Soja亚属内进行了SSR标记的遗传多样性差异评价和对半野生大豆的分类地位归属问题进行了分析。结果显示,小粒组野生大豆(2.5g以下)和大粒组(2.5~3.0g)有明显的分化。大粒野生大豆和小粒半野生大豆(3.01~5.0g)遗传关系密切,百粒重5.01~10.0g和超过10.0g的半野生大豆组遗传关系密切。大粒野生大豆在遗传上与半野生大豆类型密切。从小粒野生大豆到大粒半野生大豆各类型的遗传分化与它们的百粒重大小有密切关联,即使与小粒秣食豆的百粒重相重叠甚至超过小粒秣食豆的半野生大豆都与小粒栽培大豆有显著的遗传差异。我们所获得的结果清楚地表明:半野生大豆属于野生种内的变异而非栽培种内变异。百粒重大小可以当作评价野生大豆物种内的遗传分化或进化程度的主要指标之一有其遗传上的理论依据。

Genetic Divergence in Different Seed Weights within the Subgenus Soja and Taxonomic Assignment of Semi-wild Soybean(Clycine gracilis Skvortzow)

The subgenus Soja includes wild,semi-wild and cultivated soybcans,of which the semi-wild soybcan is the most abundant morphologically and overlaps with wild and cultivated soybeans in morphology.However,semi-wild soybean has been retained inconsistent in its taxonomic belongingness between other two species.In this research,we evaluated the genetic differentiation in the subgenus Soja and determined the assignment of semi-wild soybean using 421 accessions of wild(two groups),semi-wild(three groups)and"Moshidou"-type soybean landrace(one group).The results showed that small-seeded(below 2.5 g 100-seed weight)and large-seeded (2.51～3.0 g 100-seed weight)wild soybeans had significantly genetic differentiations.The genetic relationship between large-seeded wild soybean and small-seeded semi-wild soybean (3.01～5.0 g 100-seed weight) was closer,that between larger-seeded semi-wild soybean (5.01～10.0 g 100-seed weight)and large-seeded semi-wild soybean(over 10.0 g 100-seed weight)was close too,and also between large-seeded wild soybean and semi-wild soybean genetically.The degrees of genetic differentiation from small-seed wild soybean to large-seeded semi-wild soybcan were related to their seed sizes for various seed size types;even the semi-wild soybeans that overlapped with or exceeded "Moshidou"in 100-seed weight had significantly genetic differences from the"Moshidou".Therefore,the results obtained here clearly stated that semi-wild soybean is an intraspecies variant of wild soybean but not of cultivated soybeans.The 100-seed weight showed genetic evidence that seed size could be used as an index of evolutionary degree in the subgenus Soja soybeans.The 100-seed weight showed genetic evidence that seed size could be used as an index ofevolutionary degree in the subgenus Soja.