关于棉属四倍体种起源问题的过氧化物酶同工酶研究

Peroxidase Isozyme Study on the Origin of Tetraploid Species in Gogsypium

本文采用聚丙烯酰胺凝胶垂直板电泳和等电聚焦技术,对棉属(Gossypium)A基因组2个二倍体种、D基因组10个二倍体野生种和四倍体2(AD)基因组的3个种进行过氧化物酶同工酶酶谱分析。种间酶谱关系符合形态学,细胞学和遗传学的研究结果,但G.gossypioides,G.thurberi和G.trilobum的酶谱与D基因组其他种有较大差异却与A基因组相似。由二倍体种酶液组成的体外人工混合体与自然四倍体的比较分析表明,四倍体棉种G.darwinii,G.barbadense和G.hirsutum是A基因组和D基因组的异质组合,G.raimondii而不是G.thurberi或G.trilobum为四倍体种祖先基因组的最可能的D亚基因组供体。对过氧化物酶同工酶分析为棉属种间亲缘关系和四倍体起源的研究提供生化遗传依据的可行性进行了阐述。

Peroxidase isozyme patterns in two A-genome diploid species, ten D-genome diploid wild species and three 2(AD)-genome allotetraploid species within the genus Gossypium were analyzed by vertical polyacrylamide gel electrophoresis and isoelectric focusing. The interspecific relationships in each genome group indicated by zymograms were largely consistent with the conclusion derived from morphological, cytological and genetical studies except that G. gossypiotd-es, G. thurberi and G. trilobum showed quite different patterns from other member of D genome but similar to A genome species.Comparative studies between enzyme mixtures of root and leaf extracts from diploid species and natural allotetraploids suggested that G. darwinn, G. barbadense and G. hirsuium were evolved from an ancestral genome composed of A and D subgenomes, and that it was G. rai-mondii rather than G. thurberi or G. trilobum which most likely contributed the D subgenome. The feasibility of using peroxidase isozyme to study interspecific relationships and the origin of allotetraploids in Gossypium was discussed.