摘要： 本文分析了5个拟直立型组和2个花生组野生种的染色体组型:7个种皆为二倍体2n=2x=20,染色体长度介于2.69～6.47μm之间,臂比为1.07～2.54;在10对染色体中,8、9对具中部着丝点,其他具近中部着丝点。根据染色体长度、臂比及随体的位置,可把每个种(系)中6～10对染色体加以区分。研究中还把染色体的臂比作为独立性状,分析了供试种(系)间的遗传距离(D~2)。其中拟直立型组5个种(系)间的D~2差异很大(0.136～11.523),说明该组在进化过程中染色体组型已出现较大分化和变异。拟直立型组与花生组在染色体组型上虽有一定相似性,但差异更显著,首先,花生组中“A”“B”两个标志染色体在拟直立型组中不存在,其次是对称性优于拟直立型组。文中对上述两个组的进化程度作了进一步的讨论。
关键词:
花生属,
拟直立型组,
染色体组型,
遗传距离,
野生种
Abstract: The arm ratio of the respective pair of chromosomes was taken as an independent quantitative character on which genetic distances (D)among all the investigated species were calculated.Within section Erectoides, D2 varied dramatically, indicating great differentiations in karyomorphology have taken place during its long process of evolution.Sections Erectoides and Arachis share some similarities in karyotype as revealed by D2 analysis, but differences are even more prominent (1)The marker chromosomes of section Arachis, "A" and "B", were not observed in Erectoides;(2)Karyotypes of Erectoides species are less symetrical than that of section Arachis, It is assumed that section Erectoides may be of more recent origin than section Arachis.
Key words:
Arachis,
Section Erectoides,
Karyotype,
Genetic distance,
Evolution,
Wild species
张新友. 花生属拟直立型组野生种在栽培种改良中的应用——Ⅱ.染色体组型分析[J]. 华北农学报, 1992, 7(1): 47-55. doi: 10.3321/j.issn:1000-7091.1992.01.009.
Zhang Xinyou. Utilization cf Wild Erectoides Species in the Genus Arachis for the Improvement of Cultivated Groundnut[J]. ACTA AGRICULTURAE BOREALI-SINICA, 1992, 7(1): 47-55. doi: 10.3321/j.issn:1000-7091.1992.01.009.