论文部分内容阅读
有关国际玉米与小麦改良中心(CIMM-YT)玉米群体和基因库杂种优势模式的研究较少。Vasal 等(1986)在综合鉴定 CIMMYT、不同玉米群体和基因库间的杂交种后,划分了几个基本杂种优势组。但在多数情况下,由于杂种优势太弱还无法区别群体或基因库间的杂交种。两个群体间杂交种的优势较弱可能产生于两群体间缺少遗传多样性或在其不同位点和等位基因组配时存在抵消效应的结果。Cress(1966)指出两群体间遗传多样性与杂种优势
There are few studies on the heterosis patterns of maize populations and gene banks in CIMM-YT. Vasal et al. (1986) identified several basic heterotic groups after a comprehensive identification of crosses between CIMMYT, different maize populations and gene banks. In most cases, however, hybrids between populations or gene pools can not be distinguished due to poor heterosis. Weak heterosis in hybrids between two populations may result from the lack of genetic diversity between the two populations or the presence of offsetting effects at different loci and allelic timing. Cress (1966) points out the genetic diversity and heterosis between two populations