十年来中国玉米杂种优势群及其模式变化的分析

Analysis of Maize Heterotic Groups and Patterns During Past ecade in China

以中国大面积推广的71个优良玉米杂交种的84份自交系为材料,在利用SSR分子标记计算的遗传距离将其划分为7个杂种优势群的基础上,根据杂交种的年种植面积,分析了1992年至2001年我国杂种优势群及其模式的变化趋势。结果表明,十年来,我国玉米杂种优势群的主次地位发生了一定的变化。在20世纪90年代初期,主要的杂种优势群是Lancaster、Reid、唐四平头、自330和E28。到21世纪初,主要的杂种优势群则为Reid、温热I、自330、唐四平头和Lancaster,其中温热I是一个含热带玉米种质的新类群。十年来,我国玉米杂种优势模式也发生了明显的变化,这些变化主要反应在两个方面,其一是出现了含温热I群的新模式,Reid×温热I、自330×温热I、唐四平头×温热I等,由此大大拓宽了我国玉米杂种优势的利用模式。其二是模式的主次位置有明显的改变。从20世纪90年代初期至中期,前五名的杂种优势模式是Reid×唐四平头、自330×Lancaster、Lancaster×唐四平头、Lancaster×E28和Reid×自330。到2001年,前五位的主要杂种优势模式是,Reid×温热I、Reid×自330、Reid×唐四平头、自330×温热I和Lancaster×唐四平头。2001年,Reid×温热I和自330×温热I已分别成为全国第一和第四大主要的杂种优势模式。

In this investigation, maize heterotic groups and patterns were analyzed based on the planting areas of hybrids in 1992 to 2001 using 84 parent lines of 71 widely extended hybrids and classification of SSR markers, in which these lines were assigned into seven heteritic groups based on Ni-LI抯 genetic distances. The results indicated that a certain extent change of position for major heterotic groups of maize took place during past decade in China. The major heterotic groups were Lancaster, Reid, TangSPT, Zi330 and E28 in the early 1990s, while they were Reid, Tem-tropic I, Zi330, TangSPT and Lancaster in the early 21st century. Tem-tropic I was a new heterotic group to elite germlpasm used in China widely, which contained tropic maize germplasm. The great changes for heterotic patterns also occurred. Some new heterotic patterns with Tem-tropic I appeared such as ReidTem-tropic I, Zi330Tem-tropic I, TangSPTTem-tropic I and etc, which broaden maize heterotic patterns used in China. Another change was the order of heterotic patterns. In the early and middle 1990s, the top five heterotic patterns were ReidTangSPT, Zi330Lancaster, LancasterTangSPT, LancasterE28 and ReidZi330, while they were ReidTem-tropic I, ReidZi330, ReidTangSPT, Zi330Tem-tropic I and LancasterTangSPT in early 21 century. ReidTem-tropic I and Zi330Tem-tropic I were the first and forth Chinese heterotic patterns, respectively, in 2001. These results provided significant information to understand the maize heterotic groups and patterns in China at molecular level.