玉米自交系杂种优势类群与杂优模式构建的初步研究

Heterotic Groups and Patterns of Maize Inbred Lines Established by RAPDs

以15个来源不同的玉米自交系及其105个双列杂交组合为材料,通过RAPD分析技术及试验材料的多点田间鉴定,初步研究了玉米自交系杂种优势类群的划分和利用模式的构建。根据RAPD分类与杂种优势分类、系谱追踪的比较研究,认为RAPD技术在玉米自交系杂种优势群划分上应用是可行的。通过对杂优类群间F_1产量,杂种优势与配合力的测定结果的综合分析,提出了7个杂种优势利用模式。

The objectives of this study were (1) to examint the potential of RAPDs for assigning maize inbreds to heterotic groups, (2) to establish heterotic group and pattern for Chi nese main maize inbred lines. Fifting inbreds were analyzed for RAPDs with 6 random primers 10-mer and amplified 29 polymorphic bands. The genetic distance (RD) based on RAPD data were estimated by Rogers' method. The fifting inbred lines were classified into 6 heterotic groups by Group Average Method (Sokal and Michene, 1968). These results correspond well with mid- parent heterosis and pedigree study. On the other hand,the 105 diallel single cross combinations coming from 15 inbred Lines were planted in four enviroments in China to evaluated F1 yield, mid-parent heterosis (MPH) and specific combining ability (SCA). The F1 yield,MPH and SCA varied signifcantly among heterotic groups. The comparision of different heterotic patterns showed that 7 patterns could be used in breeding. Our results suggest that RAPD markers may be valuable method to establish heterotic groups and patterns.