小麦杂种优势群分类方法的比较研究

分类的方法和依据不同，小麦群内和群间杂种优势的测定结果也不同。为了客观评价各类方法的优劣，作者根据小麦产量性状、产量性状的一般配合力、RAPD标记等将小麦品种(系)分别归为不同的类群，试验结果表明：以RAPD标记为分类依据效果最好，GroupI与Group Ⅲ间具有明显的杂种优势，它们F1杂种的平均产量优势高达18．8％。以产量构成因素为分类依据效果稍差，但仍能区分开优势群和非优势群，群间杂种的平均产量优势最高为15．06％。以一般配合力为分类依据效果最差，群间杂种的平均产量优势甚至不及群内杂种，最高的群内杂种优势也仅有12．1％。因此认为小麦杂种优势群的建立应以RAPD标记为主要依据，兼顾产量性状，而根据亲本的一般配合力无法准确预测杂种的产量优势。

Comparison of Three Methods for Developing Heterotic Groups in Wheat (Triticum aestivume)

Wheat lines could be clustered into different groups based on their agronomic traits, or general (combining) ability (GCA) of agronomic traits, or molecular markers. Hybrids from parents in different groups were generally superior to most hybrids from parents in the same group. But there were apparent differences in (heterosis) for different (heterotic) groups based on different methods. An outstanding (heterotic) group was found based on RAPD markers. The average yield (heterosis) of F_1 between GroupI and GroupIII was 18.8%, which was much higher than that of other inter-group and intra-group hybrids. When parents were clustered on the basis of yield (components), one (heterotic) group was also found and its inter-group hybrid displayed an average yield (heterosis) of 15.06%. However, no (heterotic) group was found when parents clustered on the basis of GCA. Its intra-group hybrids were even superior to most of inter-group hybrids and the highest average (heterosis) of its intra-group hybrids was 12.1%. The results indicated that GCA had little value in clustering parents for (predicting) (heterosis). Molecular markers would be the first choice for developing (heterotic) groups in wheat with a consideration of yield traits.