紧凑型油菜数量性状的遗传与杂种优势研究

Study on Inheritance and Heterosis of Plant-type Traits in Compact Rapeseed Lines

采用ADM模型及MINQUE(1)统计方法对6个不同遗传背景的紧凑型和松散型油菜品种(系)及其30个F1组合的14个数量性状进行了遗传和杂种优势分析。结果表明,株高、有效分枝高度、一次分枝角果数、主花序角果数、单株角果数、角果粒数、千粒重、角果长度和分枝夹角等性状同时受基因的加性和显性作用控制,其中株高的显性作用大于加性作用,其余性状的加性效应大于显性效应。主花序长度、一次分枝数、角果宽度和一次分枝长主要受基因加性效应控制;单株角果数、角果粒数、千粒重和角果长度4个性状除受核基因控制外,还受到母体基因型的显著影响。一次分枝数、一次分枝角果数和分枝夹角的F1和F2代群体平均优势为负向优势,其中仅分枝夹角达极显著水平,其余性状均为正向杂种优势。F1代群体正向超亲优势仅株高和单株产量达到显著水平,且以单株产量的F1、F2代超亲优势较大(29.5%和12.0%)。分枝夹角的F1和F2代负向超亲优势达极显著水平(-20.6%和-17.7%),表明配制紧凑型F1代杂交种仅需一个紧凑型亲本。

Heterosis and genetic effects of 14 quantitative traits were studied in 6 different genesis cul tivars and their 30 F1 crosses in Brassica. napus L. by ADM model and MINQUE（1） approaches. The results showed that both additive genes and dominant genes controlled the traits of plant height, effective branch height, pods of primary branches, pods of main raceme, No. of pods per plant, seeds per pod, 1000-seed weight, length of pod, the angle between stem and primary branch. However, dominant effect was more important than additive effect for plant height, for others were opposite. It was additive genes that mainly dominated length of main raceme, No. of primary branches, width of pod and length of primary branch. Besides nuclear genes, maternal genes significantly affected No. of pods per plant, seeds per pod, 1000-seed weight and length of pod. The mid-heterosis was negative in No. of primary branches,pods of primary branches and the angle between stem and primary branch, but it was positive in other traits. Only the angle between stem and primary branch was significant in F1 and F2 generation at 0.01 levels. F1 positive better-parent heterosis was significant only in plant height and seed yield per plant, and which of seed yield per plant was better （29.5% and 12.0%） in F1 and F2 generation. The negative less-parent heterosis of the angle between stem and primary branch was highly significant in F1and F2 generation （-20.6% and -17.7%）. These results showed that only one compact parent was necessary to get compact F1 hybrid .