甘蓝型油菜主要农艺和产量性状的杂种优势及其分离世代的分析

Heterosis and segregation on agronomic and yield traits in Brassica napus L.

利用1个细胞质雄性不育恢复系垦C1为父本,与2个不同来源的保持系配置杂交种F1,并构建了F2和F2∶3家系,对重要农艺和产量性状的杂种优势及其在分离世代的分离情况进行分析。对2个群体杂交种F1两年的杂种优势分析结果表明,单株产量、单株角果总数、一次分枝角果数等具有显著的正向杂种优势。在单株产量的3个构成因素中,单株角果总数杂种优势最强,而且不同群体、不同年份结果一致;每角粒数、千粒重的优势较小,而且不同群体、不同年份结果一致。对F2和F2∶3家系杂种优势的分析结果表明,重要农艺和产量性状如单株产量、小区产量、单株角果总数、一次分枝角果数等比杂种F1杂种优势显著降低,出现严重的分离现象。另一方面,各重要农艺性状的杂种优势同样存在丰富的变异,最大值与最小值间相差显著。在分离群体中还出现了超优亲现象,这为育种选择提供了丰富的遗传变异材料。

Two cytoplasmic male sterile maintainers （pure line from different background） as female parent were crossed with one restorer to produce two F2 segregating populations and one F2. 3 families population. The heterosis of Flfor two populations were analysed. Results indicated that seed yield/plant, total number of siliques per plant, total number siliques of first branches per plant had significant positive heterosis. Heterosis for 3 yield components from field showed that seed yield/plant of F1 hybrids had highest positive mid-parent heterosis. The heterosis for seeds/silique and 1000-seed weight was low. Heterosis for 3 yield components was total number of siliques per plant〉1000-seed weight〉seeds/silique. The heterosis of seed yield per plant, seed yield per pot, total silique number in first branch in F2 segregating population and F2：3 family populations decreased significantly than that in F1 generation. There was a great segregation in F2 and F2. 3 families populations. Superior heterosis was found out in segregating populations.