杂交粳稻亲本产量性状优异配合力的标记基因型筛选

提高杂交粳稻竞争优势的关键是改良其恢复系产量性状的配合力。为使之更富成效,选用115个SSR引物扩增6个粳稻BT型不育系和12个恢复系的标记基因型,并按NCII遗传设计配制72个F1组合,分析18个亲本的单株日产量、单株有效穗数、每穗总粒数、每穗实粒数、千粒重5个性状的配合力,结合亲本SSR分子标记数据和性状配合力数据筛选了5个性状优异配合力的标记基因型。结果发现20个SSR标记基因型与亲本产量及其构成性状配合力显著相关。其中8个与亲本单个性状配合力相关;6个同时与亲本2个性状配合力相关;4个同时与亲本3个性状配合力相关;2个同时与亲本4个性状配合力相关。同时与多个性状配合力相关的标记基因型,对各性状的作用方向有正有负。RM152-165/170是单株日产量和单株有效穗数优异配合力效应最大的标记基因型,可使F1的相应性状值增加20.6%和12.7%。优异配合力的标记基因型可直接用于粳稻恢复系配合力的分子标记辅助改良。

Screening Marker Genotypes with Elite Combining Ability for Yield Traits in Parents of Hybrid Japonica Rice(Oryza sativa L.)

The area of japonica rice planted annually is 8 280 000 ha and accounts for 27% of total rice area in China. The area planting japonica hybrid rice is only 3% of the total area of japonica rice. The major reason for this situation is that competitive heterosis of hybrid cultivar is not conspicuous in yield, compared with conventional cultivar in japonica rice. The key factor of enhancing competitive heterosis of hybrid cultivar in japonica rice is to improve combining ability of yield related traits of restorer lines. In order to improve combining ability of restorer lines more efficiently, SSR marker genotypes with elite combining ability for five traits were screened in this study, by analyzing the data of combining ability and SSR markers in six CMS lines and twelve restorer lines that were genotyped using 115 pairs of SSR primers. Combining ability of the 18 parental lines was analyzed for daily yield per plant (DYP), panicles per plant (PP), total spikelets per panicle (TSP), filled spikelets per panicle (FSP) and 1000-grain weight (1000-GW), using the data of 72 F₁s made with NC II genetic design. Results showed that twenty SSR marker genotypes were significantly associated with combining ability of the five traits. Among them, eight for only one trait, six for two traits, four for three traits and two for four traits. Marker genotypes associated with combining ability of multiple traits increased or decreased trait value of F₁. RM152-165/170 was a marker genotype of elite combining ability for PP and DYP with the maximum increasing effect, which increased 20.6% of DYP and 12.7% of PP in F₁ respectively. Those marker genotypes with increasing effect could be directly used to improve combining ability of restorer lines through the marker- assistant selection.