水稻种子低氧发芽力的QTL定位和上位性分析

Quantitative Trait Loci and Epistatic Analysis for Seed Anoxia Germin ability in Rice (Oryza sativa)

利用 35份水稻品种资源 ,评价了在不同水深、温度等低氧条件下的种子萌发情况 ,表明水温 30℃、水深 0 .2m下黑暗萌发 5d为最佳鉴定方法 ,并以此条件下水稻种子萌发的芽长为鉴定指标 ,评价了 35 9份水稻品种低氧发芽力地区间、籼粳间的差异。进一步利用 81个Kinmaze/DV85重组自交系群体进行了水稻低氧发芽力数量性状位点分析 ,在第 1、2、5、7染色体上检测到 5个低氧发芽力QTL ,其中第 5染色体上存在 2个QTL ,各QTL的贡献率为 10 .5 %～ 19.6 %。同时进行上位性分析 ,检测到 3对互作位点 ,分别位于第 2、3、5、11染色体上 ,其中位于第 3染色体上标记C5 6 3-X182之间的位点与第 5染色体上标记R830 -X2 0 8之间的位点的互作贡献率高达 4 8.78%。

Anoxia germinability (AG) of 35 rice varieties wa s evaluated under anoxia conditions with different temperatures and different dept hes. Shoot length of seedlings germinated at 30℃, in 0.2 m depth of water fo r 5 d, could be used as an optimal criteria for the AG evaluation of all the va rieties. There existed difference among the AG of 359 varieties from different regions and subspecies. Moreover, 81 recombinant inbred lines(RILs) derived fr om a cross of Kinmaze (japonica)/DV85 (indica) were used to detect quantitative trait loci (QTL) conferring AG. A total of five QTLs for AG in the RIL populati on were detected on chromosomes 1, 2, 5 and 7, respectively. Phenotypic variatio ns explained by each QTL ranged from 10.5% to 19.6%. According to the direction of the additive effects, at three loci of qAG-1, qAG-2 and qAG-7, the alleles from Kinmaze increased AG,while at qAG-5a, qAG-5b, the DV 85 alleles increased AG. Meanwhile, three pairs of epistatic loci were detected on chromosomes 2, 3, 5 and 11 with significant epistatic effects from 16.7% to 4 8.8%, and especially the epistatic effects between C563-X182 on chromosome 3 and R830-X208 on chromosome 5 was 48.78%.