水稻种子休眠性QTL定位及其对干热处理的响应

Analysis of QTL for Seed Dormancy and Their Response to Dry Heat Treatment in Rice (Oryza sativa L.)

利用Kinmaze(粳稻)/DV85(籼稻)杂交组合衍生的重组自交F11家系 (Recombinant Inbred Lines, RILs)进行了种子休眠性QTL的检测和遗传效应分析。以抽穗后35 d的种子发芽率作为种子休眠性的表型值,分析亲本和81个家系的休眠性表现,利用Windows QTL Cartographer 1.13a软件共检测到4个种子休眠性QTL,分别位于第2、5、11染色体上,其中第2染色体存在2个QTL,各QTL的贡献率变幅8.37%～17.40%。进一步研究了这些休眠性基因位点对干热破除休眠处理的响应,结果表明,来自DV85增强休眠性的QTL位点qDOR-2-1和qDOR-5,以及来自Kinmaze增强休眠性的QTL位点qDOR-11,易被干热处理破除休眠,这3个QTL效应较强,可在种子休眠性状的遗传改良中加以利用;而位于第2染色体上标记XNpb227-XNpb132之间的QTL位点qDOR-2-2却不易被干热处理破除休眠,该位点增强休眠性的基因来自DV85。

Quantitative trait loci (QTL) controlling seed dormancy in rice were identified using recombinant inbred lines (RILs) population derived from the cross between a japonica variety Kinmaze and an indica variety DV85. Seeds of two parents and each RIL were harvested in 35d after heading. The germination percentage of these seeds at 30℃ for 7 days were measured as the degree of seed dormancy. QTL analysis was performed with Windows QTL Cartographer 1.13a program by composite interval mapping. A total of four QTL for seed dormancy were detected on chromosome 2 (two regions), 5 and 11, respectively. Phenotypic variation explained by each QTL ranged from 8.37% to 17.40%. Responses of such loci to a dormancy-broken with a dry heat treatment were further detected. The results showed that two alleles of qDOR-2-1 and qDOR-5 from DV85 as well as the allele of qDOR-11 from Kinmaze increased the seed dormancy, which seemed to be easily broken by dry heat treatment. Such loci of seed dormancy may be applied to rice genetic improvement. The allele of qDOR-2-2 from DV85 increased the seed dormancy, which could not be broken by dry heat treatment.