水稻籼粳杂种生殖障碍的基因定位分析

籼稻(Oryza sativa L.ssp.indica)与粳稻(O.sativa ssp.japonica)杂交优势明显但存在生殖隔离。生殖障碍主要表现为胚囊败育、花粉败育、开花时花药不开裂和雌雄异熟。应用具有137个标记位点的籼、粳杂交(“窄叶青8号”/“京系17”)F_1花药培养获得的127个双单倍体(DH)群体构建的RFLP图谱,对控制籼、粳杂种小穗败育的基因座位进行了定位研究。结果在第1、3、4、5、6、7、8、12染色体上检测到10个基因座位,其中第3、12染色体上的2个不育基因位点stj-3和stj-12与同一杂交组合F_2分离群体中发现的异常分离热点处于相同的染色体区段。Ssj-6的基因加性效应为负值,有增加籼、粳亲和性的作用;其余的不育基因座位皆有增加籼、粳杂种不育性的作用。

MAPPING QUANTITATIVE TRAIT LOCI FOR REPRODUCTIVE BARRIERS OCCURRING IN HYBRID BETWEEN INDICA AND JAPONICA RICE

Hybridization between Oryza saliva L. ssp. indica and 0. saliva ssp.japonica could produce heterosis but various reproductive barriers existed. The barriers included embryo sac sterility , pollen sterility, anther indehiscence and non-synchronization of male and female gamete development in the same spikelet. A molecular linkage map comprising 137 markers was constructed based on 127 doubled haploid (DH) progenies from anther culture of Fj hybrid between an indica rice variety "Zhaiyeqing 8" and a japonica rice variety "Jingxi 17" . The linkage map was employed to locate quantitative trait loci (QTL) for reproductive barriers in DH population and its derived two backcross populations by interval mapping. Ten QTLs were detected and located on chromosomes 1, 3,4,5,6,7, 8, and 12 respectively. The positions of two QTLs located on chromosomes 3 and 12 were identical to the positions for distorted segregation detected in F2 population from the same cross. All the QTLs had additive effects in increasing sterility except for stj-6 that increased fertility.