水稻遗传图谱构建及粒形相关性状的QTL定位

目的]构建水稻遗传连锁图谱,并对水稻粒形相关性状进行QTL分析,为水稻高效育种提供理论依据和育种材料.方法]对具有极端粒形差异的两份水稻材料K1561和G1025进行杂交、自交获得F2分离群体,通过软件Map-maker/Exp 3.0构建水稻遗传连锁图谱,并利用软件QTLNetwork-2.0对2011年F2群体、2012年F2∶3家系群体的粒形相关性状数据进行相关性状的QTL定位.结果]两个亲本的粒形性状指标差异明显,以千粒重相差最大;F2、F2∶3两个群体的相关粒形指标基本上呈连续分布状态且分布频率范围广.与F2单株相比,F2∶3家系的千粒重、粒长和粒宽的平均值更偏向于大粒亲本K1561.构建了含161对SSR标记的水稻遗传连锁图谱;共检测到18个粒形相关性状的QTL,分别分布于第1、2、3、7、9和12染色体上.其中,控制千粒重、粒长、粒宽和长宽比的QTL分别有7、5、5和1个,除qGL/GW12外,其他增效等位基因均来源于大粒亲本K1561.两个群体均能检测到的QTL有8个,分别为qTGW3、qTGW7、qTGW9.2、qTGW12、qG L1、qGL9、qGW12和qGL/GW12,其平均加性遗传力为6.04％、12.59％、6.29％、22.08％、4.86％、15.39％、22.12％和10.83％.结论]定位获得3个效应值较大的新QTL位点qTGW12、qGL9和qGW12,为进一步定位并克隆这些粒形相关基因、阐明水稻产量和品质的控制机理提供了较好的遗传材料.

Construction of genetic map and mapping quantitative trait loci for grain shape-related traits in rice

Objective]Construction of genetic map,mapping quantitative trait loci （QTL） for grain shape-related traits were conducted in order to provide a theoretical basis and breeding materials for rice efficient breeding.Method]An F2 population was established from a cross between rice line K1561 with large grain and G1025 with small grain to construct whole genome genetic linkage map with Mapmaker/Exp 3.0.QTL mapping of the traits related to grain shape,were determined using F2 population and F2∶3 families by using QTLNetwork-2.0.Result]The grain shape traits varied large in two parents,in particular 1000-grain weight.The grain shape-related traits in F2 and F2∶3 populations presented continuous distribution with a wide frequency.As compared with F2 plants,the average of 1000-grain weight,grain length and width in F2∶3 families were partial to large grain parent K1561.A genetic linkage map containing 161 pairs of SSR markers of rice were constructed by using 188 plants of F2 population.As a result of QTL mapping,18 QTLs for grain shape-related traits were detected,and they distributed on the 1,2,3,7,9 and 12 chromosomes.Except for qGL/GW12,these alleles were derived from its large grain parent K1561.Among all the QTLs,the QTL number for controlling 1000-grain weight,grain length,grain width and ratio of grain length to width were 7,5,5 and 1,respectively.Eight QTLs viz.,qTGW3,qTGW7,qTGW9.2,qTGW12,qGL1,qGL9,qGW12,and qGL/GW12,could be detected on two populations,whose average value of additive effect were 6.04％,12.59％,6.29％,22.08％,4.86％,15.39％,22.12％ and 10.83％,respectively.Conclusion] Three detected QTLs qTGW12,qGL9 and qGW12 with higher effects among eight QTLs may be new sites.This result provides better genetic materials for further work on fine mapping and cloning of gene for grain shape-related traits,and elucidating the controlling mechanism of rice yield and quality traits.