摘要
对典型籼粳杂种育性遗传基础的研究是快速进行广亲和系培育的前提。以回交群体Balilla 南特号∥Ba lilla为育性基因的分析群体 ,利用SSR标记研究了该群体中控制小穗育性和花粉育性的基因位点 ,对于小穗育性共检测到 2个QTLs ,qSPTF1和qSPTF6 ,分别位于第 1和第 6染色体上 ,其加性效应分别为 13 5 0 1和 - 16 4 14。根据前人的研究结果 ,以及qSPTF6在第 6染色体上所处的位置 ,可以推断qSPTF6即为S 5位点。在花粉育性的QTLs检测中 ,发现在第 7和第 9染色体上有两个QTLs,qPLLN7和qPLLN9,其加性效应分别为 - 12 0 0 3和 - 11 0 12 ,可以分别解释表型变异的 12 9%和 10 3%。位点的互作分析表明 ,在该研究群体中 ,存在大量的位点互作影响小穗育性和花粉育性 ,在 0 0 0 5显著水平上 ,检测到 6 1对和 5 1对位点互作分别影响小穗育性和花粉育性。说明籼粳杂种的不育性除了主效基因的单独作用以外 ,位点之间的互作 ,即上位性也是一重要的遗传因素。
To explore the genes differentiated between typical indica and japonica varieties,two typical indica/japonica varieties,Balilla (japonica) and Nantehao (NTH,indica),were selected to construct genetic populations based on the widely surveying for spikelet and pollen fertility of 90 indica/japonica F 1 hybrids,which also were used as the wide compatibility testers.In order to analyze the genes (QTLs) related to spikelet and pollen fertility,two reciprocal backcross populations Balilla/NTH∥Balilla and Balilla/NTH∥NTH were constructed and the spikelet and pollen fertility of each individuals were assessed.In both populations,two traits all appeared distorted normal distribution,but in the first population,they forwarded to low-level fertility type,the later population,forwarded to high-level fertility type relatively.The results indicated that both of male and female gametophytes of Balilla/NTH hybrids were partial sterile.Then we analyzed the SSR marker genotype of each individuals of Balilla/NTH//Balilla population containing 142 individuals,and constructed a SSR linkage map,in which,there were 108 information markers distributing on all 12 chromosomes equably,average marker distance was about 11.9 cM.Therefore the linkage map was qualified for QTL analysis.Two methods were employed to conduct QTLs analysis,i.e.single marker analysis and interval mapping.According to single marker analysis,17 and 12 markers were found significantly responsible for spikelet and pollen fertility,respectively.And further study by means of MAPMAKER/QTL software,for spikelet fertility trait,two QTLs were detected,qSPTF1 on chromosome 1 and qSPTF6 on chromosome 6,and their additive effect were 13.501 and -16.414,respectively.According to previous studies,qSPTF6 was deduced to be the same locus as S-5.For pollen fertility,qPLLN7 on chromosome 7 and qPLLN9 on chromosome 9 were detected,and their additive effects were -12.003 and -11.012,respectively.Because the QTLs detected cannot explain completely the total variance of mapping population,other genetic factors must be existed to be responsible for spikelet and pollen partial sterility.Hence we let two random markers as putative covariates,and divide the 142 individuals into four groups according to the two marker genotypes,then the average values of spikelet and pollen fertility of each groups were calculated for two-way ANOVA (analysis of variance).The results indicated that there existed strong interaction for both spikelet fertility and pollen fertility.At a significance level of 0.005,there over 61 and 51 pairs loci interactions detected playing an important role in spikelet and pollen sterility expression,respectively.These results indicated that epistasis also was one of major genetic conponents controlling indica/japonica hybrid sterility.
基金
国家"8 6 3"计划 (BH0 1 0 2 0 1)资助~~
