摘要
为探明籼粳杂种低温花粉不育的遗传基础,以籼稻品种3037和粳型广亲和品种02428的F2分离群体进行了低温花粉不育的遗传分析。推迟播种后,F2群体各单株孕穗期的日平均温度为21～23℃,调查了F2群体各单株的花粉育性。利用108对SSR引物构建了包含157个F2单株,覆盖12条染色体的分子标记连锁图谱。该连锁图的总长度为1857.8cM,标记间平均距离为16.26cM,标记较均匀地分布在12条染色体上。采用区间作图法对F2群体花粉不育进行QTL分析,共检测到2个低温花粉不育QTLs,即qLTSPS2和qLTSPS5,分别位于第2、5染色体,其加性效应分别为0.021、0.045,显性效应分别为-0.246、-0.251,显性度分别为11.7和4.8,具有超显性效应,超显性是QTL作用的主要方式,这2个位点杂合基因型在低温环境下具有降低花粉育性的作用,分别解释表型变异的15.6%、11.9%。另外,两因素的方差分析表明这两个QTL之间不存在互作。
There existed a number of biological constraints in exploiting the heterosis of indica-japonica hybrid rice.The low-temperature-sensitive sterility (LTSS) of indica-japonica hybrid has become one of the major problems in indica-japonica hybrid rice breeding after the solution of poor fertility of the hybrids by the finding of wide-compatibility gene.Previous studies revealed that the LTSS might be caused by low-temperature-sensitive pollen sterility (LTSPS).However,the genetic basis of LTSPS remained unclear.To explore the genetic basis of LTSPS in indica-japonica hybrid rice,an F_2 genetic population derived from 3037 (indica) and 02428 (japonica) was developed.At the booting stage,pollen fertility of F_2 population together with parents were surveyed after the treatment with low temperature daily average of 21~23℃.The linkage map was constructed containing 108 SSR markers distributed throughout the whole 12 chromosomes with average marker interval of 16.26 cM.Using software MapMaker/QTL,two putative QTLs,namely qLTSPS2 and qLTSPS5 on chromosomes 2 and 5 were detected by interval mapping,which could explain the phenotypic variation 15.6% and 11.9% respectively.The additive effects were 0.021 and 0.045,dominant effects were -0.246 and -0.215,and the degrees of dominance were 11.7 and 4.8,respectively for the two QTLs.Therefore,the mode of gene action in response to low-temperature stress was overdominance and LTSPS was mainly the result of interaction between the indica and japonica alleles within each locus.In addition,two-way ANOVA showed that the two QTLs acted essentially independent of each other in conditioning LTSPS.
基金
国家863计划(编号:2003AA207020
2002AA2Z1001 06)
江苏省高技术项目(编号:BG2001301)~~
关键词
水稻
籼粳杂种
低温
花粉不育
QTL定位
Oryza sativa L.
indica-japonica hybrid rice
low temperature
pollen sterility
QTL mapping
