水稻苗期耐低钾品种筛选及相关性状的QTL定位

Screening of Rice Germplasm Resources and Mapping QTLs for Traits Related with Potassium Deficiency Resistance at Seedling Stage

对159份遗传差异较大的水稻品种进行耐低钾筛选,根据综合指数筛选出18份耐低钾和10份低钾敏感的水稻品种。利用筛选得到的耐低钾水稻品种台农67和低钾敏感品种制西构建重组自交系,对耐低钾相关性状进行QTL分析和定位,共检测到27个耐低钾相关性状的QTL,LOD值为2.52~9.23,可解释表型变异为2.22%~7.25%,其中贡献率最高的QTL是qKC-2,该QTL定位在水稻2号染色体上,可能是1个控制水稻钾含量的未知基因,可进一步通过构建次级群体对该基因进行精细定位和克隆。本研究中设计的Indel标记可快速筛选水稻育种材料中的耐低钾基因型,缩短育种时间,而且重组自交系中可以选出农艺性状好又耐低钾的株系直接应用于育种。

159 genetically-variable rice varieties were tested for low potassium tolerance according to the synthetic appraisal index.The results indicated that there were 18 and 10 rice varieties that were tolerant and sensitive to potassium deficiency,respectively.By deployment of the recombinant inbred lines(RILs)that were derived from the crossing between the varieties of Tainong67(potassium tolerant)and Zhixi(potassium sensitive),27 QTLs for potassium deficiency resistance were detected.The LOD values arranged from 2.52 to 9.23,which explained the phenotypic variance of 2.22%to 7.25%.A m a j o r QTL qKC-2 was mapped on chromosome 2 of rice.This locus was yet reported,and might encode for an unknown gene that is valuable for future fine mapping and gene isolation.The newly-developed indel markers could be used to rapidly screen the genotypes with potassium deficiency resistance,thus shortening the breeding period.The lines with good agronomic traits and potassium deficiency resistance could be chosen from RILs and applied to rice breeding directly.