两个水稻DH群体发芽期和幼苗前期耐碱性状QTL定位比较

QTL-Mapping Comparison of Tolerance to Alkali at Germination Period and Early Seeding Stage between two Different Double Haploid Populations in Rice

利用两个不同的加倍单倍体群体,在0.15%Na2CO3胁迫下,以发芽期和幼苗前期的发芽势(GE)等10个性状碱害相对值作为耐碱指标,进行耐碱性状QTL定位比较。碱害相对值相关分析表明,多个性状的碱害相对值存在显著或极显著相关。采用QTLMapper1.6统计软件对碱害相对值进行QTL分析。DH-1群体定位到10个主效QTL和15个上位性QTL,DH-2群体定位到14个主效QTL和15个上位性QTL。两群体定位列线比对发现:1个控制相对根长的QTL,qRRL3-1,两群体定位在第3染色体对应的区域(CT339-G62和RM7-RM3280)。其他性状两群体没有定位在相同的区域,但存在多个重要的数量基因座位,如CT158-CT550、RM3755-RM418和RM1349-RM1061等区域。在这些相同基因座位上两群体都检测到控制不同性状的主效QTL或上位性QTL,耐碱性QTL可能存在多效性、连锁性,在不同遗传背景下加性效应和上位性效应可以相互转化。多个QTL不仅与水稻耐碱性有关,还与多种抗逆性有关。这些结果将有利于耐碱性分子机制的剖析和强耐碱性水稻品种的选育。

Two rice double haploid （DH） populations were used in this study to detect quantitative trait loci （QTLs） of tolerance to alkali at germination period and early seedling stage. Relative 10trait values under 0.15% Na2CO3 stress were used as the index of tolerance to alkali. Correlation analyses showed that relative germination rate and relative vigor index had significant positive correlation with the others. Total 10 QTLs and 15 epistatic loci were mapped from DH-1 population （ZYQ8×JX 17） and 14 QTLs and 15 epistatic loci were mapped from DH-2 popula- tion （CJ06×TN 1）. Alignement of QTL mapping between these two DH populations showed that one QTE＇controlling root length, qRRL3-1, were mapped on same region of CT339-G62 and RM7-RM3280 on chromosome 3 both in DH-1 and DH-2. There was no same region from the QTLs affecting other traits between these two populations. However, some QTLs controlling different traits were detected in the same region on chromosome 1, 3, 7 and 12 between DH- 1 and DH-2, such as the regions of CT 158-CT550, RM3755-RM418 and RM 1349-RM 1061, which indicated that those loci might be pleiotropic or closely linked QTLs. Some alkali resistant QTLs had adversity resistance, salt tolerance especially. The results will be beneficial to the dissection of molecular mechanism and breeding office with tolerance to alkali.