QTL Analysis for Heading Stage and Panicle Traits at Different Years in Rice
REN Chun-yuan;FAN Shu-xiu;LIU Jin;ZHU Lin;YANG Qi-wen;LIU Dan;MA Dian-rong;WANG Jia-yu;College of Agronomy, Heilongjiang Bayi Agricultural University;Rice Research Institute/Key Laboratory of Northeast Rice Biology and Breeding,Ministry of Agriculture,Shenyang Agricultural University;Mudanjiang Branch of Heilongjiang Academy of Agricultural Sciences;
Panicle traits are closely related to the yield potential of rice varieties, and the heading date is the determining factor of whether rice varieties can be planted in area region. It is important to understand the genetic basis of panicle traits and heading date and its relationship with yield traits. The backcross recombinant inbred lines(BILs) derived from the cross between Sasanisiki(japonica) and Habataki(indica) were used to identify QTLs for heading stage and panicle traits in different environments. The results showed that there were significant differences between heading dates and between grain number per panicle, and there was significant negative correlation between heading date and seed setting rate. A total of eight QTLs were mapped for plant heading stage, among these QTL, qHD3, qHD7 and qHD8 were identified in two years, and they were able to extend the heading date. Five QTLs were mapped for spikelets per panicle, among them, qGN1a and qGN5 were detected in two years. Five QTLs were detected for filled grain number per panicle, qSN1a was a stable expression of the main effect QTL. Four QTLs were detected for seed setting rates, qSSR12 was a stable expression of the main effect QTL. In addition, among them,pleiotropic QTL qHD1a and qSSR1, qHD12 and qSSR12, qHD1b and qGN1c and qSN1b qSN2 and qSSR2, qSSR6 and qGN6 and qSN6 were detected on the same region of chromosome, which indicated that heading date and grains per panicle were the most important factors affecting grain filling. The identification of genes constituting the QTLs will help to further understand the molecular mechanisms underlying heading stage and provide a theoretical reference for the molecular marker assisted selection.