A QTL analysis of main agronomic characters in rice，Oryza sativa

【Objective】 To identify excellent main effect QTLs conferring high yield, high quality in rice.【Method】 A genetic linkage map consisting of 142 simple sequence repeat (SSR) markers was constructed based on a recombinant inbred line (RIL) population derived from a cross between Japonica Zhongye 1211 and Indica Zhongda 304 in rice，Oryza sativa. Through an interval mapping method, a genome-wide quantitative trait loci (QTL) analysis was carried out for 13 agronomic traits of rice in the early and late seasons in 2012, including heading period, effective tillers per plant, plant height, panicle length, filled grains per plant, grains per panicle, seed setting rate, grain density per panicle, grain length, grain width, grain shape, 1000-grain mass, grain mass per plant.【Result and conclusion】 The number of QTLs related with the traits except that plant height was 2-15. A total of 73 QTLs for 12 traits were identified and mapped on all of the 12 rice chromosomes. Among all the 73 QTLs, there were 34 QTLs identified in the early season rice, 23 QTLs in the late season rice, and 16 QTLs in both of the early and late season rices. Each of the QTLs individually explained 5.3%-28.4% of the phenotypic variations, among which 10 QTLs were more than 20%. In both cropping seasons, many QTLs closely linked each other were detected in multiple sections of most chromosomes. Twelve new QTL loci are discovered, and 16 QTLs are identified in both cropping seasons can be used in marker-assistant-selected method.