Abstract:

Rice (Oryza sativa L.) is an important food crop, which provides more than 50 percent of foods in China. Most of crop traits are quantitative in nature, which are controlled by polygene, so it’s very important for crop improvement to map quantitative trait loci (QTLs). In this research, rice varieties which whole genome have been sequenced, Nippinbare and 93-11, and their F₂ lines were planted at Lingshui County, Hainan Province in 2004. The phenotypic values of 8 agronomic traits including number of tillers (TN), number of effective tillers (ETN), number of panicle (PN), panicle length (PL), main panicle length (MPL), days to heading (DH), plant height (PH), and flag length (FL) were surveyed with three replication. Correlation coefficients between these traits calculated by means of the software of Excel 2000 were found to be similar to other research conclusions. A F₂ linkage map (152 simple sequence repeats (SSRs) markers and covering 2 455.7 cM of the genome length) was applied to detect QTLs with Mapmaker/QTL 1.1b. Under the condition that LOD>2.0 and P＜0.005, 41 QTLs were detected, which distributed on all rice chromosomes. The phenotypic variations (VE) explained by individual QTL were ranged from 11.0% to 46.4%, among which 22 QTLs explained VE by more than 20%. The molecular basis of inheritance and the applications of QTL for rice agronomic traits with sequenced rice materials as mapping parents were discussed.

Key words: Rice (Oryza sativa L.), Agronomic trait, SSR marker, QTL, Mapping