Genetic Analysis And QTL Mapping Reasearch Of Appearance Quality Traits In Indica Rice

Rice traits mainly include appearance traits, milling traits, nutrition traits and cooking traits. Appearance trait is the first elements of rice commercial quality, which could directly affect commercial values. Rice appearance trait is mainly referred to grain length (GL), grain width (GW), ratio of length and width (L/W), chalkiness (CH) and grain weight (WE). In this paper, we conducted molecular genetic research of rice appearance trait to analyze the genetic rule in the progress of Jiafuzhan hybrided with other parents for guiding the choosen of parents, and analyzed the localization of Quantitative Trait Loci (QTLs)by constructing A RIL(F7)populations derived from Jiafuzhan×MInghui86 with the purposes to get several accurated QTLs for the following research of gene localization and molecular marker-assisted breeding work. The main results as following:A RIL populations derived from Jiafuzhan×MInghui86 (abbr: MJ86) was constructed, which the number of individuals is 390. Phenotyping shows that the average value of GL, GW and L/W are very close to mid-parent value, without super-parent value in the population, the average value of WE is also very close to mid-parent value but with super-parent value. The average value of CH is partial to low-value parent with super-parent value. Analysis of t-test shows that the distribution of GL, GW, L/W, and WE are following significantly or very significantly normal distribution, which indicates that the traits of GL, GW, L/W and we belongs to quantitative traits, and CH looks like quality-quantitative traits. Correlation analysis among rice appearance traits indicates that correlations between GL and L/W, GW and CH are very significantly positive, but those of between GL and GW, GW and L/W were very significantly negative. It also shows correlations between GL and WE, GW and CH are very significantly positive.We constructed a genetic linkage map, consisting of 20 linkage groups, by 131 polymorphic SSR markers showed between two parents. It covered the rice genome about 1,263.6 cM. The average interval between two markers is about 9.6 cM, meeting the need of analysis of QTL localization.We detected 32 QTLs controlling rice appearance trait distributed on chr.1, chr.2, and chr.3, chr.5, chr.7 chr.8, chr.9, chr.10, and chr.12, 8 for GL, 4 for GW, 8 for L/W, 2 for CH and 10 for WE, which could explain the total variance 52.48%, 36.72%, 60.84%, 30.37% and 67.91% respectively. We also detected 6 main intervals of QTLs in this paper: RM84-RM490, RM580-RM595, RM485-RM423, RM318-RM207, RM126-RM404 and RM257-RM328, which are locoted chr1, chr2, chr8 and chr9.