Correlation Analysis Of Eating Quality With Wx Gene And Main Quality Traits In Indica Rice

With China’s economic development and supply-side structural reform,rice quality has received more and more attention,and the improvement of eating quality has become the main goal of rice breeding.There are many varieties of rice in the world,and there are huge differences in quality traits.How to quickly screen out germplasm materials that meet the requirements is the key to improving breeding efficiency.In this paper,the eating quality and related quality traits,Wx genotype（waxy gene）and RVA spectrum of conventional indica rice and hybrid indica rice were measured and analyzed.The difference of rice quality between conventional indica rice and hybrid indica rice was compared,and the characteristics of excellent eating indica rice varieties were analyzed,so as to provide reference for the selection of germplasm materials in breeding work.below are key research findings:1.The sensory evaluation results of indica rice varieties showed that the 4 grades of poor,medium,good,and excellent varieties of 163 indica materials in the taste score were 80,32,33,and 18 respectively,and the varieties with poor taste score accounted for the highest proportion.The number of varieties with excellent and good cooking appearance score is more than the number of varieties with excellent and good taste score,and the appearance and taste of rice are inconsistent.The three genotypes of indica rice used in the experiment were Wx^bWx^b,Wx^aWx^b,and Wx^aWx^a.Wx^bWx^b genotype indica rice had the best taste quality;Wx^aWx^a and Wx^aWx^b,genotype indica rice all had poor taste scores;among Wx^bWx^b genotype indica rice,conventional and excellent taste quality Good-rated varieties accounted for more than hybrid indica rice.2.The chalkiness of indica rice materials has the largest variation coefficient,and the chalkiness of most varieties meets the third-grade standard of high-quality rice stipulated by the Ministry of Agriculture,and the head milled rice rate is between9.62%and 70.63%.The head milled rice rate was low and the broken rice rate was high in most varieties of hybrid indica rice.The taste value was significantly or extremely significantly negatively correlated with chalkiness,grain width,transparency and broken rice rate,and extremely significantly positively correlated with head milled rice rate,milled rice rate and aspect ratio.The whole milled rice rate of indica rice varieties with good taste score was mostly higher than 30%,and the taste score of varieties with whole milled rice rate lower than 22%did not reach the excellent grade.The varieties with low chalkiness had better eating quality.The chalkiness rate of excellent,good conventional indica and hybrid indica rice was less than 21.77%and 13.39%,respectively,and the chalkiness degree was less than 4.03%and 3.28%,respectively.3.The amylose content ranged from 14.15%to 28.96%,and the alkali elimination value ranged from 1.17 to 7.The taste scores of varieties with amylose content more than 23%were all poor.The amylose content of conventional indica rice with poor taste was more than 23%,but the indica hybrid rice with poor taste appeared in each concentration of amylose content.The amylose content of excellent and good taste varieties ranged from 14%to 23%,but there was no correlation between taste and amylose content in this range.There was no significant correlation between alkali elimination value and taste value of indica rice.In F₂ grains of some indica hybrid rice varieties,there was a large difference in alkali elimination value between grains,but it had little effect on taste.4.The taste value was highly significantly correlated with breakdown viscosity and setback viscosity in conventional indica rice,but not significantly correlated with hybrid indica rice.However,in hybrid indica rice,the breakdown viscosity of varieties with excellent and good taste score was greater than 1531 c P,and the setback viscosity was less than 78 c P.Compared with conventional indica rice,hybrid indica rice with the same taste score has higher breakdown viscosity and setback viscosity.5.According to the standard of eigenvalue>1,four principal components were extracted from conventional indica rice,and the cumulative contribution rate was84.97%.Five principal components were extracted from hybrid indica rice,and the cumulative contribution rate was 90.60%.Viscosity factor,amylose content and processing factor were the major contributors to the taste value of indica rice.The viscosity characteristics and amylose content of starch should be first considered in the breeding of indica rice varieties with good taste,followed by grinding factor.