Genetic Effect Of Soluble Starch Synthesis Genes On Cooking And Eating Qulities Under The Semi-glutinou Gene Wx-mq In Rice

Cooking and eating quality is an important aspect of rice quality.It was closely related to amylose content（AC）,gelatinization temperature（GT）,gel consistency（GC）and Rice Starch Viscosity（RVA）.In this study,the genotypes of starch synthesis genes were systematically screened among different rice varieties using molecular markers.63 breeding lines derived from the cross of "Kanto 194" and Wu jing 13" were used to evaluate the genetic effects of SSIIa and SSⅢa genes by detecting genotypes and measuring AC,GT,GC and RVA.The main research results are as follows:1.Molecular markers screening showed that starch synthesis-related genes had good polymorphism between indica and japonica varieties.Compared to the conservation of japonica varieties,larger variation was found among indica varieties.Genotypes of indica varieties 9311 and Minghui 63 were closer to that of japonica varieties.Two or three alleles of six starch synthesis-related genes were found in 28 japonica parents.Four genotypes of the two soluble starch synthesis genes,SSⅡa and SSⅢa,were detected in 63 breeding lines derived from the cross of’Guandong 194’ and ’Wujing 13’.2.The values of AC,GC,GT and RVA profiles varied little and their variation coefficient was not large.Correlation analysis indicated that AC and GC was significantly positive correlation with the correlation coefficient 0.392.The correlations between AC and GT and GT and GC were not significant,but there were significant correlations between them and some RVA values and among RVA profiles.3.We analyzed genetic effects of AC under different genotypes.Single gene analysis revealed that SSⅡa of "Wu jing 13" and SSⅢa of "Kanto 194" resulted in a 0.58%and 0.48%increase of amylose content,respectively,with a higher effect of SSⅡa compared with SSⅢa.Multiple comparisons of four genotypes from two gene combinations showed that there were significant differences between SSⅡa^b-SSⅢa^b and SSⅡa^mq-SSⅢa^mq,SSⅡa^b-SSⅢa^b and SSⅡa^mq-SSⅢa^b,SSⅡa^b-SSⅢa^mq and SSⅡa^mq-SSⅢa^b genotypes,while amylose content of the remaining genotypes were not significantly different.4.We analyzed the genetic effects of GT and GC under different genotypes.Single gene analysis revealed that genotypes SSIIa and SSIIIa originate from different parents all were not significantly different.Multiple comparisons of four genotypes from two gene combinations showed that GT values between SSⅡa^mq-SSⅢa^mq and SSⅡa^b-SSⅢIa^b genotypes were significant differences,while the remaining genotypes were not significantly different.GC values of all genotypes were not significantly different.5.We analyzed the genetic effects of RVA under different genotypes.Single gene analysis revealed that only hot viscosity and cold viscosity between different SSⅢa genotypes showed not significant differences.Other characteristic values between different genotypes of SSⅡa and SSⅢa had significant differences.Multiple comparisons of four genotypes from two gene combinations showed that each characteristic values among four kinds of genotypes had significant differences,while each characteristic value was not significantly different between SSⅡa^mq-SSⅢa^mq and SSⅡa^mq-SSⅢa^b.Only consistency values had significant difference between SSⅡa^b-SSⅢa^mq and SSⅡa^b-SSⅢa^b.Peak viscosity,hot viscosity and cold viscosity had no significant differences between SSⅡa^mq-SSⅢa^b and SSⅡa^b-SSⅢa^b.