Genotypic Variation In Grain Quality Tralts Among Mutants Of Japonica Rice Cultivar Wuyujing3

Production of rice with high grain yield and appreciable quality is great challenge for all rice researchers and producers.Jiangsu province is one of the major production areas in China,and in the last three decades has been dominated by japonica rice.However,its poor appearance quality has become great issue.This study was conducted to evaluate 112 mutants of japonica rice cultivar Wuyujing3 for selecting elite germplasm of rice quality.Grain yield(GY)and yield components such as panicles per m2(PnSm),grains per panicle(GPn),grain weight(GW)and grains per m2(GSm)were measured.For quality traits,four quality parameters including:(?)appearance quality such as chalkiness grain rate(CGR),grain length(GL),grain width(Gwd),length to width ratio(L/W),grain thickness(GT),percentage of imperfect grains(PIG);(?)milling quality such as brown rice yield(BRY),milled rice yield(MRY),degree of milling(DM),(?)eating quality such as amylose content(AC)total starch(TS);and(?)nutritional quality such as protein content(PC)were measured.The relationships among physical and chemical quality traits were also determined.Results showed that GY ranged from 2.15 t/ha to 12.49 t/ha with mean of 6.4 t/ha.The PnSm,GPn,and GW ranged from 251.32 to 712.89,27.52 to 152.2 and 17.08 mg to 25.93 mg,with mean of 339.23,84.88 and 22.42 mg,respectively.The GSm was the most important yield component and responsible for high variations in grain yield among rice mutants,it accounts for 94.7%in variation of grain yield.With regard of quality traits,CGR ranged from 4.67%to 73.33%with mean of 15.7%.GL,Gwd and L/W ranged from 4.26 mm to 5.17 mm,2.31 mm to 3,07 mm and 1.48 to 2.03,with mean of 4.84 mm,2.8 mm and 1.73,respectively.GT and PIG ranged from 1.86 mm to 2.18 mm and 3%to 38.02%,with mean of 2.03 mm and 10.64%,respectively.BRY,MRY and DM ranged from 79.16%to 85.24%,65.29%to 72.9%and 13.91%to 19.42%with mean of 83.71%,71.04%and 15.36%,respectively.AC and TS ranged from 12.44%to 19.93%and 73.23%to 81.59%,with mean of 16.92%and 76.99%,respectively.PC ranged from 4.75%to 7.53%with mean of 6.15%.Correlation analysis showed that CGR was significantly negatively correlated with MRY and significantly positively correlated with DM.BRY and MRY were significantly negatively correlated with DM.PC and TS were significantly positively correlated with MRY and negatively correlated with DM,while AC had not significant correlation with these quality traits.Based on criteria of AC ? 18%(good eating rice,i.e.soft when cooked),CGR<20%(CGR of Class-?)and GY ? 7.45 t/ha(current mean of japonica GY in Jiangsu = 7.496 to 8.995 t/ha)was selected 25 rice mutants such as D12W031,D12W202,D12W060,D12W091,D12W177,etc.,which fulfilled those major requirements of standard Jiangsu japonica rice,and they may be used as elite germplasm.Furthermore,the variations and relationships among rice mutants observed in present study is great opportunity to choose them according their specific desired trait in breeding programs.