Effect Of Indica Lineage On Eating Qualities Of The Japonica Rice

In the breeding practice of using inter-subspecific hybridization rice to create excellent japonica Rice in order to integrate the advantages of the two subspecies,the phenomenon of significant decline in eating quality of the cultivated japonica rice often occurs due to the infiltration of the consanguinity of indica rice.In order to find out the genetic basis of the influence of consanguineous infiltration of indica Rice on the eating quality of japonica rice,K1240 with good eating quality was used as the recipient parent and TN013 with poor eating quality as the donor parent to construct the chromosome single segment substitution line Lines,CSSSLs(KT1-KT40)and their two parents(K,T)were used to carry out genetic mapping analysis and environmental interaction analysis.In the experiment,KT families and their parents were planted in Hainan and Beijing respectively,and K,the recipient parent,was used as the control to explore the different ecological environment,and the eating indexes of each family were significantly inferior to those of K,the background parent,so as to determine the chromosome segments that affect the eating indexes.At the same time,the stability of the genetic effect of the chromosome segments related to cooking taste index in different environments was investigated to find out the chromosome segments that are less affected by environmental factors and can be inherited stably,so as to lay a foundation for the fine positioning of subsequent genes.The results show that1.Under the two different ecological environments of Hainan and Beijing,the single segment substitution line KT population and its two parents used in this study showed no significant difference in a few eating quality related index characters between the two parents,and most eating quality related index characters showed significant difference between the two parents.Among them,there was no significant difference in amylose content and gelatinization temperature between the two parents,and the coefficient of variation of amylose content and gelatinization temperature of the single segment substitution line was also low.There were significant differences in appearance score,viscosity score,balance value score,taste value score,hot paste viscosity,breakdown value,cool paste viscosity and consistency value between the two parents,and the coefficient of variation of the single segment substitution line was also higher.Some parents showed different trends in two different ecological environments,Hainan and Beijing.It is speculated that these indicators are greatly affected by the environment,and the chromosome segments carried by their families are environmentally sensitive2.By comparing the distribution of amylopectin chain length between the two parents in Beijing ecological environment,it was found that the two parents were rich in amylopectin with different degree of polymerization,the content of amylopectin with degree of polymerization 5-12 was more abundant in the parent K with high cooking quality,and the content of amylopectin with degree of polymerization 13-60 was more abundant in the parent T with poor cooking quality3.The correlation of eating quality of rice in the ecological environment of Hainan and Beijing was studied.It was found that there was no significant correlation between the eating quality of rice and amylose content,amylopectin chain length distribution;there were significant or extremely significant differences with protein content,peak viscosity,hot paste viscosity,breakdown value,cool paste viscosity and consistency value4.Through the principal component analysis,many indexes affecting the eating quality of rice were dimensionally reduced,and the key components affecting the eating quality of rice were found.It was found that the distribution of amylopectin chain length,the cooking characteristic index of rice and the RVA characteristic value were the first component,the second component and the third component,with the contribution rate of 32.89%,25.15%and 18.60%respectively。5.Through the identification of QTLs related to eating quality of KT segment substitution lines in different ecological environments,21 QTLs were found in Hainan and 74 in Beijing,including 7 environmentally insensitive QTLs.The specific situation is as follows:there are 6 peak viscosity QTL16 in Beijing,6 hot pulp viscosity QTL6 in Hainan,18 in Beijing,and 4 in the two places,5 disintegration value QTL5 in Hainan,and 3 in Beijing,20 cold glue viscosity QTL3 in Hainan,and QTL2 in Beijing,recovery value QTL2 in Beijing,7 appearance QTL7 in Hainan,and 4 in Beijing,and a total of 4 in the two places There are QTL1,5 viscosity QTLs,3 balance value QTLs,and 3 eating value QTLs in Beijing6.The ultrastructural observation on the cross section of rice grains of the low food value family material and the receptor parent K1240 showed that the shape,size and spatial arrangement of starch grains of the low food value family material and the receptor parent K were quite different.The starch grains of K parent were regular and angular,arranged closely,and there was no gap between the starch grains;the starch grains of low food value families were more smooth,arranged loosely,and the gap between the starch grains was larger.