Genectic Studies On Amylose Content Of Rice And Utilization

The single grain method modified by author was used to analyze the inheritance of amylose content based on triploid genetic mode firstly proposed by Mo huidong in five kinds of combinations made between 10 rice varieties with different amylose ,invovling with high amylose content /low amylose content, high amylose content/ high amylose content, low amylose contenten/low amylose content, high amylose content/waxy, low amylose content/ waxy .together ten crosses .the results were follows.1 In the analysis of the results obtained from single rice grain method and NY-147-88 method , it indicated that two results agreed with each other. Coeffcients of Variation is very low,it followed that single rice grain method may be properly used to analyze the inheritance of amylose content .2 In the analysis of inheritance for F2 generation in ten combinations, it recluded that the regulations for the heritance of amylose content.2. 1 Inheritance in high/waxy cross and low/waxy reciprocal . Amylose content was controlled by a pair of major effect genes with Wx being completely dominant over wx. There are two allele genes in Wx, which respectively controlled high amylose and low amylose.There are four genetypes WxWxWx, WxWxwx, Wxwxwx, wxwxwx distributed with the same frequence, the segregation ratio for non-waxy and waxy in F2 generation rice grain is 3:1. 2. 2 Inheritance in three high/low crosses. Amylose content was controlled by a pair of major genes with high amylose content being completely dominant over low amylose content propably with some monor modifing genes There are four genetypes WxaWxaWxa,WxaWxaWxb,WxaXbWxb,WxbWxbWxb distributed with the same frequence, the segregation ratio for amylose content of F2 generation rice between high and low is all 3:1. The crosses made between with F1 generation of high/low crosses as male parent , low AC and highAC as female paren, the segeration ratio for BC1F1 generation is 1:1, there were two genetypes WxaWxaWxa, WxaWxaWxb and WxaWxbWxb, WxbWxbWxb respectively, which reprent high AC, intermediate AC, and mediate AC, low AC. 2. 3 Inheritance in three crosses of high /high and one cross of low /low.Amylose content is genetically controlled by allel gene for high amylose content or for low amylose content, propably with some modifying genes. There were no segeration for amylose content of F2 generation seeds , showing normal distribution . Difference of amylose content between grains derived from the enviroment.3 The analysis of 2303S/2301S, WANDA064/JINGNU04921 reciprocals showed that amylose content is only controlled by endosperm nucleus gene without genetical effect of cytoplasm .4 The analysis of gene dosage effct in six combinations showed that the first dosage were able to increase amylose content significantly, about 53. 10-80. 61%, but the second and third dosage are more lower than it.5 The analysis of gene effecting in the inheritance of amylose content showed that amylose content be largely controlled by heredity, less the enviroment affecting. The proption of additive in the total genetic variation was 89.41%, while dominant was low ,only 10.52%. Regression analysis of amylose content showed that regression equation between amylose content (Y) and additive(X,), dominant(X2), (X3)was:Y=0. 985X.+0. 807X2+0. 864 X3+19. 119, the multiple coefficient of correlation was R2=0. 7854. The path analysis for amylose content that the direct path coeffient between amylose content and additive was 0. 764, between first dominant was 0. 246, between second dominant was 0. 163.