Genetic Studies on Amylose Content and Amylographic Breakdown Viscosity of Milled Rice by Means of Generation Mean Analysis

Amylose content and amylographic breakdown viscosity are important parameters for predicting eating and processing quality of rice. A total of 6 populations, P1, P2, F1, F2, BC1 and BC2, derived from two rice cultivars Guichow and Lemont, were used as experimental materials to elucidate the genetic information about the two endosperm characteristics. Genetic mechanism of two studied endosperm characteristics deduced from generation mean analysis were different. An additive-dominance genetic model was perfectly adequate to describe the amylose content data set, and inadequate to the data set of amylographic breakdown viscosity. Conclusion inferred suggested that amylose content of milled rice was mainly controlled by additive gene effect although dominant gene effect was also involved. Furthermore, the gene producing high amylose content was dominant. On the other hand, additive, dominant and additive×dominant interaction were involved to differentiate the level of amylographic breakdown viscosity among materials studied and additive and dominant gene effects were more or less equal. It was also found that low amylographic breakdown viscosity was dominant. A genetic hypothesis deduced from the distribution observation and Chisquare test indicated that a segregation ratio resulting from one single incompletely dominance gene in controlling amylose content was confirmed, and, however, was not confirmed in differentiating amylographic breakdown viscosity.