The genetic effects of the cooking quality traits amylose content (AC) and gel consistency (GC) of japonica rice were analyzed by using a genetic model including genotype environment (GE) interaction effects for quality traits of the endosperm in cereal crops. The results indicated that AC and GC of japonica rice were greatly controlled by the genetic main effects from endosperm, cytoplasm and maternal plant genes, but were also affected by GE interaction effects. The endosperm effects were most important among genetic main effects for the performance of AC and GC, while the cytoplasmic interaction effect or maternal interaction effects for AC or GC were more essential among GE interaction effects, respectively. Additive effects and cytoplasmic interaction effect were the main factors ontrolling the performance of AC, but GC was mainly affected by additive effects, additive interaction effects and cytoplasmic interaction effect. The endosperm general heritabilities were the largest ones among heritability components for AC and GC. A significant negative genotypic correlation was found between AC and GC. The genetic effects predicted for 13 parents showed that Liaojing 326 A and Hu 161 were the better parents for improving the rice cooking quality traits.

The low fertility of naked seed rice (NSR) was investigated by the following observations: somatic chromosome constitute, behavior of pollen mother cells (PMCs), the germination of mature pollen grains, the development of male and female gametes and the structure of the anther opening. The results indicated that somatic chromosomal number was 2n=24, behavior of PMCs were normal and most of pollen grains could regularly develop further to mature male gametophytes in NSR. And dehiscence chamber and thickened endothecium cell (TEC) in numerous anthers of the NSR were developed abnormally after dicaryotic phase, result in few anthers complete opening and most partly opening or failure to opening, therefore much fewer of pollen grains attach on the stigma as compared with normal variety. Furthermore most of embryo sacs possessed abnormal structure and were sterile. All of above illustrated that the failure of the anther opening and the abortion of female gametophyte were main factors controlling the low seed-setting rate of the NSR.

Identification of genetic main effects and genotype

The dynamic changes of genetic effects, including main effects, and genotype

Investigations to identify quantitative trait loci (QTLs) governing cooking quality traits including amylose content, gel consistency and elatinization temperature (expressed by the alkali spread value) were conducted using a set of 241 RIL populations derived from an elite hybrid cross of "Zhenshan 97" 9 "Minghui 63" and their reciprocal backcrosses BC1F1 and BC2F1 populations in two environments. QTLs and QTL 9 environment interactions were analyzed by using the genetic model with endosperm and maternal effects and environmental interaction effects on quantitative traits of seed in cereal crops. The results suggested that a total of seven QTLs were associated with cooking quality of rice, which were subsequently mapped to chromosomes 1, 4 and 6. Six of these QTLs were also found to have environmental interaction effects.