| The mating design used in this experiment was a factorial design with 4 females and 9 males ofjaponica rice (Oryza saliva L.). Four cytoplasmic male sterile (CMS) lines used as females were Ning 67 A, 76-27 A, Xiushui 04 A and Liaojing 326 A, and nine restorer lines used as males were K1722, Zhi 7, Hu 161, Xiangqing, T1027, 2674, Zhongyou 123, Pei C312 and Liao 418. The rice quality traits analyzed were brown rice length (BRL), ratio of brown rice length to width (LWR), ratio of brown rice length to thickness (LTR), chalky grain rate (CGR), chalkiness (CH), translucency (TR), brown rice recovery (BRR), milled rice recovery (MRR), head milled rice recovery (HMRR), amylose content (AC) and gel consistency (GC) for parents, F^ and F2s, and the plant agronomic traits analyzed were plant height (PH), flag leaf length (FLL), flag leaf width (FLW), panicle length (PL), panicles per plant (PPP), grains per panicle (GPP), seed setting rate (SSR) and 1000-grain weight (TGW) for parents and FIS in different environments. Analysis of seed, cytoplasm and maternal effects and genotype * environment (GE) interaction effects for rice quality traits of japonic a rice was conducted and the genetic correlation analysis among rice quality traits was made by using a genetic model including GE interaction effects for quality traits of endosperm in cereal crops. The genetic relationship between rice quality traits and plant agronomic traits of japonica rice was analyzed by using a mixed model approaches, which could estimate the genetic covariances between two traits with unequal design matrices. The study of improving method for appearance quality traits in japonica rice was also conducted. The main result were as follows:1. The quality traits of japonica rice were simultaneously affected by GE interaction effects as well as the genetic main effects from seed, cytoplasm and maternal genes. BRL, LWR, LTR, BRR, AC and GC were mainly controlled by the genetic main effects, and TR, MRR and HMRR was mainly affected by GE interaction effects. The genetic main effects and GE interaction effects were similar for CGR and CH. These results indicated that the expression of genes for BRL, LWR, LTR, BRR, AC and GC were steady in different environments, while those for TR, MRR and HMRR were more easily influenced by the environment conditions.2. The maternal effects were more important than others for BRL, LWR and LTR, and the seed effects were larger for HMRR, AC and GC, while the seed effects andmaternal effects were similar for CGR, CH, BRR and MRR. All quality traits of japonica rice were mainly controlled by maternal additive effects and/or seed additive effects, while LWR, LTR, CGR and AC were also significantly affected by cytoplasmic effects. The analysis of GE interaction effects showed that the expression of maternal additive effects for BRL, LWR, LTR, CGR, and GC, seed additive effects for CH, TR and MRR and cytoplasmic effects for BRR and AC were more easily influenced by environment conditions.3. The heritabilities were high for most quality traits of japonica rice. The general heritability was the main parts for BRL, LWR, LTR, CGR, CH, BRR and AC, but the interaction heritability was more important for TR, MRR, HMRR and GC.4. The positive genotypic covariances were significant between BRL and LWR, BRL and LTR, LWR and LTR, LWR and TR, BRR and MRR, MRR and HMRR, TR and MRR, TR and HMRR, while the negative genotypic covariance significantly exited between LWR and CGR, LWR and CH, AC and GC, CGR and BRR, CGR and MRR, CH and MRR, CH and HMRR. The genotypic relationships among quality traits could be applied for simultaneously improving the rice quality traits or indirect selection for these pairwise traits in japonica rice quality breeding.5. Analysis of relationship between rice quality and plant agronomic traits of japonica rice indicated that significant positive genotypic covariances were found between BRL, LWR, LTR, TR, GC and PH or PL, and between BRR, MRR, HMRR and PH or PPP. The neg...
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