| In the present study,46 rice cultivars(lines) were planted in Changsha and Huizhou, then the brown rice rate,milled rice ratio,head rice ratio,grain length, grain width,grain length/width, chalky rice rate, chalkiness, alkali spreading value, gel consistency, amylose content and protein content were tested.Meanwhile, the RVA profile characteristics such as peak viscosity, trough viscosity, breakdown,final viscosity,peak time, pasting temperature, setback,consistency and the cadmium content in milled rice of the all cultivars (lines) were also tested. The main results were as follows.1.There were significant differences between different rice cultivars (lines) of grain quality traits in different sites. The variation coefficients of chalkiness and chalky rice rate were the biggest among the grain quality trats of 46 rice cultivars (lines) in both Changsha and Huizhou.In Changsha, the variation coefficients of chalkiness and chalky rice rate were 120.01% and 104.21%, which were 263.51% and 217.03% in Huizhou. ANOVA results indicated that the effects of cultivars (lines),sites and cultivars (lines)×sites were highly significant, the variance of head rice ratio(F=17115.352**)was the biggest between different sites of all the grain quality traits.2. The analysis of correlations between grain quality trats in Changsha and Huizhou showed that:there were significantly positive correlation between brown rice rate and milled rice ratio (r= 0.55** and r=0.70**),and there were significantly negative correlation between head rice ratio and grain length in two sites (r=-0.40** and -0.45**).Still, the correlations between grain length, grain length/width and chalkiness,chalky rice rate presents highly negative significance(r=-0.43** and r=-0.44*?r=-0.30* and r=-0.40**?r=-0.62** and r=-0.54**?r=-0.51** and r=-0.53**). Furthermore, the correlations between gel consistency and amylase content, protein content were significantly negative(r=-0.58** and r=-0.-0.74**,r=-0.41** and r=-0.42**).3.The research of RVA profile characteristics of different rice cultivars (lines) in Changsha and Huizhou showed that:the effects of cultivars (lines),sites and cultivars (lines)xsites were highly significant. Variation coefficients of setback was maximum among 8 RVA profile characteristics in two sites, with 137.7% in Changsha and 71.3% in Huizhou.4. RVA profile characteristics and grain quality trats were closely related in different rice cultivars (lines) and sites.The final viscosity, setback and consistency showed closely relations with milling quality traits. Moreover, the peak viscosity, breakdown and pasting temperature showed closely relations with appearance quality traits.Besides,the peak viscosity, breakdown and setback showed closely relations with cooking & eating and nutritional quality. The study also suggested that selecting the peak viscosity medium rice cultivars could take account of cooking & eating and nutritional quality.5. The cadmium content in milled rice analysis results of different rice cultivars(lines) in Changsha and Huizhou showed that:the effects of cultivars (lines), sites and cultivars (lines)×sites were highly significant. Of which, the district difference in Changsha and Huizhou were the greatest (F=2387.78**). This showed that soil cadmium content was the main factor that influenced rice cadmium accumulation in different cultivating environment.6. The principal component and cluster analysis of rice cadmium content and various rice traits of different rice cultivars(lines) in Changsha and Huizhou showed that, the accumulated contribution rate of milling factor, appearance factor and nutrition factor towards rice quality of different cultivars(lines) in Changsha was 66.72%, the accumulation contribution rate of milling factor and cooking & eating factor in Huizhou district was 59.6%;according to the various rice traits of different rice cultivars(lines) in Changsha and Huizhou, the different cultivars(lines) could be classified into 3 categories, each was equipped with different qualities. |
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