[Objective] This study was conducted to improve unit yield of rice in Longyang District and find the relationship between transplanting density and rice yield. [Method] Under the condition of field plot test, effects ...[Objective] This study was conducted to improve unit yield of rice in Longyang District and find the relationship between transplanting density and rice yield. [Method] Under the condition of field plot test, effects of cultivation density on yield and yield components were investigated with japonica rice Longke 16 as a test material. [Result] Under a planting density of 2.7-3.3×10^5 clusters/hm^2, equivalent to a density of seedlings with tillers of 5.4-6.6×10^5/hm^2, the yield reached 11 250-12 000 kg/hm^2. [Conclusion] Longke 16 is a japonica rice variety with good comprehensive characters, and rational dense planting and accurate quantitative cultivation could give full play to its high yield potential.展开更多
[Objective] This study aimed to analyze the yield potential of newly developed Yinshui-type japonica hybrid rice parents and provide the theoretical basis for breeding of Yinshui-type japonica hybrid rice. [Method] An...[Objective] This study aimed to analyze the yield potential of newly developed Yinshui-type japonica hybrid rice parents and provide the theoretical basis for breeding of Yinshui-type japonica hybrid rice. [Method] An incomplete diallel cross of four cytoplasmic male sterile （CMS） lines and four restorer lines was designed to investigate the combining ability for yield and yield components of Yinshui-type japonica hybrid rice. [Result] The variances of general combining ability （GCA） for yield traits were extremely significantly different. GCA variances of male parents were higher than that of female parents except for seed-setting rate. The variances of specific combining ability （SCA） for grain yield per plant, number of effective spikes and seed-setting rate were significantly or extremely significantly different. 139A and Wanlun 422 exhibited higher GCA effects. Most yield traits of these two parents be- longed to type II. Combinations 139AxWanlun 422 and Liaojingl0AxWanlun 422 had relatively high grain yield per plant and SCA effects. GCA effects of restorer lines and SCA effects of combinations greatly affected yield traits, while GCA ef- fects of CMS lines slightly affected yield traits. [Conclusion] In this study, restorer lines exhibited greater genetic differences and impact on yield traits than CMS lines; 139A and Wanlun 422 possessed higher application potential.展开更多
To create the japonica germplasm with long grain and fragrance,we edited GS3 and OsBADH2 of a japonica rice cultivar Chunjiang 151 by using CRISPR/Cas9 system for multiplex genome editing.10 long-grain fragrant japoni...To create the japonica germplasm with long grain and fragrance,we edited GS3 and OsBADH2 of a japonica rice cultivar Chunjiang 151 by using CRISPR/Cas9 system for multiplex genome editing.10 long-grain fragrant japonica rice plants without transgenic components were obtained.Compared with those of Chunjiang 151,the grain length,thousand-grain weight,and yield per plant of the edited line increased 12.20%,18.45%,and 8.31%,respectively.We created the fragrant japonica rice line with improved grain length and yield,which enriched the germplasm resource of japonica rice and provided reference for the improvement of rice quality.展开更多
Meeting the demand for high-quality japonica rice is a major challenge facing China's grain security. In the present study, a two-year field experiment was conducted to investigate the yield, quality, and profitab...Meeting the demand for high-quality japonica rice is a major challenge facing China's grain security. In the present study, a two-year field experiment was conducted to investigate the yield, quality, and profitability of japonica rice varieties(including hybrids and inbreds) grown in the late season as compared with local elite indica hybrids in a double rice cropping system of China where indicas are traditionally planted. Indica hybrids had significantly longer vegetative(from sowing to heading) and total(from sowing to maturity) growth durations than japonicas in both2011 and 2012, while reproductive growth duration(from heading to maturity) was longer for indica hybrids than for japonicas in 2011 but not in 2012. Indica hybrids produced higher grain yield than japonicas in 2011, but with no significant differences in 2012. Japonicas had higher brown rice, milled rice, and head rice percentages than indicas, but had lower gelatinization temperature and amylose content,while with no significant differences in gel consistency and protein content. Indica hybrids tended to have lower chalky grain percentage and chalkiness degree than japonicas, though the differences were not statistically significant due to large genotypic variations. The net returns were 16.1% and 9.9% greater for indica hybrids than for japonica hybrids and japonica inbreds in 2011, with only 3.8% and 1.3% in2012, respectively. Thus, our results suggest that replacing indicas with japonica varieties as late rice may not be feasible at the present site unless locally adapted japonica varieties are developed.展开更多
基金Supported by Longyang District Regional Extension Station of Agricultural Research System for Rice Industry in Yunnan Province[YNKZ(2009)53,YCNZ(2009)171]~~
文摘[Objective] This study was conducted to improve unit yield of rice in Longyang District and find the relationship between transplanting density and rice yield. [Method] Under the condition of field plot test, effects of cultivation density on yield and yield components were investigated with japonica rice Longke 16 as a test material. [Result] Under a planting density of 2.7-3.3×10^5 clusters/hm^2, equivalent to a density of seedlings with tillers of 5.4-6.6×10^5/hm^2, the yield reached 11 250-12 000 kg/hm^2. [Conclusion] Longke 16 is a japonica rice variety with good comprehensive characters, and rational dense planting and accurate quantitative cultivation could give full play to its high yield potential.
文摘[Objective] This study aimed to analyze the yield potential of newly developed Yinshui-type japonica hybrid rice parents and provide the theoretical basis for breeding of Yinshui-type japonica hybrid rice. [Method] An incomplete diallel cross of four cytoplasmic male sterile （CMS） lines and four restorer lines was designed to investigate the combining ability for yield and yield components of Yinshui-type japonica hybrid rice. [Result] The variances of general combining ability （GCA） for yield traits were extremely significantly different. GCA variances of male parents were higher than that of female parents except for seed-setting rate. The variances of specific combining ability （SCA） for grain yield per plant, number of effective spikes and seed-setting rate were significantly or extremely significantly different. 139A and Wanlun 422 exhibited higher GCA effects. Most yield traits of these two parents be- longed to type II. Combinations 139AxWanlun 422 and Liaojingl0AxWanlun 422 had relatively high grain yield per plant and SCA effects. GCA effects of restorer lines and SCA effects of combinations greatly affected yield traits, while GCA ef- fects of CMS lines slightly affected yield traits. [Conclusion] In this study, restorer lines exhibited greater genetic differences and impact on yield traits than CMS lines; 139A and Wanlun 422 possessed higher application potential.
文摘To create the japonica germplasm with long grain and fragrance,we edited GS3 and OsBADH2 of a japonica rice cultivar Chunjiang 151 by using CRISPR/Cas9 system for multiplex genome editing.10 long-grain fragrant japonica rice plants without transgenic components were obtained.Compared with those of Chunjiang 151,the grain length,thousand-grain weight,and yield per plant of the edited line increased 12.20%,18.45%,and 8.31%,respectively.We created the fragrant japonica rice line with improved grain length and yield,which enriched the germplasm resource of japonica rice and provided reference for the improvement of rice quality.
基金Supported by grants from the China National Rice Research Institute and Jiangxi Province(GJJ12215 and 555 Talents Program)
文摘Meeting the demand for high-quality japonica rice is a major challenge facing China's grain security. In the present study, a two-year field experiment was conducted to investigate the yield, quality, and profitability of japonica rice varieties(including hybrids and inbreds) grown in the late season as compared with local elite indica hybrids in a double rice cropping system of China where indicas are traditionally planted. Indica hybrids had significantly longer vegetative(from sowing to heading) and total(from sowing to maturity) growth durations than japonicas in both2011 and 2012, while reproductive growth duration(from heading to maturity) was longer for indica hybrids than for japonicas in 2011 but not in 2012. Indica hybrids produced higher grain yield than japonicas in 2011, but with no significant differences in 2012. Japonicas had higher brown rice, milled rice, and head rice percentages than indicas, but had lower gelatinization temperature and amylose content,while with no significant differences in gel consistency and protein content. Indica hybrids tended to have lower chalky grain percentage and chalkiness degree than japonicas, though the differences were not statistically significant due to large genotypic variations. The net returns were 16.1% and 9.9% greater for indica hybrids than for japonica hybrids and japonica inbreds in 2011, with only 3.8% and 1.3% in2012, respectively. Thus, our results suggest that replacing indicas with japonica varieties as late rice may not be feasible at the present site unless locally adapted japonica varieties are developed.
