Rice is the staple food for more than half of the world＇s population and for more than 60% of China population. Increasing rice yield is therefore crucial for solving food shortage problem, ensuring food secruity, an...Rice is the staple food for more than half of the world＇s population and for more than 60% of China population. Increasing rice yield is therefore crucial for solving food shortage problem, ensuring food secruity, and reducing poverty. Given the vast population and limited per capita cultivated land in China, meeting food demands by increasing the yield per unit area with the aid of advanced sciences and technologies would be the only option. Several alternative measures for increasing crop yield, such as building water conservancy facilities, increasing fertilizer application, improving soil texture, forming interrelated cultivation techniques, more effective controlling of pests and diseases, and using of elite varieties, have been undertaken. Among these alternative measures, adopting elite varieties, particularly popularizing super hybrid rice, proves to be the most economical and effective option.展开更多
The developmental genetics of plant height was analyzed from two groups of three-line indica hybrid rice at two environmental conditions based on the NCII design, using the additive-dominant developmental genetics mod...The developmental genetics of plant height was analyzed from two groups of three-line indica hybrid rice at two environmental conditions based on the NCII design, using the additive-dominant developmental genetics models and the statistic methods. The results showed that the rice genotypes and environmental conditions could both affect plant height, and the effects of environment on plant height decreased gradually with plant development. Additive and dominant effects both governed the performance of plant height at all developmental stages. However, the degrees of effect varied among the rice genotypes. Moreover, the interaction between environments and genotypes also affected plant height. The genetic effects differed at most developmental stages. Furthermore, the expressJon of additive effect was more active than that of dominant effect. Conditional interaction effects with environment also influenced plant height during genetic development, especially at the eady stage. Mid-parent heterosis （HMP） increased gradually with the developmental stage of plant height, and maximized at the latest stage, whereas the heterosis over the better parent （HBP） showed small differences among the genotypes, and kept stable at the later stage, with positive numeric value. At most developmental stages, conditional HMP was positively significant, while conditional HBP was negatively significant. All above results suggest that HMP and HBP have some new expressions in all developmental periods and the levels and directions are quite different.展开更多
Following NCI design, the developmental genetic behavior of tiller number (TN) in three-line indica hybrid rice was studied using additive-dominance developmental genetic models and the corresponding statistical metho...Following NCI design, the developmental genetic behavior of tiller number (TN) in three-line indica hybrid rice was studied using additive-dominance developmental genetic models and the corresponding statistical methods. The results showed that dominance effects were predominant for TN. The expression of those additive effects were affected by environment and genotype interaction, but the expression of dominance effects were not affected. Heterosis was the strongest in the middle developmental periods of TN. Additive effects and dominance effects were selectively expressed throughout in the entire tillering developmental stage. Analysis of genetic correlation between TN at different stages and the productive panicles indicated that a close correlation appeared earlier in the populations with higher heterosis than in those with less heterosis. Utilization of heterosis at the middle tillering stage might enhance the final biomass but reduce the percentage of productive panicles.展开更多
The purpose of this study was to identify the existing rice breeding programs in Myanmar and to determine researchers＇ attitudes on hybrid rice research mid its determinmlts. A sample consists of 56 researchers who a...The purpose of this study was to identify the existing rice breeding programs in Myanmar and to determine researchers＇ attitudes on hybrid rice research mid its determinmlts. A sample consists of 56 researchers who are working in Department of Agricultural Research, Department of Agriculture and Yezin Agricultural University, and involving varietal development of hybrid rice. The research instruments were a questionnaire used by 4 points Likert scale of strongly agree, agree, less agree and not agree to measure on researchers＇ attitudes towards 14 determinants of varietal development of hybrid rice production. The study revealed that the average age of the researchers was 46.5 years ranged from 25 to 60 years. The majority of researchers were 51-60 years old （41.1%）. The working experience of researchers ranged from 5 to 36 years and the metal of their experience was 20 years. The educational level was Ph.D. （35.7%）, M.Agr.Sc. （26.8%）, and B.Agr.Sc. （37.5%）. Majority of researchers were female （76.8%） and 58.9% were rice breeders. Moreover, 48.2% of researchers obtained the hybrid rice technology from breeding training and the researchers who believed in their current breeding works were 51.8%. Among 33 rice breeders, 72.7% of the rice breeders applied only convention breeding method. In addition, researchers＇ opinions on farmer＇s perception of hybrid rice technology, 60.7% of the researchers agreed on inferior grain quality and 73.2% of researchers strongly agreed on not stable market. This study found out more thin1 half of the researchers strongly agreed on 10 out of 14 determinmlts such as poor infrastructure, low human resource development, parental problem, insufficient experience, limit germplasm resource, limit research facilities, no incentive for breeders, weak public-private partnership, fewer quality breeders and not enough research fund. Moreover, half of the researchers agreed on 3 determinants likely need special technical training, need international assistance and climate change challenges. Finally, development of hybrid rice research in Mymlmar, there will be needed international assistmlce, and upgraded to hybrid rice research center from currently hybrid rice research section and need integrated hybrid rice policy supported by government.展开更多
The developmental genetic behaviors of brown rice width （BRW） have been studied in indica-japonica hybrid rice （Oryza sativa L.）, in which seven indica male sterile lines and five japonica restorer lines were appl...The developmental genetic behaviors of brown rice width （BRW） have been studied in indica-japonica hybrid rice （Oryza sativa L.）, in which seven indica male sterile lines and five japonica restorer lines were applied, by using the developmental genetic models and corresponding statistical approaches for quantitative traits of triploid in cereal crops. The BRW of indica-japonica hybrid rice was co-determined by gene expression of tdploid endosperm, cytoplasm, diploid maternal plant and their genotype × environmental interaction effects. Unconditional analysis showed that the endosperm additive and matemal additive effects were predominant for the development of BRW from early- to late-stage of the grain development, but the endosperm dominant effect together with matemal effect and cytoplasmic effect became the major factor determing the BRW at the ripening stage. Moreover, conditional analysis found that there were new onset and offset of gene expression at different developmental stages of BRW in indica-japonica hybrid rice. Maternal and cytoplasm general heritabilities and their interaction heritabilities were more important compared to other components of heritability for BRW at all the five developmental stages.展开更多
Genetic control of leucine content in indica-japonica hybrid rice (Oryza sativa L.) was studied in 35 crosses of F1 and F2 generations, which were derived from crossing 7 male sterile indica rice lines with 5 restorer...Genetic control of leucine content in indica-japonica hybrid rice (Oryza sativa L.) was studied in 35 crosses of F1 and F2 generations, which were derived from crossing 7 male sterile indica rice lines with 5 restorer japonica rice lines along with their parents. Two genetic models and their corresponding statistical methods for quantitative traits of triploid seeds in cereal crops were used for the analysis. The first was the unconditional genetic model, which refers to the analysis of cumulative measurements (from flowering to a specific time) along the developmental stages, while the second was the conditional genetic model, which relates to analysis from one developmental stage to another stage (t - 1→t). The results showed that leucine content of indica-japonica hybrid rice was controlled by the expression of triploid endosperm effect (endosperm additive effect and endosperm dominant effect), cytoplasm effect, diploid maternal plant effect (maternal additive effect and maternal dominant effect) and their environmental interaction effects. Of these effects, endosperm dominant effect and maternal dominant effect were more important at the earlier stages, while endosperm additive effect and maternal additive effect were more important at the later stages of rice grain development under both unconditional and conditional genetic analyses. Due to the high heritabilities, which came from endosperm, maternal and cytoplasm effects for leucine content at different developmental stages, selection for leucine content of indica-japonica hybrid rice would be more efficient at early generations in breeding programs.展开更多
Male sterile lines serve as a pivotal tool in plant breeding,offering an effective strategy for developing hybrid cultivars.In cucumber(Cucumis sativus L.),the creation of male sterile lines,most of which exhibit abno...Male sterile lines serve as a pivotal tool in plant breeding,offering an effective strategy for developing hybrid cultivars.In cucumber(Cucumis sativus L.),the creation of male sterile lines,most of which exhibit abnormal pollen development,is essential for harnessing heterosis.Accumulating evidence suggests that male sterility in plants is linked to the overaccumulation of Reactive Oxygen Species(ROS),which causes oxidative damage to biomolecules and cellular structures,ultimately leading to aberrant anther development(Li et al.,2004).展开更多
目的应用高分辨微阵列比较基因组杂交技术（array—comparative genomic hybridization，aCGH）对55例不明原阂的智力低下或发育迟缓（mental retardation or developmental delay，MR／DD）患儿进行拷贝数变异（copy number variations...目的应用高分辨微阵列比较基因组杂交技术（array—comparative genomic hybridization，aCGH）对55例不明原阂的智力低下或发育迟缓（mental retardation or developmental delay，MR／DD）患儿进行拷贝数变异（copy number variations，CNVs）检测，寻求与遗传学相关的致病因素，探讨aCGH对不明原因MR／DD患儿可能的分子病因诊断的作用。方法收集2013年6月-2013年12月到本院儿科初步诊断为MR／DD的患儿55例，应用25～50K CytoScanHD芯片检测全基因组CNVs，联合生物信息学分析手段分析致病性CNVs。结果在55例不明原因MR／DD患者中共检测到21例存在罕见CNVs。通过比对数据库，21处CNVs确认为致病性CNVs。19例患者携带与MR／DD相关的CNVs。2例为已知综合征患者，其中1例为Turner综合征，1例为1p36缺失综合征。结论基因组CNVs相关的微缺失或微重复是不明原因MR／DD的病因之一，这些片段均无法被常规染色体G带检查所识别。aCGH可以提高对不明原因MR／DD患儿的分子病因诊断水平，对深入研究MR／DD病因机制有重要意义，为患儿预后和家庭再发风险评估提供指导。展开更多
文摘Rice is the staple food for more than half of the world＇s population and for more than 60% of China population. Increasing rice yield is therefore crucial for solving food shortage problem, ensuring food secruity, and reducing poverty. Given the vast population and limited per capita cultivated land in China, meeting food demands by increasing the yield per unit area with the aid of advanced sciences and technologies would be the only option. Several alternative measures for increasing crop yield, such as building water conservancy facilities, increasing fertilizer application, improving soil texture, forming interrelated cultivation techniques, more effective controlling of pests and diseases, and using of elite varieties, have been undertaken. Among these alternative measures, adopting elite varieties, particularly popularizing super hybrid rice, proves to be the most economical and effective option.
基金supported by the National Natural Science Foundation of China(Grant No. 30370865) and the Innovation Projects of New Plant and Animal Breeding in Chongqing Municipality, China
文摘The developmental genetics of plant height was analyzed from two groups of three-line indica hybrid rice at two environmental conditions based on the NCII design, using the additive-dominant developmental genetics models and the statistic methods. The results showed that the rice genotypes and environmental conditions could both affect plant height, and the effects of environment on plant height decreased gradually with plant development. Additive and dominant effects both governed the performance of plant height at all developmental stages. However, the degrees of effect varied among the rice genotypes. Moreover, the interaction between environments and genotypes also affected plant height. The genetic effects differed at most developmental stages. Furthermore, the expressJon of additive effect was more active than that of dominant effect. Conditional interaction effects with environment also influenced plant height during genetic development, especially at the eady stage. Mid-parent heterosis （HMP） increased gradually with the developmental stage of plant height, and maximized at the latest stage, whereas the heterosis over the better parent （HBP） showed small differences among the genotypes, and kept stable at the later stage, with positive numeric value. At most developmental stages, conditional HMP was positively significant, while conditional HBP was negatively significant. All above results suggest that HMP and HBP have some new expressions in all developmental periods and the levels and directions are quite different.
文摘Following NCI design, the developmental genetic behavior of tiller number (TN) in three-line indica hybrid rice was studied using additive-dominance developmental genetic models and the corresponding statistical methods. The results showed that dominance effects were predominant for TN. The expression of those additive effects were affected by environment and genotype interaction, but the expression of dominance effects were not affected. Heterosis was the strongest in the middle developmental periods of TN. Additive effects and dominance effects were selectively expressed throughout in the entire tillering developmental stage. Analysis of genetic correlation between TN at different stages and the productive panicles indicated that a close correlation appeared earlier in the populations with higher heterosis than in those with less heterosis. Utilization of heterosis at the middle tillering stage might enhance the final biomass but reduce the percentage of productive panicles.
文摘The purpose of this study was to identify the existing rice breeding programs in Myanmar and to determine researchers＇ attitudes on hybrid rice research mid its determinmlts. A sample consists of 56 researchers who are working in Department of Agricultural Research, Department of Agriculture and Yezin Agricultural University, and involving varietal development of hybrid rice. The research instruments were a questionnaire used by 4 points Likert scale of strongly agree, agree, less agree and not agree to measure on researchers＇ attitudes towards 14 determinants of varietal development of hybrid rice production. The study revealed that the average age of the researchers was 46.5 years ranged from 25 to 60 years. The majority of researchers were 51-60 years old （41.1%）. The working experience of researchers ranged from 5 to 36 years and the metal of their experience was 20 years. The educational level was Ph.D. （35.7%）, M.Agr.Sc. （26.8%）, and B.Agr.Sc. （37.5%）. Majority of researchers were female （76.8%） and 58.9% were rice breeders. Moreover, 48.2% of researchers obtained the hybrid rice technology from breeding training and the researchers who believed in their current breeding works were 51.8%. Among 33 rice breeders, 72.7% of the rice breeders applied only convention breeding method. In addition, researchers＇ opinions on farmer＇s perception of hybrid rice technology, 60.7% of the researchers agreed on inferior grain quality and 73.2% of researchers strongly agreed on not stable market. This study found out more thin1 half of the researchers strongly agreed on 10 out of 14 determinmlts such as poor infrastructure, low human resource development, parental problem, insufficient experience, limit germplasm resource, limit research facilities, no incentive for breeders, weak public-private partnership, fewer quality breeders and not enough research fund. Moreover, half of the researchers agreed on 3 determinants likely need special technical training, need international assistance and climate change challenges. Finally, development of hybrid rice research in Mymlmar, there will be needed international assistmlce, and upgraded to hybrid rice research center from currently hybrid rice research section and need integrated hybrid rice policy supported by government.
文摘The developmental genetic behaviors of brown rice width （BRW） have been studied in indica-japonica hybrid rice （Oryza sativa L.）, in which seven indica male sterile lines and five japonica restorer lines were applied, by using the developmental genetic models and corresponding statistical approaches for quantitative traits of triploid in cereal crops. The BRW of indica-japonica hybrid rice was co-determined by gene expression of tdploid endosperm, cytoplasm, diploid maternal plant and their genotype × environmental interaction effects. Unconditional analysis showed that the endosperm additive and matemal additive effects were predominant for the development of BRW from early- to late-stage of the grain development, but the endosperm dominant effect together with matemal effect and cytoplasmic effect became the major factor determing the BRW at the ripening stage. Moreover, conditional analysis found that there were new onset and offset of gene expression at different developmental stages of BRW in indica-japonica hybrid rice. Maternal and cytoplasm general heritabilities and their interaction heritabilities were more important compared to other components of heritability for BRW at all the five developmental stages.
文摘Genetic control of leucine content in indica-japonica hybrid rice (Oryza sativa L.) was studied in 35 crosses of F1 and F2 generations, which were derived from crossing 7 male sterile indica rice lines with 5 restorer japonica rice lines along with their parents. Two genetic models and their corresponding statistical methods for quantitative traits of triploid seeds in cereal crops were used for the analysis. The first was the unconditional genetic model, which refers to the analysis of cumulative measurements (from flowering to a specific time) along the developmental stages, while the second was the conditional genetic model, which relates to analysis from one developmental stage to another stage (t - 1→t). The results showed that leucine content of indica-japonica hybrid rice was controlled by the expression of triploid endosperm effect (endosperm additive effect and endosperm dominant effect), cytoplasm effect, diploid maternal plant effect (maternal additive effect and maternal dominant effect) and their environmental interaction effects. Of these effects, endosperm dominant effect and maternal dominant effect were more important at the earlier stages, while endosperm additive effect and maternal additive effect were more important at the later stages of rice grain development under both unconditional and conditional genetic analyses. Due to the high heritabilities, which came from endosperm, maternal and cytoplasm effects for leucine content at different developmental stages, selection for leucine content of indica-japonica hybrid rice would be more efficient at early generations in breeding programs.
基金supported by the Project of National Key Research and Development Program‘Strategic Science and Technology Innovation Cooperation’Key Special Project(Grant No.2023YFE0206900)the 2115 Talent Development Program of China Agricultural University,the 111 project(B17043)the Project of Yazhouwan Scientific,Technological Administration of Sanya.
文摘Male sterile lines serve as a pivotal tool in plant breeding,offering an effective strategy for developing hybrid cultivars.In cucumber(Cucumis sativus L.),the creation of male sterile lines,most of which exhibit abnormal pollen development,is essential for harnessing heterosis.Accumulating evidence suggests that male sterility in plants is linked to the overaccumulation of Reactive Oxygen Species(ROS),which causes oxidative damage to biomolecules and cellular structures,ultimately leading to aberrant anther development(Li et al.,2004).
文摘目的应用高分辨微阵列比较基因组杂交技术（array—comparative genomic hybridization，aCGH）对55例不明原阂的智力低下或发育迟缓（mental retardation or developmental delay，MR／DD）患儿进行拷贝数变异（copy number variations，CNVs）检测，寻求与遗传学相关的致病因素，探讨aCGH对不明原因MR／DD患儿可能的分子病因诊断的作用。方法收集2013年6月-2013年12月到本院儿科初步诊断为MR／DD的患儿55例，应用25～50K CytoScanHD芯片检测全基因组CNVs，联合生物信息学分析手段分析致病性CNVs。结果在55例不明原因MR／DD患者中共检测到21例存在罕见CNVs。通过比对数据库，21处CNVs确认为致病性CNVs。19例患者携带与MR／DD相关的CNVs。2例为已知综合征患者，其中1例为Turner综合征，1例为1p36缺失综合征。结论基因组CNVs相关的微缺失或微重复是不明原因MR／DD的病因之一，这些片段均无法被常规染色体G带检查所识别。aCGH可以提高对不明原因MR／DD患儿的分子病因诊断水平，对深入研究MR／DD病因机制有重要意义，为患儿预后和家庭再发风险评估提供指导。
