Grain shape as a major determinant of rice yield and quality is widely believed to be controlled by quantitative trait loci(QTL). We have identified a novel gene 'GS2' to largely regulate grain length and widt...Grain shape as a major determinant of rice yield and quality is widely believed to be controlled by quantitative trait loci(QTL). We have identified a novel gene 'GS2' to largely regulate grain length and width in rice. The GS2 allele in the big-grain rice line ‘CDL’functioned in a dominant manner. In the present study, we employed a chromosome walking strategy in the residual heterozygous lines from recombinant inbred population between cultivar 'R1126' and CDL, and located the GS2 gene in an interval of ~33.2 kb flanked by marker GL2-35-1 and GL2-12 in the long arm of rice chromosome 2. According to genome annotations, three putative gene loci, LOC_Os02g47280, LOC_Os02g47290 and LOC_Os02g47300, exist in this candidate region. In addition, allelic analysis with previously reported genes demonstrated that GS2 was novel for regulating rice grain shape. These results will help promote the cloning and functional characterization of the GS2 gene and further develop linked markers to be used in marker-assisted breeding.展开更多
Breeding sterile lines is the key to the development of hybrid rice with wide adaptability. However, at present, few wide-adaptability sterile lines have been applied in production practice. In this study, Yungu 3A, a...Breeding sterile lines is the key to the development of hybrid rice with wide adaptability. However, at present, few wide-adaptability sterile lines have been applied in production practice. In this study, Yungu 3A, a new WA-type Indica CMS line with good grain quality, was developed by hybridization between Yunfeng 66A with wide adaptability as female parent and F1 plants of Yunfeng 66B/D62B as male parent and continuous backcrossing. According to the results, the finally obtained lndica CMS line Yungu 3A has good plant type and leaf shape, strong tillering ability, excellent flowering habit, stable and complete male sterility with the sterile plant rate and pollen sterility rate of 100%, strong combining ability, high outcrossing rate, low sensitivity to light and temperature, and strong disease resistance, which was approved by Yunnan Provincial Crop Variety Appraisal Committee in 2013. Yungu 3A is conducive to the development of new hybrid rice combinations with good quality and wide adaptability, exhibiting a promising prospect of application.展开更多
Traits such as grain shape, panicle length and seed shattering, play important roles in grain yield and harvest. In this study, the cloning and functional analysis of PANICLE TRAITS 2 （PT2）, a novel gene from the In...Traits such as grain shape, panicle length and seed shattering, play important roles in grain yield and harvest. In this study, the cloning and functional analysis of PANICLE TRAITS 2 （PT2）, a novel gene from the Indica rice Chuandali （CDL）, is reported. PT2 is synonymous with Growth-Regulating Factor 4 （OsGRF4）, which encodes a growth-regulating factor that positively regulates grain shape and panicle length and negatively regulates seed shattering. Higher expression of OsGRF4 is correlated with larger grain, longer panicle and lower seed shattering. A unique OsGRF4 mutation, which occurs at the OsmiRNA396 target site of OsGRF4, seems to be associated with high levels of OsGRF4 expression, and results in phenotypic difference. Further research showed that OsGRF4 regulated two cytokinin dehydrogenase precursor genes （CKX5 and CKX1） resulting in increased cytokinin levels, which might affect the panicle traits. High storage capacity and moderate seed shattering of OsGRF4 may be useful in high-yield breeding and mechanized harvesting of rice. Our findings provide additional insight into the molecular basis of panicle growth.展开更多
基金supported by the National High Technology Research and Development Program of China (2011AA10A101)the Hunan Provincial Natural Science Foundation of China (10JJ2025)
文摘Grain shape as a major determinant of rice yield and quality is widely believed to be controlled by quantitative trait loci(QTL). We have identified a novel gene 'GS2' to largely regulate grain length and width in rice. The GS2 allele in the big-grain rice line ‘CDL’functioned in a dominant manner. In the present study, we employed a chromosome walking strategy in the residual heterozygous lines from recombinant inbred population between cultivar 'R1126' and CDL, and located the GS2 gene in an interval of ~33.2 kb flanked by marker GL2-35-1 and GL2-12 in the long arm of rice chromosome 2. According to genome annotations, three putative gene loci, LOC_Os02g47280, LOC_Os02g47290 and LOC_Os02g47300, exist in this candidate region. In addition, allelic analysis with previously reported genes demonstrated that GS2 was novel for regulating rice grain shape. These results will help promote the cloning and functional characterization of the GS2 gene and further develop linked markers to be used in marker-assisted breeding.
基金Supported by Project for Introduction and Training of High-Level Technological Talents of Yunnan Province(2009CI126)New Product Program of Yunnan Province(2011BB002)Project for Construction of Science and Technology Innovation Platform of Yunnan Province(2013DH006)
文摘Breeding sterile lines is the key to the development of hybrid rice with wide adaptability. However, at present, few wide-adaptability sterile lines have been applied in production practice. In this study, Yungu 3A, a new WA-type Indica CMS line with good grain quality, was developed by hybridization between Yunfeng 66A with wide adaptability as female parent and F1 plants of Yunfeng 66B/D62B as male parent and continuous backcrossing. According to the results, the finally obtained lndica CMS line Yungu 3A has good plant type and leaf shape, strong tillering ability, excellent flowering habit, stable and complete male sterility with the sterile plant rate and pollen sterility rate of 100%, strong combining ability, high outcrossing rate, low sensitivity to light and temperature, and strong disease resistance, which was approved by Yunnan Provincial Crop Variety Appraisal Committee in 2013. Yungu 3A is conducive to the development of new hybrid rice combinations with good quality and wide adaptability, exhibiting a promising prospect of application.
基金supported by National Natural Science Foundation of China (31571259)National High Technology Research and Development Program of China (2011AA10A101)
文摘Traits such as grain shape, panicle length and seed shattering, play important roles in grain yield and harvest. In this study, the cloning and functional analysis of PANICLE TRAITS 2 （PT2）, a novel gene from the Indica rice Chuandali （CDL）, is reported. PT2 is synonymous with Growth-Regulating Factor 4 （OsGRF4）, which encodes a growth-regulating factor that positively regulates grain shape and panicle length and negatively regulates seed shattering. Higher expression of OsGRF4 is correlated with larger grain, longer panicle and lower seed shattering. A unique OsGRF4 mutation, which occurs at the OsmiRNA396 target site of OsGRF4, seems to be associated with high levels of OsGRF4 expression, and results in phenotypic difference. Further research showed that OsGRF4 regulated two cytokinin dehydrogenase precursor genes （CKX5 and CKX1） resulting in increased cytokinin levels, which might affect the panicle traits. High storage capacity and moderate seed shattering of OsGRF4 may be useful in high-yield breeding and mechanized harvesting of rice. Our findings provide additional insight into the molecular basis of panicle growth.
