Rice blast,caused by the fungus Magnaporthe oryzae,reduces rice yields by 10%to 35%.Incorporating blast resistance genes into breeding programs is an effective strategy to combat this disease.Understanding the genetic...Rice blast,caused by the fungus Magnaporthe oryzae,reduces rice yields by 10%to 35%.Incorporating blast resistance genes into breeding programs is an effective strategy to combat this disease.Understanding the genetic variants that confer resistance is crucial to this strategy.The gene Bsr-d1 encodes a C2H2-like transcription factor,and its recessive allele confers broad-spectrum resistance against infections by various strains of M.oryzae.In this study,we investigated the molecular evolution of the rice blast resistance gene bsr-d1 in a representative population consisting of 827 cultivated and wild rice accessions.Our results revealed that wild rice exhibited significantly higher nucleotide diversity,with polymorphic regions primarily concentrated in the promoter region,in contrast to indica and japonica rice varieties.The Bsr-d1 gene displayed significant differentiation between indica and japonica rice varieties,with the bsr-d1 resistance allele being unique to indica rice.Haplotype network and phylogenetic analyses suggested that the bsr-d1 resistance allele most likely originated from Oryza nivara in the region adjacent to the Indian Peninsula and the Indochina Peninsula.Moreover,we explored the utilization of bsr-d1 resistance alleles in China and designed a pair of DNA primers based on the polymorphic sites for the detection of the bsr-d1 resistance gene.In summary,our study uncovering the origin and evolution of bsr-d1 will enhance our understanding of resistance gene variation and expedite the resistance breeding process.展开更多
Rice blast disease,caused by fungus pathogen Magnaporthe oryzae,is one of the most destructive diseases that impact rice farming.In the worldwide,rice harvests lose 10%to 30%of the total production because of blast in...Rice blast disease,caused by fungus pathogen Magnaporthe oryzae,is one of the most destructive diseases that impact rice farming.In the worldwide,rice harvests lose 10%to 30%of the total production because of blast infection,which is estimated to be enough for feeding 60 million people(Skamnioti and Gurr,2009).展开更多
Despite extensive studies on cultivated rice, the population structure and genetic diversity of the indica photoperiod-and thermo-sensitive genic male sterility(P/TGMS) lines in China remains unclear. Using 48 simple ...Despite extensive studies on cultivated rice, the population structure and genetic diversity of the indica photoperiod-and thermo-sensitive genic male sterility(P/TGMS) lines in China remains unclear. Using 48 simple sequence repeat(SSR) markers, we genotyped a panel of 208 indica P/TGMS lines and confirmed three subgroups, named indica-I, indica-II and indica-III, in indica P/TGMS lines. Further diversity analysis indicated indica-II had the highest genetic diversity. The genetic differentiation between indica-II and indica-III was demonstrated as the largest among the three subgroups. Moreover, indica/japonica component identification was detected that five P/TGMS lines possess indica components less than 0.900. These results improve our knowledge on the genetic background for P/TGMS lines in China and will be beneficial for hybrid rice breeding programs.展开更多
This study characterizes a brittle culm (bc88) mutant of rice (Oryza sativa L.) obtained by ethylene methylsulfonate (EMS)-induced mutagenesis of Wuyunjing 7. The bc88 mutant exhibits a diversity of pleiotropic phenot...This study characterizes a brittle culm (bc88) mutant of rice (Oryza sativa L.) obtained by ethylene methylsulfonate (EMS)-induced mutagenesis of Wuyunjing 7. The bc88 mutant exhibits a diversity of pleiotropic phenotypes, including brittle culm at the whole-plant growth stages, withered leaf tips at the seedling stage, and 18-d delay in heading date at the mature stage. Genetic analysis indicates that the bc88 mutant is controlled by a single recessive nuclear gene. The mutated bc88 gene isolated by map-based cloning contains only one point mutation in the 5th exon relative to its wild-type BC88 (LOC_Os09g25490 and Os09g0422500), leading to an amino acid change from P to L in bc88 plants. Alignment of the putative protein sequence with its homologs indicates that the mutation is located in the conserved region of the sequence. Detection of the transcription level of BC88 in rice plants shows that the expression level of BC88 is higher in spikes and culms than in leaves, roots, and leaf sheaths. These contribute to understanding of the molecular mechanism of cellulose synthesis. The target gene BC88 can be a useful tool in molecular marker-assisted selection for rice culm trait breeding.展开更多
An es-t (early senescence-temporary) mutant, produced by ethylene methylsulfonate treatment of strain Nipponbare, was identified in rice. The leaves of es-t appeared yellow at the seedling stage, and had decreased chl...An es-t (early senescence-temporary) mutant, produced by ethylene methylsulfonate treatment of strain Nipponbare, was identified in rice. The leaves of es-t appeared yellow at the seedling stage, and had decreased chlorophyll content. Rust spots were found during growth in es-t, especially at the leaf margin and tip. The plants showed a typical early-senescence phenotype at the milky stage. The leaf surface of es-t appeared smoother than wild-type leaves under a scanning electron microscope, because the leaves lack siliceous protuberances around the stoma. Chloroplasts grow abnormally and are filled with many starch grains in es-t. Paraffin section analysis showed that the development of the sclerenchyma cells and vascular bundles were also abnormal in es-t. Genetic analysis indicated that es-t was controlled by a recessive gene, which was finely mapped to a 42-kb interval on chromosome 5. These results will facilitate the positional cloning and functional studies of the gene.展开更多
基金supported by the National Key Research and Development Program of China (Grant No.2023YFD1202600)the Zhejiang Lab independently establishes research projects (Research and Development of Intelligent Technologies and Platforms for Rice Breeding,Grant No.2021PE0AC05)the Natural Science Foundation of Zhejiang Province,China (Grant No.LQ22C130006)。
文摘Rice blast,caused by the fungus Magnaporthe oryzae,reduces rice yields by 10%to 35%.Incorporating blast resistance genes into breeding programs is an effective strategy to combat this disease.Understanding the genetic variants that confer resistance is crucial to this strategy.The gene Bsr-d1 encodes a C2H2-like transcription factor,and its recessive allele confers broad-spectrum resistance against infections by various strains of M.oryzae.In this study,we investigated the molecular evolution of the rice blast resistance gene bsr-d1 in a representative population consisting of 827 cultivated and wild rice accessions.Our results revealed that wild rice exhibited significantly higher nucleotide diversity,with polymorphic regions primarily concentrated in the promoter region,in contrast to indica and japonica rice varieties.The Bsr-d1 gene displayed significant differentiation between indica and japonica rice varieties,with the bsr-d1 resistance allele being unique to indica rice.Haplotype network and phylogenetic analyses suggested that the bsr-d1 resistance allele most likely originated from Oryza nivara in the region adjacent to the Indian Peninsula and the Indochina Peninsula.Moreover,we explored the utilization of bsr-d1 resistance alleles in China and designed a pair of DNA primers based on the polymorphic sites for the detection of the bsr-d1 resistance gene.In summary,our study uncovering the origin and evolution of bsr-d1 will enhance our understanding of resistance gene variation and expedite the resistance breeding process.
基金supported by the Ministry of Science and Technology of China(Grant No.2017YFD0102002)National Natural Science Foundation of China(Grant Nos.31600999 and 31601282)。
文摘Rice blast disease,caused by fungus pathogen Magnaporthe oryzae,is one of the most destructive diseases that impact rice farming.In the worldwide,rice harvests lose 10%to 30%of the total production because of blast infection,which is estimated to be enough for feeding 60 million people(Skamnioti and Gurr,2009).
基金supported by the Chinese Academy of Agricultural Sciences (Grant No. CAAS-ASTIP-201X-CNRRI)the Major Scientific and Technological Project for New Varieties Breeding of Zhejiang Province, China (Grant No. 2016C02050-6-1)
文摘Despite extensive studies on cultivated rice, the population structure and genetic diversity of the indica photoperiod-and thermo-sensitive genic male sterility(P/TGMS) lines in China remains unclear. Using 48 simple sequence repeat(SSR) markers, we genotyped a panel of 208 indica P/TGMS lines and confirmed three subgroups, named indica-I, indica-II and indica-III, in indica P/TGMS lines. Further diversity analysis indicated indica-II had the highest genetic diversity. The genetic differentiation between indica-II and indica-III was demonstrated as the largest among the three subgroups. Moreover, indica/japonica component identification was detected that five P/TGMS lines possess indica components less than 0.900. These results improve our knowledge on the genetic background for P/TGMS lines in China and will be beneficial for hybrid rice breeding programs.
基金supported by the National Natural Science Foundation of China (30971760, 31201183)the Zhejiang Provincial Qianjiang Talents Program of China ( 2010R10085)the Zhejiang Program of Education Department (Y201225687)
文摘This study characterizes a brittle culm (bc88) mutant of rice (Oryza sativa L.) obtained by ethylene methylsulfonate (EMS)-induced mutagenesis of Wuyunjing 7. The bc88 mutant exhibits a diversity of pleiotropic phenotypes, including brittle culm at the whole-plant growth stages, withered leaf tips at the seedling stage, and 18-d delay in heading date at the mature stage. Genetic analysis indicates that the bc88 mutant is controlled by a single recessive nuclear gene. The mutated bc88 gene isolated by map-based cloning contains only one point mutation in the 5th exon relative to its wild-type BC88 (LOC_Os09g25490 and Os09g0422500), leading to an amino acid change from P to L in bc88 plants. Alignment of the putative protein sequence with its homologs indicates that the mutation is located in the conserved region of the sequence. Detection of the transcription level of BC88 in rice plants shows that the expression level of BC88 is higher in spikes and culms than in leaves, roots, and leaf sheaths. These contribute to understanding of the molecular mechanism of cellulose synthesis. The target gene BC88 can be a useful tool in molecular marker-assisted selection for rice culm trait breeding.
基金supported by the National Special Program for Research and Transgenic Plants (2011ZX08009-003)the National Key Basic Research Program of China (2007CB10920203)the National Natural Science Foundation of China (30971760)
文摘An es-t (early senescence-temporary) mutant, produced by ethylene methylsulfonate treatment of strain Nipponbare, was identified in rice. The leaves of es-t appeared yellow at the seedling stage, and had decreased chlorophyll content. Rust spots were found during growth in es-t, especially at the leaf margin and tip. The plants showed a typical early-senescence phenotype at the milky stage. The leaf surface of es-t appeared smoother than wild-type leaves under a scanning electron microscope, because the leaves lack siliceous protuberances around the stoma. Chloroplasts grow abnormally and are filled with many starch grains in es-t. Paraffin section analysis showed that the development of the sclerenchyma cells and vascular bundles were also abnormal in es-t. Genetic analysis indicated that es-t was controlled by a recessive gene, which was finely mapped to a 42-kb interval on chromosome 5. These results will facilitate the positional cloning and functional studies of the gene.
