Grain size is frequently selected during domestication and breeding. It influences the preferences of consumers, thus affecting the commercial value of rice. In present study, a mutant named as SLENDER GRAIN3(sg3) was...Grain size is frequently selected during domestication and breeding. It influences the preferences of consumers, thus affecting the commercial value of rice. In present study, a mutant named as SLENDER GRAIN3(sg3) was identified from cultivar Zhenong 41(Oryza sativa L. ssp. indica) with ethyl methanesulfonate(EMS) treatment. Histological analysis showed that the slender grain of sg3 mutant resulted from increased cell division longitudinally and decreased cell division horizontally. Compared with the wild type Zhenong 41, starch granules in sg3 mutant were more closely packed, thus decreasing the chalkiness. Moreover, grain yield per plant in sg3 mutant was improved by 14%. By map-based cloning, SG3 was located on the long arm of chromosome 3 with a physical distance of 82 kb, and a 9-bp deletion in the 5′-UTR of LOC_Os03 g27110 was identified, which upregulated the expression level significantly. Moreover, a molecular marker for SG3 was developed to identify the grain size during the early generation breeding in rice. The novel factor SG3 regulated the grain size mainly through changing the cell division and the endosperm formation in rice.展开更多
GW2 is an important gene that regulates grain width and weight. We used cDNA clone to obtain the sequences of GW2 from large- and small-grained rice varieties, TD70 and Kasalath, respectively. Then, we developed a dCA...GW2 is an important gene that regulates grain width and weight. We used cDNA clone to obtain the sequences of GW2 from large- and small-grained rice varieties, TD70 and Kasalath, respectively. Then, we developed a dCAPS （derived cleaved amplified polymorphic sequence） marker on the basis of the sequence difference between functional and nonfunctional GW2 genes to analyze the genotypes and phenotypes of recombinant inbred lines. Results showed that the sequence of GW2To7~ had a single nucleotide deletion at site 316 that generates a termination codon. This codon terminated the GW2 protein in advance. By contrast, the sequence of GW2Kasalath encoded an intact protein. A novel dCAPS marker was designed in accordance with a base A deletion at site 316 of the sequence. After the PCR product was digested by Apol, TD70 showed 21 and 30 bp fragments, and Kasalath showed a 51 bp fragment. Up to 82 lines contained GW2TDTO, and 158 lines contained GW2Kasalath. The lines that contained TD70 alleles displayed substantial increases in width and 1000-grain weight. This result suggested that GW2 played a critical role in rice breeding.展开更多
1000-Grain weight and spikelet number per panicle are two important components for rice grain yield. In our previous study, eight quantitative trait loci （QTLs） conferring spikelet number per panicle and 1000-grain ...1000-Grain weight and spikelet number per panicle are two important components for rice grain yield. In our previous study, eight quantitative trait loci （QTLs） conferring spikelet number per panicle and 1000-grain weight were mapped through sequencing-based genotyping of 150 rice recombinant inbred lines （RILs）. In this study, we validated the effects of four QTLs from Nipponbare using chromosome segment substitution lines （CSSLs）, and pyramided eight grain yield related QTLs. The new lines containing the eight QTLs with positive effects showed increased panicle and spikelet size as compared with the parent variety 93-11. We further proposed a novel pyramid breeding scheme based on marker-assistant and phenotype selection （MAPS）. This scheme allowed pyramiding of as many as 24 QTLs at a single hybridization without massive cross work. This study provided insights into the molecular basis of rice grain yield for direct wealth for high-yielding rice breeding.展开更多
基金supported by the Science and Technology Office of Zhejiang Province, China (Grant Nos. 2016C32085, 2016C02050-6 and 2012C12901-2)the National Key Research and Development of China (Grant No. 2017YFD0100300-5)
文摘Grain size is frequently selected during domestication and breeding. It influences the preferences of consumers, thus affecting the commercial value of rice. In present study, a mutant named as SLENDER GRAIN3(sg3) was identified from cultivar Zhenong 41(Oryza sativa L. ssp. indica) with ethyl methanesulfonate(EMS) treatment. Histological analysis showed that the slender grain of sg3 mutant resulted from increased cell division longitudinally and decreased cell division horizontally. Compared with the wild type Zhenong 41, starch granules in sg3 mutant were more closely packed, thus decreasing the chalkiness. Moreover, grain yield per plant in sg3 mutant was improved by 14%. By map-based cloning, SG3 was located on the long arm of chromosome 3 with a physical distance of 82 kb, and a 9-bp deletion in the 5′-UTR of LOC_Os03 g27110 was identified, which upregulated the expression level significantly. Moreover, a molecular marker for SG3 was developed to identify the grain size during the early generation breeding in rice. The novel factor SG3 regulated the grain size mainly through changing the cell division and the endosperm formation in rice.
基金supported by the National Natural Science Foundation of China (Grant No.31271678)the Jiangsu Agricultural Scientific Self-Innovation Fund (Grant No.CX[12]1003)Jiangsu Province Agricultural Science and Technology Support Program (Grant No.BE2013301)
文摘GW2 is an important gene that regulates grain width and weight. We used cDNA clone to obtain the sequences of GW2 from large- and small-grained rice varieties, TD70 and Kasalath, respectively. Then, we developed a dCAPS （derived cleaved amplified polymorphic sequence） marker on the basis of the sequence difference between functional and nonfunctional GW2 genes to analyze the genotypes and phenotypes of recombinant inbred lines. Results showed that the sequence of GW2To7~ had a single nucleotide deletion at site 316 that generates a termination codon. This codon terminated the GW2 protein in advance. By contrast, the sequence of GW2Kasalath encoded an intact protein. A novel dCAPS marker was designed in accordance with a base A deletion at site 316 of the sequence. After the PCR product was digested by Apol, TD70 showed 21 and 30 bp fragments, and Kasalath showed a 51 bp fragment. Up to 82 lines contained GW2TDTO, and 158 lines contained GW2Kasalath. The lines that contained TD70 alleles displayed substantial increases in width and 1000-grain weight. This result suggested that GW2 played a critical role in rice breeding.
基金supported by the Ministry of Science and Technology(Grant No. 2011 CB 100205)the Ministry of Agriculture of China (Grant Nos.2011ZX08001-004 and 2011ZX08009-002)the National Natural Science Foundation of China(Grant No. 31121063)
文摘1000-Grain weight and spikelet number per panicle are two important components for rice grain yield. In our previous study, eight quantitative trait loci （QTLs） conferring spikelet number per panicle and 1000-grain weight were mapped through sequencing-based genotyping of 150 rice recombinant inbred lines （RILs）. In this study, we validated the effects of four QTLs from Nipponbare using chromosome segment substitution lines （CSSLs）, and pyramided eight grain yield related QTLs. The new lines containing the eight QTLs with positive effects showed increased panicle and spikelet size as compared with the parent variety 93-11. We further proposed a novel pyramid breeding scheme based on marker-assistant and phenotype selection （MAPS）. This scheme allowed pyramiding of as many as 24 QTLs at a single hybridization without massive cross work. This study provided insights into the molecular basis of rice grain yield for direct wealth for high-yielding rice breeding.
