Soil salinity is one of the major abiotic stresses affecting plant growth and crop production.In the present study,salt tolerance at rice seedling stage was evaluated using 87 introgression lines（ILs）,which were der...Soil salinity is one of the major abiotic stresses affecting plant growth and crop production.In the present study,salt tolerance at rice seedling stage was evaluated using 87 introgression lines（ILs）,which were derived from a cross between an elite indica cultivar Teqing and an accession of common wild rice（Oryza rufipogon Griff.）.Substantial variation was observed for four traits including salt tolerance score（STS）, relative root dry weight（RRW）,relative shoot dry weight（RSW） and relative total dry weight（RTW）.STS was significantly positively correlated with all other three traits.A total of 15 putative quantitative trait loci（QTLs） associated with these four traits were detected using single-point analysis,which were located on chromosomes 1,2,3,6,7,9 and 10 with 8%-26%explaining the phenotypic variance.The O. rufipogon-derived alleles at 13 QTLs（86.7%） could improve the salt tolerance in the Teqing background.Four QTL clusters affecting RRW, RSW and RTW were found on chromosomes 6,7,9 and 10,respectively.Among these four QTL clusters,a major cluster including three QTLs （qRRWIO,qRSWIO and qRTWIO） was found near the maker RM271 on the long arm of chromosome 10,and the O.rufipogon-derived alleles at these three loci increased RRW,RSW and RTW with additive effects of 22.7%,17.3%and 18.5%,respectively,while the phenotypic variance explained by these three individual QTLs for the three traits varied from 19%to 26%.In addition,several salt tolerant ILs were selected and could be used for identifying and utilizing favorable salt tolerant genes from common wild rice and used in the salt tolerant rice breeding program.展开更多
Pollen sterility is commonly found in the intra-specific hybrids of indica and japonica rice,which is one of the main constrains for the utilization of heterosis between indica and japonica.Six loci controlling the po...Pollen sterility is commonly found in the intra-specific hybrids of indica and japonica rice,which is one of the main constrains for the utilization of heterosis between indica and japonica.Six loci controlling the pollen sterility of F1 between indica and japonica have been identified from previous studies.Neutral alleles at each locus are potential to overcome the F1 pollen sterility associated with the locus.Therefore,exploitation and utilization of neutral alleles are of significant importance.The present research was based on fine mapping of the F1 pollen-sterility gene Sb and the abundant genetic diversity of Oryza rufipogon Griff.indigenous to Gaozhou,Guangdong Province(referred to as Gaozhou wild rice).Crosses were made using Taichung65(with the genotype of SbjSbj and referred to as E1) and its near-isogenic line of F1 pollen sterility gene Sb(with the genotype of SbiSbi,E2) as female parents,and 12 different accessions of Gaozhou wild rice as male parents.F1 pollen fertility was examined to identify the materials having the neutral alleles at the F1 pollen-sterility locus.Segregation of 4 molecular markers tightly linked with the Sb locus was analyzed in the F2 populations derived from the F1s carrying the neutral gene.The pollen fertility related to the 3 genotypes of the molecular markers was also checked by statistical test to determine whether it was consistent with the hypothesis.The results showed that the pollen fertility of two F1s from one accession of Gaozhou wild rice(GZW099) with E1 and E2 was(89.22±1.07)% and(85.65±1.05)%,respectively.Both of them were fertile and showed no significant difference by t-test.Segregation of the 3 genotypes of the 4 molecular markers followed the expected Mendelian ratio(1:2:1) in the F2 populations.There was no significant difference for the averaged pollen fertility of the plants related to the 3 genotypes,suggesting that no interaction exists between the alleles at the Sb locus in GZW099 and Taichung65 or E2.Evidentially,GZW099 carried the neutral gene(named SbnSbn) at the Sb locus,which provides valuable theoretical basis and resources for further studying and overcoming the sterility of indica-japonica hybrids.展开更多
基金supported by the Project of Conservation and Utilization of Agro-Wild Plants of the Ministry of Agriculture of China and Special Fund for Agro-scientific Research in the Public Interest(No.201003021)
文摘Soil salinity is one of the major abiotic stresses affecting plant growth and crop production.In the present study,salt tolerance at rice seedling stage was evaluated using 87 introgression lines（ILs）,which were derived from a cross between an elite indica cultivar Teqing and an accession of common wild rice（Oryza rufipogon Griff.）.Substantial variation was observed for four traits including salt tolerance score（STS）, relative root dry weight（RRW）,relative shoot dry weight（RSW） and relative total dry weight（RTW）.STS was significantly positively correlated with all other three traits.A total of 15 putative quantitative trait loci（QTLs） associated with these four traits were detected using single-point analysis,which were located on chromosomes 1,2,3,6,7,9 and 10 with 8%-26%explaining the phenotypic variance.The O. rufipogon-derived alleles at 13 QTLs（86.7%） could improve the salt tolerance in the Teqing background.Four QTL clusters affecting RRW, RSW and RTW were found on chromosomes 6,7,9 and 10,respectively.Among these four QTL clusters,a major cluster including three QTLs （qRRWIO,qRSWIO and qRTWIO） was found near the maker RM271 on the long arm of chromosome 10,and the O.rufipogon-derived alleles at these three loci increased RRW,RSW and RTW with additive effects of 22.7%,17.3%and 18.5%,respectively,while the phenotypic variance explained by these three individual QTLs for the three traits varied from 19%to 26%.In addition,several salt tolerant ILs were selected and could be used for identifying and utilizing favorable salt tolerant genes from common wild rice and used in the salt tolerant rice breeding program.
基金Supported by the Joint Funds of the National Natural Science Foundation of ChinaGuangdong Province(Grant No.U0631003)Natural Science Foundation of Guangdong Province(Grant No.5300831)
文摘Pollen sterility is commonly found in the intra-specific hybrids of indica and japonica rice,which is one of the main constrains for the utilization of heterosis between indica and japonica.Six loci controlling the pollen sterility of F1 between indica and japonica have been identified from previous studies.Neutral alleles at each locus are potential to overcome the F1 pollen sterility associated with the locus.Therefore,exploitation and utilization of neutral alleles are of significant importance.The present research was based on fine mapping of the F1 pollen-sterility gene Sb and the abundant genetic diversity of Oryza rufipogon Griff.indigenous to Gaozhou,Guangdong Province(referred to as Gaozhou wild rice).Crosses were made using Taichung65(with the genotype of SbjSbj and referred to as E1) and its near-isogenic line of F1 pollen sterility gene Sb(with the genotype of SbiSbi,E2) as female parents,and 12 different accessions of Gaozhou wild rice as male parents.F1 pollen fertility was examined to identify the materials having the neutral alleles at the F1 pollen-sterility locus.Segregation of 4 molecular markers tightly linked with the Sb locus was analyzed in the F2 populations derived from the F1s carrying the neutral gene.The pollen fertility related to the 3 genotypes of the molecular markers was also checked by statistical test to determine whether it was consistent with the hypothesis.The results showed that the pollen fertility of two F1s from one accession of Gaozhou wild rice(GZW099) with E1 and E2 was(89.22±1.07)% and(85.65±1.05)%,respectively.Both of them were fertile and showed no significant difference by t-test.Segregation of the 3 genotypes of the 4 molecular markers followed the expected Mendelian ratio(1:2:1) in the F2 populations.There was no significant difference for the averaged pollen fertility of the plants related to the 3 genotypes,suggesting that no interaction exists between the alleles at the Sb locus in GZW099 and Taichung65 or E2.Evidentially,GZW099 carried the neutral gene(named SbnSbn) at the Sb locus,which provides valuable theoretical basis and resources for further studying and overcoming the sterility of indica-japonica hybrids.
