Thousand-grain weight (TGW) is a key component of grain yield in rice. This study was conducted to validate and fine-map qTGW1.2a, a quantitative trait locus for grain weight and grain size previously located in a 933...Thousand-grain weight (TGW) is a key component of grain yield in rice. This study was conducted to validate and fine-map qTGW1.2a, a quantitative trait locus for grain weight and grain size previously located in a 933.6-kb region on the long arm of rice chromosome 1. Firstly, three residual heterozygotes (RHs) were selected from a BC2F11 population of the indica rice cross Zhenshan 97 (ZS97)///ZS97//ZS97/Milyang 46. The heterozygous segments in these RHs were arranged successively in physical positions, forming one set of sequential residual heterozygotes (SeqRHs). In each of the populations derived, non-recombinant homozygotes were identified to produce near isogenic lines (NILs) comprising the two homozygous genotypes. The NILs were tested for grain weight, grain length and grain width. QTL analyses for the three traits were performed. Then, the updated QTL location was followed for a new run of SeqRHs identification-NIL development-QTL mapping. Altogether, 11 NIL populations derived from four sets of SeqRHs were developed and used. qTGW1.2a was finally delimitated into a 77.5-kb region containing 13 annotated genes. In the six populations segregating this QTL, which were in four generations and were tested across four years, the allelic direction of qTGW1.2a remained consistent and the genetic effects were stable. For TGW, the additive effects ranged from 0.23 to 0.38 g and the proportions of phenotypic variance explained ranged from 26.15% to 41.65%. These results provide a good foundation for the cloning and functional analysis of qTGW1.2a.展开更多
Although cultivated rice originated from the tropical region,a long process of domestication and human selection has enabled cultivated rice to grow in a wide range of geographical regions.Diversification of photoperi...Although cultivated rice originated from the tropical region,a long process of domestication and human selection has enabled cultivated rice to grow in a wide range of geographical regions.Diversification of photoperiodic flowering provides a foundation for this diverse adaptation.Intensive studies have focused on elucidating how japonica varieties lost photoperiodic sensitivity(PS)to expand their cultivation areas to high latitudes,where rice is grown in a short season when day-length is long(Fujino et al,2013;Naranjo et al,2014;Gomez-Ariza et al,2015;Li et al,2015,2018;Goretti et al,2017;Ye et al,2018).By contrast,limited attention has been paid to the genetic architecture of heading date(HD)variation among varieties in middle and low latitudes.The southern China rice region,located in middle and low latitudes,occupies the most important rice cultivation region in China.This region is predominantly planted with indica varieties,which presents a rich diversity of regional and seasonal adaptations.In the present study,improved varieties and landraces used in this region were analyzed for allelic variations of 12 cloned QTLs controlling HD,as well as for the genotypic effects of these genes on HD and PS.Our objective was to clarify predominant genetic factors influencing ecogeographical adaption of rice varieties in southern China by comparing improved varieties with landraces.展开更多
The present paper describes multiple splicing types of OsRIX4,an RAD21 homolog in rice. A type of alternative splicing (AS),distinctive from all five previously known splicing types,was identified in which interior se...The present paper describes multiple splicing types of OsRIX4,an RAD21 homolog in rice. A type of alternative splicing (AS),distinctive from all five previously known splicing types,was identified in which interior sequences of a constitutive exon could be spliced. Translation of the transcript produced with this AS type was demonstrated at the protein level. Expression of multiple transcripts was organ specific. The expression abundance of transcripts,OsRIX4-4 and OsRIX4-5,was positively correlated with fertility in rice. The splicing type identified in the present study provided the means to further un-derstand and define different mRNA splicing types in plants and suggested that post-transcription processing of mRNA and its regulation mechanism are complex.展开更多
基金funded by the National Key R&D Program of China (Grant No. 2017YFD0100305)the National Natural Science Foundation of China (Grant No. 31521064)a project of the China National Rice Research Institute (Grant No. 2017RG001-2)
文摘Thousand-grain weight (TGW) is a key component of grain yield in rice. This study was conducted to validate and fine-map qTGW1.2a, a quantitative trait locus for grain weight and grain size previously located in a 933.6-kb region on the long arm of rice chromosome 1. Firstly, three residual heterozygotes (RHs) were selected from a BC2F11 population of the indica rice cross Zhenshan 97 (ZS97)///ZS97//ZS97/Milyang 46. The heterozygous segments in these RHs were arranged successively in physical positions, forming one set of sequential residual heterozygotes (SeqRHs). In each of the populations derived, non-recombinant homozygotes were identified to produce near isogenic lines (NILs) comprising the two homozygous genotypes. The NILs were tested for grain weight, grain length and grain width. QTL analyses for the three traits were performed. Then, the updated QTL location was followed for a new run of SeqRHs identification-NIL development-QTL mapping. Altogether, 11 NIL populations derived from four sets of SeqRHs were developed and used. qTGW1.2a was finally delimitated into a 77.5-kb region containing 13 annotated genes. In the six populations segregating this QTL, which were in four generations and were tested across four years, the allelic direction of qTGW1.2a remained consistent and the genetic effects were stable. For TGW, the additive effects ranged from 0.23 to 0.38 g and the proportions of phenotypic variance explained ranged from 26.15% to 41.65%. These results provide a good foundation for the cloning and functional analysis of qTGW1.2a.
基金the National Natural Science Foundation of China(Grant No.31571637)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Science(CAAS-ASTIP-2013-CNRRI).We thank the National Medium Rice Genebank at the China National Rice Research Institute for providing rice varieties.
文摘Although cultivated rice originated from the tropical region,a long process of domestication and human selection has enabled cultivated rice to grow in a wide range of geographical regions.Diversification of photoperiodic flowering provides a foundation for this diverse adaptation.Intensive studies have focused on elucidating how japonica varieties lost photoperiodic sensitivity(PS)to expand their cultivation areas to high latitudes,where rice is grown in a short season when day-length is long(Fujino et al,2013;Naranjo et al,2014;Gomez-Ariza et al,2015;Li et al,2015,2018;Goretti et al,2017;Ye et al,2018).By contrast,limited attention has been paid to the genetic architecture of heading date(HD)variation among varieties in middle and low latitudes.The southern China rice region,located in middle and low latitudes,occupies the most important rice cultivation region in China.This region is predominantly planted with indica varieties,which presents a rich diversity of regional and seasonal adaptations.In the present study,improved varieties and landraces used in this region were analyzed for allelic variations of 12 cloned QTLs controlling HD,as well as for the genotypic effects of these genes on HD and PS.Our objective was to clarify predominant genetic factors influencing ecogeographical adaption of rice varieties in southern China by comparing improved varieties with landraces.
基金Supported by the National Natural Science Foundation of China (Grant No. 30170592)Zhejiang Provincial Science and Technology Project (Grant No. 2005C22002)
文摘The present paper describes multiple splicing types of OsRIX4,an RAD21 homolog in rice. A type of alternative splicing (AS),distinctive from all five previously known splicing types,was identified in which interior sequences of a constitutive exon could be spliced. Translation of the transcript produced with this AS type was demonstrated at the protein level. Expression of multiple transcripts was organ specific. The expression abundance of transcripts,OsRIX4-4 and OsRIX4-5,was positively correlated with fertility in rice. The splicing type identified in the present study provided the means to further un-derstand and define different mRNA splicing types in plants and suggested that post-transcription processing of mRNA and its regulation mechanism are complex.
