Rice grain shape, grain length （GL）, width （GW）, thickness （GT） and length-to-width ratio （LWR）, are usually controlled by multiple quantitative trait locus （QTL）. To elucidate the genetic basis of extremely...Rice grain shape, grain length （GL）, width （GW）, thickness （GT） and length-to-width ratio （LWR）, are usually controlled by multiple quantitative trait locus （QTL）. To elucidate the genetic basis of extremely large grain shape, QTL analysis was performed using an F2 population derived from a cross between a japonica cuttivar ＇JZI560＇ （extremely large grain） and a contrasting indica cultivar ＇FAZI＇ （small grain）. A total number of 24 QTLs were detected on seven different chromosomes. QTLs for GL, GW, GT and LWR explained 11.6%, 95.62%, 91.5% and 89.9% of total phenotypic variation, respectively. Many QTLs pleiotropically controlled different grain traits, contributing complex traits correlation. GW2 and qSW5/GW5, which have been cloned previously to control GW, showed similar chromosomal locations with qGW2-1/qGT2-1/qLWR2-2 and qGW5-2/qLWR5-1 and should be the right candidate genes. Plants pyramiding GW2 and qSW5/GW5 showed a significant increase in GW compared with those carrying one of the two major QTLs. Furthermore, no significant QTL interaction was observed between GW2 and qSW5/GW5. These results suggested that GW2 and qSW5/GW5 might work in independent pathways to regulate grain traits. ＇JZ1560＇ alleles underlying all QTLs contributed an increase in GW and GT and the accumulation of additive effects generates the extremely large grain shape in ＇JZ1560＇.展开更多
To understand the responses of flag leaf shape in rice to elevated CO2 environment and their genetic characteristics, quantitative trait loci （QTLs） for flag leaf shape in rice were mapped onto the molecular marker ...To understand the responses of flag leaf shape in rice to elevated CO2 environment and their genetic characteristics, quantitative trait loci （QTLs） for flag leaf shape in rice were mapped onto the molecular marker linkage map of chromosome segment substitution lines （CSSLs） derived from a cross between a japonica variety Asominori and an indica variety IR24 under free air carbon dioxide enrichment （FACE, 200 μmol/mol above current levels） and current CO2 concentration （Ambient, about 370 μmol/mol）. Three flag-leaf traits, flag-leaf length （LL）, width （LW） and the ratio of LL to LW （RLW）, were estimated for each CSSL and their parental varieties. The differences in LL, LW and RLW between parents and in LL and LW within IR24 between FACE and Ambient were significant at 1% level. The continuous distributions and transgressive segregations of LL, LW and RLW were also observed in CSSL population, showing that the three traits were quantitatively inherited under both FACE and Ambient. A total of 16 QTLs for the three traits were detected on chromosomes 1, 2, 3, 4, 6, 8 and 11 with LOD （Log10-1ikelihood ratio） scores ranging from 3.0 to 6.7. Among them, four QTLs （qLL-6＊, qLL-8＊ qLW-4＊ and qRLW-6＊） were commonly detected under both FACE and Ambient. Therefore, based on the different responses to elevated CO2 in comparison with current CO2 level, it can be suggested that the expressions of several QTLs associated with flag-leaf shape in rice could be induced by the high CO2 level.展开更多
基金supported by grants from the Ministry of Agriculture of China(2009ZX08009-102B)Chinese Academy of Sciences(KSCX3-EW-N-01)+2 种基金the Ministry of Science and Technology of China(2012CB944800)the National Natural Science Foundation of China(31130071)the Zhejiang Provincial Natural Science Foundation of China (Y3110394)
文摘Rice grain shape, grain length （GL）, width （GW）, thickness （GT） and length-to-width ratio （LWR）, are usually controlled by multiple quantitative trait locus （QTL）. To elucidate the genetic basis of extremely large grain shape, QTL analysis was performed using an F2 population derived from a cross between a japonica cuttivar ＇JZI560＇ （extremely large grain） and a contrasting indica cultivar ＇FAZI＇ （small grain）. A total number of 24 QTLs were detected on seven different chromosomes. QTLs for GL, GW, GT and LWR explained 11.6%, 95.62%, 91.5% and 89.9% of total phenotypic variation, respectively. Many QTLs pleiotropically controlled different grain traits, contributing complex traits correlation. GW2 and qSW5/GW5, which have been cloned previously to control GW, showed similar chromosomal locations with qGW2-1/qGT2-1/qLWR2-2 and qGW5-2/qLWR5-1 and should be the right candidate genes. Plants pyramiding GW2 and qSW5/GW5 showed a significant increase in GW compared with those carrying one of the two major QTLs. Furthermore, no significant QTL interaction was observed between GW2 and qSW5/GW5. These results suggested that GW2 and qSW5/GW5 might work in independent pathways to regulate grain traits. ＇JZ1560＇ alleles underlying all QTLs contributed an increase in GW and GT and the accumulation of additive effects generates the extremely large grain shape in ＇JZ1560＇.
基金The study was supported by the National Natural Science Foundation, China （Grant Nos. 30270800 and 40231003）
文摘To understand the responses of flag leaf shape in rice to elevated CO2 environment and their genetic characteristics, quantitative trait loci （QTLs） for flag leaf shape in rice were mapped onto the molecular marker linkage map of chromosome segment substitution lines （CSSLs） derived from a cross between a japonica variety Asominori and an indica variety IR24 under free air carbon dioxide enrichment （FACE, 200 μmol/mol above current levels） and current CO2 concentration （Ambient, about 370 μmol/mol）. Three flag-leaf traits, flag-leaf length （LL）, width （LW） and the ratio of LL to LW （RLW）, were estimated for each CSSL and their parental varieties. The differences in LL, LW and RLW between parents and in LL and LW within IR24 between FACE and Ambient were significant at 1% level. The continuous distributions and transgressive segregations of LL, LW and RLW were also observed in CSSL population, showing that the three traits were quantitatively inherited under both FACE and Ambient. A total of 16 QTLs for the three traits were detected on chromosomes 1, 2, 3, 4, 6, 8 and 11 with LOD （Log10-1ikelihood ratio） scores ranging from 3.0 to 6.7. Among them, four QTLs （qLL-6＊, qLL-8＊ qLW-4＊ and qRLW-6＊） were commonly detected under both FACE and Ambient. Therefore, based on the different responses to elevated CO2 in comparison with current CO2 level, it can be suggested that the expressions of several QTLs associated with flag-leaf shape in rice could be induced by the high CO2 level.
