Carbon isotope discrimination（△13C） is considered a useful indicator for indirect selection of grain yield（GY） in cereals.Therefore,it is important to evaluate the genetic variation in △13C and its relationship ...Carbon isotope discrimination（△13C） is considered a useful indicator for indirect selection of grain yield（GY） in cereals.Therefore,it is important to evaluate the genetic variation in △13C and its relationship with GY.A doubled haploid（DH） population derived from a cross of two common wheat varieties,Hanxuan 10（H10） and Lumai 14（L14）,was phenotyped for △13C in the flag leaf,GY and yield associated traits in two trials contrasted by water availability,specifically,rain-fed and irrigated.Quantitative trait loci（QTLs） were identified by single locus and two locus QTL analyses.QTLs for △13C were located on chromosomes 1A,2B,3B,5A,7A and 7B,and QTLs for other traits on all chromosomes except 1A,4D,5A,5B and 6D.The population selected for high △13C had an increased frequency of QTL for high △13C,GY and number of spikes per plant（NSP） when grown under rain-fed conditions and only for high △13C and NSP when grown under irrigated conditions,which was consistent with agronomic performance of the corresponding trait values in the high △13C progeny;that is,significantly greater than that in the low △13C.Therefore,selection for △13C was beneficial in increasing grain yield in rain-fed environments.展开更多
In C3 plants, carbon isotope discrimination （A） has been proposed as an indirect selection criterion for grain yield. Reported correlations between A and grain yield however, differ highly according to the analyzed ...In C3 plants, carbon isotope discrimination （A） has been proposed as an indirect selection criterion for grain yield. Reported correlations between A and grain yield however, differ highly according to the analyzed organ or tissue, the stage of sampling, and the environment and water regime. In a first experiment carried out in spring wheat during two consecutive seasons in the dry conditions of northwest Mexico （Ciudad Obregon, Sonora）, different water treatments were applied, corresponding to the main water regimes available to spring wheat worldwide, and the relationships between A values of different organs and grain yield were examined. Under terminal （post-anthesis） water stress, grain yield was positively associated with A in grain at maturity and in leaf at anthesis, confirming results previously obtained under Mediterranean environments. Under early （pre-anthesis） water stress and residual moisture stress, the association between grain A and yield was weaker and highly depended on the quantity of water stored in the soil at sowing. No correlation was found between A and grain yield under optimal irrigation. The relationship between A and grain yield was also studied during two consecutive seasons in 20 bread wheat cultivars in the Ningxia region （Northern China）, characterized by winter drought （pre-anthesis water stress）. Wheat was grown under rainfed conditions in two locations （Guyuan and Pengyang） and under irrigated conditions in another two （Yinchuan and Huinong）. In Huinong, the crop was also exposed to salt stress. Highly significant positive associations were found between leaf and grain A and grain yields across the environments. The relationship between A and yield within environments highly depended on the quantity of water stored in the soil at sowing, the quantity and distribution of rainfall during the growth cycle, the presence of salt in the soil, and the occurrence of irrigation before anthesis. These two experiments confirmed the value of A as an indirect selection criterion for yield and a phenotyping tool under post-anthesis water stress （including limited irrigation）.展开更多
基金supported by the State Key Basic Research & Development Plan of China (2010CB951501)the CGIAR Generation Challenge Program (G7010.02.01)
文摘Carbon isotope discrimination（△13C） is considered a useful indicator for indirect selection of grain yield（GY） in cereals.Therefore,it is important to evaluate the genetic variation in △13C and its relationship with GY.A doubled haploid（DH） population derived from a cross of two common wheat varieties,Hanxuan 10（H10） and Lumai 14（L14）,was phenotyped for △13C in the flag leaf,GY and yield associated traits in two trials contrasted by water availability,specifically,rain-fed and irrigated.Quantitative trait loci（QTLs） were identified by single locus and two locus QTL analyses.QTLs for △13C were located on chromosomes 1A,2B,3B,5A,7A and 7B,and QTLs for other traits on all chromosomes except 1A,4D,5A,5B and 6D.The population selected for high △13C had an increased frequency of QTL for high △13C,GY and number of spikes per plant（NSP） when grown under rain-fed conditions and only for high △13C and NSP when grown under irrigated conditions,which was consistent with agronomic performance of the corresponding trait values in the high △13C progeny;that is,significantly greater than that in the low △13C.Therefore,selection for △13C was beneficial in increasing grain yield in rain-fed environments.
文摘In C3 plants, carbon isotope discrimination （A） has been proposed as an indirect selection criterion for grain yield. Reported correlations between A and grain yield however, differ highly according to the analyzed organ or tissue, the stage of sampling, and the environment and water regime. In a first experiment carried out in spring wheat during two consecutive seasons in the dry conditions of northwest Mexico （Ciudad Obregon, Sonora）, different water treatments were applied, corresponding to the main water regimes available to spring wheat worldwide, and the relationships between A values of different organs and grain yield were examined. Under terminal （post-anthesis） water stress, grain yield was positively associated with A in grain at maturity and in leaf at anthesis, confirming results previously obtained under Mediterranean environments. Under early （pre-anthesis） water stress and residual moisture stress, the association between grain A and yield was weaker and highly depended on the quantity of water stored in the soil at sowing. No correlation was found between A and grain yield under optimal irrigation. The relationship between A and grain yield was also studied during two consecutive seasons in 20 bread wheat cultivars in the Ningxia region （Northern China）, characterized by winter drought （pre-anthesis water stress）. Wheat was grown under rainfed conditions in two locations （Guyuan and Pengyang） and under irrigated conditions in another two （Yinchuan and Huinong）. In Huinong, the crop was also exposed to salt stress. Highly significant positive associations were found between leaf and grain A and grain yields across the environments. The relationship between A and yield within environments highly depended on the quantity of water stored in the soil at sowing, the quantity and distribution of rainfall during the growth cycle, the presence of salt in the soil, and the occurrence of irrigation before anthesis. These two experiments confirmed the value of A as an indirect selection criterion for yield and a phenotyping tool under post-anthesis water stress （including limited irrigation）.
