The yield potential of current rice varieties has reached a high plateau and fluc-tuated within a narrow range. Based on the theory and practice of rice breedingfor super-high-yield, we put forward a concept of "...The yield potential of current rice varieties has reached a high plateau and fluc-tuated within a narrow range. Based on the theory and practice of rice breedingfor super-high-yield, we put forward a concept of " Two high and one early",which means high biomass and high efficiency of light energy conversion, as wellas fast growing in the early growth stage. The agronomic characters of 15 U. S展开更多
Cultivation experiments on super-high-yield (^12000kg/ha) of summer corn (Zea mays L.) were conducted in Laizhou, Shangdong Province, from 1986 to 1997, and in Wenxian, Henan Province, from 1996 to 1997. The results s...Cultivation experiments on super-high-yield (^12000kg/ha) of summer corn (Zea mays L.) were conducted in Laizhou, Shangdong Province, from 1986 to 1997, and in Wenxian, Henan Province, from 1996 to 1997. The results showed that requirements of accumulated temperature and hours of sunshine for super-high-yield of summer corn could be met in normal years in the areas of the Huanghuaihai Plain. Amount of precipitation influenced the yield most strongly in indirect way among all the meteorological factors, and the relationship between them displayed significant negative correlation (r= - 0.5418). The regression equation between yield and amount of precipitation at seedling stage and grain filling stage both reached significant level, and the partial regression coefficients were - 4.8735 and - 13.7415, respectively. Further research revealed that the key climatic-ecological factors influencing yield were as fellows: the average temperature in the third and the ninth Xun (note: a Xun indicates ten days and the accounting of Xun was from the corresponding sowing date), the hours of sunshine in the sixth and the eighth Xun, the amount of precipitation in the sixth, the seventh and the second Xun. Results obtained by analyzing yield components of summer corn showed that grain numbers per ear (GN/E) made greater contribution to super-high-yield than kernel weight (KW) and the numbers of ears did. The key factors influencing GN/E were the amount of precipitation in the sixth and the eighth Xun and the hours of sunshine in the sixth Xun, with the correlation coefficients of -0.6074, 0.5793 and 0.5854, respectively.展开更多
In past 30 years, the wheat yield per unit area of China has increased by 79%. The super-high-yield(SH) cultivation played an important role in improving the wheat photosynthesis and yield. In order to find the ecophy...In past 30 years, the wheat yield per unit area of China has increased by 79%. The super-high-yield(SH) cultivation played an important role in improving the wheat photosynthesis and yield. In order to find the ecophysiological mechanism underneath the high photosynthesis of SH cultivation, in situ diurnal changes in the photosynthetic gas exchange and chlorophyll(Chl) a fluorescence of field-grown wheat plants during the grain-filling stage and environmental factors were investigated. During the late grain-filling stage at 24 days after anthesis(DAA), the diurnal changes in net CO_(2) assimilation rate were higher under SH treatment than under high-yield(H) treatment. From 8 to 24 DAA, the actual quantum yield of photosystem II(PSII) electron transport in the light-adapted state(ΦPSII) in the flag leaves at noon under SH treatment were significantly higher than those under H treatment. The leaf temperature, soil temperature and soil moisture were better suited for higher rates of leaf photosynthesis under SH treatment than those under H treatment at noon. Such diurnal changes in environmental factors in wheat fields could be one of the mechanisms for the higher biomass and yield under SH cultivation than those under H cultivation. ΦPSII and CO_(2) exchange rate in wheat flag leaves under SH and H treatments had a linear correlation which could provide new insight to evaluate the wheat photosynthesis performance under different conditions.展开更多
文摘The yield potential of current rice varieties has reached a high plateau and fluc-tuated within a narrow range. Based on the theory and practice of rice breedingfor super-high-yield, we put forward a concept of " Two high and one early",which means high biomass and high efficiency of light energy conversion, as wellas fast growing in the early growth stage. The agronomic characters of 15 U. S
文摘Cultivation experiments on super-high-yield (^12000kg/ha) of summer corn (Zea mays L.) were conducted in Laizhou, Shangdong Province, from 1986 to 1997, and in Wenxian, Henan Province, from 1996 to 1997. The results showed that requirements of accumulated temperature and hours of sunshine for super-high-yield of summer corn could be met in normal years in the areas of the Huanghuaihai Plain. Amount of precipitation influenced the yield most strongly in indirect way among all the meteorological factors, and the relationship between them displayed significant negative correlation (r= - 0.5418). The regression equation between yield and amount of precipitation at seedling stage and grain filling stage both reached significant level, and the partial regression coefficients were - 4.8735 and - 13.7415, respectively. Further research revealed that the key climatic-ecological factors influencing yield were as fellows: the average temperature in the third and the ninth Xun (note: a Xun indicates ten days and the accounting of Xun was from the corresponding sowing date), the hours of sunshine in the sixth and the eighth Xun, the amount of precipitation in the sixth, the seventh and the second Xun. Results obtained by analyzing yield components of summer corn showed that grain numbers per ear (GN/E) made greater contribution to super-high-yield than kernel weight (KW) and the numbers of ears did. The key factors influencing GN/E were the amount of precipitation in the sixth and the eighth Xun and the hours of sunshine in the sixth Xun, with the correlation coefficients of -0.6074, 0.5793 and 0.5854, respectively.
基金supported by the National Key Research and Development Program of China(2016YFD0300102 and 2016YFD0300105)the Key Research and Development Plan in Shaanxi Province,China(2019NY-054)the“Western Light”Visiting Scholarship Program,China。
文摘In past 30 years, the wheat yield per unit area of China has increased by 79%. The super-high-yield(SH) cultivation played an important role in improving the wheat photosynthesis and yield. In order to find the ecophysiological mechanism underneath the high photosynthesis of SH cultivation, in situ diurnal changes in the photosynthetic gas exchange and chlorophyll(Chl) a fluorescence of field-grown wheat plants during the grain-filling stage and environmental factors were investigated. During the late grain-filling stage at 24 days after anthesis(DAA), the diurnal changes in net CO_(2) assimilation rate were higher under SH treatment than under high-yield(H) treatment. From 8 to 24 DAA, the actual quantum yield of photosystem II(PSII) electron transport in the light-adapted state(ΦPSII) in the flag leaves at noon under SH treatment were significantly higher than those under H treatment. The leaf temperature, soil temperature and soil moisture were better suited for higher rates of leaf photosynthesis under SH treatment than those under H treatment at noon. Such diurnal changes in environmental factors in wheat fields could be one of the mechanisms for the higher biomass and yield under SH cultivation than those under H cultivation. ΦPSII and CO_(2) exchange rate in wheat flag leaves under SH and H treatments had a linear correlation which could provide new insight to evaluate the wheat photosynthesis performance under different conditions.
