[Objective] The study aimed to compare the difference of organ morphology and yield composition in 10 rice cultivars with 3 sowing date,and to correlate leaf length and plant height with exogenous variables like tempe...[Objective] The study aimed to compare the difference of organ morphology and yield composition in 10 rice cultivars with 3 sowing date,and to correlate leaf length and plant height with exogenous variables like temperature accumulation and sunshine duration.[Method] Detailed data of organ morphology and yield component were obtained and analyzed through repeated field observations and destructive samplings over the growing season,including leaf length,node number,tiller number,plant height and grain yield of 10 rice cultivars（Takanari,IR72,Sankeiso,CH86,IR65564-44-2-2,Nipponbare,Takenari,Banten,WAB450-1-B-P-38-HB,Wuxiangjing 9） with 3 sowing dates（May 11,May 22,and June 19,2002）.[Result] Max leaf length for each node increased at the early growth stage and decreased at the later growth stage.The leaf length of CH86 and Banten was the maximum in 4 Indica cultivars and 6 Japonica cultivars,respectively.Node number and plant height decreased with the later sowing date,and that of CH86 was the maximum.The maximum grain yield was found in Wuxiangjing 9,and the greatest genotypic variation existed in rice yield,panicle number,spikelet per panicle,and grain weight;the grain yield ranged from 4 358 to 7 443 kg ha-1;the panicle number ranged from 158×104 to 330×104 ha-1;no direct correlation between yield,tiller number and plant height was observed in this experiment.[Conclusion] Empirical regression fitting of the resulting data was developed for leaf length and plant height prediction and yield component comparison,which could be used to construct deeper and more mechanistic models or to optimize rice growing conditions.展开更多
After exposure of one-year old seedlings of Swietenia macrophylla to an overnight temperature (13 C, 19 C, 25 C, 31 C or 35 C), the leaf net photosynthetic rate (Pn) was researched through measuring photosynthetic lig...After exposure of one-year old seedlings of Swietenia macrophylla to an overnight temperature (13 C, 19 C, 25 C, 31 C or 35 C), the leaf net photosynthetic rate (Pn) was researched through measuring photosynthetic light-response curves at 360 mmolmol-1 CO2, and photosynthetic CO2-response curves at light-saturated intensity (1500 mmolm-2 s-1). The optimal temperature for photosynthesis measured at 360 mmol穖ol-1 CO2 was from 25 C to 31 C, but which was from 31C to 35 C at saturating CO2 concentration. At temperature of below 25 C, the decline in Pn was mainly due to the drop in carboxylation efficiency (Ce), while as temperature was over 31 C, the reduction in Pn resulted from both decrease in Ce and increase in leaf respiration. The CO2-induced stimulation of photosynthesis was strongly inhibited at temperatures below 13 C. The results showed that, the leaf photosynthesis of tropical evergreen plants should not be accelerated at low temperature in winter season with elevated CO2 concentration in the future.展开更多
基金Supported by National Natural Science Foundation of China(31101084)Scientific Research Fund for the Returned Overseas Chinese Scholars,Ministry of Education~~
文摘[Objective] The study aimed to compare the difference of organ morphology and yield composition in 10 rice cultivars with 3 sowing date,and to correlate leaf length and plant height with exogenous variables like temperature accumulation and sunshine duration.[Method] Detailed data of organ morphology and yield component were obtained and analyzed through repeated field observations and destructive samplings over the growing season,including leaf length,node number,tiller number,plant height and grain yield of 10 rice cultivars（Takanari,IR72,Sankeiso,CH86,IR65564-44-2-2,Nipponbare,Takenari,Banten,WAB450-1-B-P-38-HB,Wuxiangjing 9） with 3 sowing dates（May 11,May 22,and June 19,2002）.[Result] Max leaf length for each node increased at the early growth stage and decreased at the later growth stage.The leaf length of CH86 and Banten was the maximum in 4 Indica cultivars and 6 Japonica cultivars,respectively.Node number and plant height decreased with the later sowing date,and that of CH86 was the maximum.The maximum grain yield was found in Wuxiangjing 9,and the greatest genotypic variation existed in rice yield,panicle number,spikelet per panicle,and grain weight;the grain yield ranged from 4 358 to 7 443 kg ha-1;the panicle number ranged from 158×104 to 330×104 ha-1;no direct correlation between yield,tiller number and plant height was observed in this experiment.[Conclusion] Empirical regression fitting of the resulting data was developed for leaf length and plant height prediction and yield component comparison,which could be used to construct deeper and more mechanistic models or to optimize rice growing conditions.
文摘After exposure of one-year old seedlings of Swietenia macrophylla to an overnight temperature (13 C, 19 C, 25 C, 31 C or 35 C), the leaf net photosynthetic rate (Pn) was researched through measuring photosynthetic light-response curves at 360 mmolmol-1 CO2, and photosynthetic CO2-response curves at light-saturated intensity (1500 mmolm-2 s-1). The optimal temperature for photosynthesis measured at 360 mmol穖ol-1 CO2 was from 25 C to 31 C, but which was from 31C to 35 C at saturating CO2 concentration. At temperature of below 25 C, the decline in Pn was mainly due to the drop in carboxylation efficiency (Ce), while as temperature was over 31 C, the reduction in Pn resulted from both decrease in Ce and increase in leaf respiration. The CO2-induced stimulation of photosynthesis was strongly inhibited at temperatures below 13 C. The results showed that, the leaf photosynthesis of tropical evergreen plants should not be accelerated at low temperature in winter season with elevated CO2 concentration in the future.
