Study On Morphological Trait And Yield And Evaluation Of High Photosynthetic Efficiency Soybean To Elevated Atmospheric CO₂ Concerntration And Temperature

In this paper,varieties of high photosynthetic efficiency Hei Nong41?HN41?and its growth period is relatively consistent Zhou Dou 16?ZD16?,Zhong Dou35?ZD35?and Gui Huangdou?GHD2?as a routine check varieties as the research object,through the Open top chamber?Open-top chamber;OTC?simulating?650 PPM?and temperature?±0.5?0.6??control experiment,the system studied soybean growth and yield of the change,and the change of photosynthesis related indicators,as well as the study of soybean aphid population dynamics in OTC.The main results were as follows:1.Responses of morphological trait and yield of soybean to elevated atmospheric CO₂ concentration and temperatureThe results indicated that CO₂ levels significantly affected plant height and stem diameter,and dry weight and seed weight per plant.And temperature levels and the interactions between CO₂ levels and soybean cultivars significantly affected seed weight per plant.Relative to ambient CO₂,elevated CO₂ is was much more favorable to promote plant height and stem diameter,and dry weight and seed weight per plant,particularly in plant height and stem diameter with higher temperature.Moreover,elevated CO₂ significantly increased plant height of all the cultivars HN41,ZD 16 and GHD2 at high temperature?18.9%,24.4%and 31.5%?,and significantly enhanced the dry weight per plant of all the cultivars of HN41,ZD 16,ZD35 and GHD2 at normal temperature?7.3%,4.7%,16.0%,18.8%?,in contrast to ambient CO₂.Compared with ambient temperature,higher temperature can only significantly increase the stem diameter of HN41 under elevated CO₂,and significantly enhanced grain weight per plant of HN41 under ambient CO₂.In addition,the stem diameter,root/shoot ratio and grain weight per plant of the cultivar HN41 were significantly greater than those of normal cultivars?i.e.ZD16,ZD35 and GHD2?at the same conditions of atmospheric CO₂ and temperature levels.But only dry biomass per plant was found to be significant increasion inthe cultivar HN41 comparing with the cultivars ZD 16 and GHD2.In conclusion,both the increase levels of atmospheric CO₂ concentration and temperature significantly affected plant growth of the high photosynthetic-efficiency soybean.The elevated CO₂ concentration can promote plant growth particularly at high temperature;however,elevated CO₂ is favorable to accumulate photosynthetic production at ambient temperature especially for the high photosynthetic-efficiency soybean.2.Responses of of photosynthesis indicators of high photosynthetic-efficiency soybean to elevated atmospheric CO₂ concentration and temperature This study result shows that the photosynthetic rate of soybean in two CO₂ levels?P<0.001?,two temperature level?P<0.001?,the two varieties?P<0.001?,and the interaction between temperature and varieties?P<0.01?have significant difference,indicating that CO₂ and temperature can significantly affect the photosynthetic rate of soybean,promote the photosynthesis of soybean;Evaporation in addition to the significant difference between the two CO₂ water product,other did not show significant difference,water use efficiency in two CO₂ levels?P<0.01?,the two temperature levels?P<0.05?,CO₂ and temperature?P<0.05?,and the interaction between temperature and varieties?P<0.01?significant difference,while stomatal resistance only in CO₂ and varieties of interaction3.Responses of soybean aphids population dynamic of high photosynthetic efficiency soybean to elevated atmospheric CO₂ concentration and temperature In 2013 and 2014 by the results of the survey and repetitive measure analysis of variance showed that three factors aphid number in two CO₂ levels,temperature level,between the two varieties and varieties of CO₂ and extremely significant difference,temperature,and the variety of interactions,aphids in 2014 number in two CO₂ levels,temperature level,between the two varieties and between CO₂ and temperature,CO₂ and variety,significant difference was found in the interaction between temperature and variety,the CO₂ and temperature can significantly affect the number of soybean aphids on soybean,analysis the reason of elevated atmospheric CO₂ concentration and temperature can promote plant growth and development,and influence of soybean aphid population dynamics,through the indirect effect to regulate plant growth and reproduction of soybean aphids,And direct effect of soybean aphids remains to be further research.