Response Of Wheat Photosynthate Allocation Pattern To Environmental Factors

Wheat is the crop with the largest harvested areas,ensuring stable and increased yield of wheat is of great significance to global food security.Climatic factors and soil factors have an important influence on the allocation of wheat photosynthate.However,the comprehensive effects of environmental factors are less considered in the current studies and there are some differences in the results of the research.In this study,the linear mixed effect model was used to study the response of root : shoot ratio at maturity stage and yield of wheat,and the response of their relationship to the climate condition during growth stage and physical and chemical properties of soil with 308 sets of data were collected from 61 articles,moreover,the optimal model was selected by Frequentist Model Averaging.Based on the preliminary results of meta-analysis,a pot experiment was designed to explore the effects of drought on dynamics of the allocation of recently assimilated carbon between above and below ground in wheat at booting stage.The main results are as follows:1?The root : shoot ratio of wheat at maturity decreased significantly with the increase of precipitation during the growing stage.Precipitation and 0? accumulated temperature during growth stage were no significant linear correlation with wheat yield.2?The interaction of precipitation and 0? accumulated temperature during growth stage significantly affected root : shoot ratio at maturity stage.When the 0 ? accumulated temperature during the growth stage increased in the range of 1796 ?-2861 ?,the decreased extent of root : shoot ratio of wheat at maturity went up with the increase of precipitation at growth stage.If the precipitation was less than 155 mm in the growing stage,the root : shoot ratio of wheat at maturity went up with the increase of 0? accumulated temperature in the growing stage,and if the precipitation was higher than 155 mm,the root : shoot ratio at maturity went down with the increase of 0? accumulated temperature in the growing stage.3?The interaction of precipitation during the growth stage and plough layer soil clay content significantly affected the root : shoot ratio of wheat at maturity.When plough layer soil clay content increased in the range of 18%-28%,the decreased extent of root : shoot ratio of wheat at maturity went down with the increase of precipitation at growth stage.If the precipitation in the growth stage was less than 225 mm,the root : shoot ratio of wheat at maturity went down with the increase of plough layer clay content,and if the precipitation was higher than 225 mm,the root : shoot ratio at maturity went up with the increase of plough layer clay content.4?Comparing the precipitation of different growth stages,it is true that with the increase of precipitation after anthesis stage,the root : shoot ratio of wheat at maturity decreased significantly and the yield increased substantially.With a increased proportion of precipitation after anthesis stage,the root : shoot ratio of wheat at maturity increased significantly,but the yield did not change dramatically.5?With the increase of plough layer soil organic matter,the root : shoot ratio of wheat at maturity decreased significantly and the yield increased substantially.6?Under drought conditions,the root : shoot ratio of wheat at booting stage increased significantly.The total amount of recently assimilated carbon of wheat decreased at booting stage.A higher proportion of recently assimilated carbon was transferred underground,and the efficiency of transfer reduced.7?Wheat yield decreased with the increase of root : shoot ratio at maturity.The root : shoot ratio of wheat at maturity influenced the effect of the precipitation after anthesis stage on yield.When the root : shoot ratio of wheat at maturity was lower than 0.24,the yield increased with the increase of precipitation after anthesis stage.When the root : shoot ratio was higher than 0.24,the yield decreased with the increase of precipitation after anthesis stage.To summarize,plough layer soil organic matter,plough layer soil clay content,precipitation during growth stage,precipitation distribution pattern and 0? accumulated temperature during growth stage all affect the allocation of photosynthate in wheat.The effect direction of precipitation during growth stage on root : shoot ratio at maturity is not affected by other environmental factors,but the effect degree depends on the plough layer soil clay content and 0? accumulated temperature during growth stage.The influence direction and degree of 0? accumulated temperature and plough layer soil clay content on the root : shoot ratio at maturity all depend on the value of precipitation during growth stage.There was a negative correlation between the plough layer soil organic matter and the precipitation after anthesis stage with the root : shoot ratio at maturity,with a positive correlation with the yield.There was a negative correlation between the root : shoot ratio and yield of wheat at maturity,precipitation during growth stage and its distribution pattern can't change the correlation direction.