Modeling Genotype By Climate Effect On Wheat Prductivity

It is of important practical significance to ensure national food security, and promote modernization of agriculture by using wheat growth model to evaluate the effects of genotype, climate on wheat production. This study used a wheat growth model, WheatGrow as a tool to analyze wheat production. Firstly, WheatGrow model was calibrated and validated using the data of field experiments involving different eco-sites, cultivars and nitrogen treatments. Secondly, this study aimed to investigate the quantified effects of phenological parameters on wheat phenology and productivity by designing the combinations of different cultivars parameters related to phenology. Then, the trends of climate variables of 1951-2009 during pre-anthesis and post-anthesis stage of wheat in five eco-sites were analyzed by WheatGrow model. Finally, the changes of wheat phenology and productivity during the year 1951-2009 and climate change scenario in five eco-sites were analyzed. This study would lay a foundation for wheat production management and regulation, variety design and evaluation and national food security.Wheat growth model WheatGrow was calibrated and validated by the field experiments involving different genotypes and N rates at Nanjing, Xuzhou, Huaian and Zhengzhou four eco-sites. The RMSE (Root Mean Square Error) and NRMSE (Normalized Root Mean Square Error) between the simulated values and observed values of phenology, grain yield were:5d,247 kg ha-1, and were 2.84%,3.45%, respectively. The results showed that WheatGrow model had a good performance in predicting phenology, grain yield at different eco-sites.This study aimed to investigate the quantified effects of phenology parameters on wheat productivity by designing the combinations of different genetic parameters related to phenology. Taking WheatGrow model as a tool, Simulation experiments were conducted to quantify and analyze the impacts of single parameter and the combination among PS-IE, PS-TS, IE-TS and PS-IE-TS-PVT on wheat productivity in Nanjing, Xuzhou, Zhengzhou, Tai'an and Baoding by setting the value range and step among five different parameters which were Physiological vernalization time (PVT),Photoperiod sensitivity (PS),Intrinsic earliness (IE),Temperature sensitivity (TS) and Filling duration factor (FDF). The results showed that the impacts of PVT, PS, IE, TS on wheat yield and growth days were significance and all met the 0.01 significance level. Increasing IE could remarkably decrease wheat growth days, and increasing TS and PS had a contrary trend; Among the two different genetic parameters sets, the simulation results of phenology between the combination sets comparably changed in the range of-17%～35%, and the yield ranged from 3444kg ha-1-13324kg ha-1. Simulation results of PVT-PS-IE-TS combination phenology and yield had the significant regional differences. Based on the genetic parameters of comparable varieties in the five eco-sites, the changes of growth days and yield in the five eco-sites were almost consistent by increasing or reducing the above four parameters by 10%,20%,30%, but the differences between the parameters was significant. And the combination of the design of excellent variety was consistent in different eco-sites. This study might provide the theoretical direction for the innovation of germplasm resources on wheat, also for the design and evaluation of excellent variety.The effects of climate change on winter wheat productivity were analyzed by a wheat growth model, WheatGrow in this study. Based on 1951-2009 daily weather data of five eco-sites, Nanjing, Xuzhou, Zhengzhou, Tai'an and Baoding, this paper analyzed the trend of climatic factors (daily average temperature, daily maximum temperature, minimum temperature days, sunshine hours, rainfall) during the whole growth period and two wheat growth phases (pre-anthesisand post-anthesis). Then the trend of wheat phenology and yield change in five eco-sites simulated from 1951 to 2009 by using WheatGrow model, Finally, the study analyzed the changes of phenology and grain yield at different eco-sites under the climate change scenario of the year of 2020,2030 and 2050. The results showed that mean temperature during wheat growth stage in Nanjing, Xuzhou, Zhengzhou, Taian and Baoding eco-sites increased and all met the 0.01 significance level. Maximum temperature of the five eco-sites changed slowly, only the change of Tai'an increased and met the 0.01 significance level, and Nanjing increased and met the 0.05 significance level, the other eco-sites all declined. Minimum temperature of Nanjing increased and met the 0.05 significance level, and the other eco-sites increased and met the 0.01 significance level, Sunshine hours during wheat growth stage in five eco-sites all declined and the changes of Nanjing and Baoding met the 0.01 significance level. Precipitation in five eco-sites all increased but not met the 0.05 significance level. The changes of climate factors during pre-anthesis were larger than that during post-anthesis. The length of pre-anthesis and the whole growth period in Nanjing, Xuzhou, Zhengzhou, Taian and Baoding all reduced and met the 0.01 significance level, and the yield in five eco-sites reduced and not met 0.05 significance level. This study also analyszed the effect of climate variables and genotype parameters during wheat pre-anthesis and pre-anthesis stages in five eco-sites on wheat phenology. The changes of phenology in the year 2020,2030 and 2050 compared with the baseline at different eco-sites reduced by 5-14 days,10-20days and 13-25days, and the changes of grain yield compared with the baseline were-5.7%～3.8%,-11.5%～5.5%,-14%～9.5%.