Physiological Basis And Regulation Of Nitrogen Uptake And Utilization Efficiency Of Coix

This study used 14 coix cultivars that collected from all over place namely,Longlin 1,Xilin 1,Xingren Little White Husk,Qianyin 1,Longlin 2,0,1,2,10,and 11 varieties,Vietnam Patterned Husk,XYYBT and XYYH 12-1.Under field conditions were determined coix nitrogen utilization efficiency also other related indicators;were used 4 cultivars that have been screened previously,cultivars that have relatively low and relatively high ability in the utilization of nitrogen,each of which two cultivars.By using pot experiments,study was conducted to analyze relationship between coix nitrogen utilization efficiency and their physiological characteristics.At the same time,experiments at field was also conducted,used 3 kinds of nitrogen levels as follows 10 kg N/acre;15 kg N/acre;20 kg N/acre and used 3 ways of combining fertilizer to explore comprehensive effect of nitrogen application,nitrogen utilization efficiency to the quality and quantity yield of coix.The main results and conclusions are as follows:1.Inter-variety difference of nitrogen utilization efficiency of coixAccumulation of nitrogen,physiological and agronomical of nitrogen utilization efficiency,and other nitrogen utilization efficiency indexes are significantly different among different cultivars.Nitrogen harvest index of cultivar was not significantly different.Leaf area index,root condition,dry matter accumulation,total nitrogen content among cultivars also showed significant differences.In this study,under various treatments,Xilin 1,Qianyin 1,and 2 varieties showed relatively high leaf area index and dry matter accumulation.Enhancing application of nitrogen fertilizer can boost nitrogen utilization efficiency indexes such as nitrogen accumulation,physiological utilization efficiency and agricultural utilization efficiency as well as agronomic indexes such as leaf area,root condition and dry matter accumulation.The results demonstrated that coix of Qianyin 1,Xilin 1 and 2 varieties were higher nitrogen utilization efficiency and relevant agronomic characteristics than Longlin 1 and 10 varieties among all 14 cultivars.2.Nitrogen utilization efficiency,functional of root absorption and leaf photosynthesis of coix was closely relevance.Under without nitrogen fertilization,root length,root surface area,root diameter and root volume were not clearly about nitrogen utilization efficiency.Whereas,with nitrogen fertilization,Xilin 1 and Qianyin 1 varieties demonstrated higher root surface area and root volume compared with Longlin 1 and 10 variesties.The results also displayed that coix cultivars with higher-efficiency of nitrogen utilization,root surface area and root volume develop more rapidly under nitrogen induction.In root system characteristics,root vigor could be an important factor to the gross efficiency of nitrogen utilization.Among the 4 coix cultivars experimented,Xiliin 1 and Qianyin 1 demonstrated higher leaf area,chlorophyll content and gross photosynthesis rate at top 3rd leaf photosynthesis rate,especially during heading stage to maturing stage compared with Longlin 1 and 10 varieties.The experiment indicated that good photosynthetic characteristics could play boost the efficiency of nitrogen utilization.However,significant relations were not found between chlorophyll fluorescence and nitrogen utilization efficiency in this experiment.Coix GPT activity is not an important factor for nitrogen utilization efficiency.After application of nitrogen,Xilin 1 and Qianyin 1's varieties nitrate reeducate activity was easier to be enhanced by induction,hence a potential contributory factor for high-efficiency nitrogen utilization.The results of study showed that cultivar with higher of efficiency nitrogen utilization have higher content of nitrate,free amino acid and Rubisco-N.3.Nitrogen fertilizer application was significantly efficiency to coix's quality and quantity.Addition of nitrogen fertilizer might enhance total nitrogen accumulation,nitrogen recycle efficiency,nitrogen agricultural application efficiency and leaf area.However,they cannot promote nitrogen harvest index significantly,and will reduce physiological application of nitrogen to a certain extent.The increase of nitrogen,the coix grain glycerol trioleate content results indicated that the application of nitrogen fertilizer was decreased the quality of coix grain.Early season and late season of coix used differently nitrogen fertilizer and the operational performance requirements.During early season,nitrogen fertilizer was used less basal fertilizer until top application is implemented later.For example,in this study N10F3.However,in late season nitrogen fertilizer shall be applied more and basal fertilizer shall be reapplied without top application.For instance,in this study N20F1 was used for late season in this study.