Screening Of Potato Nitrogen High-efficiency Materials And Key Enzymes For Nitrogen Metabolism Difference In Gene Expression

Increasing nitrogen production by applying nitrogen fertilizers is one of the main agricultural measures adopted in potato production.However,blind over-application of nitrogen will not only reduce the yield and quality of tubers,but also cause a decrease in nitrogen utilization rate,waste of resources,and increase the risk of environmental pollution.Therefore,it has become a hot research field to reduce the application of nitrogen fertilizer while ensuring the yield and quality.Optimizing the nitrogen fertilizer application technology can effectively increase the nitrogen fertilizer utilization rate.In addition,nitrogen high-efficiency breeding is also one of the ways to increase the nitrogen utilization rate.In order to clarify the differences in nitrogen utilization of different potato genotypes in Northeast China,the first preliminary screening of 11 major cultivars at the three nitrogen levels(low,medium,and high)was conducted in pot experiments in this study,and evaluate the screening indicators.Through field experiments under three levels of nitrogen(low,medium and high),the differences in the morphology,physiology and related gene expressions of the selected representative varieties were compared and analyzed for the future potato nitrogen efficient genotypes.Screening and utilization provide a theoretical basis.The main conclusions of the experiment are as follows:(1)Nitrogen accumulation at seedling stage of Dongnong 310,Yanshu 4,Kexin 13,and Kexin 22 increases significantly with the increase of nitrogen supply,and the response to nitrogen is high;The nitrogen accumulations of potato varieties such as Nong 311,Dongnong 312,Dongnong 316,Yanshu 7,Yanshu 9,Kexin 19,Atlantic,etc.,increased slightly with increasing levels of nitrogen supply,and responded to nitrogen.The degree is lower.Physiological and morphological indexes of genotypes with high nitrogen responsiveness increased significantly with increasing levels of nitrogen supply,and there was no significant difference among genotypes with low nitrogen responsiveness.(2)Nitrogen accumulation under nitrogen stress at seedling stage was positively correlated with nitrogen content,Root vitality,SPAD value,Dry Weight and Key Enzyme Activity of Nitrogen Metabolism.Nitrogen accumulation under high nitrogen was positively correlated with Enzyme Activity and Dry Weight.,but negative correlation with SPAD and Root vitality.NRA,NiRA,GSA,GOGATA,Dry Weight,Nitrogen content and other indicators can be used as the main indicators to measure potato nitrogen uptake efficiency at seedling stage,and SPAD value and root activity as auxiliary indicators.(3)The yields of Dongnong 310,Kexin 22,Yanshu 9 and Dongnong 311 under low nitrogen stress were relatively high.After adding nitrogen fertilizer,the yields of Dongnong 310 and Kexin 22 still increased,and the yield difference between nitrogen treatments was also significant.Significantly;Yanshu 9 and Dongnong 311 showed no significant increase in yield after nitrogen application;Atlantic production was low under low nitrogen and high nitrogen,and the increase was not significant.Nitrogen fertilizer increased moderately,and the yield increase of Dongnong 310 and Kexin 22 with higher nitrogen response was greater than that of Yanshu 9,Dongnong 311 and Atlantic with low response to nitrogen.The Nitrogen Content,Nitrogen Accumulation,Root vitality,SPAD value,Dry Weight,and Key Enzyme Activity of Nitrogen Metabolism of Dongnong 310 and Kexin 22 increased significantly with the increase of nitrogen application amount.Dongnong 311,Yanshu 9 and Daxiyang There was no significant difference between the nitrogen treatments.(4)The expression of nitrogen metabolism enzyme gene in Kexin 22 and Dongnong 310 under low nitrogen stress was greater than that in Yanshu 9,Dongnong 311 and Daxiyang,and the expression of NR gene increased in high nitrogen Xia Kexin 22 and Dongnong 310.Significantly;Yanshu 9 and Dongnong 311 had higher levels of NR gene expression than the Atlantic under low nitrogen stress and high nitrogen,but there was no significant difference between the nitrogen treatments;the Atlantic showed low levels of NR gene expression under low nitrogen stress and high nitrogen levels.low.(5)The nitrogen metabolism enzyme gene expression patterns of Dongnong 310 and Kexin 22 varieties with high nitrogen responsiveness were different.Dongnong 310 had high expression of NR gene and GS-3 gene,and Kexin 22 had NiR gene and The high expression level of FdGOGAT gene predicts that the contribution rates of different nitrogen metabolism enzyme genes in different nitrogen metabolism pathways are different.