Screening And Identification Of Resistance To Low Nitrogen Varieties Of Foxtail Millet

Foxtail millet is an important crop in nature,in recent years the demand for foxtail millet continues to rise.Therefore,nitrogen fertilizer is widely used to improve foxtail millet production.However,nitrogen is not beneficial to the environment,nor is it conducive to the economic benefits.Therefore,screening and identification of low nitrogen tolerance but effective foxtail millet varieties are very important.In this study,the combination of field and seedling stage were used to establish the two treatments with normal nitrogen supply and low nitrogen stress,and the resistance of 60 foxtail millet cultivars to low nitrogen stress was analyzed by principal component and membership function.The main results are as follows:1.The low nitrogen stress revealed diminishing amounts of the seed weight of all cultivars and the seedling height,dry weight and nitrogen accumulation.However,the difference of reduction rate indicating that there was a significant difference in resistance to low nitrogen between different foxtail millet varieties.2.Under field test the relative spike weight(CV2014=20.33%,CV2016=15.14%),relative grass weight(CV2014=25.53%,CV2016=22.44%),and relative grain size(CV2014=12.39%,CV2016=10.11%)were screened from the plant height,panicle length,neck length,panicle weight,grass weight,grain weight and heading date according to the coefficient of variation of the relative value of each index weight,the 3 indicators can be used as foxtail millet resistant low nitrogen varieties screening.3.In the seedling experiment,the relative indexes of relative dry weight(CV=21.64%),relative nitrogen accumulation(CV=19.41%)and nitrogen use efficiency(CV=28.44%)were selected as the reliable indexes for the selection of nitrogen efficient varieties at foxtail millet seedling stage according to the variation coefficient of relative value of each index.4.In this paper,the principal component analysis and the membership function were combined for the evaluation of low nitrogen tolerance of different foxtail millet varieties.First,using the principal component we converted the original index into several independent comprehensive indexes,combined with the membership function to weight,through the comprehensive index evaluation value D to reflect the resistance to low nitrogen capacity of the size,D value is greater,the stronger the ability to withstand low nitrogen..Finally,the longest distance method was used to cluster,and the tested varieties were divided into three types:low nitrogen resistance,nitrogen sensitivity and intermediate type.5.Based on the results of field experiment and seedling experiment,two varieties with low nitrogen tolerance were selected from 60 varieties are GZ6 and GZ52.