| Foxtail millet is one of the important cereal crops originating in our country.The germplasm resources are extremely rich.Analysis of its genetic diversity,screening of available excellent germplasm,indepth exploration of excellent parents,increasing the exchange accumulation of excellent alleles,can further improve the level of breeding in foxtail millet.Selenium is an essential trace element for the human body and is of great significance to human health.Reasonable application of exogenous selenium can promote the growth and development of crops,increase the selenium content in grains,and effectively supplement the selenium element for the population in selenium-deficient areas.In this study,200 pieces of foxtail millet germplasm resources were used as test materials,and13 phenotypic traits were identified to evaluate the genetic diversity of millet germplasm resources and screen excellent germplasm.In addition,110g·hm-2 of Na2SeO4 was sprayed on the leaf surface at the heading stage of millet to analyze the agronomic characteristics of different germplasm and the changes in the selenium content of grains,providing a material basis for the mining of seleniumrich germplasm and the cultivation of new varieties.The main findings are as follows:（1）The genetic diversity of millet germplasm resources is rich.The coefficients of variation in panicle length,panicle diameter,spike weight,spike grain weight,thousand-grain weight,plant height,steam diameter are all above 10%,and the average genetic diversity index was 2.774.Among them,the coefficient of variation of spike grain weight was the largest,reaching 50.16%,and the coefficient of variation of thousand-grain weight was the smallest,reaching 13.36%.（2）The agronomic characteristics of foxtail millet in different ecological regions are significantly different.The panicle length in the Early Maturity Spring-sowing Northwest is significantly（P<0.05）longer,and the spike weight,spike grain weight and thousand-grain weight are smaller than other ecological regions and the coefficient of variation is larger,all at 30 %;the spike weight and spike grain weight in the Middle and Late Maturity of Spring-sowing Northwest were significantly（P<0.05）higher than those in other ecological zones,and the spike number was smaller than that in other ecological zones;the plant height in the North China Summer-Sowing Region a was significantly（P<0.05）lower than that in other ecological zones,but the thousand-grain weight is the largest;the panicle diameter,spike number and stem diameter are the largest in the Northeast Spring-snowing Region.（3）The spike diameter,spike weight,spike grain weight,spike number,plant height and stem diameter of the cultivar are larger than that of the landrace.Among them,the increase of the spike and grain weight is the largest,which is 24.72% higher than that of the landrace;The average ear length and variation are smaller than that of local varieties.From the point of view of coefficient of variation,the coefficients of variation of main agronomic traits of cultivar are smaller than that of landrace,with the largest decrease in spike weight and grain weight,which are 11.7% and 13.18%less than that of landrace.（4）Four principal components were extracted through principal component analysis,and the cumulative contribution rate reached 80.94%.The main load factors were spike weight,spike grain weight,plant height,spike length,spike number and thousand-grain weight;Using the comprehensive evaluation equation to calculate the comprehensive F score of 200 millet germplasm resources.The results show that Shenggu has the highest comprehensive F value of 2.31;followed by Sanbianlian（1.91）and Dongfangliang（1.86）,both local varieties;the bred variety Zhongchangsui 1（1.64）,Changsuigu 3（1.56）and Changsui 4（1.52）have the highest comprehensive F values.（5）Correlation analysis showed that panicle length,panicle diameter,panicle weight,panicle grain weight,1000-grain weight,and selenium content were all significantly（P<0.01）positively correlated.Among them,the correlation coefficient between panicle weight and panicle grain weight was the largest.Up to 0.833;the length of the bristles was significantly（P<0.05）negatively correlated with the spike tightness;the spike neck shape was extremely significantly（P<0.01）positively correlated with the spike tightness.After selenium treatment,panicle length was significantly（P<0.05）negatively correlated with panicle diameter,and selenium content was extremely significantly（P<0.01）positively correlated with plant height.（6）After selenium treatment,among 200 millet germplasm resources,Suxuan 5 had the largest increase in panicle length and spike number,and the difference was extremely significant（P<0.01）;The panicle diameter,spike weight,and spike grain weight of Lugu 10 increased the most,and the difference was significant（P<0.05）,with significant difference（P<0.05）;the plant height of landrace Yuzhou Huang increased the most,30.1cm more than the control,the difference was significant（P<0.05）;the stem diameter of Kangu 214 increased the most,the difference was significant（P<0.05）.（7）110 g·hm-2 Na2SeO4 significantly（P<0.05）increased the selenium content of foxtail millet.Before selenium treatment,the average grain selenium content of foxtail millet was 0.104 mg·kg-1.After selenium treatment,the selenium content of grains was 0.104 mg·kg-1.Increased to 0.137mg·kg-1,an increase of 31%;the selenium content of foxtail millet in different ecological regions is quite different.The average grain selenium content in the middle and late spring-snowing maturing regions of Northwest is the highest,reaching 0.114 mg·kg-1;after selenium treatment,the selenium content of foxtail millet in North China Summer-Sowing Region increased the most,with an increase of 36.08%;the selenium content of landrace was higher than that of cultivar,the average selenium content is 0.180 mg·kg-1,and the coefficient of variation is larger,reaching 28.44%;cluster analysis can divide the millet germplasm resources into four categories,and the selenium-enrichment capacity of the first three categories Strong,including Ji’aigan 6,Jingu 29,Baimiao Sisanshi,97 Waiyin 4,Jingu 32,Niuwei Huanggu,Eyanggu,Changnong 35,Xia 2,Chang 0301 and Taixuan 5,There is no significant difference in the selenium enrichment capacity of other varieties. |
