175份谷子种质在2种环境下的表型变异分析OA

Breakthroughs in breeding new crop varieties depend strongly on the genetic diversity of germplasm resources.How-ever,research on foxtail millet(Setaria italica)germplasm is often limited by unrepresentative sampling,phenotyping in a single environment,and an overreliance on quantitative indices,all of which constrain the efficient identification of breeding materials.To address these limitations,we evaluated 175 foxtail millet accessions from diverse origins and systematically characterized 21 phenotypic traits at two sites(Luoyang and Zhengzhou,Henan province)in 2023.Comprehensive assessments were performed using correlation analysis,principal component analysis,stepwise regression,and cluster analysis.The aims were to(i)elucidate patterns of phenotypic variation among foxtail millet germplasm,(ii)define core evaluation indicators,and(iii)identify elite ac-cessions adapted to the agroecological conditions of Henan province,thereby providing targeted germplasm resources and a theo-retical basis for breeding summer-sown foxtail millet.The results showed substantial diversity among the 175 accessions:the diversity index for nine qualitative traits ranged from 0.086 to 1.218,and that for 12 quantitative traits ranged from 1.173 to 1.399.The coefficients of variation for four quantitative traits differed markedly between sites;plant height showed the smallest varia-tion(followed by grain number per spikelet),whereas 1000-grain weight showed the largest variation(followed by spike diame-ter).Principal component analysis extracted 14 principal components at a cumulative contribution rate of 90％,capturing most of the phenotypic variation.The mean comprehensive phenotypic score(F value)calculated using the membership function method was 0.538;Yugu 2 had the highest F value(1.078)and the best overall performance,whereas Longgu 25 had the lowest F value(0.079).Stepwise regression produced a model with 11 phenotypic traits(e.g.,grain number per spike and spikelet number per spike)as independent variables(R2=0.971,P<0.05),which can serve as a core set of indicators for identifying superior foxtail millet germplasm.Based on F values,cluster analysis grouped the accessions into six clusters;Group Ⅱ contained two accessions with outstanding agronomic performance and the highest mean F value,indicating their potential as preferred parents for germ-plasm innovation and hybrid breeding.Overall,the tested foxtail millet germplasm exhibits rich genetic variation and provides diverse material support for the improvement and cultivar development of summer-sown foxtail millet.