玉米自交系芽期耐冷性评价及耐冷种质筛选OA

Low-temperature injury has emerged as a serious threat to maize production in recent years,particularly in high-latitude regions of China,such as the Northeast and Northwest,which are major maize-producing areas.Enhancing cold tolerance at the germination stage is one of the key strategies to inhibited low-temperature damage and ensuring stable,high yields.Establishing a scientific,efficient,and practical evaluation system for maize cold tolerance at the germination stage is of great significance,and essential for screening and identifying cold-tolerant maize materials.In this study,a panel of 292 maize inbred lines with diverse genetic backgrounds were used for a comprehensive evaluation of cold tolerance under indoor conditions,with principal component analysis and the weighted membership function method(D-value)for further analysis.The results showed that low-temperature stress significantly inhibited the development of most of detected traits at the germination stage,including germination rate,germination potential,sprouting speed,germination index,simple vigor index,average root growth speed,average shoot growth speed.Additionally shoot length was significantly shortened,and significant differences were observed in these traits among different inbred lines.Comprehensive evaluation of cold tolerance using the D-value revealed substantial variation within the population,with a mean value of 0.359 and a range from 0.079 to 0.747.Among these lines,SY1039 exhibited the highest D-value,demonstrating the strongest cold tolerance.Furthermore,based on the D-value,the 292 inbred lines were successfully clustered into five distinct cold-tolerant subgroup,namely the extremely low-temperature-tolerant group,strong low-temperature-tolerant group,moderately low-temperature-tolerant group,weak low-temperature-tolerant group,and extremely weak low-temperature-tolerant group.Notably,the inbred lines from tropical and subtropical germplasm groups showing excellent cold tolerance.Correlation analysis revealed the highest positive correlation(correlation coefficient=1.00)between relative shoot length and relative average shoot growth rate,as well as between relative root length,while the highest negative correlation was observed between relative germination potential and relative germination index(-0.20).This study provides a methodological reference for evaluating cold tolerance in maize and offers a material foundation for research on cold tolerance mechanisms and the screening of cold-tolerant materials.