1.山西农业大学;2.中国农业大学;3.中国农业科学院作物科学研究所
中国农业科学院科技创新工程基础科学研究中心(CAAS- CSIAF -202303)
1.China Agricultural University;2.Shanxi Agricultural University
Innovation in Agricultural Research, Chinese Academy of Agricultural Sciences (NCAAS-CSIAF-202303)
低温冷害严重威胁我国东北、西北等高纬度玉米主产区生产安全。提高芽期耐冷性是预防玉米低温冷害、实现稳产高产的重要方式之一。利用科学、高效、实用的玉米芽期耐冷性评价体系开展玉米材料耐冷性筛选与鉴定具有重要的理论和生产意义。本研究以遗传来源广泛的292份玉米自交系为试验材料,采用室内鉴定的模式,通过加权隶属函数法(D值)、主成分分析等方法开展玉米芽期耐冷性综合评价。结果显示低温胁迫可显著降低玉米种子芽期发芽率、发芽势、出芽速度、发芽指数、简单活力指数、根平均生长速度,芽平均生长速度,根长和芽长也显著减小,且不同自交系性状间表现出显著差异;利用D值对玉米自交系耐冷性综合评价,群体均值为 0.359, 变化范围在 0.079~0.747之间,表现出较大的变异范围。其中SY1039 的 D 值最高,表现最耐冷。此外,利用D值还将292份自交系群体划分为5个不同耐冷型亚群。有意思的是,来源于热带/亚热带杂种优势群的自交系也有较好的耐冷表现。通过相关性分析显示,相对芽长和相对芽平均生长速度及相对根长和相对根平均生长速度之间正相关性最高,相对发芽势和相对发芽指数间负相关性最高,分别为1.00和-0.19。本研究为玉米耐冷性鉴定提供方法参考, 为耐冷机制研究和耐冷材料筛选提供材料基础。
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 inhibiited 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 the weighted membership function method (D-value) and principal component analysis for further analysis.The results showed that low-temperature stress significantly inhibited the development of all detected traits at the germination stage, including germination rate, germination potential. 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. 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 (-0.19). 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.
