1040份玉米地方品种苗期耐渍性鉴定与优异种质资源筛选OA

To excavate key germplasm resources for waterlogging tolerance breeding in maize(Zea mays L.),1 040 maize landraces collected from the third national census of crop germplasm resources were used as materials,and their waterlogging tolerance was sys-tematically evaluated by applying continuous waterlogging stress for four weeks at the five-leaf-and-one-heart seedling stage under field conditions.The results showed that the survival rate of germplasm was 42.8%,with a kurtosis of-1.28 and a skewness of-0.068,indicating an approximately symmetrical and platykurtic distribution of the data.Analysis of geographic origins showed that the surviv-al rate of germplasm from the southwest region was 53.9%,which was significantly higher than that from the Huang-Huai-Hai region(32.4%),and the difference in waterlogging tolerance between the two regions reached an extremely significant level(P=7.87×10-36<0.01).Based on survival rates,the tested varieties were classified into five waterlogging tolerance grades.110 accessions(accounting for 10.6%)with a survival rate>80%were defined as grade 1(extremely strong waterlogging tolerance),among which two germ-plasm accessions(Batangbai and Yangyumi from the Huang-Huai-Hai region)showed a 100%survival rate after four weeks of water-logging stress,and 25 accessions had a survival rate≥90%.These materials with extremely strong waterlogging tolerance represented core resources for mining waterlogging tolerance genes and improving cultivar waterlogging tolerance,providing a material foundation for the genetic improvement of waterlogging tolerance in maize,thereby enhancing the climate resilience of production systems and en-suring food security.