不同玉米种质萌发期和苗期对干旱胁迫的响应

Response of Different Maize Germplasms to Drought Stress at Germination Stage and Seedling Stage

为探究不同玉米种质萌发期和苗期的抗旱性差异,本研究以热带、温带和温热玉米种质各20份为试验材料,分别在萌发期和苗期进行正常处理和干旱胁迫处理。播种后第8天测定发芽率、发芽指数、胚根数、胚根长、胚芽长、胚根干重、胚芽干重等性状,苗期干旱处理7 d后测定株高、根干重、叶面积、根冠比、叶绿素含量、F_(v)/F_(o)和F_(v)/F_(m)等性状,分析不同玉米种质的抗旱性。结果表明,不同玉米种质间14个性状均差异极显著,不同材料间14个性状均差异显著,干旱胁迫显著影响14个性状的表现。不同玉米种质间萌发期和苗期对干旱胁迫响应的变化趋势一致,萌发期和苗期对干旱胁迫响应最大的性状分别是胚芽长和叶面积。不同玉米种质间的抗旱系数在多数性状中差异显著。热带种质的多数性状相对温带种质具有更高的萌发期抗旱性和苗期抗旱性,且热带种质中具有更多高抗材料。热带种质、温带种质和温热种质抗旱表现优良材料数分别为8个、5个和7个,其中TroG04、TemG15和MixG02萌发期和苗期均具有强抗旱性,可用于选育萌发期和苗期抗旱性较好的品种。

In order to investigate the difference of drought resistance of different maize germplasm at germination and seedling stage,20 tropical,temperate and warm maize germplasm were used asexperimental materials,and normal treatment and drought stress treatment were carried out at germination and trileaf stage(seedling stage),respectively.Germination rate,germination index,radicle number,radicle length,germ length,radicle dry weight and germ dry weight were measured on the 8 th day after seeding.Plant height,root dry weight,leaf area,root-shoot ratio,chlorophyll content,F_(v)/F_(o) and F_(v)/F_(m) were measured after 7 days of drought treatment at seedling stage.The results showed that there were significant differenceSin 14 traitSamong different germplasm and 14 traitSamong different materials,and drought stress significantly affected the performance of 14 traits.The variation trend of drought stress response at germination stage and seedling stage wasthe same among different maize germplasm.Germ length and leaf area were the most responsive traitSat germination stage and seedling stage,respectively.The drought resistance coefficient of different maize germplasm wassignificantly different in most traits.Compared with temperate germplasm,tropical germplasm had higher drought resistance at germination stage and seedling stage,and tropical germplasm had more high resistance materials.There were 8,5 and 7 excellent drought resistance materialSin tropical,temperate and warm germplasm,respectively.TroG04,TemG15 and MixG02 had strong drought resistance at germination and seedling stages,and could be used to select varieties with good drought resistance at germination and seedling stages.