棉花萌发期抗旱指标筛选及种质资源抗旱性综合评价

Cotton Drought Resistance Index Screening and Comprehensive Evaluation of Drought Resistance of Germplasm Resources During Germination Period

棉花是重要的经济作物和油料作物。为研究棉花种子萌发期形态指标与抗旱性的关系,筛选棉花萌发期适宜的抗旱性指标,以40个棉花品种为材料,聚乙二醇-6000(polyethylene glycol-6000,PEG-6000)溶液模拟干旱胁迫,清水为对照,采用相关性分析比较了与棉花萌发期抗旱性相关的7个指标(相对种子吸水率、相对发芽势、相对发芽率、相对萌发指数、胚根/下胚轴指数、相对胚根干/鲜重和相对胚芽干/鲜重),依据隶属函数得到综合抗旱性评价值,并将其与7个指标进行相关性分析,以得到最适宜的抗旱性指标。结果显示,相对发芽势、相对发芽率和相对萌发指数是供试40个棉花品种萌发期抗旱性鉴定的3个重要指标。干旱胁迫下,可通过测定这3个指标对不同品种棉花萌发期的耐旱性进行快速准确的鉴定及评价。供试的40个棉花材料中,‘中85271’抗旱性最强,‘CF75落6’抗旱性最弱。

Cotton is an important cash crop and oil crop.In order to study the relationship between morphological indicators and drought resistance at the germination stage of cotton seeds,the suitable drought resistance indexes in the germination stage of cotton were screened.Took 40 cotton varieties as materials,polyethylene glycol-6000(PEG-6000)solution simulating drought stress,and clean water as control,seven indicators(relative seed water absorption,relative germination potential,relative germination rate,relative germination exponent,radicle/hypocotyl index,relative radicle stem/fresh weight,and relative germ stem/fresh weight)related to drought resistance in the germination stage of cotton were compared by correlation analysis,and the comprehensive drought resistance evaluation value was obtained according to the membership function,and the correlation analysis was carried out with seven indicators to obtain the most suitable drought resistance index.Results showed that the relative germination potential,relative germination rate and relative germination index were screened out as important indicators for the identification of drought resistance during the germination stage of 40 cotton varieties.Under drought stress,the drought tolerance of different varieties of cotton in the germination stage can be quickly and accurately identified and evaluated by measuring these three indicators.Among the 40 cotton materials tested,‘Zhong 85271’had the strongest drought resistance and‘CF75 drop 6’had the weakest drought resistance.