30份普通菜豆苗期抗旱性鉴定及抗旱指标的确定

Evaluation of Drought Tolerance of 30 Common Bean in Seedling Stage and Screening of Drought-tolerance Assessment Index

以30份普通菜豆为试验材料,采用PEG6000溶液模拟干旱胁迫处理种子和苗期盆栽自然干旱法,研究了干旱胁迫对种子发芽率、植株地上部鲜重、地下部鲜重、叶片含水量、电导率和叶绿素荧光参数等11个指标的影响,通过隶属函数法和灰色关联分析法对普通菜豆进行抗旱性和抗旱指标综合评定。结果显示,每个抗旱指标在不同材料之间都具有明显差异,说明材料之间存在明显的抗旱差异性;发芽率、地下鲜重、地上鲜重、全株鲜重、电导率和Fv/Fm的关联度均大于0.8,与综合抗旱指数的关系较为紧密,可以作为普通菜豆苗期抗旱性筛选的主要鉴定指标;鉴定出F1863、F2973、F3992和F3057抗旱性较强的普通菜豆。以上结果表明应用多抗旱指标综合分析法能很好地评价材料的抗旱性。

30 accessions of common bean were employed for evaluation of drought tolerance in seedling stage.Drought stress treatments for common bean seed germination modulated using PEG6000 solution and for common bean seedlings used the method of withholding water content of soil. Eleven traits were evaluated for assessment of drought resistance,including seed germination rate,relative shoot fresh weight,relative root fresh weigh,relative water content,relative electrical conductivity and three chlorophyll fluorescence parameters. Comprehensive assessment of drought tolerance based on membership function and grey-relation analysis indicate that the materials have different responses to drought stress,accessions of F1863、F2973、F3992 and F3057 showed the strongest drought tolerance among all tested materials. Relative seed germination rate,relative shoot fresh weight,relative root fresh weigh,relative plant fresh weight,relative electrical conductivity and chlorophyll fluorescence parameters Fv/Fmhas closed association with comprehensive drought resistance index,and the association degree are more than 0. 8,thus could be used as comprehensive index for identification of drought resistance at the seedling stage.