向日葵种质资源苗期抗旱性鉴定及抗旱指标筛选

Drought resistance identification and drought resistance index screening of sunflower germplasm resources at seedling stage

以226份向日葵种质为材料,采用盆栽试验,设置干旱胁迫和正常浇水2个处理,测定株高、单株叶面积、SPAD值、叶片相对含水量、根长、根体积、根冠比、根表面积8个指标,计算抗旱系数和综合评价值(D值)及进行相关统计分析,鉴定苗期抗旱性。结果表明:8个指标抗旱系数间均存在显著相关性,且与综合评价值(D值)存在极显著或显著相关性,说明8个指标均可用作向日葵苗期抗旱性的评价指标;利用多元逐步回归分析建立了初步预测向日葵抗旱性的方程;基于综合抗旱评价值(D值),将参试种质划分为5个不同抗旱等级:极耐旱型、耐旱型、中间型、不耐旱型和极不耐旱型,其中175、106、117、117、161、132、162、194、174、127、15、110、133、224、109、120等15份极耐旱型与耐旱型材料可用作向日葵抗旱育种的主要材料。

This study used 226 sunflower germplasm resources as experimental materials.Two treatments of pot experiment were with normal irrigation and drought stress.Plant height,leaf area per plant,SPAD value,leaf relative water content,root length,root volume,root cap ratio index and root surface areawere recorded to calculate the comprehensive evaluation value and drought-resistant coefficient(D value)andconduct correlation analysis,linear regression analysis as well as identify seedling index of drought resistance.The results showed that the significant correlations were found amongthe eight drought resistance indexes.Additionally,there was a significant correlation or correlation between the 8 indexes and the comprehensive evaluation D value,indicfating that all the eight traits could be used as evaluation indexes of drought resistance of sunflower at seedling stage.Multiple stepwise regression analysis established an equation that could preliminarily predict drought resistance of sunflower.Based on the comprehensive drought resistance ability(D value),germplasm resources were divided into five different drought resistance levels(strong drought-tolerant type,drought-tolerant type,normal type,drought-sensitive typeand highly drought-sensitive type).Of which the extremely drought-tolerant and drought-tolerant types(175,106,117,117,161,132,162,194,174,127,15,110,133,224,109,120)can be used as the main reference materials for sunflower breeding in the future.