大麦萌发期优异耐碱性种质筛选与鉴定

Screening and identification of excellent alkali-tolerant germplasm of barley at the germination stage

土壤盐碱化已成为影响我国农业生产和生态安全的重要问题,筛选耐碱大麦(Hordeum vulgare)种质对于盐碱土地的开发与利用具有重要意义。为了解大麦萌发期耐碱性差异和生理响应特征,对199份大麦材料进行碱胁迫下的种子萌发试验,并对不同耐碱基因型大麦材料进行萌发期耐碱生理响应试验。结果表明:大麦种质在萌发期耐碱性差异显著,筛选出发芽率、发芽指数、活力指数、芽长和根长可作为大麦萌发期耐碱性评价指标。基于主成分分析的综合得分F值与熵权模糊隶属函数法的综合指数Z值进行聚类分析,将199份大麦种质分为4类,包括耐碱性类群(43份)、中度耐碱类群(96份)、碱敏感类群(35份)和极端碱敏感类群(27份),其中耐碱性最强的品种为‘2011C/26’,其次为‘鄂大麦259’。不同耐碱基因型大麦碱胁迫下的生理响应分析表明,耐碱基因型与碱敏感基因型相比具有较强的超氧化物歧化酶、过氧化物酶和过氧化氢酶活性,抗坏血酸-谷胱甘肽循环的运行效率高,且积累的丙二醛含量较少。

Soil salinization and/or alkalization is a major problem affecting agricultural production and ecological security in China,and screening barley germplasm with strong alkali tolerance plays a significant role in the improvement and utilization of saline-alkali land.To elucidate the acquisition of barley alkali tolerance and the associated physiological responses during the germination stage,we systematically evaluated the physiological responses of 199 barley germplasms with different genetic backgrounds during the germination stage under alkali tolerance.The results revealed that germination rate,germination index,vigor index,shoot length,and root length were selected as the key indexes to evaluate barley alkali resistance at the germination stage.These barley germplasms were divided into four categories based on the F value from principal component analysis and the Z value from the entropy-weighted fuzzy affiliation function method.They include 43 alkali-tolerant germplasms,96 moderately alkali-tolerant germplasms,35 alkali-sensitive germplasms,and 27 extreme alkali-sensitive germplasms.Among them,‘2011C/26’was the most alkali-tolerant germplasm,and the second one was‘Edamai 259’.Further analysis of physiological characteristics responding to alkali stress showed that the alkali-tolerant germplasm has stronger enzyme activities of superoxide dismutase,peroxidase,and catalase,a more active AsA-GSH cycle,and less malondialdehyde accumulation.