基于多重表型分析的准确评价高粱抗旱性方法的建立

Establishment of an accurate evaluation method for drought resistance based on multilevel phenotype analysis in sorghum

干旱是制约农业生产的重要非生物胁迫之一,因此作物抗旱性研究具有重要理论和应用价值。本研究对73份高粱材料萌发期和苗期的抗旱性进行了初筛,从中选择15份抗旱材料和6份敏感材料,通过室内和田间试验,获得干旱胁迫下幼苗的株高、叶长、叶宽等形态特征以及超氧化物歧化酶、丙二醛、过氧化物酶等生理生化指标的响应数据,并对高粱的抗旱性做进一步的验证,最终确定抗旱型材料1份,中等抗旱型材料1份,干旱敏感型材料2份。本研究建立了一套基于多重表型分析的高粱抗旱性研究新方法,即综合运用多种数据分析方法(包括隶属函数法、主成分分析法、聚类分析法),结合不同生长环境(田间试验和室内试验)和不同生育期(萌发期和苗期)高粱响应干旱胁迫的多种表型数据(形态特征、生理生化指标),通过多重比较高粱抗旱性评价结果的一致性,旨在系统、高效、准确地判定高粱的抗旱性,为高粱抗旱机制的研究和抗旱新品种的选育提供技术支撑。

Drought is one of the important abiotic stresses that restrict agricultural production. Research on drought resistance of crops is of significance in both theoretical and practical aspects. In this study, 73 sorghum accessions were preliminarily evaluated for drought resistance at the germination and seedling stages under simulated drought environment with PEG-6000. Among them, 21 accessions including 15 tolerant and 6 susceptible, were screened to measure the morphological characteristics such as plant height, leaf length and leaf width, and physiological and biochemical indicators such as superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and peroxidase (POD) activity. Finally, one accession was identified with high drought resistance, one accession was moderate drought resistance and two accessions with drought-sensitivity. A new evaluation method for sorghum drought resistance was established based on the multilevel phenotypic analysis, in which the data from subordinate function method, principal component analysis and clustering analysis were comprehensively applied, and combined with various phenotypic data (morphological, physiological and biochemical indicators) at different growth stages (germination and seedling stages) in different growth environments (field test and laboratory test). This method can be used to systematically, efficiently and accurately identify the drought resistance of sorghum based on the consistency of evaluation results by multiple comparison analysis, which is useful in the research on drought resistance mechanism and sorghum breeding for drought resistance.