不同毛花雀稗种质对干旱胁迫的响应及其抗旱性评价

Drought Stress Responses of Six Paspalum dilatatum Germplasms and Drought Resistance Evaluation

【目的】筛选抗旱性较强的毛花雀稗种质,为其抗旱型种质的选育与推广提供理论依据。【方法】以6个毛花雀稗(Paspalum dilatatum)种质为试验材料,采用盆栽干旱模拟试验,结合主成分分析法与隶属函数法研究干旱胁迫下各种质的生理指标变化并进行综合评价。【结果】干旱胁迫下,各种质的丙二醛含量在0~21 d增加趋势缓慢,在21~28 d增加趋势迅速;过氧化物酶活性、过氧化氢酶活性、可溶性蛋白含量呈先升后降趋势,除贵州湄潭种质的可溶性蛋白含量在第7天达到峰值外,其他种质上述各指标均在第14天时达到峰值;随干旱时间延长,可溶性糖含量呈显著上升趋势,而叶绿素含量呈显著下降趋势。主成分分析前3个主成分的累积贡献率达92.64%;抗旱性综合评价得出,美国种质抗旱性最强,其次为贵州安龙(草坡)种质,越南种质的抗旱性较弱,其余种质居中。【结论】在毛花雀稗抗旱性牧草种质的选育与推广中,应优先选择抗旱性较强的美国种质。

【Objective】The aim of this paper was to screen Paspalum dilatatum germplasms with strong drought resistance,and provide theoretical basis for the breeding and promotion of drought resistant germplasm.【Method】A drought simulation pot experiment was carried out with six P.dilatatum germplasms,and then the changes of various physiological indexes under drought stress were evaluated by means of principal component analysis and membership function.【Result】Under drought stress,the malondialdehyde contents of all the six germplasms gradually increased from the start to the 21st day,then a sharp increase was observed during 21st-28th days.The peroxidase activity,catalase activity,and soluble protein content increased first and then decreased,reached the maximum at 14 day,with one exception that the soluble protein in P.dilatatum germplasm coming from Meitan,Guizhou reached the maximum at 7th d.The total soluble sugar content displayed a significant upward trend,while the chlorophyll content showed a significant downward trend.The results of principal component analysis showed that the cumulative contribution rate of the first three principal components reached 92.64%,which could be identified as a comprehensive index for drought resistance evaluation.Comprehensive evaluation of drought resistance showed that the drought resistance of the P.dilatatum germplasm from USA was the strongest,followed by the one from Anlong(grass slope),Guizhou,the one from Vietnam was relatively weak,and the other germplasms rank in the medium position.【Conclusion】In the breeding and promotion of drought-resistant P.dilatatum germplasms,American P.dilatatum germplasms with stalwart drought resistance should be selected priorly.