马铃薯(Solanum tuberosum L.)干旱胁迫生理特性及耐旱性分析

Analysis of Physiological Characteristics and Drought Tolerance of Potato (Solanum tuberosum L.) under Drought Stress

干旱是一个世界性问题,也是造成中国作物产量低的重要原因。为探究干旱胁迫对马铃薯生理的影响和鉴定耐旱材料,本研究以‘青薯9号’和‘陇薯5号’两基因型马铃薯组培苗为试材,用0%、10%、20%、30%和40%浓度(m/V)的PEG-6000胁迫96 h模拟干旱筛选适宜的胁迫浓度,在含有适宜胁迫浓度的培养液中培养0、20、24、48、72和96 h后,测定抗氧化酶活性、可溶性物质和丙二醛(MDA)含量的变化,最后利用差异变化的生理指标的抗旱系数及主成分分析综合评价马铃薯耐旱能力。结果表明:20%浓度PEG-6000是适宜的胁迫浓度。干旱胁迫处理后,与对照相比,‘陇薯5号’超氧化物歧化酶(SOD)有显著增加,过氧化物酶(POD)和丙二醛(MDA)没有显著差异,可溶性糖在20 h开始显著增加;‘青薯9号’SOD没有显著变化,POD活性显著下降,可溶性糖72 h显著增加,MDA含量没有显著变化。7项生理指标可作为鉴定指标进行主成分分析综合评价,并提取出3个主成分,累积贡献率达79.2%,综合得分评价结果表明,‘陇薯5号’的综合耐旱能力强于‘青薯9号’。本研究对马铃薯干旱胁迫生理特性及耐旱性进行深入研究以及培育耐旱性马铃薯具有重要意义。

Drought is a worldwide problem and an important cause of low crop yield in China.In order to investigate the effects of drought stress on potato physiology and identificate drought-resistant material,the tissue culture seedlings of’Qingshu No.9’and’Longshu No.5’were used as test materials for simulate drought and screen suitable stress concentrations under PEG-6000 stress of 0%,10%,30%and 40%(m/V)for 96 h.The antioxidant enzyme activity,soluble substance and malondialdehyde(MDA)content were measured after cultured in MS medium containing suitable PEG-6000 stress concentration for 0,20,24,48,72 and 96 h.Finally,the changes of physiological indictors were measured.Drought tolerance of potato was evaluated by drought resistance coefficient and principal component analysis(PCA)of physiological indexes.The results showed that 20%PEG-6000 was the suitable stress concentration.Under drought stress,compared with the control,there was a significant increase in superoxide dismutas(SOD),no significant difference in peroxide(POD)and malondialdehyde(MDA),and a significant increase in soluble sugar of’Longshu No.5’at 20 h,while for’Qingshu No.9’,SOD did not change significantly,POD activity decreased significantly,soluble sugar content increased significantly at 72 h,and the increase of MDA content was not significant.The seven physiological indexes could be used as the main component analysis and comprehensive evaluation.In order to identify the drought tolerance,the comprehensive evaluation of principal component analysis was carried out,and three principal components were extracted,and the cumulative contribution rate was 79.2%.The results showed that the comprehensive drought tolerance of’Longshu No.5’was stronger than that of’Qingshu No.9’.In this study,the physiological characteristics and drought tolerance of potato under drought stress were studied in depth,which is of great significance to the cultivation of potato with drought tolerance.