干旱对高羊茅生理特性的影响及抗旱性评价

Effects of Drought Stress on Physiological Characteristics of Festuca arundinacea and Evaluation of Their Drought Resistances

为揭示干旱胁迫对高羊茅生理特性的影响,评价不同种质间抗旱性差异,以项目组杂交创制的19份新种质为试验材料,以水城高羊茅和黔草1号高羊茅为对照,采用室内连续干旱法测定分析干旱胁迫下各种质叶片的5个生理指标的变化,利用主成分分析与隶属函数相结合的方法对种质间抗旱性进行综合评价。结果表明,随着干旱胁迫强度增加,高羊茅的丙二醛(MDA)含量、过氧化氢酶(CAT)和过氧化物酶(POD)酶活性均呈升高趋势(除种质Ⅰ-12外),脯氨酸(Pro)含量和超氧化物歧化酶(SOD)酶活性呈先升高后降低趋势,说明干旱胁迫下高羊茅通过增加Pro含量、提高SOD、POD和CAT酶活性来减少干旱伤害;但干旱30d时,Pro渗透调节能力和三种保护酶协调作用降低,保护能力减弱;利用累计贡献率达96.806%的2个综合指标评价出高羊茅种质的抗旱性顺序为Ⅲ-17>Ⅱ-11>Ⅰ-4>Ⅳ-2>Ⅰ-7>Ⅱ-10>Ⅲ-3>Ⅰ-12>Ⅰ-17>水城>Ⅳ-3>Ⅳ-1>Ⅱ-13>Ⅳ-5>Ⅲ-11>Ⅱ-3>Ⅱ-15>Ⅳ-4>Ⅲ-8>Ⅰ-20>黔草1号。

The experiment was to reveal the drought stress effects on physiological characteristics ana to estimate the drought resistances of Festuca arundinacea, The seeds of Festuca arundinacea were plan- ted in pots in greenhouse. Five physiology indices were measured and analyzed under drought stress. The drought resistances was comprehensively evaluated by principal components analysis and fuzzy subordinate function based on the measurement values. The results showed that with the increase of drought stress in- tensity, the MDA content, CAT activity and POD （Except I -12） activity increased. Praline content and SOD activity increased in the beginning and decreased at last. Under drought stress, F. arundinacea ac- cumulated proline content to maintain their expansion pressure of cell, increased antioxidases activity, such as SOD, POD and CAT, to protect cell membranes from damage. Osmotic adjustment ability of pro- line and coordinating role of antioxidases decreased under drought for 30 days, the protection ability de- creased too. Using two comprehensive indexes with an accumulative contribution rate of 96. 806%, the drought resistances of F. arundinacea germplasm resources was comprehensively evaluated and ordered as follows, Ⅲ-17〉 Ⅱ-11〉 I-4〉Ⅳ-2〉 I-7〉 Ⅱ-10〉 Ⅲ-3〉 I-12〉 I-17〉F. arundinacea cv. Shuicheng〉 Ⅳ-3〉Ⅳ-1〉 -13〉Ⅳ-5〉Ⅲ-11〉 Ⅱ -3〉 Ⅱ-15〉Ⅳ-4〉Ⅲ-8〉 1-20〉F. arundinacea cv. Qiancao No. 1.