保水剂对干旱胁迫槟榔幼苗生理特征的影响

[目的]探讨不同剂量保水剂对干旱胁迫槟榔幼苗生理特征的影响,为槟榔节水抗旱栽培提供理论依据.[方法]以盆栽热研一号槟榔幼苗为材料,在干旱条件下施用0.1%~0.4%保水剂20d后,测定不同处理槟榔幼苗叶片的相对水含量、可溶性蛋白含量、丙二醛(MDA)含量、叶绿素含量、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,分析槟榔幼苗叶绿素荧光参数、光能利用和耗散指标的变化情况.[结果]在干旱胁迫下,施用0.1%~0.4%保水剂可有效提高槟榔幼苗叶片的相对水含量、叶绿素和可溶性蛋白含量及SOD和POD活性;当保水剂施用剂量为0.3%时,槟榔幼苗叶片的相对水含量、可溶性蛋白含量和叶绿素含量最高,MDA含量最低,POD活性最高;槟榔叶片的叶绿素荧光参数光系统II(PSII)最大光能转化效率(Fv/Fm)和PSII实际光化学量子产量[Y(II)]在保水剂施用剂量为0.3%时最大,光化学猝灭系数(qP)随保水剂施用剂量的增大而增加,非光化学猝灭系数(NPQ)随保水剂剂量的增大呈先下降后上升的变化趋势.[结论]施用保水剂可有效提高干旱胁迫槟榔幼苗叶片的渗透调节物质含量及其抗氧化酶活性,保障光合作用顺利进行,缓解干旱胁迫对槟榔幼苗的伤害,以施用0.3%保水剂的效果最佳.

Effects of super absorbent polymer on physiological characteristics of Areca catechu L.under drought stress

[Objective]The effects of different dosages of super absorbent polymers(SAP)on physiological characteri-stics of Areca catechu L.seedlings under drought stress were explored to provide theoretical basis for water-saving and drought-resistant cultivation of it.[Method]Potted A.catechu Reyan 1 seedlings were used as materials.After 20 d of applying 0.1%-0.4% SAP under drought condition,relative water content,soluble protein content,malondialdehyde (MDA)content,chlorophyll content,superoxide dismutase(SOD)activity and peroxidase(POD)activity of A.catechu seedlings in different treatments were detected,and variation of chlorophyll fluorescence parameters,light energy utiliza-tion and dissipation indicators were analyzed.[Result]Under drought stress,application of 0.1%-0.4% SAP effectively in-creased leaf relative water content,chlorophyll content,soluble protein content,SOD activity and POD activity;but when the dose reached 0.3%,relative water content,soluble protein content and chlorophyll content in A.catechu leaves reached the peak,MDA content was the smallest and POD activity was the highest.The maximal photochemical efficien-cy(Fv/Fm)chlorophyll fluorescence parameters photosystem II(PSII)and actual photochemical efficiency[Y(II)]of PSII reached the maximum when SAP dose was 0.3%.As SAP dose rose,photochemical quenching coefficient(qP)in-creased,but non-photochemical quenching coefficient(NPQ)went through a down-up variation.[Conclusion]The appli-cation of SAP can effectively increase osmolytes contents and antioxidant enzymes in leaves of A.catechu under drought stress,ensure the progress of photosynthesis and alleviate the damage of drought stress on A.catechu seedlings.The opti-mal dose of SAP is 0.3%.