H_2O_2预处理对盐胁迫下黄瓜幼苗生长和K^+,Na^+,Cl^-分布的影响

Effects of H_2O_2 Pretreatment on Distribution of K^+,Na^+ and Cl^- in Cucumber Seedlings under Salt Stress

以黄瓜品种津春2号为试材,采用营养液水培,研究了H2O2预处理对NaCl胁迫下幼苗植株不同器官中K+,Na+和Cl-含量的影响。结果表明,NaCl胁迫下黄瓜植株体内K+含量下降、Na+和Cl-含量升高、K/Na和Cl/Na比值降低;H2O2预处理抑制了盐胁迫下黄瓜幼苗植株体内K+含量的降低,减少了Na+和Cl-在叶片的积累,提高了K+,Na+吸收和运输的选择性及K/Na比值,缓解了盐胁迫的伤害,改善了盐胁迫下黄瓜幼苗的生长,显著提高了根、茎、叶的干重和幼苗株高。说明,叶面喷施外源H2O2可通过调控盐胁迫下植株体内离子在器官水平的区域化分布,进而提高黄瓜幼苗的耐盐性。

Taking the seedlings of cucumber （Cucumis sativus L. ） cultivar Jinchun No. 2 as experimental material, the effects of H2O2 pretreatment on contents of K＋ ,Na＋ and Cl- in different organs were studied by the method of hydroponics. The results showed that under salt stress, the K＋ content decreased while Na＋ and Cl- contents increased in cucumber seedlings, so the ratios of K/Na and Cl/Na all decreased. Compared with the seedlings treated with salt stress only.cucumber seedlings treated with exogenous H2O2 combined with salinity showed higher levels of K＋ ac- cumulation in all the organs and lower levels of Na＋ and Cl- in leaves. For salt-stressed cucumber seedlings,the supplement of exogenous H2O2 increased the absorbing and transporting selectivity ratio of K＋ to Na＋ ,increased K/Na ratio, and alleviated damage of salt stress, enhanced seedling growth, increased Significantly dry weight of root, stem and leaf and shoot height. In conclusion. exogenous foliar spraying H2O2 could improve the tolerance of cucumber seedlings to salt stress by regulating the ionic compartmentalization in organs.