黄连木对干旱胁迫的生理响应

The physiological response of Pistacia chinensis Bunge to drought stress

研究了自然干旱条件下黄连木(Pistacia chinensisBunge)的生理变化。结果表明,随土壤含水量的减少,叶绿素b含量、光合速率、叶片相对含水量与叶水势均下降;叶绿素a和可溶性糖含量、叶绿素a和b的比值及总叶绿素含量呈现上升的趋势;超氧化物歧化酶活性先升后降;丙二醛含量干旱胁迫前期升高,后期变化不明显;净光合速率、气孔导度和蒸腾速率随土壤含水量的减少逐步降低。气孔和可溶性糖含量都是影响黄连木光合速率的关键因子,干旱胁迫前12 d光合速率主要受气孔限制,之后为非气孔限制。干旱胁迫前期渗透调节物质以可溶性糖为主,干旱胁迫较重时脯氨酸含量急剧升高,与可溶性糖同时起渗透调节作用。

The physiological change of Pistacia chinensis Bunge under drought stress was studied. The results showed that with the decrease of soil water content, Chlb content, photosynthesis rate, leaf relative water content and water potential declined; contents of Chla and Chl, soluble sugar content and ratio of Chla/Chlb increased ; activity of SOD increased firstly then decreased ; MDA content changed a little after a period of increase. Net photosynthetic rate, stomatic conductance and transpiration rate reduced gradually. Stomatic and soluble sugar content were the key elements to influence photosynthesis rate of P. chinensis, photosynthesis rate was influenced mainly by stomatic limitation early twelve days during drought stress, then by nonstomatic limitation. Soluble sugar was the main osmoregulatory material in early period of drought stress, proline content increased sharp under heavy drought stress, at the same time, both of proline and soluble sugar acted as osmoregulatory materials.