新疆尉犁县防护林带内四种杨树苗期耐盐性比较

Salt tolerance comparison among four Populus tree seedlings in shelter belt of Yuli County,Xinjiang

在新疆尉犁县的防护林带内,乔木的主栽树种是4种杨树,包括中天杨(Populus×xiaozhuanica"Zhongtian")、新疆杨(Populus alba var.pyramidalis)、银新杨(Populus alba×Populus alba var.pyra-midalis)和胡杨(Populus euphratica)。文中选择叶片脯氨酸含量、K+/Na+、Cl-含量、SOD(超氧化物歧化酶)活性、MDA(丙二醛)含量和δ13C值等6个生理生态指标,对4种杨树苗期的耐盐性进行综合评价,为尉犁县建立耐盐型防护林选择适宜树种提供依据。研究的初步结论是中天杨和胡杨的耐盐性较强,所受的土壤盐胁迫较轻,表现在叶片MDA含量较低,δ13C值较高。但是二者的耐盐机理不同,中天杨主要通过提高叶片的Cl-含量和SOD活性耐盐,而胡杨主要通过增加叶片脯氨酸含量和K+/Na+来耐盐。

Four populars are the main trees in the shelter belt of Yuli County,Xinjiang Uygur Autonomous Region,including Populus × xiaozhuanica ＂Zhongtian＂,Populus alba var.pyramidalis,Populus alba × Populus alba var.pyramidalis and Populus euphratica.Six ecophysiological indexes of which is leaf proline content,K＋/Na＋,Cl-content,SOD activity,MDA content and δ13C value were chosen to evaluate salt tolerance of four Populus tree seedlings.The purpose of this study was to choose suitable trees for salt tolerant shelter belt for Yuli County.The results showed that the salt tolerance of P.× xiaozhuanica ＂Zhongtian＂ and P.euphratica were higher in four Populus trees,because they suffered slightly from soil salt stress,reflecting in lower leaf MDA content and higher δ13C value.However,their salt tolerance mechanism were different： P.× xiaozhuanica ＂Zhongtian＂ tolerated salt by improving leaf Cl-content and SOD activity whereas P.euphratica resisted salt by increasing leaf proline content and K＋/Na＋.