干旱胁迫下薄壳山核桃实生苗内源激素的变化规律

Content Changes of Endogenous Hormones under Drought Stress of Carya illinoensis Seedlings

以绍兴、金华、贝克、卡多和抛尼5个种源种子培育的2年生薄壳山核桃(Carya illinoensis)实生苗为试材,采用不同浓度聚乙二醇(PEG-6000)溶液模拟干旱胁迫,研究薄壳山核桃实生幼苗叶片IAA、GA3、ZR和ABA 4个内源激素含量的变化规律,并评价幼苗的抗旱能力。结果表明,IAA、GA3和ZR含量在不同种源中表现不同。绍兴种源的IAA和GA3含量呈上升趋势,ZR含量先升后降;金华种源的IAA和ZR含量呈上升趋势,GA3含量在重度胁迫下大幅度下降;贝克种源的IAA和GA3含量呈下降趋势,ZR含量先升后降,呈持续受抑制状态;卡多种源的IAA含量持续下降,GA3含量在重度胁迫下大幅下降,ZR含量先升后降;抛尼种源在重度胁迫下IAA和GA3含量下降,ZR含量大幅上升。随干旱程度的加剧,5个种源的ABA含量持续累积;绍兴种源的变化幅度较小,金华种源的变化幅度最大。5个种源的IAA/ABA、GA3/ABA和ZR/ABA整体上随胁迫程度加剧而下降,干旱对薄壳山核桃的生长和发育表现出明显的抑制作用。以各干旱处理下内源激素间的平衡比例为指标,对不同种源薄壳山核桃的抗旱性进行评价,绍兴种源表现最优,其次为贝克种源,抛尼种源较弱。

Taking two-year-old Carya illinoensis seedlings from Shaoxing,Jinhua,Baker,Caddo and Pawnee provenances as materials,content changes of endogenous hormones such as IAA,GA3,ZR and ABA in leaves were analyzed and resistance ability of seedlings was evaluated in drought stresses with different concentrations of PEG-6000.Results showed that contents of IAA,GA3 and ZR were different in different provenances.Contents of IAA and GA3 showed uptrend,and content of ZR increased first and decreased afterwards in Shaoxing provenance.Contents of IAA and ZR showed uptrend,and content of GA3 significantly decreased in severe drought in Jinhua provenance.Contents of IAA and GA3 showed downtrend and content of ZR increased first and decreased afterwards in Baker provenance which was inhibited continously.Content of IAA decreased gradually and content of GA3 significantly decreased in severe drought in Caddo provenance,in which content of ZR increased first and decreased afterwards.Contents of IAA and GA3 decreased,and content of ZR increased obviously in severe drought in Pawnee provenance.With deepening of drought stress,content of ABA accumulated continuously in all five provenances.Content of ABA had the smallest change in Shaoxing provenance and had the largest change in Jinhua provenance.As drought stress increasing,growth and development of seedlings were inhibited characterized by ratios of IAA/ABA,GA3/ABA and ZR/ABA which had reduction trend in five provenances.Taking balance ratios as indexes to evaluate drought resistance,results showed that Shaoxing provenance has the best drought resistance,followed by Baker.Pawnee has the weakest resistance.