NaCl与Na_2CO_3对高羊茅种子萌发及幼苗生长胁迫效应比较

Comparison of Stress Effects of NaCl and Na_2CO_3 on Seed Germination and Seedling Growth of Festuca arundinacea Schreb

分别用NaCl(50、100、200、300 mmol/L)和Na2CO3(5、10、15、25 mmol/L)对高羊茅(Festuca arundinacea Schreb)种子和幼苗进行胁迫处理,测定高羊茅种子发芽势、发芽率、幼苗根长、苗高、鲜重、叶绿素含量、根系脱氢酶活性、质膜透性和丙二醛含量等指标。结果表明:与对照相比,随着NaCl浓度的增加,高羊茅的发芽势、发芽率、幼苗根长呈下降趋势,叶质膜透性和根丙二醛含量呈上升趋势,苗高、鲜重、叶绿素含量和根系脱氢酶活性呈先上升后下降趋势,根质膜透性和叶丙二醛含量则呈先略下降后上升趋势;随着Na2CO3浓度的增加,其种子发芽势、发芽率、幼苗根长、苗高、鲜重、叶绿素含量均呈下降趋势,根和叶质膜透性和丙二醛含量均呈上升趋势,根系脱氢酶活性则呈先上升后下降趋势。综合分析表明,高羊茅对NaCl和Na2CO3的耐受浓度阈值分别为246.9 mmol/L和20.4 mmol/L,因此,高羊茅的耐盐性强于其耐碱性。

The seeds and seedlings of Festuca arundinacea Schreb were treated with NaC1 （50, 100, 200, 300 mmol/L）and Na2CO3（5, 10, 15, 25 mmol/L）respectively, and the gernmination potential, gernmination rate, root length, seedling height, fresh weight, chlorophyll content, root activity, membrane permeability and MDA content were determined. The results showed： compared with the control, with the NaCI concentration increased, the germination potential, germination rate, root length of E arundinacea decreased, leaf membrane permeability and root MDA contents increased, seedling height, fresh weight, chlorophyll content, root activity initially increased and then decreased; and root membrane permea^i｜ity and leaf MDA content was iniiially slightly decreased and then increased. With NazCO3 concentration increased, the seed germination potential, gez^nination rate, root length, seedling height, fresh weight, chlorophyll content decreased, while membrane permeability and MDA content of root and leaf showed an upward trend, and root activity was initially increased and then decreased. Comprehensive analysis indicated that the threshold concentration of F. arundinacea tolerance to NaC1 and Na2CO3 were 246.9, 20.4 mmol/L respectively, therefore, the salt tolerance of F. arundinacea was stronger than that alkaline.