铅胁迫对澳洲坚果幼苗生长及生理特性的影响

Effects of Plumbum Stress on Growth and Physiological Characteristics of Macadamia integrifolia Seedlings

为探究澳洲坚果(Macadamia integrifolia)对土壤铅胁迫的耐受性,以3年生澳洲坚果实生苗为材料,研究不同浓度铅处理下(0、200、400、800、1 200、1 600和2 000 mg/kg)澳洲坚果幼苗生长及生理特性的变化。结果表明,除地径增量和可溶性糖含量外,铅浓度对澳洲坚果幼苗生长及生理特性均影响极显著。随铅浓度升高,幼苗株高和地径增量、叶绿素含量、可溶性蛋白和游离脯氨酸含量及SOD和POD活性均呈先升后降的趋势;可溶性糖含量呈先降后升的趋势;MDA含量逐渐上升。澳洲坚果幼苗对1 200 mg/kg以下的铅胁迫有一定抗性;1 200 mg/kg以上会对其造成毒害,抑制其生长。

In order to explore tolerance of Macadamia integrifolia to plumbum stress, taking 3-year-old M. integrifolia seedlings as materials, changes of growth and physiological characteristics of M. integrifolia seedlings in treatments with different plumbum concentrations(0, 200, 400, 800, 1 200, 1 600 and 2 000 mg/kg) were studied.Results showed that plumbum concentration had extremely significant effects on growth and physiological characteristics of M. integrifolia seedlings except for ground diameter increment and soluble sugar content. With increase of plumbum concentration, increments of plant height and ground diameter, chlorophyll contents, contents of soluble protein and free proline, and activities of SOD and POD increased firstly and then decreased. Soluble sugar content decreased firstly and then increased with increase of plumbum concentration. MDA content increased gradually with increase of plumbum concentration. M. integrifolia seedlings had certain resistance to plumbum concentration under1 200 mg/kg. Plumbum concentration above 1 200 mg/kg could cause toxicity and inhibit growth.