钙浓度对马尾松幼苗生长和生理特征的影响

摘要

Objective]To select the optimal Ca2 + concentration for Pinus massoniana seedling growth and to provide evidence for plantation cultivation and rational application of calcium fertilization by studying the effects of Ca2 +con-centration on growth and physiological characteristics of P.massoniana seedlings.[Method]A greenhouse sand culture experiment was carried out to study the growth and physiological characteristics of half-year-old seedlings of P.massoniana in different Ca2 + concentrations (0.0,0.4,1.0,2.0,3.0 mmol·L -1 and 4.0 mmol·L -1 (CK)).[Result]The results showed that both the height and stem increments of P.massoniana under 1.0—2.0 mmol·L -1 Ca2 + for five months were higher,and seedlings grew best in 2.0 mmol·L -1 Ca2 +.The adaptable strong-to-weak sequence of P.massoniana seedlings was 2.0,1.0,0.4,3.0,0.0 mmol·L -1 and 4.0 mmol· L -1 (CK)of Ca2 +.At different growth periods,these indices of pine needles,including O2 -generation rate,H2 O2 content,protective enzyme activities (SOD,POD,CAT and APX),the contents of GSH,AsA and proline,de-creased at first and then increased subsequently along with the increasing Ca2 + concentration,and all minimums oc-curred at 1.0 mmol·L -1 or 2.0 mmol·L -1 of Ca2 +.[Conclusion]P.massoniana seedlings is suitable to grow in the soil with Ca2 + concentration of 1.0—2.0 mmol·L -1 according to the experiment results.Based on comprehen-sive analysis to soil available calcium of P.massoniana forestland,the growth and physiological characteristics of seedlings,it is necessary to applying rationally calcium fertilization so as to boost the productivity of P.massoniana.%[目的]在不同供 Ca2＋水平下对马尾松幼苗生长及生理特性进行研究，以确定适宜马尾松生长的钙浓度，为马尾松人工林培育及合理施用钙肥提供参考。[方法]以半年生马尾松幼苗为试材，采用温室内砂培，研究不同供Ca2＋水平（0．0、0．4、1．0、2．0、3．0、4．0 mmol·L －1（CK））对马尾松生长及生理指标的影响。[结果]不同供 Ca2＋水平处理5个月后，在 Ca2＋水平为1．0、2．0 mmol·L －1时，马尾松幼苗的株高增量和地径增量较高，其中，2．0 mmol· L －1 Ca2＋水平的株高增量和地径增量最高。马尾松幼苗对 Ca2＋水平适应能力强弱顺序为2．0＞1．0＞0．4＞3．0＞0．0＞4．0 mmol·L －1（CK）。在不同生长期内，随着供 Ca2＋水平的增加，马尾松针叶中 ROS（O2－产生速率、H2 O2浓度）、MDA 含量、抗氧化酶（SOD、POD、CAT 和 APX）活性、抗氧化物质（GSH、AsA）含量、脯氨酸含量均先降低后增加，最小值均在1．0 mmol·L －1或2．0 mmol·L －1处理中；类胡萝卜素含量先增加后降低，其最高值均在2．0 mmol· L －1处理中。马尾松幼苗的株高增量和地径增量与类胡萝卜素含量关系不明显，而与其他生理指标均呈显著负相关。[结论]马尾松幼苗适宜在1．02．0 mmol·L －1 Ca2＋水平的环境中生长。在马尾松林地中，应对土壤有效钙含量进行测定，并结合植株的生长和生理特征进行综合评价后，科学合理施肥以提高生产力。