钙对马尾松针叶生理生化特性及细胞超微结构的影响

Effects of Calcium Concentration on Physio-biochemical Characteristics and Ultrastructure of Pinus massoniana Needles

以1年生马尾松(Pinus massoniana)苗为试验材料,通过温室砂培试验,研究不同钙浓度(0、0.4、1、2、3mmol·L^(-1)Ca^(2+)和4mmol·L^(-1)Ca^(2+))对马尾松针叶生理生化特性和细胞超微结构的影响,阐明马尾松对钙的适应性机理,为马尾松人工林经营及管理提供理论参考。结果表明,随供钙浓度增加,马尾松苗生物量、针叶叶绿素、GA、ZR和IAA含量及叶绿素a/b值随钙浓度增加先增加后降低,在2mmol·L^(-1) Ca^(2+)条件下达到最高值;针叶相对电导率、ABA含量、ABA/GA、ABA/ZR、ABA/IAA和ABA/(GA+ZR+IAA)值随钙浓度增加先降低后增加,在2mmol·L^(-1)Ca^(2+)条件下达到最低值;2mmol·L^(-1) Ca^(2+)处理的针叶细胞中叶绿体和线粒体形态完整,淀粉粒含量较多,嗜锇颗粒和线粒体数量相对较少,未出现质壁分离,而在其余5个处理中,针叶细胞均出现不同程度质壁分离现象,细胞器结构和功能受损,其中0mmol·L^(-1) Ca^(2+)处理的细胞受损程度较重,并在部分叶绿体内出现空泡现象,而4mmol·L^(-1) Ca^(2+)的细胞受损程度次之。在不同供钙水平下,马尾松苗通过调节体内激素含量及比值,稳定细胞内正常生理生化代谢进程,改善针叶的光合状况,从而保护细胞膜、细胞器的结构和功能完整,以利于自身生长发育,且Ca^(2+)在2mmol·L^(-1)时对马尾松生长最有利。

To provide reference for Pinus massoniana plantation management,a greenhouse sand culture experiment was designed to observe physico-biochemical responses and cell ultrastructure of P. massoniana needles in different Ca2＋ concentrations （0,0.4,1,2,3 and 4 mmol · L-1） and to illuminate the adapting mechanisms of P. rnassoniana seedlings to different Ca2＋ concentrations. The results indicated that the seedling＇s biomass,needle＇s chlorophyll,GA,ZR and IAA contents and ratio of chlorophyll a/b increased and then decreased with the increase of Ca2＋ concentrations, and all their maximum values appeared in 2 mmol · L-1 Ca2＋ ,but the rule was varied inversely with the needle＇s relative conductivity rate,ABA content and ratio of ABA/GA,ABA/ZR,ABA/IAA and ABA/（GA＋ZR＋IAA）. For the mesophyll cell of P. mas soniana with 2 mmol · L-1Ca2＋ ,chloroplasts and mitochondria were all complete,its content of starch was higher,osmiophilic granule and mitochondrion all had lower contents and all cells had no caused plasmolysis. Nevertheless, mesophyll cells of other 5 treatments all appeared plasmolysis at different calcium tevels, and which finally caused cellular structure damage and function disorder. Mesophyll cells of P. massoniana under 0 mmol · L-1 Ca2＋ was most severely damaged, and appeared cavitations within chloroplasts. The next was P. massoniana with 4 mmol · L-1 Ca2＋ according to the degree of cellular structure damage. Thus, P. massoniana seedling treated with different Ca2＋ levels could regulate endohormone contents and their comparative ratios, physiological metabolism and photosynthesis, to protect the normal structure and function of cell membrane and organelles, effectively to promote seedling growth. The treatment of 2 mmol ·L-1Ca2＋ concentration was the best for P. massoniana seedlings.