【摘要】 探讨不同育苗基质下桢楠(Phoebe zhennan)苗木对周期性干旱胁迫的适应能力及生存对策,为筛选抗旱育苗基质提供参考。以耕作土、森林腐殖土、泥炭土、蛭石为原料,按体积比配制成5种育苗基质,T1:耕作土=10(传统桢楠育苗)、T2:森林腐殖土=10、T3:耕作土∶森林腐殖土∶泥炭土∶蛭石=4∶3∶2∶1、T4:耕作土∶森林腐殖土∶泥炭土∶蛭石=3∶2∶4∶1、T5:耕作土∶森林腐殖土∶泥炭土∶蛭石=2∶1∶6∶1,采用随机区组设置干旱胁迫梯度,分析不同胁迫水平对桢楠幼苗生长的影响。结果表明:(1)配比基质的理化性质与苗木生长密切相关,正常浇水时,基质处理苗生长质量均优于传统育苗,但重度胁迫下,仅T3、T4处理苗木生长较好;(2)随着干旱胁迫程度的增加,各基质配比桢楠苗木株高、基径、叶面积、叶面积指数、地上生物量、地下生物量等生长指标均受到抑制,但受影响程度存在差异;(3)各基质处理苗木质量隶属函数值T3>T4=T1>T2>T5,T3基质配比最优,所育苗木生长优良,耐旱抗旱性强,显著提高造林成效。表明适宜的基质配比能够协调植物生长所需的水、肥、气、热,有利于植物在逆境中生存。更多还原

【Abstract】 Adaptability and survival strategy of Phoebe zhennan in different substrates under periodic drought stress were studied to provide a reference for substrate selection of seedling cultivation to combat drought stress.According to the volume ratio,the seedlings of P.zhennan were cultured on five different substrates:T1:cultivated soil = 10,T2:forest humus = 10,T3:cultivated soil∶ forest humus∶ peat soil∶ pearlite = 4 ∶3 ∶2 ∶1,T4:cultivated soil∶ forest humus∶ peat soil∶ pearlite = 3 ∶ 2 ∶ 4 ∶ 1,T5:cultivated soil ∶ forest humus∶ peat soil ∶ pearlite =2∶1∶6∶1.The drought stress gradients were designed randomly to study the effects of drought stress on the growth of P.zhennan seedling.The results were:(1) The physical and chemical properties of different substrates composition were closely related to the seedling growth and the seedling exhibited better growth performance inthe substrates than traditional seedlings,but only T3 and T4 had better growth under heavy stress.(2) Along with the increase of the drought stress,the seedling height,basal diameter,leaf area,leaf area index,above ground biomass and underground biomass were aggravated,but the degree of influence was different.(3) The membership function value of the seedling quality was T3 > T4 = T1 > T2 > T5,and T3 had the best quality and a strong tolerance of seedling to adapt to drought stress,improving the effectiveness of afforestation significantly.The suitable ratio of light substrates could coordinate the water,fertilizer,gas and heat,being propitious to the growth of the seedling in adversity.更多还原