摘要
滨海盐碱地高盐低磷的现状严重威胁重要海防林建群树种木麻黄(Casuarina equisetifolia)人工林林下幼树的生长.为揭示磷影响木麻黄耐盐性机制,以一年生木麻黄幼苗为研究对象,设置0‰(CK)、2‰(T1)、4‰(T2)、6‰(T3)、8‰(T4)Na Cl 5个盐分梯度处理和6个盐磷处理组[T2P1、T2P2、T3P1、T3P2、T4P1、T4P2,P1、P2分别为0.5g/kg、1.5 g/kg Ca(H_(2)PO_(4))_(2)],检测盐胁迫和盐磷交互作用下木麻黄幼苗生长、生物量、光合作用和小枝矿质元素含量.结果表明:(1)木麻黄幼苗的各生长指标随盐浓度增加而降低,盐胁迫对木麻黄不同器官生物量的抑制强度表现为小枝>茎>根.施磷对小枝生物量及比例提升效果最好,施1.5 g/kg Ca(H_(2)PO_(4))_(2)显著提高不同盐胁迫下木麻黄幼苗地上部分生物量.(2)木麻黄的P_(n)、G_(s)、C_(i)、T_(r)、F_(m)、F_(v)/F_(m)随盐浓度增加整体上呈下降趋势;不同施磷量对上述指标的影响存在差异,整体上在T2P2、T3P1、T4P1处理下增加幅度最大.2‰-6‰Na Cl下木麻黄叶绿素a、叶绿素b和叶绿素总量小幅度提高,而高盐胁迫下显著降低;4‰-6‰Na Cl下施磷导致木麻黄叶绿素含量减少,高盐施磷显著增加.(3)沙土中盐浓度提高使木麻黄小枝中Na含量显著增加,并对P、K、Fe、Mn、Al含量有不同程度影响;施磷提高木麻黄小枝中P、Fe、Mn含量,高盐施磷有效减少木麻黄小枝的Na含量.因此,施磷能减少中高盐胁迫下木麻黄小枝中Na含量,提高光合能力和养分吸收,增强木麻黄耐盐性,进而促进盐胁迫下木麻黄幼苗的生长发育.施磷量应根据受盐害程度进行调整,整体上需随盐胁迫程度提高适当减少.本研究揭示了木麻黄幼苗对不同盐胁迫和盐胁迫下施磷的响应机制,可为提高我国木麻黄海防林育林效率提供参考.(图5表3参55)
The current situation of high salt and low phosphorus levels in coastal saline–alkali lands seriously threatens the growth of seedlings of Casuarina equisetifolia,an important coastal defense forest species.To understand the mechanism by which phosphorus influences salt tolerance in C.equisetifolia,five salt gradient treatments were established for 1-year-old C.equisetifolia seedlings:0‰(CK),2‰(T1),4‰(T2),6‰(T3),and 8‰(T4) Na Cl.Additionally,six treatment groups involving salt and phosphorus (T2P1,T2P2,T3P1,T3P2,T4P1,and T4P2) were used,where P1 and P2 represent Ca(H_(2)PO_(4))_(2) at concentrations of 0.5 and 1.5 g/kg,respectively.Detection of salt stress and the interaction between salt and phosphorus on the growth,biomass,photosynthesis,and twig nutrient content of C.equisetifolia seedlings was carried out.The results showed that:(1) The growth indices of C.equisetifolia seedlings decreased with increasing salt concentration,and the inhibitory intensity of salt stress on the biomass of different organs was as follows:twigs>stems>roots.Phosphorus application had the greatest effect on the biomass and proportion of twigs,and the application of1.5 g/kg Ca(H_(2)PO_(4))_(2) significantly increased the aboveground biomass of the seedlings under different levels of salt stress.(2) P_(n),G_(s),C_(i),T_(r),F_(m),F_(v)/F_(m) of C.equisetifolia seedlings showed an overall decreasing trend with increasing salt concentration.The effects of different phosphorus applications on the above indices varied,and the overall increase was the greatest under treatments T2P2,T3P1,and T4P1.The chlorophyll a,chlorophyll b,and total chlorophyll of C.equisetifolia increased slightly under 2‰–6‰Na Cl but decreased significantly under high salt stress.Phosphorus application with 4‰–6‰Na Cl resulted in a decrease in chlorophyll content and a significant increase in phosphorus application with a high salt content.(3) Low salt concentrations in sandy soil significantly increased the content of Na in C.equisetifolia twigs,as well as the contents of P,K,Fe,Mn,and Al.Additionally,P application increased the contents of P,Fe,and Mn in C.equisetifolia branchlets.Conversely,high-salt P application effectively reduced Na content in C.equisetifolia branchlets.Therefore,phosphorus application can reduce the Na content in C.equisetifolia twigs under medium and high salt stress,improve photosynthetic capacity and nutrient absorption,enhance salt tolerance of C.equisetifolia,and promote the growth and development of C.equisetifolia seedlings under salt stress.The amount of phosphorus applied should be adjusted according to the degree of salt damage and should be reduced appropriately with an increase in salt stress.The present study revealed the response mechanisms of C.equisetifolia seedlings to different levels of salt stress and phosphorus application.The findings of this study can serve as a reference for enhancing the efficiency of C.equisetifolia in sea defense forests in China.
作者
范德志
陈灿
林晗
袁锋
谢安强
肖祥希
陈煜
徐云鹏
吴承祯
FAN Dezhi;CHEN Can;LIN Han;YUAN Feng;XIE Anqiang;XIAO Xiangxi;CHEN Yu;XU Yunpeng;WU Chengzhen(College of Forestry,Fujian Agriculture and Forestry University,Fuzhou 350002,China;College of JunCao Science and Ecology,Fujian Agriculture and Forestry University,Fuzhou 350002,China;Fujian Southern Forest Resources and Environmental Engineering Technology Research Center,Fujian Agriculture and Forestry University,Fuzhou 350002,China;College of Life Sciences,Fujian Agriculture and Forestry University,Fuzhou 350002,China;Fujian Academy of Forestry,Fuzhou 350012,China;Diantou State-Owned Protective Forest Farm of Jinjiang,Quanzhou 362200,China;Wuyi University,Nanping 354300,China)
出处
《应用与环境生物学报》
北大核心
2025年第1期96-108,共13页
Chinese Journal of Applied and Environmental Biology
基金
福建省科技特派项目(KTP21113A)
福建省林业科技项目(2021FKJ22)
福建农林大学优秀研究生学位论文基金(1122YS01010)资助。
关键词
木麻黄
盐胁迫
磷添加
生物量
光合能力
营养元素
Casuarina equisetifolia
salt stress
phosphorus addition
biomass
photosynthetic capacity
nutrient element
