旱-盐复合胁迫对降香黄檀幼苗生长和生理生化特性的影响

Effects of Combined Drought and Salt Stress on Growth, Physio-chemical Characteristics of Dalbergia odorifera Seedlings

摘要:

为探究干旱-盐复合胁迫对陆生木本植物生长发育及生理生化特性的影响，通过盆栽试验在旱-盐复合胁迫(SD, 25%~30%田间持水量+150 mmol/L NaCl)下对3种种植密度[每盆种植1株(DI)、2株(DII)、3株(DIII)]的降香黄檀(Dalbergia odorifera)幼苗的生长、光合色素含量和生理生化指标进行了研究。结果表明，DI密度下SD处理显著抑制了株高增长量、基径增长量、总叶面积、主根长、总叶绿素含量和相对含水量，但过氧化氢酶和谷胱甘肽还原酶(GR)活性、可溶性蛋白和可溶性糖含量提高。与DI密度相比，DIII密度进一步降低了GR活性和还原性谷胱甘肽含量，导致幼苗生长受到抑制。因此，在旱-盐复合胁迫的环境下，种植密度会对降香黄檀的生长产生影响，在海岸带栽植降香黄檀幼苗的过程中，应考虑低密度栽植模式进行栽培。

关键词:干旱胁迫;盐胁迫;种植密度;生长性状

Abstract:

In order to explore the effects of drought-salt combined stress on the growth, physio-chemical characteristics of terrestrial woody plants, pot experiments were conducted in drought-salt combined stress (SD), the growth, photosynthetic pigment content and physiological and biochemical indexes of Dalbergia odorifera seedlings with three planting densities [1 plant (DI), 2 plants (DII) and 3 plants (DIII) per pot, respectively] were studied under 25%-30% field water capacity + 150 mmol/L NaCl. The results showed that SD treatment significantly inhibited the growth of plant height, basal diameter, total leaf area, taproot length, total chlorophyll content and relative water content at DI density, but increased the activities of catalase and glutathione reductase (GR), soluble protein and soluble sugar content. Compared with DI density, DIII density further reduced GR activity and reduced glutathione content, resulting in inhibition of seedling growth. Therefore, under the combined drought and salt stress environment, planting density would affect the growth of D. odorifera, and low density planting mode should be considered in the coastal zone.

Key words:Drought stress;Salt stress;Planting density;Growth trait