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

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