Effects of Salt Stress on Seed Germination of Four Ornamental Non- Halophyte Species

摘要

The seeds of Pinus taeda, P. elliottii, Lagerstroemia indica and Fraxinus chinensis were germinated at various salinity regimes (0, 50, 100, 150 and 200 mM NaCl). The results indicate that germinated seeds of four investigated tree species were inhibited at different saline levels. Germination speed and seed vigour, which were indicated by germination index and vigour index, decreased with increase in salt stress, whereas different descending patterns were observed among all the seeds. The salt-resistant capacity of seeds in four tree species was arranged in numerical order by their relative germination percentage and vigour index; however, they could not be clearly identified from each other when NaCl levels were 50 and 200 mM. At 100 mM NaCl, salt-tolerance was ranked from highest to lowest as follows: P. elliottii, F. chinensis, P. taeda and L. indica. However, P. elliottii ranked lower than F. chinensis at 150 mM NaCl, indicating that F. chinensis exhibited better adaptation to salt stress than P. elliottii.