The Evaluation of Salt Tolerance during Germination and Vegetative Growth of Asparagus, Table Beet and Sea Aster

Abstract

The value of sea aster, a wild halophyte species, as an agricultural genetic resource was demonstrated by comparing the effects of salt stess on seed germination and vegetative growth with two salt-tolerant vegetables, asparagus and table beet. Germination percentages of asparagus and table beet were about 90% in control, but, decreased respectively to 50% and 61% in 50 mM NaCl, and to 12% and 21% in 100 mM NaCl. In sea aster, seed germination was suppressed with increasing NaCl concentration to more than 50% of the control in 150 mM NaCl, indicating that the seeds are salt-tolerant at the germination stage. Asparagus and table beet seedlings were withered and killed by sudden exposure to 50 and 100 mM NaCl. In asparagus and table beet plants salt-stressed gradually and sea aster suddenly exposed to the final concentrations of NaCl in hydroponics, plant height was not significantly inhibited, but root length in salt-stressed plants elongated significantly compared with the controls in all three species. In asparagus and table beet, dry matter gain of roots seemed to be inhibited at 100 mM NaCl, whereas that of the sea aster at 150 mM NaCl was equal to the control; at 300 mM NaCl, dry weight gain was inhibited.