Variation in Salt Tolerance within a Batch of Acacia salicina Seeds

다국어 초록 (Multilingual Abstract)

Seeds of Acacia salicina Lindl., germinated in the presence of 2000 mol m^-3 NaCl (tolerant), seeds that failed to germinate in NaCl but germinated after washing in distilled water (sensitive), and seeds germinated in distilled water (unselected) were transplanted to a greenhouse. After 1 week, they were treated with 0, 100 or 200 mol m^-3 NaCl in half-strength Hoagland's solution for 5 weeks. Plants from tolerant seeds grew larger without, but not with, salt stress, and suffered lower mortality in NaCl. In order to select for salt tolerance at the seedling stage, 6 week-old plants were treated with NaCl solutions increasing to 200 mol m^-3 over 3 weeks, and then divided into tall (tolerant) and short (sensitive) plants. These were treated with NaCl in the greenhouse as above. Selection of plants on the basis of their height under stress provided plants with greater survival and less reduction in growth when subsequently exposed to NaCl stress. However, it is unclear whether the procedures employed selected for physiological salt tolerance or merely for general plant vigour.