NEW ZEALAND JOURNAL OF CROP AND HORTICULTURAL SCIENCE, cilt.33, sa.2, ss.193-197, 2005 (SCI-Expanded)
The controlled deterioration (CD) test (45 degrees C and 24% moisture content) was used to assess the seed vigour of three winter squash (Cucurbita maxima) seed lots. Germination after CD was correlated with seedling growth parameters under salt stress conditions (50, 100, and 150 mM NaCl) in an unheated glasshouse emergence test. Germinations after CD for 24,48, and 72 h were all 94% or greater, and these treatments were not successful in ranking the lots. However, germination of squash seeds after CD for 96 h ranged from 25% to 75% for the three lots. Seedling emergence was > 90% at both 50 and 100 mM NaCl and did not differ among lots. However, at 150 mM NaCl, emergence did differ among the lots, and the CD 96-h germinations were positively and significantly related to mean seedling emergence time, seedling fresh and dry weight, hypocotyl length, and cotyledon width. The CD test can be used to predict seedling performance of winter squash seed lots under salt stress. However, the method should be further verified by using a larger number of seed lots.