The Effects of Pregermination and Ageing on Germinability under Different Salt Concentrations of Soybean (Glycine max (L.) Merrill) Seeds

Abstract

Seeds of 2 soybean varieties namely SJ5 and CM60 were pregerminated by allowing the seeds to slowly absorb moisture vapour at high relative humidity and low temperature (3 degree C-100%RH and 25 degree C-100%RH, 24 hours) and were artificially aged at 42 degree C-100%RH for 2 and 3 days before being subjected to germination tests under different salt concentrations. The results revealed that pregerminated seeds by both temperatures showed a higher germination percentage under salt stress than untreated seeds when tested in the between paper method but in the sand emergence test this effect was not found. In the latter test, the improper moisture status affected by the low relative himidity (50-55%) of the surrounding atmosphere may result in a loss of effectiveness of pregermination. Aged seeds at 3 days were found to be low in germination even though in non-saline media but 2-day aged seeds were not significantly different from unaged seeds. Increasing NaCl concentrations reduced seed germinability and between the two varieties studied, CM60 tended to be more susceptible to salinity than SJ15. It can be concluded that pregermination improved the ability of soybean seeds to germinate under salinity stress when the moisture status of the media during seed germination was suitable.