Water-deficit tolerance induction during germination of Jalo Precoce bean (Phaseolus vulgaris L.) cultivar

Abstract

Bean (Phaseolus vulgaris L.) cultivars are susceptible to water stress, especially during germination. Salicylic acid and thermal shock improve tolerance level in this plant to different kinds of stresses. However, in the present work, effects of cold shock and salicylic acid alone or combined on germinating beans under imposed water deficit were evaluated. Bean seeds from the Jalo Precoce cultivar were imbibed either in water or in salicylic acid for 24 h. After treatment, lots were divided and exposed to cold shock (7 °C) for another 24 h. The seeds were then placed on paper rolls imbibed with different concentrations of mannitol to impose a water deficit on them. They were evaluated for germination; seedling vigour; dry and total weights and length of shoot root; superoxide dismutase activity and proline content. Proline accumulates as a response to water-deficit stress, and SA alone or combined with cold shock improves this response. The use of SA increases many of the physiological variables than cold shock and decreases the antioxidant activity of SOD.