Effect of nutri-priming on germination indices and physiological characteristics of stevia seedling under salinity stress

Efeito do amortecimento de nutrientes nos índices de germinação e nas características fisiológicas da plântula de stevia sob o estresse de salinidade

Abstract:

Poor germination and low seedling growth of stevia (Stevia rebuadiana Bertoni) are common problems in the cultivation of the plant. On the other hand, salinity is one of the abiotic environmental stresses that reduce the performance of the product. The objective in this study was to assess the effect of nutri-priming with selenium (Se), iron (Fe) and boron (B) on stevia seed germination indices and physiological characteristics in sodium chloride (NaCl) salinity condition (0, 30, 60 and 90 mM). Results indicated that the effect of salinity in nutri-priming were significant on germination percentage, germination rate, germination uniformity, germination value, seedling length, seedling vigor index, total chlorophyll, free proline content and enzymatic activity of catalase (CAT) and superoxide dismutase (SOD). Salinity stress decreased the percentage and rate of germination and seed vigor, however, nutri-priming reduces the adverse effects of salinity stress. Salinity also reduced the amount of chlorophyll content, in spite of all that this decrease was very low in terms of nutri-priming with Se, Se+Fe and Se+Fe+B in high salinity level (90 mM). Salinity stress increased proline content and antioxidant enzyme activities of CAT and SOD, that nutri-priming especially with the Se more increased. The finding of this study leads to the conclusion that nutri-priming with nutrients, especially Se and Fe increased the antioxidant capacity of the plant to improve germination and seedling growth of stevia under salinity stress.

Index terms:
antioxidant activity; chlorophyll; germination rate; germination uniformity; seed vigor