Salt stress induced changes in germination, sugars, starch and enzyme of carbohydrate metabolism in Abelmoschus esculentus (L.) Moench seeds

Abstract

During germination stage, the influence of NaCl on cumulative germination percentage, starch, total soluble sugar and phenol content in okra (Abelmoschus esculentus (L.) Moench, cultivar Marsaouia) seeds and growth seedlings components (cotyledons and embryonic axes) were studied. Seeds were sown in Petri dishes with varying concentrations of saline solutions (0, 20, 40, 60, 80 and 100 mM NaCl) at 25°C. Seed germination decreased significantly with the increase in NaCl concentration, optimal germination percentage occurred in non saline solution reaching 100%. With increasing stress, there was more accumulation of sugar and phenol, starch level decreased markedly especially in cotyledons along with lower amylase activity. Amounts of sodium increased but amounts of potassium did not change significantly with increasing stress.   Key words: Abelmoschus esculentus, germination, seeds, salinity, starch, total soluble sugars, phenols, amylase, ion uptake.