Drought treatment on in vitro cultures of Cryptocoryne elliptica

Abstract

Osmotic stress is the main problems in aquatic plant as this stress decreasing water content, inhibiting the rate of photosynthesis, decreasing the rate of respiration, decreasing the protein synthesis or increasing protein hydrolysis and also increasing the accumulation of sugars. In this study, the responses of Cryptocoryne elliptica to drought stress were investigated in vitro. The plantlets were cultured in Gamborg B5 media added with osmotic stress agent, mannitol at different concentrations (0, 20 and 40 mM). The changes in plant growth, total chlorophyll, soluble protein and reducing sugar content were measured at every 5 day intervals for 30 days. The drought stress restricted significantly the growth and development of C. elliptica cultures. The biomass of control plants increased progressively during the 30 days treatment, in contrast to that both mannitol-stressed plants which decreased. The drought stress decreased significantly the total chlorophyll and soluble protein content after 10 days of treatment. At the final harvest, total chlorophyll and soluble protein content was higher in control plants than stressed plants. Drought treatments cause the accumulation of reducing sugar. The high reducing sugar content was observed in plants treated with 40 mM mannitol. The effect of drought stress on plants increasing as the mannitol concentration increased. Drought stress affects the physiology and biochemical activity of C. elliptica cultures.