BIOCHEMICAL RESPONSE OF Allium sativum L. GROWN IN SELENIUM-ENRICHED HYDROPONIC CULTURE

Selenium (Se) enriched Allium sativum (Garlic) could be an excellent source of dietary Se in combat against cancer chemoprevention and various other nutritional deficiencies. Soil modification is one way to attain enrichment in consumable parts of the plant but it can never reject the possibilities of such soil polluting the environment. Hence, hydroponics offers a closed system that allows better control over Se availability to the plants without imposing any deleterious consequences on the environment.

We examined the effect of sulfur deficient and selenium-rich medium on growth, biochemical parameters in garlic seedlings when grown in hydroponic cultivation. Garlic cloves were grown in the nutrient solution without Se for the first 2 weeks, and further with varying concentrations of Se (0-10 mgL-1 as sodium selenate (Na2SeO4)) for 2 weeks in different groups. The overall experiment expressed a few changes in growth parameters such as dry matter and moisture content and chlorophyll content among the groups. The content of total protein and total phenols, however, showed a significant rise at 4 and 6 mgL-1 but later decreased at higher concentrations. Proline showed an upward trend up to the final treatment group. The enzymes superoxide dismutase (SOD) and glutathione reductase (GR) activities increased with increasing selenium concentrations but catalase (CAT) expressed a regression in the higher treatment groups. These results indicated that Se had a positive physiological effect on some growth parameters and antioxidant defense systems of garlic which is in accordance with previous reports. But importantly it is reflected that however garlic could tolerate high concentrations of Se in growth medium but best overall growth and development is evidenced at Se concentrations of 4-6 mgL-1.