SHORT TERM EXPOSURE OF UV-B RADIATION ENHANCES SALINITY TOLERANCE IN VIGNA RADIATA

Electromagnetic radiation (7%) emitted from the sun is in the UV range (200–400) nm. Several morphological and anatomical changes have been reported from plants grown under long-term UV-B regimes. The effect of UV-B radiation (280-320nm) and salinity alone and in combination were studied. Fifteen days old seedlings of Vigna radiata were exposed to UV-B radiation for 10, 20 and 30 minutes and salinity treatment was given to the plants 3 days before the UV-B treatment. UV radiation was artificially provided by Esco Airstream Vertical Laminar Flow Cabinet (AVC-4AI). Significant decrease (p<0.05) in root and shoot length, specific leaf area, chlorophyll and carotenoid content of in all UV-B and salinity treatments was observed as compared to control. The reduction was more pronounced in salinity treatment as compared to UV-B alone and combination of UV-B with salinity. It is concluded that the short term exposure of UV-B radiation enhances the salinity tolerance in Vigna radiata.