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INTRODUCTION Cluster bean (Cyamopsis tetragonoloba (L.) Taub.), commonly known as guar, belonging to the family Leguminosae is an indigenous, annual and self-pollinated legume crop grown for feed, green fodder, vegetable, green manuring and gum extraction from seed. Being drought hardy, it is grown mainly under rainfed conditions in India since ancient times. It is primarily grown for its tender green pods in arid and semi arid regions of our country and is a good source of carbohydrates, protein, fiber and minerals like calcium, phosphorous, iron and contains appreciable amount of vitamin C 2. Cluster bean has medicinal value for curing various diseases. The leaves of guar are used to cure night blindness, seeds as chemo-therapeutic agent against small pox and also used as laxative.

A rice variety Jyothi (PTB 39) is a red kernelled with bold grain, popular in the region of Kerala, India used in the study. Plants were grown in pots under three different conditions, natural solar UV-B conditions, UV-B excluded condition using UV-B filters and supplemental UV-B using UV-B lamps along with ambient solar radiation. During the study period, UV-B radiation was in the range of 1.30 to 3.58 Wm2 which affected the productivity of the crop under open solar condition. A decrease in morphological traits like plant height, number of tillers, flag leaf angle and increase in leaf thickness were observed. Physiological parameters, leaf gas exchange parameters and biochemical constituents such as chlorophyll content also recorded less value under high UV-B condition along with the high content of protective compounds such as flavonoid content, catalase and PAL activity. The phenophases of the crop were also delayed by 4-5 days under UV-B radiation exposed conditions. All these negative impacts of UV-B radiation on crop leads to restricted filling of grain, lesser harvest index and grain development leading to a decrease in yield and yield attributing characters.

Western Ghats of India is the centre for biological diversity many plant species including Garcinia indica. Biologically important compound (-) -Hydroxycitric acid (HCA) is a popular anti-obesity compound extracted from the fruits of Garcinia indica. The present study was conducted to understand the extent of variation for the content of -(-)HCA in the fruits of Garcinia indica ecotypes prevailing in Western Ghats of Karnataka. The autoclave assisted extraction and the spectrophotometric analysis of 120 ecotypes of G. indica revealed significant variation in HCA content in the fruits. The average per cent HCA content on dry weight basis in fruits of G. indica was 17.90. The average mean HCA content of G. indica ecotypes in Uttara Kannada region (regarded as Uttara Kannada population) was highest (20.60%). compared to other ecotypes. The results indicated that there is a good genetic plasticity for HCA content among the ecotypes of G. indica prevailing in Western Ghats of Karnataka and there exists ample opportunity to exercise selection for the genotypes with higher -(-)HCA content.