COMPARATIVE ANALYSIS OF HEAT TREATMENTS ON MORPHOLOGY OF SELECTED CASSIA SPECIES.

Abstract

Plants are often subjected to unfavourable environmental conditions - abiotic stresses that play a major role in determining the productivity and distribution of the plant species across different types of environment. These stresses elicit complex cellular responses that help in understanding plant abiotic responses at the morphological, biochemical and molecular level. The present study was focused on two species (Cassia tora and C.auriculata) and their morphological response to the temperature. Germination percentage, leaf area index, fresh and dry weights of the leaf, root and shoot were studied in detail at different temperature treatments exposed for number of days.  High level of temperature treatments showed a significant effect on all the parameters. Results suggest that with an increase in temperature till 37ºC the physiological activities of both the species are increased with respect to control and gradually decreased at 42ºC. For percent germination there was a gradual decrease in germination from control to 42ºC in both the species. On the other hand, prolonged exposure of high temperature had a negative effect on few physiological parameters such as shoot length and root fresh weight. Others parameters such as shoot dry weight, root length, leaf dry and fresh weight, and LAI had a positive effect on temperature treatment up to 37ºC. Thus, it can be concluded that the optimum temperature at different levels of physiological activities for C. tora and C. auriculata is 37ºC.

Key words: Cassia tora, Cassia auriculata, Percent germination, Leaf area index