Abstract

The productivity of Phaseolus bean and other crops is affected by various abiotic factors, of which drought, high and low temperatures and salinity are very important. The paper makes a revision of physiological and biochemical mechanisms of resistance to these stress factors. Sufficient studies have been undertaken to investigate its effects on the physiology and production of the crop and establishing parameters for the selection of cultivars tolerant to drought, high and low temperature and salinity and finally its mechanism of resistance. For example, in case of salinity, the resistant varieties should have capacity to compensate the ionic and osmotic disbalance caused by salinity and other stress factors. The physiological parameters used as parameters of sensitivity or resistance are indices of germination, growth rate, leaf area, dry weight and index of assimilation of carbon. The response of biochemical adaptation to these salinity and other stress factors in Phaseolus vulgaris as observed in other organisms has been studied for genetic improvement of commercial varieties. Analysis has been made on the mechanism of osmoprotection which is related to the flow of water and nutrients and at the same time the process of signal transduction through hormones or other routes of transduction.