Drought Stress Tolerant Horse Gram for Sustainable Agriculture

Abstract

Sustainable development is successful development that can be maintained. In agriculture sustainable development is seen as the new paradigm of economic development. Around three billion people living in rural areas are dependent on agriculture as their main source of income. It is not easy to sustain agricultural development given the various kinds of ever changing environmental challenges like metal toxicity, drought, cold, and salinity stresses that crops have to face. Drought stress is one of the most devastating environmental stress severely affecting crop growth, development and yield. To withstand drought stress and sustain the agricultural productivity we need to identify and maintain the natural crop resources. Horse gram (Macrotyloma uniflorum) is a highly drought tolerant yet underexploited tropical legume, commonly known as ‘kulthi’. The U.S. National Academy of Sciences in 1978 identified horse gram as potential food source for the future. Insurmountable drought tolerance and pest resistance together make it agriculturally an attractive crop. Besides normal cultivation in vitro regeneration of horse gram is an asset. Its high iron, low lipid, low sodium content and slow digestible starch make it a preferred choice for diabetic and obesity patients. Dark coloured seeds of horse gram in form of sprouts usually have higher antioxidant capacity as proven by various in vitro antioxidant assays. Seed extracts from horse gram contain isoflavones and glucopyranosides which show in vitro antilithic activity leading to reduced stone formation. When different processing techniques are used in combination they act synergistically reducing most of the antinutritional factors like polyphenols, lectins protease inhibitors in horse gram. However, some of the antinutrients have also been projected as health-promoting factors having anticancerous and antioxidant properties. Here we review the major points about horse gram: (1) morphology and physiology, (2) cultivation (3) composition, (4) medical implications, (5) antinutritional factors and their processing. To enhance horse gram’s utilization potential future research areas are highlighted. Also, an effort has been made to compile updated research activities conducted on horse gram from 1968 to 2013.