Sorghum: Origin, Classification, Biology and Improvement

Abstract

Sorghum is a staple food crop for millions of poor people in the semi-arid tropics of Africa and Asia. It is one of the important dryland crops grown in marginal soils and a source of feed, fodder and biofuel apart from food. It is a short-day C₄ plant, and its easy adaptability to hot and dry agroecologies makes it a climate change-compliant crop. There are five basic races and ten intermediate races under cultivated taxa based on fundamental spikelet types. Sorghum is considered as an often cross-pollinated species, with outcrossing up to 6 % depending on the genotype and growing conditions. Extensive efforts in crop improvement have resulted in the development of a number of high-yielding cultivars with substantial yield increment over the years. The discovery and utilisation of the male sterility system have led to the successful commercial exploitation of heterosis. A number of biotic and abiotic yield-limiting factors, and changes in consumption pattern and demand have resulted in a steady decline in cultivated area over the years. Much progress has been achieved in the field of sorghum biotechnology, including genomics over the last two decades. Adoption of genomic tools and molecular breeding strategies can help in tailoring sorghum cultivars with desired traits to enhance the productivity under various limiting factors in the years to come.