Sorghum: Origin, Classification, Biology and Improvement

Abstract

Sorghum is a staple food crop for millions of poor people in the semiarid 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 cli- mate 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 grow- ing conditions. Extensive efforts in crop improvement have resulted in the develop- ment 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 success- ful 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 and grain production 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 culti- vars with desired traits to enhance the produc- tivity under various limiting factors in the years to come.