Sorghum Genetic Resources: Challenges with Acquisition, Preservation and Utilization of Germplasm for Cultivar Improvement.

Sorghum is one of the most widely cultivated food and feed cereals throughout the world. Following its expansion from its region of origin in north east Africa, the crop eventually evolved into unique ecotypes and races to adapt to new environments it was introduced to including cooler high altitudes and humid regions within Africa, and short-day temperate conditions such as the United States.  This has contributed to gradual introduction and buildup of new and novel alleles in the species. Today sorghum is recognized as one of the most genetically diverse crops. The USDA GRIN and ICRISAT each maintain about 40,000 accessions of the crop and African national gene banks preserve significant number of local collections. Much of sorghum collections in Africa were made at the time when road networks and transportation infrastructure were severely underdeveloped and thus the collections currently maintained in the gene banks are made from limited accessible areas and are far from exhaustive. Following the establishment of the national sorghum research programs in Africa which took effect following the end of colonial period, attempts were made to collect, preserve and utilize the resources in breeding programs. But those efforts were frustrated by limitations in human capital and infrastructure as well as by both natural and man-made factors such as extensive drought and civil unrest that not only undermined further collection efforts but also evidently led to loss of vital genetic resources due to massive displacement of people caused by these episodes. These coupled with mounting limitations on movement of materials among national and international organizations and lack of standardized system for utilization of the resource remains the greatest challenge.