Sorghum Vulnerability and Germplasm Resources1

The first sorghums [Sorghum bicolor (L.) Moench] introduced into the Western Hemisphere were the tropical cultivars, ‘Milo Maize’ and Guinea corn, later called ‘Guinea Kafir.’ These were tall in plant height and short‐day in photoperiod response but by a series of mutations short‐statured, day‐neutral types evolved. The kafirs and milos, and to a more limited extent the hegaris, feteritas, and shallus have formed germplasm base for the grain sorghum breeders in the USA. Most grain sorghum cultivars are derivatives from crosses between milos and kafirs. Sterile cytoplasm was first found in the milos and the nonrestorer genes in the kafirs. The parent lines of most grain sorghum hybrids are kafirs, milos, or hybrid derivatives from the two. A breeding scheme is in operation designed to transfer the germplasm from tropical cultivars into short, day‐neutral genotypes. The present breeding programs are based on this new source of germplasm. The World Sorghum Collection of over 17,000 items is now being managed by the International Crops Research Institute for the Semi‐arid Tropics. Grain quality is receiving attention since much of the grain sorghum in the world is used directly for human food.