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Leucoanthocyanidins (LAC) are structurally related to condensed tannins, a class of compounds having significant effects on the nutritional value of sorghum [Sorghum bicolor (L.) Moench) grain. Little is known of LAC inheritance in sorghum. Mature leaves of 'Colman' and 'White Collier' forage sorghum are high and low, respectively, in LAC content. The objective of the present study was to determine the inheritance of LAC content in reciprocal crosses between these two cultivars, Leaves of field-grown plants were assayed for LAC by a procedure that involved treating methanolic leaf extracts with acid at 50°C to convert the colorless LAC to an anthocyanidin having an absorbance maximum near 540 nm, Parental, F1 and F2 plants were grown and assayed in 1983. In 1984, F3 progenies from selected F2 plants representing various LAC levels were grown and assayed along with additional F2 and parental plants. Results from both years supported the conclusion that a single allelic pair with incomplete dominance was primarily responsible for the difference in LAC content between Colman and White Collier plants. Other genes with minor effects may also be involved but maternal or cytoplasmic effects were not important in determining LAC level. The LAC of Colman was not identified, but based on the work of other researchers with other sorghums, it is probably apiforol.