Trichomes in Segregating Generations of Sorghum Matings. I. Inheritance of Presence and Density¹

Abstract

The presence of trichomes on the leaves of sorghum [ Sorghum bicolor (L.) Moench] is associated with reduced susceptibility to shootfly ( Atherigona soccata Rond.) attack. Segregation ratios in successive generations of five single‐cross matings between trichomed and trichomeless parents indicated that the presence of leaf‐blade trichomes is recessive and controlled by a single locus. Inheritance of the trichome trait in three matings among four trichomed parents involved the same locus. The symbol tr is proposed for the gene controlling trichome presence. Trichome density on the abaxial leaf lamina varied among trichomed lines derived from single‐cross matings. Standard unit heritability for F 4 on F 3 . estimated only in the cross IS 1054 x B CK60, was 0.75 on a plot basis.