Lateral floret development in barley as influenced by recessive intermedium genes in a heterozygous state

The influence of heterozygous recessive intermedium gene interaction on lateral floret development in barley was studied in various F 1 constellations where 1 or 2 recessive int genes were added to a heterozygous or homozygous int gene in another locus. The study was based on three recessive int loci, inf‐a, inr‐c , and int‐e , represented by 4, 5, and 3 alleles, respectively ( a 9 a 10 a 27 a 30 ; c 5 c 13 c 29 c 62 , c 63 ; e 20 e 23 e 65 ). F 2 data for lateral floret awn length, fertility, and kernel size were contrasted with normal two‐row barley, the parental single mutant and among the different constellations. The recessive int genes alone in double and triple heterozygous combinations were unable to promote lateral floret develpment. The same genes. however, were normally able to enhance the expression of a homozygous inr locus. The degree of enhancement may differ among characters of lateral floret development, among int loci, and among alleles of an int locus. There is progressive enhancement when a second int gene is added as a potential enhancer to the initial effector.