Genetics of the “umbrella” branching habit in Capsicum annuum L.

Abstract

Three inbred lines, MSU 78-101, MSU 79-221 and MSU 74-230 were used to determine the inheritance of the "umbrella" branching habit in peppers. MSU 79-221, with the umbrella phenotype, was crossed with MSU 78-191 (dwarf) and MSU 74-230 (indeterminate growth habit). Segregating populations were separated on the basis of plant growth habit and fruit bearing habit. Genetic analyses suggested that the umbrella phenotype was controlled by three major recessive genes, ct and dt determining plant habit, and fa determining fruit bearing habit. When the dominant alleles Dt and Ct were in the dominant homozygous or heterozygous condition an indeterminate phenotype was produced. Su, a dominant suppressor gene, apparently acts to suppress the epistatic action of the Ct gene. Modifiers were involved in the control of branching in the umbrella plants. Linkage also was noted between the genes for indeterminate plant habit and non-clustered bearing habit. The information derived from this study will allow the plant breeder to design an efficient breeding program for the development of pepper cultivars suitable for mechanical harvesting systems.