The Journal of Heredity 1993:84(1):17-20
© 1993 The American Genetic Association 84:17-20
research-article |
Inheritance, Allelism, and Morphological Characterization of Unifoliate Mutations in Common Bean
From the Research and Extension Center, University of Idaho 3793 North 3600 East, Kimberly, ID 83341
The Vegetable Crops Department, University of Florida Gainesville
Address reprint requests to Dr. Myers at the address above.
Abstract
Compound leaf formation in Leguminosae is under genetic control, as shown by two unifoliate mutants (uni and Uni-2) previously discovered in common bean (Phaseolus vulgaris L.). Two additional unifoliate mutants with obtuse leaf apices were discovered independently in the University of Florida and University of Idaho breeding and genetics programs. Both mutants are under the control of a single recessive gene. Tests of allelism indicated that the two mutants are allelic to one another but are not allelic to Uni-2. The original uni mutant is extinct and was never tested for allelism with other unifoliate mutants; therefore, we propose the gene symbol uni-3 for the group represented by the present two mutants. The two mutants differ in phenotypic expression; the Florida mutant is partially fertile and shows reversion to normal leaflet number at higher nodes. In contrast, the Idaho mutant is completely female-sterile but male-fertile and shows consistently strong expression of the unifoliate trait at higher nodes. We propose the symbols uni-3nde (Florida mutant) and uni-3nie(Idahomutant). The superscripts "nde" and "nie" stand for "node dependent expression" and "node independent expression," respectively. The Idaho mutant can also produce a bi- and tricarpellate gynoecium in some flowers. The pleiotropic effect on leaves and gynoecium is consistent with the theory that the gynoecium is a modified leaf. Because the androecium and perianth are unaffected by this mutation, this would suggest that these structures are not modified leaves.