TRANSMISSION AND YIELD EFFECTS OF A GIBBERELLIN MUTANT ALLELE IN POTATO

A selected clone of Solanum tuberosum Group Andigena PI 347773 (clone Adg 11.1) and the cultivar Superior had previously been shown to be he terozygous at a gibberellin related dwarfing locus, ga1. Experiments w ere conducted to test for gametophytic selection for alleles at the ga 1 locus in reciprocal crosses and for the effect of genotype on tuber yield. The genotypes of individuals from Superior-Adg 11.1 reciprocal F1 families were determined by test crossing. Genotypic classes could be distinguished by the percentages of dwarf seedlings in their test c ross progeny. No differences were found in the genotypic distributions of the reciprocal families, which indicates gametophytic selection at this locus is not the cause of reciprocal yield differences. Superior -Adg 11.1 individuals classified by ga1 locus genotype were evaluated for tuber yield. Tuber yields were highly correlated with genotype in both reciprocal families. Yields followed the pattern of simplex > dup lex > triplex, indicating that the recessive mutant ga1 allele exhibit ed a dose effect stimulating yield.