Transmission and yield effects of a gibberellin mutant allele in potato

Summary A selected clone ofSolanum tuberosum Group Andigena PI 347773 (clone Adg 11.1) and the cultivar Superior had previously been shown to be heterozygous at a gibberellin related dwarfing locus, ga₁. Experiments were conducted to test for gametophytic selection for alleles at the ga₁ 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 cross 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>duplex>triplex, indicating that the recessive mutant ga₁ allele exhibited a dose effect stimulating yield.