Laura Schulz

Commercially cultivated potatoes in the United States have tetraploid genomes that make breeding a difficult and time consuming process. Converting potatoes to a diploid crop would allow for more efficient crop improvement, using techniques that are widely used on other diploid crops. Breeding efforts with diploid potatoes are complicated by a variety of fertility problems, including premature flower abscission. This project tested three treatments for premature flower abscission: higher light intensity, a high phosphorus and low nitrogen fertilizer, and spraying the flowers with auxin. Twelve diploid potato genotypes previously developed from commercial tetraploid varieties were used. All twelve genotypes had been observed to flower in indoor growing conditions, though only one genotype had previously produced fruit. The number of flowers produced per plant was found to be highly dependent on genotype, though the auxin treatment led to the highest average number of flowers per plant. None of the treatments were successful at eliminating premature flower abscission in the eleven genotypes that had not previously fruited, suggesting that those eleven genotypes may all be infertile as female parents. However, in the genotype that had previously produced fruit, the highest average number of fruits per plant were produced in the control treatment, and the highest average number of seeds per plant was produced in the auxin treatment. The fertility of diploid potatoes appears to be a function of both genotype and environmental conditions.