Abstract: | The cost and difficulty of producing hybrid true potato seed (TPS) currently limits their use for commercial production. Twelve clones, selected in preliminary trials for low pollen stainability but high fruit and seed set, initially seemed promising for inexpensive production of mostly hybrid open-pollinated (OP) TPS. However, in subsequent tests, pollen stainability of these clones appeared to be highly variable and fruit and seed set were not as high. Bumblebees favored the most fertile clones, especially during periods when pollen stainability was the highest. Amounts of OP fruit and seed set correlated with maximum observed pollen stainability levels of the clones. Most of the OP seeds produced by these clones were probably the result of self-pollination; therefore, other methods must be used to obtain hybrid TPS. |