The effect of Endosperm Balance Number (EBN) in interploidal and interspecific crosses between S. tuberosum dihaploids and tuber-bearing wild species was investigated. The crossability was evaluated by the percentage of berry set and the average numbe...
The effect of Endosperm Balance Number (EBN) in interploidal and interspecific crosses between S. tuberosum dihaploids and tuber-bearing wild species was investigated. The crossability was evaluated by the percentage of berry set and the average number of seeds per berry. The percentages of berry set were 11.5%, 11.4%, 7.4% and 2.2% in 4x×4x, 4x×2x, 2x×2x and 2x×4x crosses, respectively. The number of seeds per berry was in the same order as the percentages of berry set. The crossability was greatly affected by the ratio of the maternal and parternal EBN in the endosperm. The crosses with the maternal and parternal EBN ratio of 1 : 1, 1 : 1/2 and 4 : 1 in the developing endosperm did not produce hybrid seeds. However, a lot of plump hybrid seeds were produced only in 2 : 1 of EBN ratio irrespective of differences of the species used or ploidy levels of the parents.