Determination of suitable pollenizers for the apricot cultivar ‘Goldrich’

Abstract

The suitability of five apricot cultivars: ‘Aurora’, ‘Laycot’, ‘Pinkcot’, ‘Sylred’ and ‘Veecot’ as pollenizers for ‘Goldrich’ were studied. The study included the phenology of flowering, pollen germination, fruit set and growth of pollen tubes in vivo in the pistil. Pollen germination was determined on the medium with agar and 15% sucrose. The growth of pollen tubes in the pistil was determined by fluorescence microscopy, and fixation of pistils was done in three terms (2, 4 and 6 days after pollination). Regarding the flowering time, all tested cultivars overlapped well with ‘Goldrich’. Besides, all tested cultivars had good pollen germination, ranging from 58 to 74%. The highest fruit set was obtained in combinations with ‘Veecot’ (34%) and ‘Sylred’ (30%). Significantly lower fruit set was obtained in combinations with ‘Laycot’ (17%) and ‘Pinkcot’ (15%), while the combination with ‘Aurora’ gave the lowest fruit set (4%). First pollen tubes at the base of the style were observed on the second day after pollination, but their number increased significantly on the fourth day after pollination. Later, on the sixth day after pollination, the number of pollen tubes was not significantly increased. Number of pollen tubes at the base of the style and in the ovary was significantly higher in variants with ‘Veecot’, ‘Sylred’, ‘Pinkcot’ and ‘Laycot’, comparing to the variant with ‘Aurora’. Based on these results, ‘Veecot’ and ‘Sylred’ can be recommended as the best pollenizers for ‘Goldrich’. Satisfactory results were given by ‘Pinkcot’ and ‘Laycot’, while ‘Aurora’ proved to be a bad pollenizer.