Influence of Raspberry bushy dwarf virus on pollination of red raspberry (Rubus idaeus L.) cultivars

Raspberry bushy dwarf virus (RBDV) is one of the major pollen-borne pathogens of the genus Rubus that causes drastic reduction of yield and degradation of berry quality. The aim of the study was to evaluate the quality of raspberry pollen and the effect of RBDV on pollination process. The research was carried out at the Institute of Horticulture. Within two years, 2017 and 2018, the pollen viability and pollen germination capacity of nine raspberry cultivars were analysed. The cross-pollination was done and the pollination quality of 31 crossing combinations was evaluated. The study found that although the pollen viability of cultivars infected with RBDV was higher than that of uninfected cultivars, there were no statistically significant differences. The viral contamination of the mother plant played a more important role in the pollination process. Pollination was better on uninfected mother plants and pollen germinated was faster than on infected plants. However, when the virus-infected cultivars were pollinated with infected pollen, the virus had an effect on the growth rate of pollen tubes, that decreased and the pollen tubes did not reach the ovary.