Biology of flowering as an element in the red raspberry breeding, focused on avoiding interference in embryo sac development and reduction in drupelet numbers
Research on the flowering process was based on the observation of pollen viability and germination. Pollen tube and fertilization of ovules were observed. It was shown that there is between 20 to 100 pollen grains on the stigma. All the grains were germinated on the stigma. To the basis of the stale, there were only 2 to 4 pollen tubes because the transmission tissue in the base is narrowing. Fertilization occurs on the 2nd or 4th day after pollination. Fertilization comprised from 0 to 100% of the stiles located in the flower. A number of deviations have been described. The most important are distractions of the fertilization of ovules caused by the phenomenon of self-incompatibility, which is condictioned by abnormality in micro- and macro-sporogenesis. Observations were also carried out in the case of flower infection by the RBDV virus and crumbly fruit caused by genetic disorder. The fertilization of the ovules in the flowers infected by RBDV virus was calculated as 5.7%. The rest of the ovules were not fertilized due to the gradual disappearance of pollen tubes in the ovary. In the flowers of the plants that were diagnosed with crumble fruit, the tubes were overgrown to the ovary. Fertilization occurred only at 9.9% of the ovule. The rest of ovules were not fertilized and disorder in pollen tube growth among ovule was observed.
Orzeł, A., Lech, W., Jagła, J., Danek, K.B. and Bieniasz, M. (2020). Biology of flowering as an element in the red raspberry breeding, focused on avoiding interference in embryo sac development and reduction in drupelet numbers. Acta Hortic. 1277, 375-380
raspberry, pollen tube growth, fruit set