STUDIES OF POLLINATION, FERTILISATION AND EMBRYOGENESIS OF GEORGIAN WALNUT VARIETIES

The aim of this work was to study processes of pollination, fertilization and embryogenesis of some Georgian varieties.
Phenological study has shown that walnut Georgian varieties are protandrous and flowering of male starts in the second half of April while the female flowering start 8-10 days later.
Male flowers are very sensitive to summer frosts and derangement of meiosis is usual phenomenon in all mentioned species.
Derangement can involve either part or whole flower hood, what leads to the development of wide range of morphological diversity in pollens.
The reason of development of sterile pollen might be due to degeneration of male archesporium cells or degeneration of tapetum cells on the early stage of pollen sac development or derangement of meiosis, inducing development of triads and pentads.
Study of artificially pollinated stigmas revealed that in the natural conditions (freshly gathered collected pollen) lifetime of pollen grains do not exceed 2-3 days, while in the laboratory lifetime extends up to 1,5-2 months.
The research shows that the tested Georgian are self-sterile and need cross-pollination.

V International Walnut Symposium

V. Kvaliashvili, M. Samushia, L. Vashakidze, E. Abashidze, M. Marghania

pollinations, embryogenesis, Georgian varieties

https://doi.org/10.17660/ActaHortic.2005.705.34