Reproductive biology of two edible honeysuckles [Lonicera edulis Turcz. ex Freyn., Lonicera kamtchatica (Sevast.) Pojark.] in the conditions of southwestern Slovakia

Abstract

The formation and development of reproductive organs and fruits was examined for two edible honeysuckle species Lonicera edulis Turcz. ex. Freyn. and Lonicera kamtchatica (Sevast.) Pojark. 'Gerda' using cytological and embryological methods. We found out that the flower initiation has began during June in the conditions of southwestern Slovakia. Male and female arche spores were differentiated before entering winter dormancy. In most cases we have observed normally developed tetrads, normal appearance of microspores, two-celled polen grains and mature pollen grain. In both species a sufficient amount of normally developed pollen grains was observed. Disturbances during female gametophyte development occurred occasionally, most mature ovules contained 7 cells female gametophyte. Our research pointed to fact that the species are protogynous. Flowering usually takes place in the first half of April. The fruits were mature in the second half of May. We have found that 10 to 11 fully developed seeds have evolved in the fruits of both representatives of Lonicera on average. The above results show the suitability of L. edulis and L. kamtchatica cultivation in SW Slovakia with a relatively low risk of fruit loss due to climatic conditions.