Elżbieta Kaczmarska

EFFECT OF POLLINATION MODE ON FRUIT SET IN BLUE HONEYSUCKLE (Lonicera caerulea L.)

Honeyberry’s popularity has been increasing because of its valuable traits: nutritional value of fruits (a high amount of ascorbic acid, potassium and polyphenolic compounds), early ripening (14 days before strawberry), exceptional hardiness and easy cultivation. However, there is still little known about the pollination biology of this species, which is essential for practical breeding purposes. In this study we evaluated pollen fertility in five cultivars and three breeding clones of this species. The impact of the manner of pollination on the fruit set and forming seeds has also been studied. The highest percentage of viable pollen was found in cultivars ‘Duet’ and ‘Wojtek’ (96%), whereas the pollen of ‘Chelyabinka’ cultivar had the lowest fertility (90%). The percentage of blue honeysuckle fruits obtained from open-pollinated flowers was high (on average 94.7%) compared to isolated flowers (on average 8.6%). The effect of cross-pollination with cv. ‘Duet’ indicates that the percentage of the fruit set, fruit weight and mass of produced seeds was higher when this cultivar was applied as maternal than paternal form. The number of seeds affected significantly the weight of the fruit in the case when cv. ’Duet’ was used as a paternal (correlation coefficient r = 0.45) or maternal form (r = 0.66), while for other methods of pollination this effect was insignificant. These results may be used to the most efficient establishment of plantations as well as for the realization of the breeding program of this valuable species.

Inbreeding depression for seed germination and seedling vigor in strawberry (Fragaria × ananassa Duch.).

ABSTRACT Experiments leading to the procurement of subsequent inbred generations were conducted in the years 2006- 2013. Seeds obtained from open pollination and after self-pollination of four strawberry cultivars (Teresa, Senga Sengana, Kent and Chandler) and clone 1387 were used. These genotypes were evaluated for their tolerance to strong inbreeding under in vitro culture conditions. The aims of this study were to estimate the inbreeding depression of each of the progenies. During the investigation, the germination percentage as well as seedling viability were evaluated. The highest seed germination was shown for populations derived from ‘Teresa’ × open pollination (82%) and ‘Kent’ (7) S4 (78%). Seeds derived from self-pollination resulted in the lowest germination - an average of 16.8%. Generally, seed germination was significantly lower for the five S1 offspring, whose depression was 0.62, in comparison with the S4 seedlings, whose depression was 0.31. Inbred offspring showed a depression in relation to the average weight of a single seedling of 0.08 in the case of S1 progeny, whereas in the case of S4 progeny it was 0.23. The highest germination energy was shown by ‘Kent’ (7) S4 seeds (74%) and hybrids of ‘Teresa’ derived from open pollination (75%); whereas seeds obtained at the same time from self-pollination germinated 10.8% on average.