Jacek Gawroński

Modes of morphogenesis inheritance in vitro in strawberry (Fragaria x ananassa Duch.)

The phenomenon of morphogenesis observed in in vitro cultures, as the ability of cultured cells and/or plant tissues to regenerate into a complete plant, is used for propagation of orchard species plants of the genus Fragaria spp. Genetic mechanisms controlling the in vitro morphogenesis process are still not fully understood. Research has been conducted to broaden knowledge about the genetic control of this process. The aim of this study was to determine the effect of cytoplasmic loci on the inheritance of the cell morphogenetic potential within the species Fragaria x ananassa. The study included five strawberry cultivars—‘Dukat’, ‘Jota’, ‘Temptation’, ‘Pastel’ and ‘Senga Sengana’. The third Griffing method of diallel crossing was fully useful for achieving the purpose of the research, because it allowed, by comparing the effects of reciprocal crosses for each crossing combination, determining the possible impact of cytoplasmic loci on the inheritance of morphogenetic abilities in the analyzed cultivars. Evaluation of the effects of reciprocal crosses showed different modes of inheritance of the morphogenetic potential in vitro of plant cells of these strawberry cultivars. The strawberry cultivar ‘Dukat’ transmitted genetic determinants of the morphogenetic potential cytoplasmically. Nuclear transmission of the morphogenetic potential was recorded for the cultivar ‘Senga Sengana’. ‘Jota’, ‘Temptation’ and ‘Pastel’ cultivars passed on this trait in a cytoplasmic-nuclear mode. Morphogenesis efficiency of hybrids, whose maternal forms transmitted the morphogenetic potential in a cytoplasmic-nuclear mode, depended likely on the interaction between the maternal plasmotype and the paternal nuclear genes.

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.