Seed Preparation Methods for Increasing the Germination of Sour Cherry (Prunus cerasus L.)

Poor seed germination obtained in sour cherry breeding programs results in a limited number of seedlings. This makes breeding inefficient: the resulting hybridization is low in relation to human labor input. That is why a study was conducted to investigate the influence of different methods of treating seeds of three sour cherry cultivars—‘Wanda’, ‘Wroble’, and ‘Lutowka’—on their germination and the growth of the obtained seedlings under greenhouse conditions. The tested methods of seed treatment included different durations of the stratification period at 5 °C, and several variants of removing the sources of germination inhibitors present in the stones (endocarps), seed coats, and endosperm, and in the cotyledons of embryos. The highest number of germinated seeds/embryos was obtained by removing the seed coat attached to the endosperm and subjecting the exposed embryos to a temperature of 20 °C after stratifying them for a period of 90 days. The percentage of germinated seeds/embryos obtained by this method was as high as 80%–90%, and their germination occurred within 10–15 days, whereas with the traditional stratification of seeds in endocarps at 5 °C, a large number of seeds did not germinate, even after 150 days of stratification. This method produced 20–25 cm tall seedlings within five months. By contrast, the final germination percentage of the seeds in the Control Treatment was from 16.4% to 54.4%, and a large proportion of seeds had still not germinated after five months. Seedlings obtained from seeds stratified for 90 days grew better than those obtained from seeds stratified for a shorter time. The developed method makes it possible to obtain a larger number of sour cherry seedlings, thus increasing the efficiency of creative breeding. Moreover, obtaining a higher germination percentage over a shorter period shortens the breeding cycle, which contributes to reducing the costs of sour cherry breeding.