Cross-pollination increases the number of drupelets in the fruits of red raspberry [Rubus idaeus L)

摘要

The study was conducted in 2014 at the Research Institute of Horticulture in Skierniewice, Poland. Its aim was to assess the effects of self-pollination (self-fertilization) and cross-pollination (cross-fertilization) on the size of the fruit of ten red raspberry cultivars, determined as the number of drupelets in one fruit. The investigated cultivars were: 'Canby', 'Glen Ample', 'Laszka', 'Polana', 'Polka', Hadziejowa', 'Schdneman', 'Veten' and 'Willamette'. They were self- and controlled Cross-pollinated in a greenhouse in the spring of 2014. The pollination program was based on a half-diallel mating design (Griffing's method II) among these cultivars, producing 55 hybrid families (45 from controlled cross-pollination and 10 from self-pollinationof maternal cultivars), which allowed to study the influence of the pollen cultivar on the number of drupelets in a single raspberry fruit. The study revealed an overwhelming advantage of cross-pollination over self-pollination. The average number of drupelets in the fruits from cross-pollinated flowers ranged from 48.3 in 'Glen Ample' (76.9% more drupelets than in self-pollinated 'Glen Ample') to 92.9 in Hadziejowa' (96.8% more drupelets than in self-pollinated 'Radziejowa').