Pollination and hybridisation systems in genus Ribes L. (Grossulariaceae)

Abstract

Currants are important berry crops cultivated for medicinal purposes. Most currant cultivars are crossings between Ribes nigrum varieties, while many Ribes species are not used in hybridisation. Recent research on Ribes crossbreeding is scarce. Hybridisation of wild species can improve reproductive success and the taste of fruit. However, hybrids of certain currant species cannot produce fully formed berries. Crossbreeding of currant species was performed in Northwest Russia (Saint Petersburg Botanical Garden). The research included both introduced (R. sachalinense, R. sanguineum, R. rubrum, R. hispidulum, R. mandschuricum, R. spicatum, R. latifolium) and native species (R. aureum, R. alpinum, R. nigrum). The research aimed to identify the hybridisation system, pollination mechanisms and hybrids with the highest percentage of fruit and seed set. Pollen fertility and viability were assessed. Pollen is fertile (acetocarmin staining: 80.3% for R. alpinum and 96.0% for R. mandschuricum); germination is active on nutrient medium and in situ, especially in R. sachalinense, R. aureum and R. spicatum (54.2–41.8%). Pollen germination can be irregular. Flowers were castrated before pollination. Optimal hybrids with a high percentage of fruit set were identified: R. alpinum x R. mandschuricum, R. alpinum x R. aureum, R. sachalinense x R. sanguineum, R. rubrum, R. hispidulum.