Evaluation of foreign remontant raspberry cultivars for production and breeding

Abstract

The over 100 remontant raspberry cultivars worldwide continue to variegate, with breeding mostly successful in the USA, Canada, Great Britain, Poland, Switzerland, the Netherlands and Russia. In most native climates of Russia, foreign varieties unluckily do not realise their biological potential to not attain the originator-declared character. The research aimed at a comprehensive study of introduced remontant raspberry cultivars to clarify the prospects of their production and breeding. The study was being conducted over 2018-2020 on the genetic raspberry collection plot of the All-Russian Horticultural Institute for Breeding, Agrotechnology and Nursery’s Kokino base station (Bryansk Region). Research focused on ten foreign remontant raspberry cultivars. The late-maturing Atlant variety of the state-permitted crop catalogue served a control. Research followed the generally accepted protocols. Statistical experimental data analyses were accomplished with Microsoft Excel. Phenotypic evaluation of the introduced remontant raspberry cultivars by plant morphology revealed their Middle Russia-specific traits of growth and development. The greatest yield surface (238-316 cm) was observed in Joan J, Imara, Himbo Top and Carolina foreign cultivars. The remontant varieties studied were found to distinguish by late maturity and low yield (2.9-6.1 t/ha), thusly being off-focus to industrial horticulture. Imara, Erika, Sugana, Joan J, Carolina and Himbo Top leading with a 5.0-6.1 t/ha yield can be recommended in home gardening. Selected foreign cultivars deserve attention as a genetic resource in breeding for larger fruit size (Poranna Rosa, Driscoll Maravilla, Sugana), higher soluble solid content (Kweli, Karolina, Kwanza), fruit strength (Kwanza, Driscoll Maravilla), optimal fruit detachment force (Himbo Top, Joan J, Imara, Kwanza) and compact bush habitus (Poranna Rosa).