Potential of Different Actinidia Genotypes as Resistant Rootstocks for Preventing Kiwifruit Vine Decline Syndrome

Abstract

Kiwifruit Vine Decline Syndrome (KVDS) is currently affecting Italian kiwifruit cultivation, causing dramatic yield and economic losses. The syndrome’s aetiology is due to soil-borne pathogens and waterlogging, leading to the decay of roots and then the canopy. Current knowledge about the disease is limited, and the techniques to control the syndrome are ineffective. The use of tolerant rootstocks is one of the most promising tools. Six genotypes of Actinidia were tested for two years at four infected experimental sites in Friuli Venezia Giulia (NE Italy). Plant evaluation and analysis were carried out on the root system and the vegetative parts. At all experimental sites, three genotypes, all belonging to the A. macrosperma group, grew normally. In contrast, plants of A. polygama died earlier and those of A. chinensis var. deliciosa ‘Hayward’ declined during the first year. A. arguta ‘Miss Green’ survived the first year but started to decline during the second year. After two years of study, we were able to identify three putative resistant genotypes: A. macrosperma accession numbers 176 and 183, and ‘Bounty71’, which will be a useful resource as rootstocks or as parents for breeding owing to their potential genetic resistance traits.