P. Datson, S. Nardozza, K. Manako, J. Herrick, M. Martinez-Sanchez, C. Curtis, M. Montefiori
Since the first report of Pseudomonas syringae pv. actinidiae virulent form (biovar 3 or Psa-V), in Te Puke (New Zealand) in November 2010, the disease has quickly spread across the Bay of Plenty, including the Plant & Food Research (PFR) orchard in Te Puke. Within the PFR Te Puke Actinidia germplasm collection there are around 3,500 different genotypes from 24 different taxa introduced into New Zealand from more than 300 different accessions.
Field monitoring for systemic infection occurring within the kiwifruit germ-plasm has shown differing resistance/tolerance across the several species of Actinidia. More than 80% of the A. chinensis (2x) genotypes have been removed because of Psa infection and around half the A. chinensis (4x) have been removed as well. Within the A. deliciosa genotypes, either diploid or hexaploid, there is a smaller incidence of systemic infection, with only a small number of individuals removed (fewer than 10%).
Promising resistance (or tolerance) has been observed within the species belonging to the Leiocarpae section, including A. arguta, A. macrosperma, A. valvata, A. polygama, A. melanandra and A. argute var. purpurea. Only a few genotypes of these species have been removed because of Psa. These indications of host-pathogen resistance, or strong tolerance, are also supported by an in vitro bioassay using seedlings and tissue culture material challenged with Psa-V. Genotypes of A. polygama and A. macrosperma were scored as resistant, or showing light symptoms, while A. chinensis seedlings often did not survive the treatment; confirming a stronger tolerance within the Leiocarpae species than in A. chinensis.
Identification and characterization of resistance (or tolerance) to Psa within the Actinidia germplasm is an important contribution to the development of kiwifruit cultivars resistant to Pseudomonas syringae pv. actinidiae.
Datson, P., Nardozza, S., Manako, K., Herrick, J., Martinez-Sanchez, M., Curtis, C. and Montefiori, M. (2015). MONITORING THE ACTINIDIA GERMPLASM FOR RESISTANCE TO PSEUDOMONAS SYRINGAE PV. ACTINIDIAE. Acta Hortic. 1095, 181-184
DOI: 10.17660/ActaHortic.2015.1095.22
breeding, bioassay, tolerance, Actinidia deliciosa, Actinidia chinensis, Actinidia argute

Acta Horticulturae