Challenges of kiwifruit pollination in the presence of Pseudomonas syringae pv. actinidiae, causal agent of bacterial canker

S.A. Miller, A.W. Holmes, S.J. Saunders, R.K. Taylor, A.D. Mowat
Supplementary pollination with commercially milled pollen is used in conjunction with insect pollination in kiwifruit orchards to improve fruit set. However, with the arrival of bacterial canker in New Zealand, caused by Pseudomonas syringae pv. actinidiae (Psa-V), pollen production systems and the traditional management of male vines have been questioned. The objective of this work was to test whether Psa-V can survive on kiwifruit pollen throughout the milling process, and investigate the possibility of infecting kiwifruit vines via contaminated pollen. Psa-V was isolated from flowers and anthers that were collected from 30 orchards in the Bay of Plenty, New Zealand, and was detected at low to moderate levels in all milled pollen samples, using real-time PCR assays. Results were strongly positive for all pollen samples (Cq values from 19-33) and confirmed that Psa-V can survive the commercial milling process. Detection of Psa-V in pollen harvested in 2012 returned stronger positive results than in previous years and probably indicates that inoculum levels are now higher than before.
Miller, S.A., Holmes, A.W., Saunders, S.J., Taylor, R.K. and Mowat, A.D. 2015. Challenges of kiwifruit pollination in the presence of Pseudomonas syringae pv. actinidiae, causal agent of bacterial canker. Acta Hort. (ISHS) 1105:369-374
https://doi.org/10.17660/ActaHortic.2015.1105.38
Actinidia, dioecious, flowers, pollen, pathogen, Psa-V, yield
English

Acta Horticulturae