Possible transmission of Pseudomonas syringae pv. actinidiae by pollen
In November 2010, the Ministry of Agriculture and Forestry (MAF Biosecurity) of New Zealand announced that samples of pollen collected (in 2009 and 2010) from the Bay of Plenty and South Auckland tested positive for Pseudomonas syringae pv. actinidiae (EPPO Alert List). Although it was acknowledged that this finding did not provide sufficient evidence to consider that infected pollen can spread the disease, MAF advised kiwifruit growers to use only tested pollen before implementing artificial pollination. Data on the epidemiology of Pseudomonas syringae pv. actinidiae is generally lacking, but infection is thought to occur through natural openings and wounds. Spread is probably ensured by heavy rain, strong winds, mechanical means (including animal and human activities), and infected planting material. For the moment, the possibility that infected pollen could spread the disease cannot be excluded but more research is needed.
Biosecurity New Zealand. New Zealand pollen tests positive for Psa. Media release of 2010-10-20. http://www.biosecurity.govt.nz/media/20-11-10/new-Zealand-pollen-tests-positive-for-Psa