25 Aug 2011

Two strains of PSA disease identified

3:48 pm on 25 August 2011

Researchers at Otago University have determined the genome sequence of the PSA kiwifruit disease.

Since it was discovered on an orchard near Te Puke in November last year, growers and scientists have believed there were two strains of PSA in New Zealand, with one being more virulent than the other.

The virulent strain, PSA V, has been found only on orchards in Bay of Plenty.

The other strain, PSA LV, has been found in Bay of Plenty and all other kiwifruit regions except Northland.

The Otago team, whose research is funded by Seeka and Eastpack, has discovered there are very significant differences in the genomic makeup of the two strains.

They are significant enough for the team to believe that there's only one strain of PSA in New Zealand, the virulent one.

The other strain is only distantly related to PSA and is not virulent on kiwifruit.

The team says as PSA V is still limited to Bay of Plenty, it is worth considering the possibility of completely eradicating the pathogen.