Chile is collecting kiwifruit vine samples from its orchards to test for the presence of the virulent Psa-V virus.

Scientists will examine vines using a molecular biology technique, polymerase chain reaction (PCR) to amplify particular plant DNA, as well as cross referencing this with biochemical tests.

Photo: SAG

The Southern Hemisphere spring tests follow earlier examinations conducted last autumn where two cases of Psa-V were detected in Longavi in the Maule Region.

A total of 1,882 samples were collected from nurseries and orchards in regions stretching from Valparaíso to Bío Bío.

A representative from the Chilean Kiwifruit committee, said the research was conducted in conjunction with the Chilean Government's Agriculture and Livestock Service (SAG).

"We used a diagnostic protocol agreed on by experts to study the DNA in detail through PCR using two pairs of primers: PsaF1/PsaR2 and PsaF3/PSAr4."

However, he said the test in itself was not foolproof and needed to be corroborated with further biochemical tests.

"The mere use of the primers will not give a diagnosis with 100% reliability for the case of Psa-positive samples, but only refer to its possible presence,"  he added.

SAG has set mandatory controls for the pest dubbed the "bacterial cancer of kiwifruit", through resolution 5655 following extensive outbreaks in Italy and New Zealand.

Photo:

www.freshfruitportal.com