Research by Plant & Food scientists is aiming to breed kiwifruit cultivars that show resistance to the pathogen Psa.

Listen to this RNZ audio, Psa-resistant kiwifruit from 2012.

Duration: 13:09

Psa triggers large research programme

The pathogenic kiwifruit bacterium Pseudomonas syringae pv. Actinidiae, more commonly known as Psa, was first identified in Japan more than 25 years ago. The virulent strain Psa-V was first identified in New Zealand in late 2010. Since then, it has affected more than 1200 New Zealand kiwifruit orchards and is causing widespread vine deaths.The outbreak has triggered a large research programme, including work by Plant & Food Research into the development of more Psa-tolerant and resistant cultivars.

Find out more in this article: Combating kiwifruit Psa.

Plant & Food Research already had a major kiwifruit breeding programme under way at its Te Puke research orchard, focusing on traits such as flavour, colour, storage and crop yield. Now it is in the process of screening more than 100,000 cultivars in the hope that a plant that already has good commercial qualities might also be Psa resistant.

Germplasm collection potential source of resistance

Plant & Food Research’s orchard includes a germplasm collection, which contains a large variety of seedlings that have grown from about 40 original species of kiwifruit sourced from China and other parts of Asia. There are more than 1000 different seedlings in the collection with a wide variety of different traits. The germplasm collection is a valuable kiwifruit resource and offers a potential source of cultivars for breeding new commercially viable kiwifruit varieties that are Psa resistant.

In this programme, Alison Ballance visits the Te Puke orchard where kiwifruit breeder Luis Gea shows her around some of the trials, including the germplasm block.

Listen to this RNZ Kiwifruit Psa disease genetics,

Find out why and how scientists are looking for resistance genes so that kiwifruit plants can withstand Psa.

Useful link

Go to the Plant & Food Research website and do a search on Psa to learn more about Psa research in New Zealand.

Programme details: Our Changing World.

Published 21 September 2012