Testing kiwifruit susceptibility to Psa
12 Jul, 2012
Plant & Food Research is developing a range of assays to test how kiwifruit seedlings respond to Psa.
Listen to audio: Testing kiwifruit susceptibility to Psa
Developing a range of assays
Dr Tony Reglinski from Plant & Food at Ruakura near Hamilton is developing a range of assays to determine how resistant new cultivar seedlings are to Psa. He has developed a method of inoculating different types of plant material, from small seedlings through to potted plants and woody stems, with the bacteria to find out which will give an indication of resistance to the bacteria. If members of a particular population survive the inoculation, there is some optimism. The plan is to see if they can home in on a particular selection that can resist Psa.
Probing the genome
Material from a resistant selection of plants is sent to molecular biologists who probe the genome and look for resistant genes. They look for marker genes that result in a marker-assisted selection process of developing a resistant strain.
Tony emphasises how important it is to develop a range of bioassays in order to create a susceptibility index. Over 500 genotypes have been screened, but the assays need to be repeated. Replication of results is vital to developing a robust dataset.
Breeding resistant kiwifruit
The results reflect what is being seen in the field: the gold cultivar has the worst susceptibility to Psa, the green cultivar fell into the middle category so it wasn’t as susceptible as the gold, and the new gold variety is similar to the green but not absolutely resistant. These rankings help the breeders to select the parents of the next generation of more resistant kiwifruit.
Get news story: Combating kiwifruit Psa
Programme details: Our Changing World
- 29 July 2013