Articles
APPLICATIONS OF BIOTECHNOLOGY TO CULTIVAR IMPROVEMENT IN NEW ZEALAND
In line with industry priorities the HortResearch citrus research programme covers a full spectrum of activities, including breeding, entomology, pathology, and post-harvest quality.
The breeding programme is focused on the production of high quality, seedless, easy-peel citrus types, using traditional breeding and tissue culture techniques.
The tissue culture programme uses both somatic hybridisation and colchicine or oryzalin for the production of tetraploid breeding parents.
Traditional programmes use best-parent by best-parent crosses in order to achieve target outcomes.
Interesting new cultivars are accessed from overseas sources and evaluated on site and on grower properties.
Rootstock improvement is also undertaken, with rootstock evaluation trials in all the growing regions.
The programme is complemented by a citrus virus programme, which in recent years has focused on characterisation of citrus tristeza virus (CTV) and strategies for mild strain cross protection.
The New Zealand Citrus Budwood Scheme (NZCBS) has also been developed to provide superior clonal healthy budwood to the industry.
A major limitation to the export of Wase type satsuma mandarins is high fruit acidity and low sugars.
This is a direct consequence of New Zealand’s cool maritime climate, and control of acidity is another research focus.
All aspects of this work will be discussed, with emphasis on applications of biotechnology to the research programme.