Establishment of in vitro culture systems for breeding new types of kiwifruit and forActinidiagenomics studies

Abstract

During the past 20 years kiwifruit has expanded dramatically in planting area and location, in total production, and also in diversity with different types of fruit. For example, variations in flesh colour have resulted in the commercialisation of green-fleshed, yellow-fleshed and red-fleshed kiwifruit. This diversity is from two large-fruited Actinidia species, A. chinensis and A. deliciosa, now widely grown throughout many parts of the world. Other fruit types may become available through use of other Actinidia species. The New Zealand Institute for Plant & Food Research Limited (PFR) has an active kiwifruit breeding programme to produce new kiwifruit cultivars that meet market requirements. An efficient in vitro biotechnology platform had been established to preserve and create new genotypes for rapid kiwifruit breeding through in vitro culture and propagation of various Actinidia species. Petiole and nodal shoot segments are produced from cuttings collected from dormant canes of adult plants in our germplasm repositories and breeding programme. This paper reviews the establishment of in vitro culture systems to allow chromosome doubling, micro-propagation, the testing of tolerance to bacterial canker of kiwifruit, and the development of new kiwifruit cultivars.