Molecular Characterization of Three Comercial Cultivars and a New Pollinator in Kiwifruit

Abstract

We investigated the characterization of genotypes of Actinidia deliciosa (Chev.) Liang and Ferguson var. deliciosa by using isozymatic and molecular techniques [randomly amplified polymorphic DNA (RAPD), amplified fragment-length polymorphism (AFLP), standard AFLP, and modified AFLP]. Four genotypes were tested, the female cultivar `Hayward', the traditional New Zealand pollinizers `Matua' and `Tomuri', and a new pollinizer named clone A selected in a breeding program in Spain. PGI and PGM were the only isozymes that allowed us to distinguish the kiwifruit genotypes, although the accessions of `Matua' presented two different banding patterns for both isozymes. All three molecular markers differentiated between the genotypes of kiwifruit tested, although RAPD markers did not allow us to establish differences between accessions of `Matua', while both standard and modified AFLP did. These results, along with those of isozymes, support the hypothesis that the male kiwifruit genotypes present in Europe belong to different clones. None of the markers used showed differences between accessions of `Hayward', which would suggest that it is a uniform cultivar. On the other hand, clone A was a seedling derived from `Hayward' and an unknown pollinizer. The results obtained using AFLP markers strongly suggest that `Tomuri' may have been the male parent of clone A. A specific protocol for kiwifruit characterization based on a modified AFLP technique is also presented, that gave rise to the highest percentage of polymorphism while scoring the lowest number of bands. This, together with the technical features of modified AFLP markers, make them very useful for identifying propagated kiwifruit plant material in commercial nurseries.