Value of morphological characters for cultivar identification in strawberry (Fragaria x ananassa)

Strawberry (Fragaria x ananassa Duch.), like many other crops, has large numbers of cultivars both in breeding programmes and in commercial production. Problems with the accurate identification of cultivars have arisen. These difficulties are exacerbated by the need for unequivocal identification by vegetative characters alone when plants are clonally propagated from elite stocks before transplanting for fruit production. Thus, accurate identification at all stages of plant growth is essential if costly errors are to be avoided. In New Zealand, the varieties are characterised solely by morphological characters. An analysis of 17 strawberry cultivars in Auckland showed that there is substantial intra-cultivar variability for many of the characters. This, when coupled with poor discrimination between cultivars for many of the characters, leads to difficulty in their use for identification pur poses. Additionally, it was often found that our profile for a cultivar differed from that in the New Zealand Plant Variety Rights (PVR) description. Furthermore, there were often differences in the rating of the morphological characters between the New Zealand PVR description and the United States Patent for the same cultivar. However, a cluster 14 vegetative, flower, and fruit characters could used to identify the 17 cultivars used in this study. A significant problem of identification still remains for the plant breeder/propagator who deals almost exclusively with vegetative plants because vegetative characters alone are not sufficient for accurate identification.