An efficient and simple method for varietal identification of the cherry tree

Professor Ana Wünsch Blanco has presented her PhD, at the Public University of Navarre, on the application of molecular technologies in the identification and enhancement of the cherry fruit tree.

The application of molecular technologies in the identification and enhancement of the cherry tree is not something new. In fact, the varietal identification of fruit species has been accompanied, in the past few years, by the appearance of DNA markers. This has enabled an investigation of the genome of each variety, independently of the state of development and the phenological state of the tree.

Other research has used these techniques for the identification of peach trees. The significance of the study in the cherry tree arises from the fact that this is one of the economically important stone-fruit species and, moreover, Spain is one of the most important world producers of this fruit. However, this importance is not reflected in the exhaustive studies on the identification of genotypes of the different varieties of the species.

In this paper, the researcher develops an efficient method for the identification of cherry varieties based on microsatellite-type molecular markers.

More than 100 varieties of cherry

Once the method is designed it is used to identify the collection of cherry tree varieties of the Zaragoza Food Research Service (SIA)where Ana Wunsch is currently working. Moreover, the identification of 28 genotypes of the Extremadura Regional Government collection of cherry tree patterns in Barrado (Cáceres) and another 17 genotypes from the Zaragoza SIA collection. The results have been very good given that current methods for the varietal identification of the cherry tree have been accelerated and optimised.

The PhD also includes a study of the pollen-pistil incompatibility feature in the cherry tree. According to this, the varieties of auto-incompatible cherry trees require the presence of pollinating trees, pollen donors compatible for production and, therefore, this compatibility feature and the acquisition of auto-compatible varieties is an important aim for improvement in this species.

A system has been established for the identification of incompatibility groups in this species and for the identification of a auto-compatible mutant which may be used in species enhancement programmes. This has made easier and has improved the establishment of protocols for the identification and early selection of auto-compatibility and its subsequent transference to the production sector.

Genetic similitude by geographic origin

This research has enabled the establishment of profiles of genotypes of the various varieties and patterns of the three above-mentioned collections and the study of the genetic similitude between them. Thus, it has been observed that the oldest varieties of cherry tree used as parent lines in the improvement programmes are grouped together for genetic similitude into two groups which correspond to their geographic origin: varieties originating in southern Europe and varieties originating in Central Europe and North America.

These results concur with the way in which varieties have been selected at a local level and with the movement of vegetable material of this species, given that it was mainly the Central European varieties that were taken to North America.

Moreover, with respect to the traditional varieties from the Jerte Valley in Extremadura, researchers have observed that are more genetically similar to each other than other varieties introduced at a later date, indicating that a group of local, autochthonous varieties exists which can be distinguished from the rest of the cultivated varieties which have been selected empirically by farmers in the area over the centuries. Knowledge and identification of this germoplasm will be of use for its future conservation.

Contact :
Iñaki Casado Redin
Nafarroako Unibertsitate Publikoa
inaki.casado@unavarra.es
(+34) 948 16 97 82