BIP Article

Full Text

Reprint (PDF)

Argentina is one of the largest grape and wine producing countries in South America. Half of the Argentine and 70% of Mendoza grapevine growing area is cultivated with local varieties generically called "Criollas". Due to their rusticity, the "Criollas" have called the attention of local plant physiologists, who have noticed significantly higher tolerance to some environmental stresses when compared with European traditional varieties (Kaiser and Cavagnaro, 2001). These varieties can grow in soils with low water availability and high salt concentration, and still maintain their characteristic high yield and vigor. Characterizing the diversity of local populations would allow a more useful application of these materials in breeding programs. "Criollas" differ in morphology, physiology and enological aptitudes from traditional European varieties. Some "Criollas" varieties such as Moscatel Amarillo, Criolla Chica, Torrontés Mendocino and Torrontés Riojano, give raise to valuable regional wines. Torrontés Riojano has been internationally recognized for originating a dry wine with a Muscat taste (Agüero et al. 2001). The rest of the "Criollas" shows relatively low enology quality, only appropriate as table wines.

To discriminate and evaluate the genetic diversity and phenetic relatedness among Criollas, we used morphological and molecular markers in 9 Criollas, 6 European and 1 American varieties. Fifty-three morphological characters were numerically codified using a qualitative multi-status criterion and were used, after transformation, to design a data matrix of pair wise similarities between genotypes, by calculating the Simple Matching Coefficient (SMC). On the other hand, 4 primer combination were used for AFLP markers which were scored for presence or absence in each grapevine genotype. This molecular marker were used for calculating genetic similarities using the Dice Coefficient (DC) (Sneath and Sokal, 1973). Dendrograms obtained with morphologic and AFLP markers agreed in clustering the "Criollas" separately from the European and American varieties assayed, except for Muscat d' Alexandrie and Tempranillo which clustered with Criollas in the case of AFLP. The correlation between the two systems was neither significant nor very high.

The finding that "Criollas" comprise a group more or less separate from the most other vinifera varieties tested, was somewhat surprising since grapevine culture in Argentina data since the colonial times and has not been enough time to allow a natural evolution. This fact could reflect foundation of the "Criollas" from Spanish varieties more than evolution. Nevertheless, the results obtained by Agüero et al. 2003 strongly argued for a New World origin for some of the "Criollas" from Spanish and Mediterranean varieties. The close genetic relatedness between Criolla Grande and Tempranillo, as indicated by AFLP dendrogram, could reinforce this hypothesis. Our AFLP and morphology results suggest that the "Criollas" germplasm share a common genetic background differing, in genotype and morphology, from the French, American and Spanish varieties used for comparison in this study. The high degree of polymorphism detected and the possibility of screening a higher number of anonymous loci than morphological markers makes AFLP useful for studying genetic diversity within the "Criollas".

Morphological traits are relatively less reliable and inefficient for precise discrimination of closely related genotypes and for analysis of their genetic similarities when compared with DNA fingerprinting techniques. However, morphological traits, are useful for preliminary, fast, simple, and inexpensive varietal identifications and can be used as a general approach for assessing genetic diversity among phenotipically distinguishable cultivars, although they are inefficient on account of the time and cost involved.

AFLP similarities ranged from 76 to 98% (Dice coefficient), indicating an important source of genetic diversity among the "Criollas that can be exploited in future breeding programs. To our knowledge, this is the first report using AFLP markers to assess genetic variability on these materials. Another type of molecular markers like microsatellite, which are highly-abundant in the grapevine genome and shows codominant nature, will certainly contribute to determine the relationships between "Criollas" and European varieties and within "Criollas" and could be used for parentage analysis in further investigation.

References

AGÜERO, C.; RODRÍGUEZ, J.; MARTÍNEZ, L.; DANGL, G. and MEREDITH, C. P. Identity and Parentage of Torrontés cultivars in Argentina. American Journal of Enology and Viticulture, 2003 (In press).

AGÜERO, C.; MARTÍNEZ, L.; RODRÍGUEZ, J.; DANGL, G. and MEREDITH, C. P. Microsatellite DNA Analysis of Argentine Torrontés. In: American Society for Enology and Viticulture 52^nd Annual Meeting. (28^th - 30th June, 2001, San Diego, California, USA). Technical Abstracts, 2001. p. 74.

KAISER, R.M. and CAVAGNARO, J.B. Response of Argentinean and European cultivars of Vitis vinifera L. to water stress: I Vegetative growth. In: Symposium International Irrigation and water relations in grapevine and fruit trees, (4^th - 6^th December, 2001, Mendoza, Argentina). Technical Abstracts, 2001, p. 14.

SNEATH, P.H.A. and SOKAL, R.R. Numerical taxonomy. San Francisco, Freeman, 1973, 573 p.