Ampelographic Description and Sanitary Analysis of Four Istrian Grapevine Varieties (Vitis vinifera L.)

Istrian Peninsula, one of the five districts within viticultural region of Coastal Croatia, provides great geological-reliefal and climatic diversity and various production conditions. This research studied the autochthonous varieties and their sanitary status in old vineyards. Considering the age of vineyard, ten locations were chosen where four autochthonous varieties ‘Malvasia istarska’, ‘Teran’, ‘Borgonja’, and ‘Pergola velika’ were identified using ampelographic description according to OIV descriptors. Morphological characteristics of chosen varieties were described using OIV parameters and must was chemically analysed (pH value, sugar content, titratable acidity). High intra cultivar variability was found for weight of a single bunch especially for ‘Teran’. There were also differences in sugar content of must particularly for ‘Pergola velika’. Must pH was low for all varieties with predominantly low acidity value. Sanitary status of vines was determined by testing the plant samples for the presence of three grapevine viruses (GLRaV-1, GLRaV-3 and GFLV) using DAS-ELISA. The percentage of infection for GFLV was 55.6% while for GLRaV-1 and GLRaV-3 it was 61.1%. Results showed that some morphological characteristics differ from characteristics described in literature. With purpose of preserving the biodiversity of autochthonous varieties and for future researches, healthy propagation material will be collected and planted in collection field of autochthonous varieties at the Institute of Agriculture and Tourism, Poreč