Search

National audience

In spite of being a small country, Croatia presents an important source of grapevine biodiversity which can be interesting for wine industry and breeding. In last two decades our research activities are focused on preservation, genotyping and evaluation of production characteristics of native varieties. To define full potential of native varieties there is a need to define the level of their susceptibility to fungal diseases. The aim of this research was to define the level of susceptibility/resistance of Croatian grapevine varieties to downey mildew (Plasmopara viticola) using modified field screening method. Altogether 57 genotypes/varieties were included in the research: 52 Croatian native varieties, two susceptible international V. vinifera L. cultivars (Cabernet Sauvignon, Riesling), 2 resistant cultivars (Solaris, Regent) and 2 Vitis species (Vitis ripara, Vitis amurensis). Own-rooted cuttings were planted in drip irrigated pots in field conditions close to the production vineyard at experimental station “Jazbina”, Department of Viticulture and Enology, Faculty of Agriculture Zagreb. After initial growing of shoots to the certain stage the monitoring of disease symptoms was carried out according to OIV descriptor 452 (degree of resistance on leaves). Results showed small difference among native varieties and majority of them have very low and low level of resistance to downy mildew, as expected.

INTRODUCTION – Common limits for phenotyping are costs in terms of equipment, specialized researchers, and time. Moreover, phenotyping requires specific methods in relation to the studied traits, and each method is generally designed to highlight very specific characteristics of the singular trait. Thus, the obtained results are not easily comparable between different institutions. However the data sharing is clearly the most powerful approach to limit the costs and efforts optimizing the obtained results in term of number of studied accessions. It should be stressed that funds are another great limit in research, especially in East countries, where the most interesting cultivar variability is preserved. 28 AIMS AND SCOPES – The main purpose of this work is the establishment of a phenotyping network able to produce comparable data among the Pan-European grapevine collections. MATERIALS AND METHODS – Two protocols were proposed: one for phenology and, the other, for enocarpological traits. Data were recorded in two consecutive vintages: 2012 and 2013. Concerning phenology, the extended BBCH scale (universal and flexible) was adapted to our objects by moving it into a chrono- phenological scale. Then, a cubic curve was selected for modelling the phenological courses. Thus, computing for each accession specific coefficients, it was possible to obtain the relative phenograms. Considering the different site climatic conditions, it was possible to spatialize the results, obtaining reference phenological maps. Concerning eno- carpological traits, the attention was focused on characteristics with a clear impact on the production quality, such as berry morphology (weight, diameters, number of seeds …) and composition (sugar, titratable acidity, anthocyanin and phenolic contents …). The protocol was organized to concatenate the data acquisition, with the objective to generate new derived variables. The methods were selected to be easily reproduced in all the involved collections, without the necessity of expensive facilities. RESULTS AND DISCUSSIONS – The first year of dataset was used to evaluate the methods. Two publications are already available confirming the protocols quality. Concerning phenology, both the variability between accessions grown into the same collection and the phenological shifts between the reference varieties cultivated in different areas were highlighted by the protocol. Matching climatic and phenological information of reference cultivars, phenophases maps were obtained. The performances obtained by the eno-carpological protocol were satisfactory both in a global point of view and in a singular collection evaluation. The project obtained an impressive participation, considering the volunteer contribution without any material funding to cover the work costs. Twenty-four institutions collaborate to the data collection. 1724 accessions were evaluated: 931 (583 in 2012 and 348 in 2013) for phenology and 793 (424 in 2012 and 369 in 2013) for eno-carpological descriptions. CONCLUSIONS AND POSSIBLE APPLICATIONS – The protocol sharing allows the data comparison among different grapevine collections. The possible future application for this dataset could be related to scientific studies of genetic associations. Moreover, the improved knowledge of minor and neglected cultivars could have a direct impact on the industrial production, giving information concerning new varieties for future introduction in viticultural areas.

There are solid genetic evidences of Croatian origin of Zinfandel which is also known under synonym names Primitivo (Italy) and Crljenak Kastelanski (Croatia). Besides, there is five century old historic evidence of existence of this genotype in Croatia. Since 2004 there is a field experiment with Zinfandel/Primitivo/Crljenak kastelanski (ZPC) clones on the island of Hvar. First preliminary results show that they are essentially same cultivar with slight clonal differences. Propagation of Crljenak Kastelanski is undergoing two ways, (1) traditional ones by classical cloning in order to increase the number of few detected vines in Croatia and (2) in FPS-UC Davis through tissue culture in order to get virus-free stock material. Currently, ZPC is being revitalized by Croatian vine growers using plant material of Primitivo from Italy. So far, there are about 15 ha planted with this variety. Preliminary experience with viticulture aspects and experimental wine making show the great wine potential of this variety in agro-ecological growing conditions of Croatia.