Qualitative Studies of “ Bacouri ” : A Greek High Quality Vine Variety

The morphological description of the vine variety Bacouri (Vitis Vinifera L. spp. sativa) that is based on descriptors defined by the Organization Internationale de la Vigne et du Vin (OIV) is presented in this paper. The variety Bacouri was investigated as being a valuable Greek variety for the production of high-quality red wines of different classes. Morphological characteristics, technological features with recommendations for red wine production using micro wine-making methods and the economic importance of the variety are provided. Its value in vine breeding has also been taken under consideration. The origin of the variety is the Peloponnese region, in the south part of Greece and it is a descendant of the region’s wild species of Vitis sylvestris.


Introduction
The Vitaceae (Lindl) Juss family consists of at least 16 genera of which the genus Vitis (Tournef) L. is the most important.It includes 70 Vitis species and more than 40.000 varieties grouped into two sub-genera, the Euvitis Planch (2n=38) and Muscadinia Planch (2n=40).According to the existing data, varieties of Vitis (Tournef) L. are found in most continents although for many reasons, along with economical reasons, there is not yet a complete collection in a common genetic bank.The banks of genetic material around the world for Vitis differ, consisting mostly of local Vitis genotypes.The largest Vitis collections are found in France, USA, India and Ucraine.(Alleweldt and Blaich, 1988;Alleweldt and Dettweiler, 1994;Galet, 1998).
Greece is one of the oldest areas of genesis and formation of cultivated grapevine.The ancient culture in favorable natural situations, as also the long process of natural and artificial selection resulted in a great diversity of cultivated Vitis varieties that survived up to nowadays.The Vitis collection of the Institute of Viticulture at Likovrisi in Athens (Greece), one of the largest in the Balkan region, includes more than 800 Vitis varieties from all over Greece.The most of them (98%) are Vitis vinifera, while 60% of them are local varieties.Information for Greek vine varieties and their potential in breeding currently is scarce.The aim of this work, as part of a wider effort for the taxonomy and evolution of Greek vines, was to characterize the promising variety Bacouri, based on common methods, for future vine breeding and the development of new varieties.In terms of morphological parameters, the variety Bacouri is close to the wild vine Vitis vinifera L. ssp.silvestteris Gmel.In terms of its morphological-physiological parameters the variety belongs to the ecological-geographical group of varieties Vitis vinifera spp.sativa D. C. convar pontica Negr.subconvar balcanica Negr.(Negrul, 1938;Negrul, 1946;Krimbas, 1943).The variety Bacouri was investigated as being a valuable Greek variety for making high-quality wines for different classes and for its use in breeding new vine varieties with unique characteristics.

Environmental characteristics of the study region
The Vitis collection of the Institute of Viticulture in Athens, is located at the North East part of Athens (37 ο 58' N and 23 ο 24' E), 210m above the sea level.The climate is Mediterranean with hot dry summers and mild winters.The absolute maximum temperature, at shade, is +45 ºС (2007) hence the critical for the grapevine temperatures (+40 ºС) are reached every year in this area.The annual level of precipitation is around 360-600mm and occurs mainly during winter period.The soil contains 1% organic matter, whereas CaCO 3 concentration ranges between 12% -15% of the total dry mass.pH values range between 7.6-8.1.

Background information
The study of the Greek Vitis vinifera red variety with common name Bacouri, was performed in vine plants grafted on Richter-110 (R-110), a Vitis hybrid, reputed as drought-tolerant.Plants used in this study were 12 years old and 60 cm height.Applications in breeding experiments need macroscopic descriptors as basis for selection.Additionally, newer technologies based on genetic descriptors, as a valuable taxonomic tool, can be enhanced to their full potential when related to macroscopic evidences (This et al., 2006; Lefort and Roubelakis-Angelakis, 1999).The morphological description of the variety Bacouri and subsequent parameters coding were conducted based on the recommended methodology of the Organization Internationale de la Vigne et du Vin -OIV (2001).

Vine crop establishment
Grafted vines were planted in lines with 2m distance between lines and every year were shortened to 2 buds per branch, leaving in total 16 to18 buds for clematis formation.All basic cultivation procedures (e.g.fertilization and plant protection) were based on common husbandry practices and were performed regularly every year maintaining standard growth conditions.

Study of the variety
The study of the variety was conducted based on the following procedures.

Determination of the name
The determination of the variety's name was based on previous studies regarding the most commonly cultivated areas, the origin of the variety and its geographical distribution (Viala and Vermorel, 1901;Krimbas, 1943).

Botanical description
The botanical description of the variety was performed based on morphological characteristics of certain parts of the plant such as the young clematis, one year old clematis, leaf shape, flower, grape and seed.The morphological futures were evaluated and expressed according to the categorical numbering based on the definitions provided by O.I.V. (2001).

Physiological studies
The physiological studies of the variety were considered aspects of: Phenological observations, the production period from the time of bud formation to the collection of grapes, the quality and quantity of produced grapes, the woody formation of one year shootings, the successful grafting with rootstock Vitis species, the cold and draught tolerance, the disease resistance, the tolerance in active calcium, the self pollination ability and the adaptation in different environments (Pearson and Goheen, 1988)

Biochemical properties
The biochemical properties of the grapes, red wine production including the starting period for grape harvesting, sugar content, acidity and fermentation parameters (temperature, carbohydrates, alcohol) were also studied according to methods proposed by Egan et al. (1981).

Breeding potential
Clone production and inheritance of the basic characteristics was based on studies with sporophytes from breeding experiments that has been previously described (Zamanidis, 2006), using cross pollination with other Vitis varieties, collection of hybrid grape seeds, planting of the seeds and cultivation of hybrid plants, study of the hybrid plants, selection of the best hybrid plans and breeding.The duration of the productive period (from the beginning of the bud opening to the harvesting of the yield) is 136-145 days.The variety exhibits medium growth since the length of the shootings lies between 1.3-2.0 m.The degree of ripening of the shootings is high between 81 -95%.The yield can reach 17 t /ha or even higher.However, the production of high-quality wine requires the regulation of the number of bunches per grapevine.When the amount of grapes of the grapevines is 3-4 kg, then high-quality red wine is produced.The percentage of fructiferous shoots is 90%, and the number of bunches per shoot is 1-2.The weight of the separate bunches of grapes is at least 600 g whereas the variety grows well on poor, dry and limy soils.
The variety is strongly resistant to drought but responds well to fertilization and irrigation resulting in increased yields, It is relatively resistant to cold, with medium resistance to mildew (Erysiphe graminis), downy mildew (Peronospora spp.) and botrytis (Botrytis cinerea) and good compatibility to the regional rootstocks.
The stem-cup shape of the trees is done with the trunk length 40-60 cm, at planting scheme 1.2-1.5 or 2.0-2.5 m and with 3-5 branches in order to maintain stable and high-quality yield.The cutting is done at 2 buds at loading of the vines with 12-15 fruiting shoots.The variety is also cultivated as cordon royal with trunk height 110-120 cm at planting scheme 1.2-1.5 x 2.0-3.0 m.The pruning is done at 2 buds too, and the loading is increased to 15-18 or 16 -20 fructiferous canes.

Phenology observations
In the Attica region the burst of the buds begins during the first ten days of April, the blooming starts at the end of May and the beginning of the ripening the first ten days of August and is completed at the last ten days of August.The average weight of bunch is 400 g, the average weight of 100 berries is 390 g and the average weight of 100 seeds is 3.2g.As a percentage of the total weight of the bunch the grapes are 94%, and of the stem 6%.As a percentage of the total weight of the berries, the juice and the flesh are 89%, and the skin and seeds 11%.The sugar concentration in the juice of the berries is over 23 g/100cm 3 and the titrate acidity is 5-6 g/l.

Technology applications
The micro wine making method produced a unique red wine with the following parameters: alcohol content: 13.0-14.0% vol., titrate acidity 4.6-5.7 g/l while fructose content varied between 1-2g/100 cm 3 .The wine was red-purple color, with good body, light in tannins and rich in phenols which allows it to be consumed as a young wine, with a complex aroma of forest fruit and spices.The variety is very promising for cultivation in all regions for making high-quality wines.It can be used for genetic improvement of existing grape varieties and as a source of genes of valuable biological-economical significance being equally important as other popular varieties (Pino Noir, Merlot, Sirach and Cabernet-Sauvignon).

Conclusion
Studies with macroscopic descriptors of the variety Bacouri, provide basic valuable information of genetic material for the production of new quality wines.Bacouri vine variety due to its remarkable characteristics, as it is described above, along with its high quality wine production, its tolerance in drought and various common vine diseases offers new potential for wine products with new tastes and flavors.In addition it can serve as a donor for genetic material for new hybrid vine varieties with unique viticultural and oenological characteristics.

Figure 2 .Figure 3 .
Figure 2. Mature leaf of the vine variety Bacouri (a) upper (b) back side