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In this section you will get acquainted with specialized materials on topics related to the protection and restoration of endangered local vine varieties in the Greek-Bulgarian cross-border region, as part of the Project " SOS for endangered traditional vine varieties “.

The lessons were developed by a team of specialists from Bulgaria and Greece in the field of Oenology.

The aim of the project is to encourage comprehensive intervention and to enable long-term protection of endangered local grape varieties in the cross-border region in Bulgaria and Greece. The project examines local and endangered genotypes of grapes in Natura 2000. The main goal of the project directly contributes to strengthening the activities for biodiversity conservation in the region as a specific goal of the program. The contribution is presented through the following support activities:

1. improving the conservation status of local vine varieties by restricting foreign species;

2. joint DNA analysis and local species database development;

3. joint scientific work of experts from both sides of the border;

1. joint coordinated interventions;

2. increased regional identity of traditional vine varieties.

A self-check test is developed for each of the lessons.

Advantages and disadvantages of organic vine cultivation

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Organic farming aims at the cultivation of grapes and consequently the production of wines without residues from preparations used for the control of weeds and other pathogens of the vineyard. Weeds, according to organic farming, have a positive effect on the vine after feeding it with humus (organic ingredients) by increasing its natural fertility, they increase the population of worms and help reduce erosion. Earthworms contribute greatly in maintaining soil porosity and achieving the desired moisture, in the formation of humus and other compounds so that they are assimilable by the vine. Some of the most important advantages of organic agriculture and organic viticulture are:

• The protection of the crop without the use of chemicals.
• The production of nutritional products of high nutritional value.
• Respect for natural ecosystems while preserving its genetical variety.
• Respect for soil microorganisms, flora, fauna, crops and farmed animals.
• Improving soil fertility.
• Rational use of natural resources.
• Ensuring the breeding of animals with respect for their living habits.
• Avoidance of pollution.
• Assessing the effect of the interaction of cultivation techniques with the ecological and social environment.
• Organically grown plants contain less water and more nutrients and vitamins
• Natural organic farming methods do not contaminate water resources and do not exterminate beneficial insects and predators.
• Organic viticulture is a better way of producing grapes superior quality. Specific advantages of organic viticulture:
• Uses natural plant protection and nutrition-friendly preparations to the environment.
• Fertilization is done with materials of organic origin, such as animal manureorganic farming or manure, grapes, etc., as well as in use other methods, such as the co-cultivation of the vineyard with other species, but and green manure that help to enrich the soil organic matter.
• Grapes are safe for consumer health due to use natural preparations.
• The natural methods of organic cultivation of the vineyard are friendly to the environment, do not pollute water resources and do not destroy the benefits and microorganisms that help to improve soil fertility.
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Advantages and disadvantages of organic vine cultivation

In addition to the advantages, organic breeding also has weaknesses which you are called to face. More specifically:
The biological vineyards need diligent work, continuous monitoring and increased crop care (green cuttings, such as sprouting, leafing, etc.). Approved plant protection and nutrition products are available at high prices resulting in increased production costs. Lack of interest in the preparation of organic wine. Production and consumption of organic products is constantly increasing in all countries of the world. Especially in Europe, there has been observed a sharp increase in the consumption of organic products cultivation. Other disadvantages of organic farming are:

• Problems identified in their organization and operation producers and organic farms.
• Problems of farms.
• Problems of integration in the organic farming program.
• Problems of marketing and disposal of organic

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Advantages and disadvantages of organic vine cultivation

CONCLUSIONS

Concern about the negative environmental impact of modern agricultural practices, the growing use of non-renewable resources, and the long-term productivity of high external inputs of agricultural systems, led to various initiatives both governmental and non-governmental organizations in order to promote adoption and dissemination of more sustainable agricultural technologies. The growing interest in organic farming in recent years has led to a series of different surveys on producers' incentives for the adoption organic production systems. In the applied economic research, the factors that determine the adoption of new technologies and innovations, including demographic and economic characteristics of the producer (age, education, etc.), possibilities and ways of information and structural features of the holding (size, productive orientation etc.).

Results of several researches have shown that organic farms are usually smaller in size than conventional, organic farmers have a higher educational level and a lower age from contract producers, while most come from urban areas and have little agricultural experience. This may be due to the fact that the producers engaged in organic farming, have entered agriculture more recently than conventional.

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Advantages and disadvantages of organic vine cultivation

Overall, as far as it concerns keeping the soil in good condition and restoring its fertility, the basic rules of organic farming for vine production are:
a) the cultivation of legumes,
b) the application of greenery fertilization,
c) the cultivation of deciduous plants under a program rotation of crops
d) the use of manure derived from organic farming and use of organic-made compost plant materials (residues of biological origin),
e) use of grape varieties well adapted to the soil-climatic environment of the area and
f) the fight against pathogens and diseases, which is achieved by the selection of tolerant varieties, by implementing programs and avoid burning of weeds
g) covering of the ground surface and creating favorable conditions for the development of beneficial organism

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Test lesson 1

1.The basic rules of organic farming for vine production are:
a) Protection of the crop with the use of chemicals
b) Respect for soil microorganisms, flora, fauna, crops and farmed animals
c) Use technological resources for improving soil fertility
d) Organic farming use more water compared to conventional farming
e) All of them are correct
2.The most safe and beneficial method for preventing plant diseases in biological agriculture in vineyards is
a) ’burning of weeds’
b) Avoidance of air pollution
c) Selection of tolerant varieties
d) Selection of genetically modified grapevine varieties
e) None of them is correct

3.The main disadvantage of organic farming in vineyards is
a) The biological vineyards need diligent work and continuous monitoring
b) Organic farming use natural preparations natural methods of organic cultivation
c) Organically grown plants contain less water
d) Fertilization is done with materials of organic origin, such as animal manure
e) All of them are correct
4.We can increase natural fertility and soil porosity in a vineyard by
a) the cultivation of weeds
b) the cultivation of medical plants
c) the cultivation of legumes
d) the application of salicid acid
e) the use of new transgenic grapevine varieties
5.The main disadvantage of organic farming in vineyards is
a) The biological vineyards need diligent work and continuous monitoring
b) Organic farming use natural preparations natural methods of organic cultivation
c) Organically grown plants contain less water
d) Fertilization is done with materials of organic origin, such as animal manure
e) All of them are correct Check results

Effect of water status of the vine plant in the chemical composition of the grape

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Water affects basic physiological functions such as photosynthesis and as a result the quantity and quality of production. Irrigation significantly increases photosynthesis, production and vigor of vine shoots depending on irrigation time, amount of water applied, environmental conditions and other cultivation techniques. However, the application of large amounts of water increases production, with serious effects on quality, mainly due to the reduction of anthocyanins in the rail crust and the sugar content Deep knowledge of the mechanisms that regulate the photosynthesis of the vine and its differentiation under conditions of different water availability from the soil is necessary to determine the correct irrigation tactics. Irrigation is based on the climatic conditions prevailing in an area, the soil type of the vineyard and the stage of plant growth.
The concentration of sugars in the grape depends on the growing conditions, production size and climatic conditions.
The main sugars of grape are glucose, fructose and in lower content sucrose. These come from the photosynthetic activity of the leaf, but can be directed to the grapes.
The results of previous research on the effect of irrigation on carbohydrate concentration are contradictory, sometimes positive and sometimes negative, and there are cases where their concentration is not affected (Irrigation increases grape production).

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Effect of water status of the vine plant in the chemical composition of the grape

The total soluble solids can be reduced when the dilution set causes the growth of the grape in their concentration is faster than carbohydrate accumulation
The plant growth of irrigated vineyards is observed due increased leaf area and photosynthetic capacity and as a result we have the production of total soluble solids in shoots tissues.
Many researchers report that the relationship between carbohydrates and grape weight is linear regardless of the fact whether irrigation is applied or not.
The water stress of the stem affects growth of the grape both through its role in the size of the grape as well and through its effect on competition with shoots for the attraction of photosynthesis products. Nevertheless, the optimal application time and suitable aqueous soil content for the start of irrigation is difficult to identify. But it is generally accepted that a mild water stress, during the period shortly before percussion but also during the process maturation of the grape didn’t significantly affect photosynthesis activity, while further improving the ratio must / solid residue.
The estimation of total sugars can be examined before the beginning of harvesting period using a refractometer that continuously monitoring sugars with discrete analyzer (DA).
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Effect of water status of the vine plant in the chemical composition of the grape

Phenolic compounds are by-products of sugar metabolism. They are synthesized through the path of sicicic acid. The key enzyme for the synthesis of phenolics of acids is phenylalanine lyase (PAL), which removes phenylalanine from protein synthesis and leads it to the synthesis of phenolic compounds. Another biochemical pathway that starts from glycolysis, also leads to the formation of phenolic substances. The contribution of three molecules of acetyl-coenzyme A (Acetylo CoA) and CO2 result in three Monynyl-coenzyme molecules. Both different paths lead to the composition of chalcone which is a precursor of flavonoid phenolic compounds. The predominant groups of phenolic compounds in grapes are: 1. Benzoic acids (primary catechins, gallic , acid, hydroxybenzoic acid) and cinnamic acids (coumaric, ferulic). 2. Flavanols (campferol, quercetin, myricetin). 3. Flavans-3-all (catechins) and their polymers (tannins) 4. Anthocyanidins (malvidine, delphinidine, petunidine, peonidine and cyanidine). The phenolic compounds in the grape are found in the peel and in the seeds, while for some varieties of colored flesh these can also be found in the flesh
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Effect of water status of the vine plant in the chemical composition of the grape

The grape peel is particularly rich in flavanols and anthocyanins (in the case of red varieties), while flavan-3-all are distributed mainly in their seeds and to a lesser extent in the peel (skin). The concentration of phenolic compounds in the grape varies during growth development maturation depending on the intensity of solar radiation, temperature, abscisic acid concentration and cultivation practices. There is generally an increase in concentration of anthocyanins from the percussion onwards, which is proportional to the increase in the surface of the grape. There are many reports about how carbohydrate accumulation may be affected in the synthesis of anthocyanins, through their effect on osmotic potential of cells of the skin of the grape. Existing reports on the effect of water to the final content of total phenols in the grape are contradicted. Several scientists argue that early and late deficiency water help increase total phenols while each factor that after spraying causes its increase rail size is inhibitory to the growth of phenolic.
On the contrary, formation of phenolic compounds is correlated with the level of water- soluble carbohydrates during the growing season and the maturation of the grape.
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Effect of water status of the vine plant in the chemical composition of the grape

Thus any factor that increases the photosynthetic capacity of the leaf surface, increases the supply of grapes with carbohydrates and therefore increases the content of phenolic compounds. Many researchers concluded that increased rates of anthocyanins in water stress conditions are a result of increased concentration due to the reduction of the size of the grape, regardless of the biosynthesis rate of anthocyanins. According to them mild irrigation conditions during maturation enhance the content of phenolic compounds in the and in particular flavonols and proanthocyanides.
Classical methods are used to measure total phenolic content, total flavonoid content, The most common are 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP).
However, it is well known that in the mesocarp (flesh) of the grape apart from water, sugars, proteins and minerals it contains a large amount of fruit acids. Next to sugars, organic acids are the most known compounds in grapes. They are very important components of the pericarp of the grape. There are many organic acids in the grape skin and flesh (including amino acids) but malic and tartaric acid account for over 90% of the total acids. Other organic acids such as succinic, acetic, citric, lactic, fumaric, and shikimic acids. The determination of acidity is expressed as titratable acidity (TA). The TA is an important parameter that producers of vine use to estimate the quality of wine. Also measurement of acidity can be determined by ion chromatography (IC).
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Test Lesson 2

1.The methods for the evaluation of sugars content are:
a) using a refractometer
b) using a spectrometer
c) using a plant efficiency analyzer
d) using a plant fluorescence analyzer
e) using a penetometer

2.We can evaluate the acids by:
a) High Liquid chromatography
b) ion chromatography
c) PCR-polymerase chain reaction
d) elecrophoresis methods
e) all of them are correct

3.Tannins are :
a) important group of phenolic compounds
b) important group of primary plant metabolites
c) compounds of pigments
d) compounds of sugars
e) compounds of carbohydrates
4.The most classical method for measuring total phenolic content is :
a) anthrone method
b) lipid peroxidation
c) oxidative damage
d) ferric reducing antioxidant power
e) none of them is correct
5.The factors that can cause sugars fluctuations in the grape are:
a) the climatic conditions
b) the growing conditions
c) the production quantity
d) none of them is correct
e) all of them are correct
6.Water stress of the stem affects growth of the grape by:
a) inhibition photosynthesis process
b) playing important role in the colour of the grape
c) competing with grapes the photosynthetic products
d) lowering the transpiration rate
e) by changing the assimilation rate of CO2
7.Phenolic compounds are:
a) carbohydrates
b) organic acids
c) amino acids
d) terpenoids
e) by-products of sugar metabolism Check test

Grapevine adaptation to drought stress

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The terms stress and resistance to stress are used for plants in the same way they refer to animals and humans. Stress basically means a state of tension and shows the effects of a negative charge on the body. It is caused by the involvement of external factors (stressors), which lead either to damage or to a reduction in metabolism and growth. Stress factors can be biotic (ie due to other organisms) or abiotic (resulting from extreme environmental conditions outside the plant). One factor that can cause strain to plants is water. The flooding of the soil with water results in the pores of the soil being saturated and thus can cause lack of oxygen, which is necessary for the respiration of the roots of plant organisms, resulting in the latter suffering from anoxia.

On the contrary, the lack of soil water can cause a reduction in growth in mild conditions until the plant dries out intensely. In general, dehydration refers to a condition in which the water capacity and cell density are reduced to such an extent that normal functions are affected. Plants in order to cope with water stress conditions develop various mechanisms and thus ensure their survival. Grapevines’ responses to water scarcity are complex and can be either stress-adaptive or harmful. Under field conditions, these reactions can be cooperative or competitive, modified by the simultaneous action of other stresses. The reactions of vines in order to face drought involve a set of stress avoidance or tolerance mechanisms that vary depending on the genotype. This complexity is well illustrated in Mediterranean-type ecosystems where plants predominate.
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Grapevine adaptation to drought stress

Drought avoidance reactions (such as the deep root system). Rapid reactions to water stress help in immediate survival, while acclimatization, which refers to new metabolic and structural properties, is achieved by altering gene expression. This helps to improve the functionality of vines under water stress.

These reactions include:

• Stress tolerance (vines tolerate stress without major damage).

• Protection against the stress factor through appropriate protective mechanisms. Reversing the effects of stress through repairing the damage caused. Vine is a plant that is resistant to water stress. This resilience is due to anatomical and physiological changes in the whole plant, which aim in reducing its water needs and its losses through evaporation and transpiration.
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Grapevine adaptation to drought stress

A. Anatomical changes.
The vine, like many other plant species, develops various anatomical features in order to cope with dry environmental conditions such as in the Mediterranean. These characteristics may be more pronounced or less pronounced depending on the environmental conditions. Some characteristic changes are:

• Increasing the resistance of the root to the movement of water. In conditions of water stress the epidermis of the root is covered with cork, in order to protect the organ from complete dehydration. However, cork is an additive resistance to water movement.

• Embolism formation The creation of embolism ie the breaking of the water column in the xylem vessels and the interruption of its continuity, results in the increase of the resistances to the flow of water in the transport system. Specifically, when the continuum of transpiration current is interrupted, then air bubbles form inside the vascular system of the plant, which expand to fill the entire system. However, the expanding bubbles cannot easily penetrate the small pores of the membranes that exist at the junction of the trachea. This contributes to the lateral movement of the resulting water increasing the resistances to the movement of water through it vascular system.

• Reduction of the size of the vascular system. Even in controlled water stress the size of the vessels can be reduced and consequently the hydraulic conductivity of the xylem tissue.

• Disposal of strongly developed schlerenchyma tissues. The involvement of schlerenchyma tissues in the leaves seems to be associated with the prevention of the collapse mechanism in conditions of intense dehydration. In cells with inelastic walls the change in cell volume relative to sparse loss is much smaller than in cells with rubber walls.

• Thick protective tissues and hairs. They help to reduce water vapor losses and to reflect sunlight from the surface of the tissues of the plants they cover. For the same reason they develop many small stomata.

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Grapevine adaptation to drought stress

B. Physiological changes.
1. Stomatal operation.
As species have been reported the lack of water causes closure of the stomata in order to reduce respiratory losses. It is known that the width of the oral cavity is regulated through changes in tidal pressure mainly of guard cells.
These changes can be:

• Passive.
The passive changes are due to the immediate loss of water from the guard cells due to evaporation. Passive closure of the stomata is favored in an atmospheric environment with low relative humidity, when the rate of vapor loss from the guard cells. The concentration gradient of water vapor is about a hundred times that of CO2, meaning that water can diffuse out of a leaf a hundred times faster than CO2 can diffuse in when the stomata are open e cells is higher than that with which they are replenished through the adjacent epidermal occlusive (guard) cells.

• Active.
The active changes are due to a mechanism, which is activated through specialized stimuli and is due to the modification of the metabolic activity of the guard cells. The stomatal closure occurs due to the release of certain cations from the guard cells, resulting in the loss of their stretching. In this procedure also hormones like abscissic acid, regulates the stomatal opening to conserve water during times of stress.
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Test lesson 3

1.One of the most important drought avoidance reaction of the grapevine plant is:
a) increased number of roor hairs
b) increased evaporation
c) increased transpiration
d) Deep root system
e) decreased stomatal conductance

2.Grapevine succeed to reduce respiratory losses by:
a) increasing the size of the leaf
b) increasing the thickness of the leaf
c) decreasing the thickness of the leaf
d) embolism formation
e) none of them is correct

3.The role of thick protective tissues is
a) reduce water vapor losses of the plants they cover.
b) reflect sunlight from the surface of the tissues
c) develop many small stomata
d) none of them is correct
e) all of them are correct

4. The meaning of the word stress in plants is
a) a state of increased metabolism and growth.
b) a state that probably causes totally inhibition
c) a state that probably causes reduction in metabolism and growth
d) a state that causes decreased transpiration
e) none of them is correct

5.One anatomical feature that grapevine develops in order to cope with dry environmental conditions is
a) decreased resistance of the root to the movement of water.
b) damage of epidermis
c) increased size of the vascular system
d) embolism formation
e) all of them are correct

6.A plant hormone called ___ regulates the stomatal opening to conserve water during times of stress.
a) indolulelic acid.
b) absisic acid
c) auxin
d) ethylene
e) kinetin

7.Water moves from the soil through the root cortex
a) only via xylem
b) only via phloem tissues
c) via xylem and phloem tissues
d) via casparian stript
e) none of them is correct

8.Occlussive cells are
a) the schlerechymatic cells
b) the guard cells
c) parenchyma cells
d) epidermical cells
e) none of them is correct

9.The flooding of the soil with water results in the pores of the soil
a) being saturated and thus can cause lack of oxygen
b) being empty and thus can cause lack of oxygen
c) being saturated and thus can be full of oxygen
d) none of them is correct

10.The concentration gradient of water vapor is about a hundred times that of CO2, meaning
a) that water can diffuse out of a leaf a hundred times faster than CO2 can diffuse in when the stomata are open
b) that water can evaporate out of a leaf a hundred times faster than CO2 can evaporate in when the stomata are open
c) that water can diffuse into a leaf a hundred times faster than CO2 can diffuse out when the stomata are open
d) that water can dilute all the chemicals compounds, a hundred times faster than CO2 can dilute the compounds when the stomata are open
e) none of them is correct Check test