followed by the USA, Iran, Italy, Spain, Chile, and Ukraine. Sour cherry is often
called the fruit species of Eastern Europe because the most important producing
countries are located in this part of the world. Global production is about 1.3 million
tons (average 2014–2016). In countries where there is a keen interest in sour cherrybased products, such as the eastern European countries, production is usually
machine harvested and is increasing slightly. The world’s leading sour cherryproducing country is Turkey, followed by the Russian Federation, Poland, Ukraine,
Iran, the USA, Serbia, and Hungary [6].
Cherries are a deciduous fruit tree, having an attractive appearance during bloom
time. The cherry fruit is a nutrient dense food with relatively low caloric content and
significant amounts of important nutrients and bioactive food components including
fiber, polyphenols, carotenoids, vitamin C, and potassium [7]. Sweet and sour (syn.
tart) cherry ripen first among stone fruits, followed by apricot, peach, and plum.
Because sweet cherry is first on the fresh market, it is in high demand in the late
spring and early summer. The majority of sweet cherries are consumed fresh with the
remaining 20–25% processed as brined, canned, frozen, dried, or juiced. In contrast,
97% of tart cherries are processed primarily for cooking and baking and the
confectionary industries [7, 8].
Pollination is a crucial part of growing quality cherries because most of the cultivated
varieties of sweet cherry are self-incompatible. To set fruits, they require pollen from
suitable pollinating cultivars. Thus for the commercial production of sweet cherry, a
good orchard design, with enough pollinizers have to be planted [9]. Besides, pollinating
insects should be present for adequate transfer of compatible pollen to the stigma.
Among sour cherry cultivars, there are more and more self-compatible ones; however,
foreign pollination can improve quality even at these cultivars.
According to recent research, cherry flowers are very attractive to various insects
[10]. They observed activity of 31 species of insects belonging to 5 orders and 13
families of class. Honey bees (Apis mellifera) have been assumed to be the main
pollinators in cherry [11], due to their high demand for pollen and nectar and their
hairy body, which collects and disperses the pollen [12–16]. However, honey bee is
not active on temperature below 12
C or in rainy weather conditions. In that case,
pollination can be also successful since other insect species belonging to the Bombus,
Andrena, and Osmia spp. could maintain their activities on lower temperatures and
during rainy days [17]. Landscapes with wild bee habitats enhance pollination, fruit
set, and yield of sweet cherry, presumably due to their higher pollination efficiency
[18]. Therefore, it is very important to attract honey and wild bees to proper pollination
of these crops, especially commercial crop production.
2
Role of Nectar
Plant species that depend on insect (or other animal) pollinators for their reproduction have put lots of effort in many floral traits such as floral display, flower
architecture, color, scent, and nectar [19]. To attract pollinators, plants offer different
types of rewards, where floral nectar represents the main plant reward for many
29 Sugar and Polyphenolic Diversity in Floral Nectar of Cherry
757
called the fruit species of Eastern Europe because the most important producing
countries are located in this part of the world. Global production is about 1.3 million
tons (average 2014–2016). In countries where there is a keen interest in sour cherrybased products, such as the eastern European countries, production is usually
machine harvested and is increasing slightly. The world’s leading sour cherryproducing country is Turkey, followed by the Russian Federation, Poland, Ukraine,
Iran, the USA, Serbia, and Hungary [6].
Cherries are a deciduous fruit tree, having an attractive appearance during bloom
time. The cherry fruit is a nutrient dense food with relatively low caloric content and
significant amounts of important nutrients and bioactive food components including
fiber, polyphenols, carotenoids, vitamin C, and potassium [7]. Sweet and sour (syn.
tart) cherry ripen first among stone fruits, followed by apricot, peach, and plum.
Because sweet cherry is first on the fresh market, it is in high demand in the late
spring and early summer. The majority of sweet cherries are consumed fresh with the
remaining 20–25% processed as brined, canned, frozen, dried, or juiced. In contrast,
97% of tart cherries are processed primarily for cooking and baking and the
confectionary industries [7, 8].
Pollination is a crucial part of growing quality cherries because most of the cultivated
varieties of sweet cherry are self-incompatible. To set fruits, they require pollen from
suitable pollinating cultivars. Thus for the commercial production of sweet cherry, a
good orchard design, with enough pollinizers have to be planted [9]. Besides, pollinating
insects should be present for adequate transfer of compatible pollen to the stigma.
Among sour cherry cultivars, there are more and more self-compatible ones; however,
foreign pollination can improve quality even at these cultivars.
According to recent research, cherry flowers are very attractive to various insects
[10]. They observed activity of 31 species of insects belonging to 5 orders and 13
families of class. Honey bees (Apis mellifera) have been assumed to be the main
pollinators in cherry [11], due to their high demand for pollen and nectar and their
hairy body, which collects and disperses the pollen [12–16]. However, honey bee is
not active on temperature below 12
C or in rainy weather conditions. In that case,
pollination can be also successful since other insect species belonging to the Bombus,
Andrena, and Osmia spp. could maintain their activities on lower temperatures and
during rainy days [17]. Landscapes with wild bee habitats enhance pollination, fruit
set, and yield of sweet cherry, presumably due to their higher pollination efficiency
[18]. Therefore, it is very important to attract honey and wild bees to proper pollination
of these crops, especially commercial crop production.
2
Role of Nectar
Plant species that depend on insect (or other animal) pollinators for their reproduction have put lots of effort in many floral traits such as floral display, flower
architecture, color, scent, and nectar [19]. To attract pollinators, plants offer different
types of rewards, where floral nectar represents the main plant reward for many
29 Sugar and Polyphenolic Diversity in Floral Nectar of Cherry
757