Aronia

Aronia is a genus of deciduous shrubs, the chokeberries, in the family Rosaceae native to eastern North America and most commonly found in wet woods and swamps. The genus Aronia is considered to have 3 species. The most common and widely used is Aronia melanocarpa (black chokeberry) which emerged from Eastern North America. The lesser known Aronia arbutifolia (red chokeberry) and the hybrid form of the above mentioned species called Aronia prunifolia (purple chokeberry) were first cultivated in Central and Eastern North America. In the eighteenth century, the first shrubs of the best-known species Aronia melanocarpa reached Europe where they were first cultivated in Scandinavia and Russia. Chokeberries are cultivated as an ornamental plant and as a food plant. The bitter berries, or aronia berries, can be eaten fresh off the bush, but are more frequently processed. They can be used to make wine, jam, syrup, juice, soft spreads, tea, salsa, extracts, beer, ice cream, gummies, and tinctures. The name "chokeberry" comes from the astringency of the fruits, which create the sensation of making one's mouth pucker. Chokeberries are often mistakenly called chokecherries, the common name for Prunus virginiana.…

Aronia is a genus of deciduous shrubs, the chokeberries, in the family Rosaceae native to eastern North America and most commonly found in wet woods and swamps. The genus Aronia is considered to have 3 species.  The most common and widely used is Aronia melanocarpa (black chokeberry) which emerged from Eastern North America. The lesser known Aronia arbutifolia (red chokeberry) and the hybrid form of the above mentioned species called Aronia prunifolia (purple chokeberry) were first cultivated in Central and Eastern North America. In the eighteenth century, the first shrubs of the best-known species Aronia melanocarpa reached Europe where they were first cultivated in Scandinavia and Russia. Chokeberries are cultivated as an ornamental plant and as a food plant. The bitter berries, or aronia berries, can be eaten fresh off the bush, but are more frequently processed. They can be used to make wine, jam, syrup, juice, soft spreads, tea, salsa, extracts, beer, ice cream, gummies, and tinctures. The name "chokeberry" comes from the astringency of the fruits, which create the sensation of making one's mouth pucker. Chokeberries are often mistakenly called chokecherries, the common name for Prunus virginiana. Further adding to the ambiguity, a variety of Prunus virginiana is melanocarpa, and readily confused with black chokeberry because it is commonly referred to as "black chokeberry" or "aronia". Aronia berries and chokecherries both contain polyphenolic compounds, such as anthocyanins, yet the two plants are somewhat distantly related within the Amygdaloideae subfamily. Black chokeberry is grown as a common shrub in Central Europe where it is mainly used for food production.

Identification and taxonomy

The leaves are alternate, simple, and oblanceolate with crenate margins and pinnate venation; in autumn, the leaves turn a bold red color. Dark trichomes are present on the upper midrib surface. The flowers are small, with five petals and five sepals, and produced in corymbs of 10–25 together. The hypanthium is urn-shaped. The fruit is a small pome, with an astringent flavor. Aronia has been thought to be closely related to Photinia, and has been included in that genus in some classifications, but botanist Cornelis Kalkman observed that a combined genus should be under the older name Aronia. The combined genus contains about 65 species. In 2004, Kalkman expressed doubt about the monophyly of the combined group, and new molecular studies confirm this. They do not place these two genera together or even near one another. In eastern North America, two well-known species are named after their fruit color, red chokeberry and black chokeberry, plus a purple chokeberry whose origin is a natural hybrid of the two. What has been regarded as a fourth species, Aronia mitschurinii, that apparently originated in cultivation, is now treated as × Sorbaronia fallax.

Breeding

One part of the breeding efforts focuses on improving red chokeberries for their use as ornamental plants. Breeding goals include the reduction of the plants stature, reduction of its tendency towards legginess, increasing the fruit size and improving leaf retention for a longer lasting fall foliage. Breeding of the red chokeberry is difficult, because the available accessions are tetraploid plants and thus, are likely to produce apomictic seeds. Furthermore, the breeding of polyploids makes mutation breeding more challenging because the additional sets of chromosome can mask incomplete mutations. If breeders had access to a wild diploid A. arbutifolia breeding would arguably become more successful. The breeding success of the black chokeberry for food production in Europe and Russia has been restricted because the genetic pool of the domesticated Russian plants is homogeneous. Breeding efforts aim to increase the content of polyphenol compounds while maintaining or increasing the fruit size. Further breeding targets are improvement of flavor.

Polyphenols

A. melanocarpa (black chokeberry) has attracted scientific interest due to its deep purple, almost black pigmentation that arises from dense contents of polyphenols, especially anthocyanins. Total polyphenol content is 1752 mg per 100 g dry weight, anthocyanin content is 1480 mg per 100 g dry weight, and proanthocyanidin concentration is 664 mg per 100 g fresh weight. These values are among the highest measured in plants to date. The black aronia species contains higher levels of anthocyanins than purple (Aronia prunifolia) or red aronia (Aronia arbutifolia), whereas red and purple aronia are richer in phenolic acid and proanthocyanins. The plant produces these pigments mainly in the leaves and skin of the berries to protect the pulp and seeds from constant exposure to ultraviolet (UV) radiation and production of free radicals. Many of these pigments are able to absorb UV light—beyond the visible spectrum—reducing damage to plant tissues. In the visible light range, the pigments appear blue, purple, or red because they reflect those colors while absorbing other wavelengths. These same bright colors also attract birds and other animals to eat the fruit, which helps disperse the seeds. Analysis of polyphenols in chokeberries has identified the following individual chemicals (among hundreds known to exist in the plant kingdom): cyanidin-3-galactoside, cyanidin-3-arabinoside, quercetin-3-glycoside, epicatechin, caffeic acid, delphinidin, petunidin, pelargonidin, peonidin, and malvidin. All these except caffeic acid are members of the flavonoid category of phenolics. For reference to phenolics, flavonoids, anthocyanins, and similar plant-derived phytochemicals, Wikipedia has a list of phytochemicals and foods in which they are prominent.

References

External links

Evergreen Native Plant Database hort.net: Aronia melanocarpa, Plant of the Month

Text derived from https://en.wikipedia.org/w/index.php?oldid=1371428511 under CC BY-SA 4.0; modifications have been made.

Names in other languages