imported>Fire: Created page with "{{Short description|Internal makeup of fruits}} squash plant (courgette), showing the ovary, ovules, pistil and petals]] '''Fruit anatomy''' is the plant anatomy of the internal structure of fruit.{{cite book| first = Charles B. | last = Beck | name-list-style = vanc |title=An Introduction to Pl..."

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Created page with "{{Short description|Internal makeup of fruits}} thumb|upright=1.5|Longitudinal section of a female flower of a [[squash (plant)|squash plant (courgette), showing the ovary, ovules, pistil and petals]] '''Fruit anatomy''' is the plant anatomy of the internal structure of fruit.<ref name="Beck2010">{{cite book| first = Charles B. | last = Beck | name-list-style = vanc |title=An Introduction to Pl..."

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{{Short description|Internal makeup of fruits}}

[[File:Femalesquash3747.JPG|thumb|upright=1.5|Longitudinal section of a female flower of a [[squash (plant)|squash plant]] (courgette), showing the [[ovary (plants)|ovary]], [[ovule]]s, [[Carpel|pistil]] and [[petal]]s]]

'''Fruit anatomy''' is the [[plant anatomy]] of the internal structure of [[fruit]].<ref name="Beck2010">{{cite book| first = Charles B. | last = Beck | name-list-style = vanc |title=An Introduction to Plant Structure and Development: Plant Anatomy for the Twenty-First Century|url=https://books.google.com/books?id=zSK1BuxMh9cC&pg=PA378|date=22 April 2010|publisher=Cambridge University Press|isbn=978-1-139-48636-1}}</ref><ref name="NPandey1993">{{cite book | vauthors = Pandey SN, Chadha A |title=A Text Book Ofbotany: Plant Anatomy and Economic Botany|url=https://books.google.com/books?id=uMOglvnKUpQC&pg=PA228|year=1993|publisher=Vikas Publishing House Pvt Ltd|isbn=978-0-7069-8685-3}}</ref> Fruits are the mature [[ovary (plants)|ovary]] or ovaries of one or more [[flower]]s. They are found in three main anatomical categories: [[aggregate fruit]]s, [[multiple fruit]]s, and [[simple fruit]]s. Aggregate fruits are formed from a single compound flower and contain many ovaries or fruitlets.<ref name=":3" /> Examples include [[raspberry|raspberries]] and [[blackberry|blackberries]]. Multiple fruits are formed from the fused ovaries of multiple flowers or inflorescence.<ref name=":3" /> Examples include [[fig]], [[mulberry]], and [[pineapple]].<ref name=":3" />

Simple fruits are formed from a single ovary and may contain one or many [[seed]]s. They can be either fleshy or dry. In fleshy fruit, during development, the '''pericarp''' (ovary wall) and other accessory structures become the fleshy portion of the fruit.<ref name=":2" /> The types of fleshy fruits are [[berries]], [[pome]]s, and [[drupe]]s.

In some fruits, the edible portion is not derived from the ovary, but rather from the [[aril]], such as the [[mangosteen]] or [[pomegranate]], and the [[pineapple]] from which tissues of the flower and [[plant stem|stem]] provide food. The [[grain]]s of grasses are single-seed simple fruits wherein the pericarp and seed coat are fused into one layer. This type of fruit is called a [[caryopsis]]. Examples include [[cereal grain]]s, such as [[wheat]], [[barley]], [[oat]]s and [[rice]].

== Categories of fruits ==
Fruits are found in three main anatomical categories: [[aggregate fruit]]s, [[multiple fruit]]s, and [[simple fruit]]s. Aggregate fruits are formed from a single compound flower and contain many ovaries or fruitlets.<ref name=":3">{{cite book | first1 = Ray Franklin | last1 = Evert | first2 = Susan E | last2 = Eichhorn | first3 = Peter H | last3 = Raven | name-list-style = vanc |title=Raven Biology of plants |isbn=9781429219617 |edition=8th |location=New York |oclc=781446671| date = 2012-03-02 }}</ref> Examples include [[raspberry|raspberries]] and [[blackberry|blackberries]]. Multiple fruits are formed from the fused ovaries of multiple flowers or inflorescence.<ref name=":3" /> An example of multiple fruits are the fig, mulberry, and the [[pineapple]].<ref name=":3" /> Simple fruits are formed from a single ovary and may contain one or many seeds. They can be either fleshy or dry. In fleshy fruit, during development, the pericarp and other accessory structures become the fleshy portion of the fruit.<ref name=":2">{{cite book | first1 = Ray Franklin | last1 = Evert | first2 = Susan E | last2 = Eichhorn | first3 = Joy B | last3 = Perry | first4 = Peter H | last4 = Raven | name-list-style = vanc |title=Laboratory topics in botany : to accompany Raven Biology of plants | edition = 8th | date = 2013 | publisher = W.H. Freeman and Co |isbn=9781464118104 |location=New York, NY |oclc=820489734}}</ref> The types of fleshy fruits are berries, pomes, and drupes.<ref name=":0">{{cite journal | vauthors = Dardick C, Callahan AM | title = Evolution of the fruit endocarp: molecular mechanisms underlying adaptations in seed protection and dispersal strategies | language = en | journal = Frontiers in Plant Science | volume = 5 | pages = 284 | date = 2014 | pmid = 25009543 | pmc = 4070412 | doi = 10.3389/fpls.2014.00284 | doi-access = free }}</ref> In berries, the entire pericarp is fleshy but this excludes the exocarp which acts as more as a skin. There are berries that are known as pepo, a type of berry with an inseparable rind, or [[hesperidium]], which has a separable rind.<ref name=":2" /> An example of a pepo is the [[cucumber]] and a [[lemon]] would be an example of a hesperidium. The fleshy portion of the pomes is developed from the [[hypanthium|floral tube]] and like the berry most of the pericarp is fleshy but the endocarp is cartilaginous; an [[apple]] is an example of a pome.<ref name=":2" /> Lastly, drupes are known for being one-seeded with a fleshy mesocarp; an example of this would be the [[peach]].<ref name=":2" /> However, there are fruits where the fleshy portion is developed from tissues that are not the ovary, such as in the [[strawberry]]. The edible part of the strawberry is formed from the receptacle of the flower. Due to this difference the strawberry is known as a false fruit or an [[accessory fruit]].

There is a shared method of seed dispersal within fleshy fruits. These fruits depend on animals to eat the fruits and disperse the seeds in order for their populations to survive.<ref name=":0" /> Dry fruits also develop from the ovary, but unlike the fleshy fruits they do not depend on the mesocarp but the endocarp for [[seed dispersal]].<ref name=":0" /> Dry fruits depend more on physical forces, like wind and water. Dry fruits' seeds can also perform pod shattering, which involve the seed being ejected from the seed coat by shattering it. Some dry fruits are able to perform seed pod explosions, such as [[wisteria]], resulting the seed to be dispersed over long distances. Like fleshy fruits, dry fruits can also depend on animals to spread their seeds by adhering to animal's fur and skin, this is known as epizoochory. Types of dry fruits include [[achene]]s, [[capsule (fruit)|capsules]], [[follicle (fruit)|follicles]] or [[nut (fruit)|nuts]]. Dry fruits can also be separated into dehiscent and indehiscent fruits. Dry dehiscent fruits are described as a fruit where the pod has an increase in internal tension to allow seeds to be released. These include the [[sweet pea]], [[soybean]], [[alfalfa]], [[milkweed]], [[Brassicaceae|mustard]], [[cabbage]] and [[poppy]].<ref name=":0" /> Dry indehiscent fruit differ in that they do not have this mechanism and simply depend on physical forces. Examples of species indehiscent fruit are [[sunflower]] seeds, nuts, and [[dandelions]].<ref name=":0" />

=== Evolutionary history ===
There is a wide variety in the structures of fruit across the different species of plants. Evolution has selected for certain traits in plants that would increase their fitness. This diversity arose through the selection of advantageous methods for seed protection and dispersal in different environments.<ref name=":0"/> It is known that dry fruits were present before fleshy fruits and fleshy fruits diverged from them.<ref name=":0" /> A study looking at the family [[Rubiaceae]] found that within the family, fleshy fruits had evolved independently at least 12 times.<ref name=":1">{{cite journal | vauthors = Bremer R, Eriksson O |date=September 1992|title=Evolution of fruit characters and dispersal modes in the tropical family Rubiaceae|journal=Biological Journal of the Linnean Society|language=en|volume=47|issue=1|pages=79–95|doi=10.1111/j.1095-8312.1992.tb00657.x|issn=0024-4066}}</ref> This means that fleshy fruits were not passed on to following generations but that this form of fruit was selected for in different species. This may imply that fleshy fruit is a favorable and beneficial trait because not only does it disperse the seeds, but it also protects them.<ref>{{cite journal | vauthors = Xiang Y, Huang CH, Hu Y, Wen J, Li S, Yi T, Chen H, Xiang J, Ma H | title = Evolution of Rosaceae Fruit Types Based on Nuclear Phylogeny in the Context of Geological Times and Genome Duplication | journal = Molecular Biology and Evolution | volume = 34 | issue = 2 | pages = 262–281 | date = February 2017 | pmid = 27856652 | pmc = 5400374 | doi = 10.1093/molbev/msw242 }}</ref> There is also a variety of dispersal methods that are used by different plants. The origins of these modes of dispersal have been found to be a more recent evolutionary change.<ref name=":1" /> Of the methods of dispersal, the plants that use animals have not changed in many ways from the original trait. Due to this, it may be assumed that animal dispersal is an efficient form of dispersal, however there has been no evidence that it increases dispersal distances.<ref name=":1" /> Therefore, the question remains of what evolutionary mechanism causes such dramatic diversity. It has been found, however, that simple changes within developmental regulatory genes can cause large alterations within the anatomical structure of the fruit.<ref name=":0" /> Even without knowing the mechanism involved in the biodiversity of fruit, it is clear that this diversity is important to the continuation of plant populations.

== Anatomy of simple fruits ==
[[File:Drupe fruit diagram-en.svg|upright=1.5|thumb|Diagram of a typical [[drupe]] ([[peach]]), showing both [[fruit]] and [[seed]]]]
[[File:Orange cross section description.png|right|thumb|upright=1.5|A schematic picture of an [[orange (fruit)|orange]] [[hesperidium]]]]
[[File:Citrus pulp1.JPG|thumb|upright=.8|A segment of an [[orange (fruit)|orange]] that has been opened to show the pulp ([[juice vesicles]]) of the endocarp]]

In berries and [[drupe]]s, the pericarp forms the edible tissue around the seeds. In other fruits such as [[citrus]] and stone fruits ([[Prunus]]) only some layers of the pericarp are eaten. In [[accessory fruit]]s, other tissues develop into the edible portion of the fruit instead, for example the [[receptacle (botany)|receptacle]] of the flower in [[strawberry|strawberries]].

== Pericarp layers ==
{{unreferenced|section|date=October 2021}}
In fleshy fruits, the pericarp is typically made up of three distinct layers: the epicarp (also known as exocarp), which is the outermost layer; the mesocarp, which is the middle layer; and the endocarp, which is the inner layer surrounding the ovary or the seeds. In a citrus fruit, the epicarp and mesocarp make up the [[peel (fruit)|peel]]. In dry fruits, the layers of the pericarp are not clearly distinguishable

=== Epicarp ===
Epicarp (from {{lang-el|epi-}}, "on" or "upon" + ''-carp'', "fruit") is a [[botanical]] term for the outermost layer of the pericarp (or fruit). The epicarp forms the tough outer skin of the fruit, if there is one. The epicarp is sometimes called the '''exocarp''', or, especially in [[citrus]], the '''flavedo'''.

==== Flavedo ====
Flavedo is mostly composed of [[cellulose|cellulosic material]] but also contains other components, such as [[essential oil]]s, [[paraffin wax]]es, [[steroid]]s and [[triterpenoid]]s, [[fatty acid]]s, [[pigment]]s ([[carotenoid]]s, [[chlorophyll]]s, [[flavonoid]]s), bitter principles ([[limonin]]), and [[enzyme]]s.

In citrus fruits, the flavedo constitutes the peripheral surface of the pericarp. It is composed of several cell layers that become progressively thicker in the internal part; the [[epidermis (botany)|epidermic]] layer is covered with [[epicuticular wax|wax]] and contains few [[stoma]]ta, which in many cases are closed when the fruit is ripe.

When ripe, the flavedo cells contain carotenoids (mostly [[xanthophyll]]) inside [[chromoplast]]s, which, in a previous developmental stage, contained [[chlorophyll]]. This hormonally controlled progression in development is responsible for the fruit's change of color from green to yellow upon ripening. Citrus flavedo may be scraped off the fruit to create [[Zest (ingredient)|zest]].

The internal region of the flavedo is rich in multicellular bodies with spherical or [[wiktionary:pyriform|pyriform]] shapes, which are full of [[essential oil]]s.

=== Mesocarp ===

The mesocarp (from Greek: ''meso-'', "middle" + ''-carp'', "fruit") is the fleshy middle layer of the pericarp of a fruit; it is found between the epicarp and the endocarp. It is usually the part of the fruit that is eaten. For example, the mesocarp makes up most of the edible part of a peach, and a considerable part of a tomato. "Mesocarp" may also refer to any fruit that is fleshy throughout.

In a [[hesperidium]], as is found in [[citrus|citrus fruit]], the mesocarp is also referred to as ''albedo'' or [[pith]]. It is the inner part of the [[peel (fruit)|peel]] and is commonly removed before eating. In [[citron|citron fruit]], where the mesocarp is the most prominent part, it is used to produce [[succade]].

=== Endocarp ===
[[File:Almond shell.jpg|thumb|[[Almond]] endocarp]]

'''Endocarp''' (from Greek: ''endo-'', "inside" + ''-carp'', "fruit") is a [[botanical]] term for the inside layer of the pericarp (or fruit), which directly surrounds the [[seeds]]. It may be membranous as in [[citrus]] where it is the only part consumed, or thick and hard as in the [[pyrena]]s of [[drupe]] fruits of the family [[Rosaceae]] such as [[peach]]es, [[cherry|cherries]], [[plum]]s, and [[apricot]]s.

In [[nut (fruit)|nuts]], it is the stony layer that surrounds the kernel of [[pecan]]s, [[walnut]]s, etc., and that is removed before consumption.

In [[citrus fruits]], the endocarp is separated into sections, which are called ''segments''. These segments are filled with [[juice vesicles]], which contain the [[juice]] of the fruit.

== Anatomy of grass fruits ==
The grains of [[grass]]es are single-seed simple fruits wherein the pericarp (ovary wall) and seed coat are fused into one layer. This type of fruit is called a [[caryopsis]]. Examples include cereal grains, such as wheat, barley, and rice.

The dead pericarp of dry fruits represents an elaborated layer that is capable of storing active proteins and other substances for increasing survival rate of [[germination|germinating]] seeds.<ref>{{cite journal | vauthors = Godwin J, Raviv B, Grafi G | title = Dead Pericarps of Dry Fruits Function as Long-Term Storage for Active Hydrolytic Enzymes and Other Substances That Affect Germination and Microbial Growth | journal = Plants | volume = 6 | issue = 4 | pages = 64 | date = December 2017 | pmid = 29257090 | pmc = 5750640 | doi = 10.3390/plants6040064 | doi-access = free }}</ref>

== See also ==
* [[Gynoecium]]

== References ==
{{Reflist}}

== External links ==
* {{cite EB1911 |wstitle=Fruit |volume=11 |pages=254–260 |first=Alfred Barton |last=Rendle}}

{{Fruits}}

{{二次利用|date=22 June 2022}}
[[Category:Fruit morphology]]

Fruit anatomy - Revision history