Artocarpus altilis

Artocarpus altilis

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Overview

Brief Summary

Breadfruit (Artocarpus altilis) is a rapidly growing tree that is widely planted in the tropics for its edible fruit and value as an ornamental and shade tree. It is of particular economic importance in the Pacific islands, where it is a staple or subsistence crop on many islands. Peterson (2006) argues that the development of vigorous hybrid Breadfruit cultivars led to a "Breadfruit Revolution" 600 to 1200 years ago that was a major driver of sociocultural evolution across Micronesia.

Breadfruit trees are often found in home gardens, in secondary forests, and along roadsides. The spherical to cylindrical rough-skinned fruit is 10 to 30 cm in diameter and 0.25 to 6 kg, with a yellow to green rind and a starchy creamy white to yellow pulp (starch content ~20%). Depending on the variety, seed number may range from none to many. Breadfruit is a "multiple aggregate" fruit (i.e., each fruit is formed from an entire inflorescence consisting of multiple flowers). Seeded fruits have a surface composed of greenish conical spinelike projections, each from a single flower. Seedless fruits have a smoothish surface honeycombed with individual fruits around 5 mm across. The glossy leaves are very large and deeply lobed, dark green and smooth above, lighter and distinctly veined below. I

Breadfruit is monoecious (i.e., individual trees function as both males and females), with separate male and female flower clusters--each consisting of thousands of tiny flowers attached to a spongy core--emerging from leaf bases on the same tree. Breadfruit flowers are cross-pollinated, but pollination is not required for fruit development. The bark of the Breadfruit tree is smooth and brown with warty lenticels; milky juice exudes from the bark when cut (a white milky latex is present in all parts of the tree).

Potted Breadfruit trees (seedless) were brought on the Providence to the West Indies (St. Vincent and Jamaica) from Tahiti in 1793 by Captain William Bligh as a cheap food for slaves on the sugar plantations (an earlier attempt by Bligh on the Bounty was unsuccessful, ending in the famous "Mutiny on the Bounty" in 1789 upon leaving Tahiti). Around the same time, the French brought some Breadfruit trees to several other Caribbean islands.

(Little and Wadsworth 1964; Seddon and Lennox 1980; Ashton 1989; Vaughan and Geissler 1997; Ragone 2006)

The ripe fruits can be eaten raw when ripe, but are more commonly picked when mature (but not quite ripe), then cooked. Seeded varieties are most common in the southwestern Pacific. Seedless varieties are most common in Micronesia and the eastern islands of Polynesia. All the varieties elsewhere in the tropics are seedless. Seeds are dispersed by fruit bats and possibly doves and other birds.

Hundreds of named Breadfruit varieties in the Pacific Islands are propagated vegetatively. Depending on variety, age, and tree condition, fruit yield ranges from fewer than 100 to more than 700 fruits per tree, with an average around 150 to 200. In intensive cultivation, yields of 160 to 500 kg of fruit per tree per year can be achieved. (Ragone 2006)

Some Breadfruit cultivars are fertile diploids (2n = 2x = 56), but many are sterile hybrids or triploids (2n = 3x = 84) and must be vegetatively propagated (Ragone 2001; Zerega et al. 2005 and references therein).

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Comprehensive Description

Breadfruit (Artocarpus altilis) (=A. communis = A. incisus; nomenclatural issues and synonomies are reviewed by Zarega et al. 2005) is a rapidly growing tree (0.5 to 1.5 m per year under favorable conditions) that is widely planted in the tropics for its edible fruit and value as an ornamental and shade tree. It is of particular economic importance in the Pacific islands, where it is a staple or subsistence crop on many islands. Breadfruit trees are often found in home gardens, in secondary forests, and along roadsides. These spreading evergreen trees may reach 18 to 20 m or more in height, with a trunk diameter of 60 cm or more, but are more commonly 12 to 15 m tall. The trunk may reach a diameter of 2 to 4 m before branching. The spherical to cylindrical rough-skinned fruit is 10 to 30 cm in diameter and 0.25 to 6 kg, with a yellow to green rind and a starchy creamy white to yellow pulp (starch content ~20%). Depending on the variety, seed number may range from none to many. Breadfruit is a "multiple aggregate" fruit (i.e., each fruit is formed from an entire inflorescence consisting of multiple flowers). Seeded fruits have a surface composed of greenish conical spinelike projections, each from a single flower. Seedless fruits have a smoothish surface honeycombed with individual fruits around 5 mm across.

The alternately arranged dark green, obovate to ovate glossy leaves have a nearly entire margin. They are very large (typically around 45 cm, but ranging from 15 to 90 cm long, depending on the variety) and slightly to deeply pinnately 7- to 11-lobed (sinuses up to 2/3 or more of the distance from margin to midrib, with up to six pairs of lobes), with a large apical tip. In contrast to the dark green and smooth upper leaf surface, the lower surface is lighter and distinctly veined. Buds are pointed and hairy.

Breadfruit is monoecious (i.e., individual trees function as both males and females), with separate male and female flower clusters--each consisting of thousands of tiny flowers attached to a spongy core--emerging from leaf bases on the same tree. The male cluster is a cylindrical or club-shaped soft catkin around 15 to 40 cm long and 2 to 3 cm in diameter, yellow at first then turning brown. The tiny flowers, each with a single stamen, are crowded on the outside. The female flowers form elliptical or round light green prickly clusters around 6 cm long and 4 cm in diameter; the flowers fuse together and develop into the edible, fleshy portion of the fruit. Breadfruit flowers are cross-pollinated, but pollination is not required for fruit development. The bark of the Breadfruit tree is smooth and brown with warty lenticels; milky juice exudes from the bark when cut (a white milky latex is present in all parts of the tree).

Potted Breadfruit trees (seedless) were brought on the Providence to the West Indies (St. Vincent and Jamaica) from Tahiti in 1793 by Captain William Bligh as a cheap food for slaves on the sugar plantations (an earlier attempt by Bligh on the Bounty was unsuccessful, ending in the famous "Mutiny on the Bounty" in 1789 upon leaving Tahiti). Around the same time, the French brought some Breadfruit trees to several other Caribbean islands.

(Little and Wadsworth 1964; Seddon and Lennox 1980; Ashton 1989; Vaughan and Geissler 1997; Ragone 2006)

The ripe fruits can be eaten raw when ripe, but are more commonly picked when mature (but not quite ripe), then cooked. Seeded varieties are most common in the southwestern Pacific. Seedless varieties are most common in Micronesia and the eastern islands of Polynesia. All the varieties elsewhere in the tropics are seedless. Seeds are dispersed by fruit bats and possibly doves and other birds. The similar A. camansi (from which A. altilis is believed to have descended by domestication) has oblong, very spiny fruits with little pulp and numerous large, light brown seeds (darker in A. altilis) and large, shallowly dissected leaves with 4 to 6 pairs of lobes. Artocarpus mariannensis has small, cylindrical or kidney-shaped dark green fruits with yellow flesh and dark brown seeds and small entire to shallowly 1- to 3-lobed leaves. Hundreds of named Breadfruit varieties in the Pacific Islands are propagated vegetatively. Breadfruit trees generally grow best in full sun and form the overstory canopy in traditional mixed agroforests, although young trees prefer 20 to 50% shade. Depending on variety, age, and tree condition, fruit yield ranges from fewer than 100 to more than 700 fruits per tree, with an average around 150 to 200. In intensive cultivation, yields of 160 to 500 kg of fruit per tree per year can be achieved. Breadfruit grows best in equatorial lowlands below 600 to 650 m, but is found up to 1550 m. The latitudinal limits are approximately 17 N and S, but maritime climates extend this range to the Tropics of Cancer and Capricorn. Most varieties produce one or two crops per year. Trees grown from seed begin flowering and produce fruit in 6 to 10 years or sooner and vegetatively propagated trees begin to flower and fruit in 3 to 6 years. Ragone et al. provide details on propagation and cultivation of Breadfruit, as well as diverse traditional uses in the Pacific.  (Ragone 2006)

Some Breadfruit cultivars are fertile diploids (2n = 2x = 56), but many are sterile hybrids or triploids (2n = 3x = 84) and must be vegetatively propagated (Ragone 2001; Zerega et al. 2005 and references therein).

Petersen (2006) notes that eastern Micronesia’s subsistence economies are closely tied to breadfruit. In many areas, especially the Eastern Caroline high islands, Breadfruit is the main staple (only in the coral islands at the northern and southern margins, where rainfall is generally lower, is Breadfruit less economically significant). Petersen argues that the development of vigorous hybrid Breadfruit cultivars led to a "Breadfruit Revolution" 600 to 1200 years ago that was a major driver of sociocultural evolution across Micronesia.

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Description

Cytology

Ragone (2001) studied chromosome numbers in Artocarpus altilis, A. mariannensis, and A. camnansi from 16 Pacific Island groups, Indonesia, and the Philippines. Artocarpus camansi and A. mariannensis exhibit counts of 2n = 56; various cultivars of A. altilis had counts of 2n = 56 (diploidy) and 2n = 84 (triploidy). Most diploid cultivars of A. altilis were seeded, but two cultivars with reduced seed number were observed. Micronesian samples included putative interspecific hybrids between A. altilis and A. mariannensis. The majority of these samples were seedless diploids, but triploid putative hybrids were also observed.

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Ecology

Distribution

The wild, seeded ancestral form of Breadfruit, A. camansi, is native to New Guinea and possibly the Moluccas (in Indonesia) and the Philippines. Neither seeded nor seedless forms of Artocarpus altilis occur naturally in the Pacific Islands (contrary to sources which give the South Pacific as its native range). Breadfruit was first domesticated in the western Pacific and was spread throughout the region by humans beginning around 3000 years ago. Today, Breadfruit is cultivated on most Pacific islands (with the notable exceptions of New Zealand and Easter Island) and has a pantropical distribution. In the late 1700s, several seedless varieties were introduced to Jamaica and St. Vincent from Tahiti and a Tongan variety was introduced to Martinique and Cayenne via Mauritius. These Polynesian varieties were then spread through the Caribbean and to Central and South America, Africa, India, Southeast Asia, Madagascar, the Maldives, the Seychelles, Indonesia, Sri Lanka, and northern Australia. Breadfruit is now also found in south Florida (U.S.A.). (Ragone 2006)

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Evolution and Systematics

Systematics and Taxonomy

Zerega et al. (2005) used AFLP genetic markers to examine species boundaries in Breadfruit. They concluded that A. altilis (domesticated breadfruit), A. camansi, and A. mariannensis should be recognized as three distinct species (together forming a monophyletic lineage) and confirmed the existence of A. altilis X A. mariannensis hybrids. Zerega et al. provide detailed descriptions of these three taxa and a dichotomous key to separate them.  Zarega et al. (2004) report their finding that most Melanesian and Polynesian Breadfruit cultivars appear to have been derived from A. camansi through generations of vegetative propagation and selection. In contrast, most Micronesian breadfruit cultivars appear to be the result of hybridization between A. camansi-derived Breadfruit and A. mariannensis. Because Breadfruit depends on humans for dispersal, Zarega et al. suggest, their data are consistent with the well-supported theory that humans settled Polynesia via Melanesia, as well as with a proposed long-distance human migration from eastern Melanesia into Micronesia.

Zarega et al. (2010) undertook a phylogenetic analysis of Artocarpus and related genera based on chloroplast and nuclear DNA sequence data.

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Relevance

Uses

Seedlessness in breadfruit has often been attributed to sterility due to triploidy, although other factors may play a role as well. In any case, the development of few-seeded and seedless fruits had significant benefits for Pacific Islanders who relied on Breadfruit as a staple crop. The development of fruits with reduced seed numbers yielded a greater proportion of edible fleshy tissue and resulted in a shift from using this species as a nut crop (breadnut) in western Melanesia to a starch crop (breadfruit) eastward. Since breadfruit is a seasonal crop typically available for just a few months of the year, methods had to be developed to deal with and use seasonal surpluses to provide food during the annual and often extended periods of scarcity. The method developed was that of fermentation and storage in pits. The importance of fermented breadfruit, especially in Samoa, Tonga, the Marquesas, Society Islands, and Micronesia, was a critical element in a preference for seedless cultivars which drove selection and perpetuation of seedless cultivars. (Ragone 2001)

Bennett and Nozzolillo (1987) found that the average number of seeds per seeded breadfruit harvested from a single 6-yr-old tree over a period of 7 months was 59. Individual fruits contained as many as 151 or as few as 12. For seeded breadfruits, the entire interior of the fruit is dominated by a mass of brown seeds. The fruits are not picked before maturity, as is the case for the seedless breadfruit, but rather are allowed to drop. The seeds are then removed from the rotting pulp and rind, boiled in salted water (or roasted), peeled (i.e., the seed coats are removed), and eaten. They are chestnut-like in size and flavor and hence are known as "chataigne" in French-speaking areas and "castaña" in Spanish-speaking areas.

The sapwood is very susceptible to attack by dry-wood termites. Historically, surfoards were made from the light wood in Hawaii. The sticky sap has sometimes been used to catch birds. Seedless fruits are typically gathered before maturity and roasted or boiled as a starchy vegetable. The young fruits can be sliced and fried. A dessert and preserves are sometimes made from the male flower clusters. (Little and Wadsworth 1964)

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Taxonomic Children

Total: 1

Artocarpus altilis raumae

References

Ashton, P. M. S. (1989).  Forester's Field Guide to the Trees and Shrubs of Puerto Rico, 2nd edition. New Haven, Connecticut (U.S.A.): Tropical Resources Institute (Yale University).
Bennett, F. D., & Nozzolillo C. (1987).  How Many Seeds in a Seeded Breadfruit, Artocarpus altilis (Moraceae)?. Economic Botany. 41, 370-374.
Little, E. L., & Wadsworth F. H. (1964).  Common Trees of Puerto Rico and the Virgin Islands, Agriculture Handbook No. 249. Washington, D.C.: U.S. Department of Agriculture, Forest Service.
Petersen, G. (2006).  Micronesia’s Breadfruit Revolution and the evolution of a Culture Area. Archaeology in Oceania. 41, 82-92.
Ragone, D. (2001).  Chromosome Numbers and Pollen Stainability of Three Species of Pacific Island Breadfruit (Artocarpus, Moraceae). American Journal of Botany. 88, 693-696.
Ragone, D. (2006).  Artocarpus altilis (Breadfruit). Species Profiles for Pacific Island Agroforestry. 17. Hōlualoa, Hawai‘i: Permanent Agriculture Resources (PAR).
Seddon, S. A., & Lennox G. W. (1980).  Trees of the Caribbean. Oxford: Macmillan Education.
Vaughan, J. C., & Geissler C. (1997).  The New Oxford Book of Food Plants. New York: Oxford University Press.
Zerega, N. J. C., Ragone D., & Motley T. J. (2004).  Complex Origins of Breadfruit (Artocarpus altilis, Moraceae): Implications for Human Migrations in Oceania. American Journal of Botany. 91, 760-766.
Zerega, N. J. C., Ragone D., & Motley T. J. (2005).  Systematics and Species Limits of Breadfruit (Artocarpus, Moraceae). Systematic Botany. 30, 603-615.
Zerega, N. J. C., Supardi M. N. N., & Motley T. J. (2010).  Phylogeny and Recircumscription of Artocarpeae (Moraceae) with a Focus on Artocarpus. Systematic Botany. 35, 766-782.