The Pomegranate: A New Look at the Fruit of Paradise Ed Stover1 USDA/ARS, National Clonal Germplasm Repository, One Shields Avenue, University of California, Davis, CA 95616 Eric W. Mercure Paramount Farming Company, Bakersfield, CA Additional index words. antioxidant, heterostyly, Punica granatum

In this paper, a broad overview is pro- HISTORY OF CULTIVATION are reported to originate as ‘‘fruit of para- vided for the fruit known as the pomegranate dise,’’ which provides abundant demonstra- (Punica granatum). The pomegranate has a The pomegranate is widely considered tion of its appreciation in these cultures. In deep association with the cultures of the native in the region from Iran to northern India startling contrast, it was considered by the Mediterranean region and Near East, where (e.g., Morton, 1987), with apparently wild Greeks to be the ‘‘fruit of the dead’’ and it is savored as a delicacy and is an important plants in many forests of these areas. Others provided sustenance to the residents of Hades dietary component, revered in symbolism, (e.g., Mars, 2000) suggest that it is native to (Lansky et al., 2000). These two considera- and greatly appreciated for its medicinal the smaller area of Iran and vicinity, and was tions may demonstrate the amazing breadth properties. It is strange that a horticultural spread by human movement to a much broader of the pomegranate’s potential consumer icon of such importance has been largely area in prehistory. In India, the fruits of the base. The fruit’s unique flavors, with sweet- relegated to an ornamental role in the United wild pomegranate have thicker rinds and ness often counterbalanced by acidity, makes States and much of Europe. Recent trends extremely high acidity compared with culti- pomegranate easy to appreciate by most who indicate that the health-giving and flavor- vated types (Bist et al., 1994). They are also try it. In addition to their use as a fresh fruit filled properties of these fruits may soon reported to have much smaller arils (Kher, or fruit juice, the juice of the pomegranate reverse this oversight. 1999). In Central Asia, the primary difference also contributes distinctive character to many noted is the higher acidity in wild material mideastern dishes, such as the Iranian fes- TAXONOMIC ODDITY AND NAMING (Kerimov, 1934). The pomegranate’s origin senjan. As a practical contributor to the diet, in proximity to the ancient cultures of the these fruits were likely invaluable to early Botanically, the pomegranate (P. grana- Mediterranean have provided a long, recorded desert travelers as an easily carried, well- tum) is in the subclass Rosidae, order Myr- history for pomegranate. Indeed, some have protected form of water (Morton, 1987). tales, which is home to a few other fruits such argued that the pomegranate is the ‘‘apple’’ of In Zoroastrianism, the pomegranate sym- as the guava (Psidium sp.) and feijoa (Feijoa the biblical Garden of Eden, but this is bolizes both fecundity and immortality, and sp.). However, pomegranate is unusual in disputed in a recent review (McDonald, 2002). is an emblem of prosperity (Panthaky, 2006). being one of only two species in its genus, Pomegranate has been naturalized through- Pomegranate has long been associated with Punica, which is the sole genus in the family out the Mediterranean region (California love and was one of the symbols of the love Punicaceae (ITIS, 2006). Recent molecular Rare Fruit Growers, 1997). Edible pomegran- goddess Aphrodite (Encyclopedia Britann- studies suggest a taxonomic reconsideration ates were cultivated in Persia (Iran) by 3000 ica, 2006a). In the biblical Song of Songs, might place Punica within the Lythraceae BCE (Anarinco, 2006), and were also present Sheba ecstatically replies to Solomon’s blan- (Graham et al., 2005). The second species in in Jericho in modern-day Israel. By 2000 BCE, dishments: ‘‘Let us get up early to the vine- Punica, P. protopunica, is found only on the Phoenicians had established Mediterranean yards; let us see if the vine flourish, whether island of Socotra, of the Arabian Peninsula, and Sea colonies in North Africa, bringing pom- the tender grape appear, and the pomegran- is considered an ancestral species (Shilikina, egranates to modern-day Tunisia and Egypt. ates bud forth: there will I give thee my 1973) or an independent evolutionary path Around the same time, pomegranates become love.’’ Indeed Solomon describes Sheba as a (Kosenko, 1985). naturalized in western Turkey and Greece. garden whose ‘‘plants are an orchard of pome- The name Punica is the feminized Roman The pomegranate continued to be dis- granates’’ and says, ‘‘As a piece of a pome- name for Carthage, the ancient city in north- persed around the globe, reaching China by granate are thy temples within thy locks.’’ ern Tunisia from which the best pomegran- 100 BCE (Anarinco, 2006). By 800 CE, the fruit Sheba then says she wants Solomon to drink ates came to Italy. It was initially known as was spread throughout the Roman Empire, ‘‘the spiced wine of the juice of my pome- Malum punicum, the apple of Carthage. But including Spain. At the same time, it was granate.’’ Pretty potent stuff! Linneaus selected the current name, with the known to be extensively cultivated in Central It is easy to imagine that the seediness of specific epithet granatum, meaning seedy or and southern India (Morton, 1987). By the the pomegranate encouraged association with grainy. Its common name in the United early 1400s, the pomegranate had made its fertility. Perhaps this gave rise to the Greek States, therefore, means ‘‘seedy apple’’ way to Indonesia (Morton, 1987). In the myth in which Persephone must spend 6 (Encyclopedia Britannica, 2006c). While 1500s and 1600s, the Spanish introduced this months in the underworld after Hades forced considering naming, it is interesting to note species to Central America, Mexico, and her to eat six pomegranate seeds, but her re- that the fruit’s name in French, grenade, South America (LaRue, 1980). The first clear turn is celebrated with the coming of spring. provided the name for the weapon because evidence that the pomegranate was in the A bit more mysterious is the rationale for of similarities in appearance (Encyclopedia area to become the United States was in the Hebrew priests wearing vestments adorned Britannica, 2006b). early 1700s, when they were grown in with pomegranates (Exodus 28:31), or the Spanish Florida and English Georgia. By 480 BCE attempt by King Xerxes to capture 1770, the pomegranate made its way to the Greece with an army carrying spears adorned West Coast and was growing in the We acknowledge Matt Quist and Jason Haught, with pomegranates. Paramount Farming Company; Zeev Wiesman, missions of California (Morton, 1987; Seelig, Institutes for Applied Research, Ben Gurion Uni- 1970). versity of the Negev, Beer Sheva, Israel; Claudia HORTICULTURE Botti, Department of Agronomy, University of APPRECIATION AND SYMBOLISM Santiago, Chile; and Londhe Santosh Dinkar and The plant. The pomegranate plant inher- Dr. R.B. Sawant, College of Agriculture, Shivaji Both the Arabic name for pomegranate ently develops numerous trunks. In orchards, University, Kolhapur, India. (rumman) and the Hebrew name (rimmon) plants are normally trained to a single trunk,

1088 HORTSCIENCE VOL. 42(5) AUGUST 2007 forming a large shrub or small tree, and harvest ‘Wonderful’ when soluble solids The ‘Wonderful’ cultivar was discovered reaching a height of 12 to 20 ft at maturity. reach 15% (Morton, 1987). Minimum matu- in Florida and brought to California in 1896 Trees may be trained to multiple trunks in rity for ‘Wonderful’ in California is based on (California Rare Fruit Growers, 1997). This colder areas, to reduce risk of total tree loss. titratable acidity less than 1.85% and color is the primary cultivar of commerce in the Very dwarf pomegranates (such as ‘Nana’) darker than an established reference (Kader, United States. It is also grown in western are known with small plant, flower, and fruit 2006). In a Spanish study, soluble solids of Europe, Israel, and Chile (Sepulveda et al., sizes, and are widely used as ornamentals. the cultivars examined did not vary greatly 2000). ‘Wonderful’ is among the most deeply The pomegranate plant is more or less spiny from mid August through mid November, colored of pomegranates in both husk and and deciduous, with small, narrow, oblong and the principal acids were malic and citric juice, with a rich flavor, good juice yield, and leaves with short stems (Morton, 1987). (Legua et al., 2000). both sprightly acidity and slight thirst- Plants aggressively sucker from the crown Unlike most horticultural fruits, inherent quenching astringency similar to that of area and the roots. seed dispersal is not achieved through con- grapefruit juice and cranberries. Many pome- The flower. The pomegranate flowers are sumption of all or most of the fruit and seeds granate lovers consider it to be among the most commonly red to red–orange and are with accompanying spread. Rather, the best-tasting cultivars (Karp, 2006). ‘Wonder- funnel shaped, although ‘‘double’’ and varie- pomegranate fruit structure has apparently ful’ is nearly ideal for juicing, with excellent gated flowers are found in some ornamental evolved to ensure splitting of the leathery juice percentage as well as quality. It also has selections, which are not grown for fruit. husk, and exposure of the tempting arils and useful resistance to fruit cracking after rain- Pomegranate can be self-pollinated or cross- seeds (Morton, 1987) to the many happily fall on mature fruit (Karp, 2006). Other com- pollinated by insects (Morton, 1987). Flowers cooperative birds and so forth serving as mercial U.S. cultivars include ‘Granada’ (a are primarily borne subterminally, primarily dispersal agents. ‘Wonderful’ sport), ‘Early Wonderful’ (also on short lateral branches older than 1 year (El- a ‘Wonderful’ sport), and ‘Early Foothill’. Kassas et al., 1998), although some cultivars The cultivars ‘Mollar de Elche’ and ‘Valenci- flower on spurs. Flowers occur as single POMEGRANATE PRODUCTION ana’, in Spain, are among the most widely blossoms or in clusters of up to five. marketed pomegranate cultivars in western Current global production estimates for In the Central Valley of California, pome- Europe (Costa and Melgarejo, 2000). The pomegranate are unavailable. However, it is granate blooms from early May to Novem- ‘Valenciana’ cultivar is harvested early widely grown in many countries where it is ber, with most flowering from mid May to (August), with very little sun damage and lower well adapted. In India more than 100,000 ha early June. Pollination in California is pri- risk from pest attack or bad weather, but also of pomegranate are produced. It is considered marily affected by insects or hummingbirds. has low yield, average to poor internal fruit one of the most important fruits of the Stigma receptivity lasts 2 to 3 d and declines quality, and small fruit size. The ‘Mollar’ tropical and subtropical areas because of quickly in unpollinated flowers (Melgarejo cultivar is harvested much later (end of low maintenance cost, good yields, good et al., 2000). September until mid November) and displays keeping quality, and ability to thrive with Pomegranate flowers are heterostylous. more sun and split damage, but has higher limited moisture (Indian Council of Agricul- Long-styled perfect flowers are larger, have yield, excellent internal fruit quality, larger tural Research, 2005). In Iran, 65,000 ha of larger ovaries, and set more fruit than short- size, longer harvest period, and greater con- pomegranate produces 600,000 tons of fruit style types, which are either intermediate or sumer acceptance (Costa and Melgarejo, 2000) annually, with about 30% of yield exported functionally male only. The proportion of Because of differences in quality and (Mehrnews, 2006). Turkish production in these two flower types varies among cultivars productivity observed in commercial plant- 1997 was 56,000 tons/year (Gozlekci and and year to year (Martinez et al., 2000). ings, Spanish researchers have selected dis- Kaynak, 2000). Spain, with 3000 ha, is The fruit. The pomegranate fruit is berry- tinct clones of their most important cultivars. the largest western European producer of like with a leathery rind (or husk) enclosing Selections were made in 1986, in the prov- pomegranate, and production has been in- many seeds surrounded by the juicy arils, inces of Alicante and Murcia. Numbered creasing as a result of high market prices which comprise the edible portion of the fruit clones were propagated and are undergoing (Costa and Melgarejo, 2000). (Watson and Dallwitz, 1992). The aril juice replicated trials to identify the best materials In the United States, there are 5600 ha of sack is composed of many epidermal cells. (Amoros et al., 2000). commercial pomegranate, mostly in the San According to cultivar, arils range from deep The countries of pomegranate origin grow Joaquin Valley. The ‘Wonderful’ cultivar red to virtually colorless, whereas the innumerable cultivars, with many regional dominates almost completely, but there is enclosed seed varies in content of scleren- favorites. Local pomegranate germplasm col- interest in earlier and later cultivars to extend chyma tissue, which affects seed softness. lections have been established in several the market season (Kotkin, 2006). The number of locules and arils (and Mediterranean countries, including Spain, enclosed seeds) varies, but may be as high Morocco, Tunisia, Greece, Turkey, and as 1300 per fruit (Levin, 2006). The fruit has POMEGRANATE CULTIVARS Egypt (Mars, 2000). India has three collec- a prominent calyx, which is maintained to tions containing at least 30 accessions each maturity and is a distinctive feature of the More than 500 cultivars of pomegranate (Gulick and Van Sloten, 1984). Azerbaijan, pomegranate fruit. The husk is comprised of have been named (IPGRI, 2001), but such the Ukraine, Uzbekistan, and Tajikistan have two parts: the pericarp, which provides a ancient and widespread fruits often have collections of 200 to 300 accessions, and cuticle layer and fibrous mat; and the meso- considerable synonymy, in which the same the collection of the Turkmenistan Experi- carp (known also as the albedo), which is the basic genotype is known by different names mental Station of Plant Genetic Resources is spongy tissue and inner fruit wall where the in different regions. Synonymy is likely the largest in the world, containing more than arils attach. Septal membranes are the papery further encouraged by the fact that husk and 1000 accessions (Levin, 1995). The U.S. tissue that further compartmentalizes groups aril color can vary markedly when grown in National Clonal Germplasm Repository, in of arils, but arils do not attach to this tissue different regions. A number of characteristics Davis, CA, has almost 200 pomegranate (Matthew Quist, pers. comm.). There is vary between pomegranate genotypes and are accessions, including many obtained from interest in identifying or developing cultivars key to identification, consumer preference, the Turkmenistan collection. Included in that have more locules to fill the fruit interior, preferred use, and potentially niche market- this collection are several types with very fewer septal membranes for easier eating, and ing. The most important traits are fruit size, soft seeds, a trait sometimes optimistically a thinner mesocarp. husk color (ranging from yellow to purple, called ‘‘seedless.’’ Interestingly, in a prelim- Fruits ripen about 6 to 7 months after with pink and red most common), aril color inary molecular marker study, genetic vari- flowering (Morton, 1987) and are harvested (ranging from white to red), hardness of the ability was found to be quite low among when qualities are deemed most appropriate seed, maturity, juice content, acidity, sweet- the diverse cultivars in the U.S. collection for expected market use. In Israel, they ness, and astringency. (M. Aradhya, pers. comm.).

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