Underutilized Fruit Crops at a Crossroads: The Case of Annona cherimola—From Pre-Columbian to Present Times

Abstract

Fruits of the cherimoya tree (Annona cherimola Mill.) were consumed by native cultures in Central America, from where the crop was disseminated to South America in pre-Columbian times. Despite its historical significance and cultivation in subtropical regions worldwide, cherimoya remains an underutilized crop, particularly in its area of origin where the conservation of its genetic diversity is under threat. In this study, we provide a comprehensive overview of the research performed on this fruit tree over the past two decades, shedding light on its current status in terms of commercial production and germplasm conservation efforts in the main cherimoya producing countries in the Americas and Europe.

1. Taxonomy and Botanic Description

The cherimoya (Annona cherimola Mill.) belongs to the Annonaceae, a pantropical family that includes approximately 107 genera and 2400 species of flowering trees, shrubs and lianas [1] distributed worldwide. According to the APGIV classification [2], this family is included in the Magnoliales order, along with five other families (Myristicaceae, Degeneriaceae, Himantandraceae, Magnoliaceae and Eupomatiaceae), which collectively represent three-quarters of the species within the order. Together with the Canellales, Laurales and Piperales form the Magnoliid complex [3], considered a sister to the eudicot and monocot clades of angiosperms [4].

The Annonaceae family is believed to have originated in the upper Cretaceous period, about 82–98 million years ago when taxa were distributed between Laurasia and northern Gondwana [5,6,7,8]. A division from the Laurasian lineage gave rise to the genus Anaxagorea (present in the Neotropics and tropical Asia), while the Gondwana lineage gave rise to the rest of the genera in the family. Since the morphological-based classification of Fries [9], several studies have focused on the systematics of this family and its genera, based on reproductive [10,11,12,13], morphological [14,15,16,17,18] and molecular characters, using chloroplastic sequences [6,19,20,21,22,23,24,25] and nuclear markers such as RAPDs and RFLPs [26]. Among the Annonaceae, only a limited number of species, belonging to two genera, Annona and Asimina, produce edible fruits (Figure 1). The genus Asimina, the only member of the family that has successfully adapted to temperate climes, comprises a total of 12 species [27]. Asimina triloba, native to North America, is the most interesting from an agronomic perspective and has been the subject of numerous molecular studies using isoenzymes, RAPDs, AFLPs and ISSRs [28,29,30,31,32,33]. In addition, the interaction between the pistil and pollen has been characterized [34], its phenology has been studied [35] and its genome is currently being sequenced.

The genus Annona includes about 160 species [6] and is mainly distributed throughout tropical regions of the Americas, with a few native species found in Africa. Several species within this genus produce edible fruits that hold diverse value, particularly in local markets: Annona cherimola, A. reticulata, A. squamosa, A. muricata, A. macroprophyllata, A. glabra and A. purpurea. The genus Annona was named by Linnaeus [36] using the Central American vernacular name but modifying it to the Latin name Annona, which can be translated as “the harvest of a year”. It is believed to have emerged during the Miocene period, 5–23 Ma ago [6,8]. Safford [37] provided an early description of the genus, dividing it into five groups and 15 sections. Later, Fries [9], focusing on flower traits, reorganized it into 17 sections. Fries’ classification remains the most widely used for Annona, although some morphological characteristics might have evolved independently in several sections [11]. According to the dichotomous key of Fries, the section Atta, which includes A. cherimola, would have its center of origin in Central America and the Caribbean. This section is characterized by ripe, smooth-skinned fruits with raised areoles delimited by lowered furrows. However, phylogenetic studies indicate that the organization of these and closely related sections may need reconsideration, as they do not exhibit monophyly based on chloroplast genes [38]. Various studies have been carried out on species of the genus Annona at both the morphological and/or molecular levels, focusing on identification, diversity or phylogeny, providing valuable insights into the classification and evolutionary relationships within the genus [38,39,40,41,42].

Annona cherimola Mill. (Figure 2) is a semi-deciduous tree belonging to the Atta section of the genus Annona [9,38]. At maturity, it can reach a height of 7–8 m. The leaves are simple, entire, alternately arranged and vary from oval to elliptical, with variable sizes, generally 7–18 cm long and 4 to 10 cm wide, with short petioles [43]. The flowers are hermaphroditic, pendulous, inconspicuous and fragrant, usually originating in at least 1-year-old wood, either as solitary or in clusters of up to eight or nine flowers. The floral components are arranged in a helical pyramidal manner on the receptacle. Each flower has three large fleshy green tepals (2.5 to 4 cm) and three rudimentary scale-shaped inner tepals. The stamens are numerous (150–200). The pyramid of pistils has approximately 150 independent units, each with a single ovule, which must be fertilized for the ovaries to grow and develop, producing the aggregate fruit. As with other members of the Annonaceae, the flowers of A. cherimola exhibit dichogamous protogyny, which refers to the temporal separation of female and male functions. This phenomenon hinders self-pollination within the same flower, as well as between flowers of the same tree and between trees of the same variety, due to the synchronization of sexual stages. The flower cycle usually completes in two days; on the first day, the flower opens at the female stage, and on the second day, it transitions from the female to the male stage, coinciding with the dehiscence of the anthers. Pollination is mostly cantharophylous depending on the presence and visits of small Coleoptera, mainly from the family Nitidulidae [44,45,46,47,48,49]. Hand pollination is common in Spain and other countries outside the Americas with a scarcity of pollination insects. The fruit is compound, conical or heart-shaped. The skin, thin or thick, may be smooth with fingerprint-like markings or covered with conical or rounded protuberances. The white flesh is sweet and juicy, with each segment surrounding a single hard black seed. Cherimoya grows best in subtropical climates with average annual rainfall ranging from approximately 600 to 1700 mm, accompanied by low seasonal and interannual temperature fluctuations. Ideal mean temperatures range from 15 to 25 °C, with a preferred relative humidity level of 60–70%. Cherimoya thrives in well-drained sandy soils [50].

Annona cherimola, a diploid species, is considered to have 2n = 14 chromosomes [51,52,53], although some studies have reported a higher number of chromosomes (2n = 16) [54]. This discrepancy could be due to the confusion between distant satellites (or whole arms) and separate chromosomes [55]. Interestingly, an unexpectedly high proportion of triploid genotypes was found in the progeny of an interspecific cross involving the diploid species, A. cherimola and A. squamosa [52]. Cherimoya has been the subject of studies on diversity, inheritance or genetic linkage with morphological markers [56,57] isozymes [58,59,60,61,62,63], RAPDs [39], AFLPs [40] or microsatellites [64,65,66,67,68,69,70]. Most of these studies included cherimoya accessions collected at the regional level, leading to valuable conclusions about the extent of local diversity and conservation. However, some of them [63,65,68,69,70] have analyzed samples on a larger geographical scale and, consequently, have helped to advance the understanding of the genetic diversity and dispersion of the species across the Americas (see next sections). It has also been the object of the construction of different genetic maps based on microsatellite markers [71]. The discovery of a natural mutant of A. squamosa without seeds has allowed for the identification of a gene (INO; INNER NO OUTER) which is essential for seed formation [47]. Both the chloroplast [72] and nuclear [73] genomes of cherimoya have been sequenced. Other biotechnological advances in the species include the development of a micropropagation protocol from nodal explants of juvenile A. cherimola ‘Fino de Jete’, achieving a 100% acclimatization rate [74]. Micropropagation is also being adapted to other selected cherimoya cultivars and rootstocks.

2. Origin, Dispersal and Current Distribution

The term cherimoya seems to derive from the Quechua words “chiri”, meaning cold, and “muya”, meaning seed, which could refer to the relatively cold areas at high altitudes where it is cultivated in the Andean region. The species is distributed from Mexico and Central America to South America at altitudes above 900–1000 m above sea level. Until recently, the most accepted hypothesis considered a South American origin of cherimoya, specifically in the inter-Andean valleys of southern Ecuador and northern Peru, where significant phenotypic variability and archaeological remains considered to be cherimoya seeds or fruit depictions were discovered [75,76]. However, recent DNA-based studies have demonstrated a Mesoamerican origin of this species [69,70], where its closer relatives, included in the Atta section [9] and with which A. cherimola presents monophyly, are naturally distributed [38]. Since neutral microsatellites have a constant mutation frequency of 10⁻³–10⁻⁴ mutations/locus/generation [77,78], higher diversity values, which do not necessarily indicate the centers of origin of species, can provide an idea of the populations that have been settled for longer times. In this case, Honduran and Guatemalan populations showed significantly higher diversity values, although the accessions studied in those regions may derive, in turn, from other populations in places where no samples were available for analysis or where the cherimoya is no longer present. The initial dispersal of cherimoya throughout Central and North America may have been mediated by the native megafauna that inhabited this continent for 20 million years and became extinct about 13,000 years ago [79]. Species with fruits exhibiting typical characteristics that would be explained by interaction with extinct animals are considered anachronic [80] and include cherimoya and other species with large fruits that originated in the Americas, such as avocado or cacao. After the extinction of the American megafauna, the subsequent dispersal of these species would depend mainly on humans [80,81]. Several civilizations, including the Mayas, Olmecs, Izapa, Toltecs, Mexica—Tenocha or Mixtecas, among others, may have contributed to the dispersal of the cherimoya throughout Mesoamerica in Pre-Columbian times [82]. Thus, A. cherimola may have been collected and cultivated by Mesoamerican peoples and dispersed, at some point, using ancient sea trading routes, to South America, where cultivation and diversification would have continued mediated by human activity of the different Andean civilizations [69]. The existence of routes and exchanges between Ecuador, Peru and Mexico is documented in the bibliography based on shared textiles, metallurgical artifacts or mollusk shells [83,84,85], among others. This mode of dispersion could also be responsible for the extension of other plant genetic resources along the American continent in pre-Columbian times. The observed cherimoya phenotypic variation (still not studied in detail) in Central America seems to be lower than that observed in northern Peru and southern Ecuador (Scheldeman, personal communication), while the opposite occurs with the analyzed genetic diversity [69,70]. Thus, the cherimoya would fit the description of a semi-domesticated species [86]. All this points to a bottleneck before the establishment of the populations in South America, as has already been reported for other species of Mesoamerican origin such as Phaseolus vulgaris [87,88]. After the colonization of America, the cherimoya was introduced to southern Spain, very likely from the Mexican gene pool (Larranaga et al., in preparation), in the 18th century, from where it was probably spread to Italy, Madeira (Portugal), the Canary Islands, Algeria, Egypt and, possibly, to Libya, Eritrea and Somalia via Italy. Also, in the late 18th century, cherimoya was introduced to Hawaii, Jamaica and Haiti. Seeds were introduced to California from Mexico and, in the early 1900s, the United States Department of Agriculture imported seeds from Madeira [89].

3. Cherimoya Germplasm Conservation and Cultivation in Different Countries

The cherimoya is characterized by its high sugar and low acid levels. It is primarily consumed fresh, although it can also be processed into products such as ice creams, smoothies, sorbets, yogurts and even wine. Cherimoya is a valuable source of vitamins B1, B2 and B3, sugars and essential minerals such as iron, calcium or phosphorus, with concentrations of 0.5, 32 and 37 mg per 100 g of pulp, respectively [90]. Beyond the nutritional benefits of the fruit, the leaves, stems, bark and seeds of cherimoya show the presence of interesting secondary metabolites such as isoquinoline or acetogenins, with various pharmacological properties, such as antitumor or insecticide effects [91,92,93]. Traditionally, crushed cherimoya seeds have been considered to have insecticide properties, serving as a natural remedy to combat lice and treat skin diseases in different American countries [90]. The first documented report on cherimoya was by Jose de Acosta, a sixteenth-century Spanish Jesuit missionary, who wrote that “all the flesh inside is soft and tender as butter and white and of an exquisite taste and some believe that it is the best fruit in the Indies” [94]. In the 18th century, the Italian capuchin friar Ilarione da Bergamo, who traveled to Mexico (1727–1778), wrote “the chirimolla has a mild flavor and is also highly esteemed by locals. The centre is very white and is often eaten with a spoon, given that its consistency is like that of curdled milk” [95]. A young Charles Darwin also praised the cherimoya during the Beagle’s stopover on the South American continent in Lima (Peru) in 1835: “There are two things in Lima which all travelers have discussed; the ladies ‘tapadas’, or concealed in the saya and manta, and a fruit called chilimoya. To my mind the former is as beautiful as the latter is delicious” [96]. Mark Twain declared the cherimoya to be “deliciousness itself!” [97] and wrote from the Hawaii Islands: “We had an abundance of mangoes, papayas, and bananas here, but the pride of the islands, the most delicious fruit known to men, cherimoya, was not in season. It has a soft pulp, like pawpaw, and is eaten with a spoon” [98]. Despite these recognitions, the cherimoya became mostly forgotten as a fruit tree crop in the American continent after 1492.

The conservation and sustainable use of cherimoya genetic resources in its place of origin are of great importance for preserving its diversity and ensuring its availability for future genetic improvement projects. However, the current status of cherimoya conservation efforts reveals significant gaps and challenges. Thus, according to the information consulted, in Mesoamerica, the center of origin of the crop, there are only two field ex situ collections of cherimoya accessions and other species of the genus, both located in Mexico: Michoacan and the State of Mexico. In Guatemala and, especially, in Honduras, where cherimoya was once integral to rural livelihoods, cherimoya fruits are perceived to be a resource that is difficult to access in large cities, being largely confined to rural regions and where there has been a decline in the importance of the crop in backyards, potentially leading to significant genetic erosion. In addition, distribution models under the context of climate change projections suggest that cherimoya production in the areas in which the most diverse populations are present will be jeopardized [68]. These models suggest that cherimoya cultivation would be displaced to higher elevations (and therefore colder areas) in its region of origin, potentially resulting in the loss of valuable germplasm. All of this, combined with other even more imminent threats, such as land use change, habitat fragmentation or increased accessibility [99,100], underscores the urgency of implementing conservation projects, both in situ and ex situ, in the area of origin or of maximum diversity.

Cherimoya germplasm banks have been established in various countries, such as Mexico, Peru, Ecuador and Spain, with the latter being the largest collection worldwide. Usually, the different cherimoya genotypes are classified based on exocarp type [101] into the following five different types: laevis (smooth), impressa (slight depressions), umbonata (small protrusions), tuberculate (medium protrusions) and mamillata (large protrusions). Currently, cherimoya is grown in many regions with subtropical climates worldwide. Some of the most important cherimoya-producing countries in the American continent include Peru, Ecuador, Chile, Bolivia, Mexico, USA and Brazil. However, Spain is the world’s leading commercial producer. Other cherimoya-producing countries are Portugal, Italy and Israel in the Mediterranean region, and Australia, New Zealand and South Africa elsewhere in the world [90]. The following sections will cover key germplasm conservation and crop management information in the main cherimoya-producing countries in Latin America (Bolivia, Chile, Costa Rica, Ecuador, Mexico, Honduras and Peru) and Europe (Portugal and Spain) (

Table 1. Yield in tons per year, number of hectares, main cultivars and number of accessions conserved in ex situ collections across the main cherimoya-producing countries. In brackets, the source of information is indicated either with numbers (references) or personal information (PI). ND: no data available.

	Yield (t)/Year	No. Hectares	Main Cultivars (Cultivated and/or Developed)	No. Accessions Conserved
Mexico [102,103], [PI]	178.7	22.3 + 500?	Cortes II 31	106 + 33 + 2000
Honduras [PI]	ND	ND	None	0
Costa Rica [PI]	88.15	ND	None	8
Ecuador [104,105,106,107,108,109,110,111]	1200	700	MAG-Tumbaco, San José de Minas, Lojana, Fabulosa	126
Peru [112,113]	20,000	ND	Chiuna 1, Chiuna 2, Chiuna 3, Cumbe	356
Chile [114,115], [PI]	ND	300	Local Serena, Clavo, Juliana, Juniana	ND
Bolivia [116], [PI]	7000	1000 (expanded to 5000)	ND	150
Portugal [117,118,119,120,121,122]	627	120	Madeira, Mateus I, Funchal, Perry Vidal	500
Spain [123,124]	44,081	3000	Fino de Jete, Campas, Alboran	350

).

3.1. Mexico

In recent years, in situ conservation efforts in Mexico have focused on revaluing and preserving traditional agroecosystems, particularly backyard gardens, with the involvement of rural producers. In 2005, a significant milestone in Mexican cherimoya germplasm conservation was achieved with the establishment of the ex situ cherimoya National Germplasm Bank, initiated through the Mexican Annonaceae Network in collaboration with researchers from the Autonomous University of Chapingo and the Salvador Sánchez Colin Foundation (CICTAMEX, S.C.). This germplasm bank is located at the Experimental Field “La Cruz” managed by the Salvador Sánchez Colín Foundation (CICTAMEX S.C.) in Coatepec Harinas, State of Mexico, at the following coordinates: −99.7599° longitude and 18.9197° latitude. It currently conserves 106 accessions, including cultivars and selections of native seed material from the states of Michoacan, Oaxaca, Mexico and Morelos. Maintenance of the bank is overseen by researchers from CICTAMEX, S.C., with financial support for its establishment provided by the National Seed Inspection and Certification Service (SNICS) through the National Plant Genetic Resources System (SINAREFI). Ongoing research initiatives primarily focus on fruit and plant characterization for cultivar registration, with at least three registration processes currently underway. In addition, another cherimoya field collection in Mexico, with 33 accessions, including material from the National Bank, as well as some varieties from Spain, Chile and the United States for agronomic observation purposes, is located at the Central Western Regional University Center (CRUCO) of the Chapingo Autonomous University in Morelia, Michoacan, at the following coordinates: −101.2391° longitude and 19.6862° latitude. This plant material is available for producers interested in cherimoya cultivation and for experimental practices such as manual pollination and evaluation of pest and disease incidence. Furthermore, the National Plant Germplasm Bank (BANGEV) of the Autonomous University of Chapingo maintains about two thousand seeds from different Mexican states, belonging to various Annona species. These seeds are preserved ex situ using long-term cryopreservation techniques at −20 °C with 5% relative humidity, ensuring the conservation of genetic diversity for future research and breeding programs (J.A. Agustín, unpublished data).

Cherimoya is considered an underutilized crop in Mexico, primarily due to its limited cultivation area, despite the recognition of its nutritional importance and commercial potential. Although Mexican statistics on cherimoya cultivation are imprecise, data from the Servicio de Información Agroalimentaria y Pesquera [102] indicate that, in 2022, only 22.3 hectares were under cultivation, producing 178.7 tons, primarily in the states of Michoacan and Morelos. Some researchers estimate an additional 500 hectares in semi-cultivated form within backyard garden systems. Commercial cultivation of cherimoya in Mexico faces several challenges, including a lack of appropriate technology, alternative markets, technical advice to producers and competition from other crops, such as avocado, which have well-developed markets. Currently, no cherimoya cultivars are commercialized in Mexico and most cultivated cherimoya trees are derived from seeds, known as ‘criollo’, which exhibit high variability in fruit characteristics without defined and uniform quality. While some ‘criollo’ selections, such as ‘Cortes II 31’, are preferred for their flavor and low seed rate, their fruits often exhibit high asymmetry and protuberances, making postharvest handling for exportation challenging [103]. However, efforts are underway to register some ‘criollo’ trees with excellent laevis and impressa-type fruits. Varieties from other countries often face adaptation problems and poor self-pollination, resulting in very low yields and are, therefore, not widely accepted by farmers. Nevertheless, some producers in Morelos have made their selections based on local adaptations. Most cherimoya production in Mexico is currently destined for the local and national markets. While there were some shipments to Japan of ‘Cortes II 31’ in the 1990s, meeting the high-quality standards required for exportation remains challenging with the current traditional technology. The adoption of practices such as manual pollination, pruning and efficient pest and disease control is necessary to improve quality and yield. Some producers from Michoacan have participated in fairs on the United States border, generating interest in cherimoya, but meeting volume, quality and legal phytosanitary quarantine requirements remains a significant hurdle.

3.2. Honduras

Although several germplasm banks are present in the country, none of them currently includes accessions of Annona cherimola. The largest of these banks is located on the campus of the National Autonomous University of Honduras, in the city of La Ceiba (CURLA), and boasts a diverse collection of tropical and exotic fruit trees. It is imperative to prioritize the preservation of local cherimoya accessions by incorporating them into one of the existing germplasm banks to safeguard the genetic diversity of the species in Honduras.

There are no official records of cherimoya production in Honduras. The cultivation of this crop is entirely artisanal and occurs on a small scale, typically in the patios or yards of households or on small farms. There are no extensive cherimoya orchards, and production is confined to municipalities in the western region of the country, reaching elevations of up to 1900 m above sea level. Notable cherimoya-producing areas include Marcala in La Paz and Intibucá in Intibucá. Although the highest genetic diversity of Annona cherimola has been observed in western Honduras, there are currently no national or private initiatives aimed at conserving this biological wealth. Given that cherimoya production occurs only once a year, that it is limited to a small geographical region at high altitudes, the difficulty of transporting cherimoya to large cities as well as its short shelf-life, the fruit is not usually marketed beyond the municipalities where it is produced. On the other hand, other Annona species, such as A. squamosa (sugar apple), A. purpurea (soncoya) and A. muricata (soursop), which are better adapted to tropical conditions, enjoy greater acceptance in local markets and are cultivated on a larger scale across various ecosystems.

3.3. Costa Rica

A total of 17 Annona species have been described in Costa Rica, with soursop (A. muricata) and cherimoya being the most popular. However, despite its potential, cherimoya remains an underutilized species in the country, with most trees growing wild in coffee farms or backyards, receiving minimal crop management. The producers’ cooperative organization APACOOP has undertaken efforts to collect native cherimoya trees, conserving and documenting eight accessions in the areas of Copey and Dota.

There are no cherimoya monoculture orchards in Costa Rica. Instead, cherimoya trees are primarily found growing in coffee farms, serving as natural barriers or for shading purposes. Production of cherimoya is concentrated in the following five highland regions: Acosta, Aserrí, Vásquez de Coronado, Copey–Dota and Tarrazú. According to the Centro Nacional de Abastecimiento y Distribución de Alimentos (CENADA) (personal communication), production levels between 2017 and 2021 ranged from 0.40 to 88.15 t/year. Because cherimoya in Costa Rica is considered a Neglected and Underutilized Species (NUS) crop, there are no government or private initiatives focused on improvement or breeding programs. Cherimoya production in Costa Rica typically occurs from July to October, with distribution primarily to local markets and supermarkets. Hand pollination is generally not practiced and, consequently, there is a great variation in the fruit size, number of seeds and overall fruit quality. Consequently, cherimoya serves as a supplementary source of income for farmers alongside their primary crops.

3.4. Ecuador

Ecuador is considered part of the cherimoya’s second domestication center. The Tumbaco and Austro experimental fields, managed by INIAP, house a collection of 126 cherimoya accessions. Producers located in the Andean valleys play a crucial role in preserving much of the cherimoya diversity in situ, with their harvests being commercialized in local markets [104]. The environmental conditions in which cherimoya is grown in Ecuador vary between elevations of 1400 and 2600 m above sea level, with an average temperature of 17 °C, annual rainfall ranging from 400 to 1000 mm and relative humidity that varies between 60 and 85% [105].

Approximately 700 hectares are dedicated to cherimoya cultivation in the Andean Valleys of Ecuador, characterized by a semi-humid and dry climate. Annual production reaches around 1200 tons, with an average yield of 2841 kg per hectare. Cherimoya is often intercropped with other fruit trees [106]. Due to the geographical location and weather conditions in the Andean Valleys, cherimoya fruits in Ecuador can be harvested all year round [107] due to the use of appropriate techniques such as water stress management (adjusting irrigation to advance or delay tree growth and development), defoliation, induction of sprouting and pruning. These practices help to improve the quality and yield of the fruits, ultimately increasing the income of the growers [108]. In addition, high planting densities (625, 1250 and 2500 pl/ha) have an impact on the fruit size and yield, with lower densities resulting in doubling the yield per plant, with an increased fruit size.

Through selections carried out by the INIAP Fruticulture program within the chirimoya collection and growers’ cultivars, the following four varieties of cherimoya have been developed: ‘MAG-Tumbaco’, ‘San José de Minas’, ‘Lojana’ and ‘Fabulosa’. Selection criteria were based on 33 qualitative and 32 quantitative descriptors of both the plant and the fruit, based on the preferences of Ecuadorian consumers and the demands of the international market. Key criteria include the fruit size, weight, degree of oxidation, Brix degrees, seed index, skin type, resistance to abrasion and pulp texture [106,109]. In recent years, the ‘Cumbe’ cultivar has been introduced from Peru and is being cultivated in the south of the country. Studies have demonstrated a positive effect of arbuscular mycorrhizae obtained from the rhizosphere of cherimoya plants on cherimoya seedling growth and development [110].

Commercialization of cherimoya in Ecuador is primarily domestic, with the majority of the fruit sold fresh. Supermarkets receive the largest share of the fruits, followed by open markets, fairs and roadside stands in the production zones. Fruit prices fluctuate according to location, fruit size and the time of the year [111].

3.5. Peru

Cherimoya cultivation in Peru dates back to pre-Columbian times, spreading across the entire territory during the Inca era. In 1999 and 2000, the National Program for Research in Genetic Resources and Biotechnology, in collaboration with IPGRI (International Plant Genetic Resources Institute) and CSIC (Spanish National Research Council), established the national germplasm collection of the cherimoya, with 356 accessions in Huanchacc, in the Ayacucho department, situated at a longitude of −74.2958° and a latitude of −12.9278°. This collection was assembled using material collected in the departments of Ayacucho, Huancavelica, Ancash, Lima, Junín, Huánuco, Cajamarca, Cuzco, Apurímac, La Libertad and Piura. The objectives of this collection are to conserve, characterize and classify the existing genetic variability, identify promising genotypes with desirable quality traits and generate technology beneficial for small- and medium-scale farmers. Several cherimoya selections have been made in Peru, with varieties like ‘Cumbe’ exhibiting superior fruit characteristics with fewer seeds. However, in many places in the highlands, cherimoya is commonly found in mixed orchards or as living fences [112].

Cherimoya production in Peru amounts to approximately 20,000 tons annually, with the Lima region (the main region producing ‘Cumbe’) contributing around 7500 and 8000 tons, accounting for 40% of the national production. Production areas span across the departments of Lima, Cajamarca, Piura, Junín and Apurímac. In Lima, San Mateo de Otao, in the province of Huarochirí, stands out as the primary cherimoya-producing area. The peak harvesting period typically occurs between April and June. Some of the most important commercial varieties are Chiuna 1, Chiuna 2, Chiuna 3 and Cumbe [113].

3.6. Chile

The introduction of cherimoya in Chile, documented by Benjamín Vicuña in his work ‘De Valparaiso a Santiago’ [114], marks the beginning of an agricultural legacy. This fruit, introduced originally from Peru, was presented as a gift to the Marquess of La Pica, Don Santiago Irarrazaval, who planted the first seed in Quillota. Since then, the province of Quillota, located in the central zone of Chile, has become a crucial nucleus for cherimoya cultivation. Over time, small properties, known as ‘quintas’ in Quillota, have played a crucial role in the conservation and diversification of this crop. Propagation at these properties was primarily through seeds, generating a rich diversity of clones with distinctive characteristics. Despite the challenges posed by urban expansion, some local selections have been preserved thanks to conservation efforts, notably those conducted by the Pontifical Catholic University of Valparaíso (PUCV). This genetic heritage includes notable varieties like ‘Concha Lisa’, ‘Bronceada’, ‘Copucha’, ‘Copucha temprana’ or ‘Terciopelo’, which have undergone significant changes in cultivation practices over time. In a later period, in the 1960s, another cherimoya production nucleus and ecotype generation emerged in the Coquimbo region, located 300 km north of Quillota, specifically in La Serena and Coquimbo. Noteworthy selections from this area include ‘Local Serena’, ‘Clavo’, ‘Juliana’ and ‘Juniana’. ‘Juniana’, in particular, gained prominence for being the first variety to appear in the market in May, during autumn, unlike the other varieties harvested at the end of winter or very late in spring (R. Cautin, unpublished data).

The province of Quillota has emerged as a pivotal nucleus for cherimoya cultivation. The subtropical climate and river irrigation of this region have shaped a unique cultivation model, where expansive spacing between plants allows for associated cultivation, enabling the simultaneous growth of vegetables and flowers alongside cherimoya plants. The cultivation model changed at its peak in the late 1980s, with innovations such as artificial flower pollination and strategic pruning. However, urban expansion consumed a significant portion of the ‘quintas’, resulting in the loss of some locally selected clones. The evolution of cultivation practices included the exploration of different planting densities, ranging from less than 100 trees per hectare to experimental plots with up to 2500 plants per hectare [115]. Despite reaching over 1000 hectares during its peak, cherimoya cultivation faced challenges in the 1990s, when efforts were made to export the fruit to the USA. Quality issues related to quarantine protocols caused setbacks in these export initiatives. Currently, approximately 300 hectares of cherimoya are registered in Chile, primarily concentrated in the Coquimbo region. The commercial significance of cherimoya has diminished, with agro-industrial options for frozen pulps emerging as alternatives, ensuring the product’s presence throughout the year. However, the decline in cultivation interest is attributed to the high labor requirements and the need to adopt advanced technologies developed globally for achieving high yields.

3.7. Bolivia

In Bolivia, cherimoya is cultivated at different altitudinal levels ranging from 800 to 1200 m above sea level, encompassing various regions across the departments of Cochabamba, La Paz, Santa Cruz, Chuquisaca, Tarija and Potosí. While other Annona species such as Annona muricata, Annona reticulata and Annona squamosa, along with several species in the Amazonian region, are also cultivated, cherimoya is the most significant commercially. Cherimoya production in Bolivia primarily occurs in family orchards, with each family usually managing fewer than 50 trees. The National Program for Fruit Production Support, through the National Institute of Agricultural and Forestry Innovation (INIAF), has collected 150 accessions of local ecotypes selected as mother plants based on desirable phenotypic characteristics for agronomic and molecular characterization.

As of 2020, Bolivia has an annual cherimoya production of 7000 tons covering an area of 1000 hectares distributed among family orchards [116]. This production landscape has seen expansion, with over 5000 hectares of new plantations established due to significant market demand and support from national and regional projects and programs. However, despite this growth, there remains an unsatisfied demand for cherimoya, which is currently being met by imports from neighboring Peru with its ’Cumbe’ variety. Factors such as size, presentation, ripeness and locality of origin influence market segments for cherimoya, affecting its selling price, which remains stable at approximately USD 3 per kilogram. The Department of La Paz, which is close to Peru, is the market most affected by cherimoya imports. Cherimoya cultivation has transitioned from being collection-based to the establishment of commercial production hubs. This shift has led to increased investment in production, including advancements in soil selection, irrigation systems, mother plant selection, harvest technologies and artificial pollination techniques, driven by the high unsatisfied demand for the fruit.

3.8. Portugal

The Madeira Archipelago, part of the Macaronesia Region, a biogeographic area composed of four archipelagos in the North Atlantic Ocean (Azores, Canary Islands, Cape Verde and Madeira), boasts diverse landscapes and a mild climate ideal for rich biodiversity, characterized by a blend of subtropical and Mediterranean climatic elements. The germplasm bank in Madeira is managed by ISOPLexis (Center of Sustainable Agriculture and Food Technology), from the University of Madeira, located at −16.9244° longitude and 32.6589° latitude, and around 500 accessions of Annona cherimola are documented in its Information and Documentation System. According to Ponenoe [117], citing a study carried out by Grabhan in 1897, the introduction of cherimoya on Madeira’s Island dates back to the 18th century. In Portugal, cherimoya production is primarily concentrated in the Archipelagos of Madeira and Azores, where it finds conditions similar to its natural habitat. In Madeira’s Island, the fruit is grown at an altitude of 550 m above sea level on the south coast and up to 280 m above sea level on the north coast. Published data for 2021 reported an area of 117 hectares and a production of 584 tons, with a slight increase to 627 tons in 2022, in a similar area (120 hectares) [118]. In the Azores, an area of 35 hectares was reported in 2020, with a production of 245 tons [119]. Traditionally, the propagation of cherimoya was carried out by seed, resulting in scattered plants and small orchards with significant genetic variability that are still in production. New orchards have been established using grafted plants or rootstocks onto which scions of the selected varieties are grafted. These grafted plants or rootstocks are provided by the Regional Secretariat of Agriculture and Environment (RSAE) or officially recognized commercial nurseries [120]. New varieties have been explored by the RSAE, focusing on commercial characteristics such as flavor and aroma, a smaller number of seeds, a thinner peel and an optimal fruit size for consumption. Varieties such as ‘Madeira’, ‘Mateus I’, ‘Funchal’ and ‘Perry Vidal’ are well-known in the region. In 2000, the “Anona da Madeira” was registered in the National Catalog of Varieties of Fruit Species (varieties ‘Madeira’ and ‘Mateus I’), and is also recognized by the European Union as a Protected Designation of Origin (PDO), being the first regional fruit to receive such a degree of international protection. In 2019, the European Commission services were asked to amend the specifications to include in the PDO, in addition to selected varieties that were initially registered, all varieties that are characterized in Madeira and even those obtained from trees reproduced by seminal means. This change was approved, and can be confirmed on the eAmbrosia platform [121], and all the varieties from the Island are considered “Anona da Madeira”. The fruit’s exportation to the European continent has become more consistent and systematic since it began to be managed by GESBA (Banana Sector Management Company). With the synergy of the marketing and distribution channels of the “Banana da Madeira”, 14.25 tons of “Anona da Madeira” were exported to the European continent in 2019. It should be noted that, unlike bananas, which are transported by sea, given the high perishability of the cherimoya, GESBA uses air transport exclusively. The availability of cargo plane services since 2018, operating 5 days a week (from Tuesday to Saturday), has been pivotal to facilitate this export [122].

3.9. Spain

The Institute of Subtropical and Mediterranean Hortofruticulture La Mayora (IHSM La Mayora-CSIC-UMA) maintains the Cherimoya and other fruit crops of the Annonaceae germplasm bank, located in the province of Málaga, in the municipality of Algarrobo, at the coordinates −4.0431° longitude and 36.7561° latitude. This region experiences a Mediterranean climate with subtropical temperatures. Established in the 1980s, the germplasm bank aimed at collecting accessions that would address the deficiencies of the local cultivar ’Fino de Jete’, thereby facilitating genetic improvement projects. Currently, the bank has over 350 accessions of cherimoya and other fruit tree species of the Annonaceae. Most of them have a South American origin following the previous hypothesis of the center of origin, so it would be of interest to complete the bank’s accessions with genetic material from Central America to increase its diversity.

According to data published by the Ministry of Agriculture [123], Spain recorded a total cherimoya production of 44081 tons during 2020, with nearly all the production (99.6%) concentrated in the Andalusia region (mainly in the province of Granada, but also in Malaga and Cadiz). The total irrigated area dedicated to cherimoya cultivation is about 3000 hectares. Cherimoya trees are also found scattered in the Canary Islands. In Spain, the cherimoya flowering season takes place mainly in May, resulting in fruit production from September to December. Management techniques such as pruning in May, resulting in a delayed flowering (July to September), allow for extending the harvesting season up to May. Cherimoya cultivation in Spain is 95%, dependent on the local cultivar ‘Fino de Jete’ and, to a lesser extent, on ‘Campas’. Both belong to the impressa type, exhibiting excellent organoleptic qualities, and are very well adapted to the environmental conditions of the production area. However, ‘Fino de Jete’ has some disadvantages, such as a high seed content, susceptibility to Mediterranean fly (Ceratitis capitata), the concentration of the production of the best quality fruits being a period of only three months (October–December) and a limited postharvest shelf-life. Recently, a new cultivar, ‘Alboran’, has been released from the IHSM La Mayora breeding program. ‘Alboran’ has a lower seed index than ‘Fino de Jete’ and excellent organoleptic qualities in the winter months, with a much longer postharvest shelf-life. Selections from a cross between ‘Fino de Jete’ and a spontaneous mutant from Annona squamosa, Thai seedless (Ts), which produces normal fruits without seeds, are being evaluated to produce seedless cherimoyas. The absence of seeds in the seedless mutant has been attributed to the deletion of the INNER NO OUTER locus (INO) that is involved in the development of the outer integument of the ovule [47]. In Spain, as in most countries outside the Americas where the cultivation of species of the genus Annona has been introduced, manual pollination is often performed, since the native pollinating insects are not present. The growers collect pollen and manually apply it to the flowers; this also results in larger fruits of a more regular shape. However, some nitidulid beetles (Coleoptera) present in Spain can also be somewhat effective in pollination under suitable shading and humidity conditions [124].

The majority of cherimoya production in Spain is primarily consumed domestically, with exports to other European countries accounting for approximately 10% to 20% of the total production. The main importing country is Portugal, followed by France and Germany. A Protected Designation of Origin (PDO), labeled “Chirimoya de la Costa Tropical de Granada-Málaga”, was established in 2010.

4. Future Perspectives

The prioritization of conserving cherimoya genetic resources within its region of highest diversity is essential for the effective management of this species’ genetic resources. While ex situ conservation methods, like tissue or in vitro culture banks, may offer viable alternatives, the recalcitrant nature of cherimoya seeds makes it necessary to maintain the trees in the field, which is economically and labor-intensive. Instead, in situ conservation through the protection of natural areas, which includes the genotypes of interest as well as the interaction with the rest of the ecosystem’s elements, is crucial. In the case of agrodiversity, in situ conservation can involve preserving traditional crop fields (“on farm”), which also permits the preservation of traditional methodologies and, therefore, the coevolution among all the elements that generate new diversity. Promoting cherimoya cultivation and consumption in Central America could be a way to increase its demand and aid conservation efforts by diversifying crop varieties. Similarly, promoting diverse production practices in other countries can safeguard local varieties and enhance resilience against environmental or pest-related challenges. Exploring alternative production systems, like intercropping, offers promising avenues to diversify agriculture and mitigate the risks associated with monoculture.

Ongoing improvement programs aim at increasing fruit quality (such as the introgression of TS characters to produce seedless fruits), improving postharvest handling, extending the productive months and developing resistance to pests like Ceratitis capitata. These improvements can facilitate better commercialization of cherimoya, unlocking its considerable potential. In addition, understanding local pollination agents and exploring alternative management practices that could replace manual pollination in those places where it is necessary can help to reduce production costs.

The recent sequencing of the cherimoya genome opens up opportunities for more detailed genetic studies, such as understanding agronomical and/or biological gene functions, exploring population diversity or conducting phylogenetic comparisons. Such insights can inform targeted conservation strategies and bolster efforts to sustain cherimoya diversity and productivity for future generations.