Fino De Jete Research Articles

The American Cherimoya Genome Reveals Insights into the Intra-Specific Divergence, the Evolution of Magnoliales, and a Putative Gene Cluster for Acetogenin Biosynthesis.

Annona cherimola (cherimoya) is a species renowned for its delectable fruit and medicinal properties. In this study, we developed a chromosome-level genome assembly for the cherimoya 'Booth' cultivar from the United States. The genome assembly has a size of 794 Mb with a N50 = 97.59 Mb. The seven longest scaffolds account for 87.6% of the total genome length, which corresponds to the seven pseudo-chromosomes. A total of 45,272 protein-coding genes (≥30 aa) were predicted with 92.9% gene content completeness. No recent whole genome duplications were identified by an intra-genome collinearity analysis. Phylogenetic analysis supports that eudicots and magnoliids are more closely related to each other than to monocots. Moreover, the Magnoliales was found to be more closely related to the Laurales than the Piperales. Genome comparison revealed that the 'Booth' cultivar has 200 Mb less repeats than the Spanish cultivar 'Fino de Jete', despite their highly similar (>99%) genome sequence identity and collinearity. These two cultivars were diverged during the early Pleistocene (1.93 Mya), which suggests a different origin and domestication of the cherimoya. Terpene/terpenoid metabolism functions were found to be enriched in Magnoliales, while TNL (Toll/Interleukin-1-NBS-LRR) disease resistance gene has been lost in Magnoliales during evolution. We have also identified a gene cluster that is potentially responsible for the biosynthesis of acetogenins, a class of natural products found exclusively in Annonaceae. The cherimoya genome provides an invaluable resource for supporting characterization, conservation, and utilization of Annona genetic resources.

Development of an Effective Sonotrode Based Extraction Technique for the Recovery of Phenolic Compounds with Antioxidant Activities in Cherimoya Leaves.

The leaves of Annona cherimola Mill (cherimoya) are a potential source of phenolic compounds that have been shown to have beneficial properties. Therefore, this study focuses on establishing an ultrasonic-assisted extraction of phenolic compounds in cherimoya leaves using a sonotrode. For that purpose, a Box-Behnken design based on a response surface methodology (RSM) was used to optimize factors, such as amplitude, extraction time and solvent composition to obtain the maximum content of phenolic compounds by HPLC-MS and the maximum in-vitro antioxidant activity by DPPH, ABTS and FRAP assays in ‘Fino de Jete’ cherimoya leaves. The optimal conditions were 70% amplitude, 10 min and 40:60 ethanol/water (EtOH/H2O) (v/v). The results obtained under these optimum conditions by using a sonotrode were compared with those from an ultrasonic bath; briefly, recovery of phenolic compounds by sonotrode was 2.3 times higher than a bath. Therefore, these optimal conditions were applied to different varieties ‘Campas’, ‘Fino de Jete’ and ‘Negrito Joven’ harvested in the Tropical Coast of Granada (Spain). A total of 39 phenolic compounds were determined in these cherimoya leaf extracts, 24 phenolic compounds by HPLC-MS and 15 proanthocianidins by HPLC-FLD. 5-p-coumaroylquinic acid, lathyroside-7-O-α-l-rhamnopyranoside and quercetin hexose acetate were first identified in cherimoya leaves. The most concentrated phenolic compounds were the flavonoids, such as rutin and quercetin hexoside and proanthocyanidins including monomers. Almost no significant differences in the phenolic content in these cultivars were found (11–13 mg/g d.w. for phenolic compounds and 11–20 mg/g d.w. for proanthocyanidins). In addition, sonotrode ultrasonic-assisted extraction has been shown to be an efficient extraction technique in the phenolic recovery from cherimoya leaves that could be implemented on an industrial scale.

Assessment of in Vitro Pollen Germination and Pollen Tube Growth of Annona Cherimola Mill

ABSTRACT Yield in cherimoya (Annona cherimola Mill.) is affected by various factors reducing fertilization and fruit production such as: the protogynous dichogamy of the flowers, deficient natural pollination, and low pollen quality. The objective of this study was to determine in vitro the differences in pollen quality of nine ecotypes and one cultivar of A. cherimola from pollen samples collected at the female and male phenological stages of flowering. The percentage of pollen germination and the length of pollen tubes was evaluated in vitro at 2 and 24 hours after incubation at 21°C, in two phenological stages of the flowers during bloom in 2018 and 2019 seasons. The germination medium contained: 10% sucrose, 1% agar, 0.005% boric acid, and 0.025% calcium nitrate. Fabulosa and Austro ecotypes and the Fino de Jete cultivar had the highest pollen germination in the male phenological stage, after 2 and 24 hours in both seasons. Fabulosa had the highest percentage of germination in the female stage in both seasons. The ideal phenological stage for pollen collection was at anther dehiscence. Austro and Fabulosa ecotypes had the longest pollen tubes after 2 and 24 hours, in both phenological stages for both seasons. Fabulosa and Austro ecotypes, and Fino de Jete cultivar, showed promising pollen characteristics for hand pollination of cherimoya.

Pomological, Sensorial, Nutritional and Nutraceutical Profile of Seven Cultivars of Cherimoya (Annona cherimola Mill).

In this work, the food quality of four international (Campas, Chaffey, Fino de Jete and White) and three local (Daniela, Torre1 and Torre2) cultivars of Cherimoya (Annona cherimola Mill) was investigated. With this aim, pomological traits, sensorial attributes, physiochemical parameters (pH, total soluble content and total acidity), nutritional composition (macro- and micro-nutrients) and nutraceutical values (bioactive compounds, radical scavenging and antioxidant properties) were evaluated. Among the seven observed cultivars, Fino de Jete was identified as the best, not only for its commercial attributes such as pomological traits and physiochemical values, but also for its nutritional composition. On the other hand, Chaffey and Daniela were the cultivars with the highest content of polyphenols, proanthocyanidins, and with the strongest antioxidant capacity. Concerning the two local ecotypes, Torre1 and Torre2, they displayed a balanced nutritional profile that, if combined with their discrete nutraceutical, physicochemical and pomological values, may result in a reassessment of their commercial impact. In conclusion, our data provide interesting information about the pomological, nutritional, and nutraceutical properties of cherimoya fruits. Our results, in addition to promoting the commercial impact of local cultivars, may increase the use of individual cultivars in breeding programs.

Water Use and Leaf Nutrient Status for Terraced Cherimoya Trees in a Subtropical Mediterranean Environment

Water scarcity in many semi-arid agricultural areas, in particular for the Mediterranean basin, is promoting changes in irrigated agriculture, with alternative strategies being introduced for water-use optimization. The coast of Granada and Malaga (Southeast Spain) is an economically important area for subtropical fruit cultivation. This intensively irrigated agriculture is characterized by requiring extra amounts of water and the adoption of sustainable practices to improve agricultural water management. A two-season experiment was conducted to assess (1) the water use in terraced cherimoya (Annona cherimola Mill. cv. Fino de Jete) orchards under conventional and organic production systems with drainage lysimeters, and (2) the impact on fruit yield and nutritional effects between the two considered production systems. Crop coefficient (Kc) values for cherimoya were 0.60–0.66, 0.64–0.71, and 0.48–0.62 at flowering, fruit set, and fruit growth, respectively. Fruit yield was similar in both systems, ranging from 47.1 for conventional to 44.1 kg tree−1 for organic farming, averaging 13.2 and 12.3 t·ha−1, respectively. No differences between these systems were observed in terms of leaf nutrient status, with variations in the N, P, and K contents during the different phenological stages. The N, P, and K lessen during flowering and fruit growth; the highest levels of these nutrients were fixed at harvest. These patterns were the opposite in Ca and Mg, ascribable to the antagonism between K and both Ca and Mg. Thus, these findings highlight the need to establish the optimal use of irrigation water with respect to crop requirements, thereby encouraging sustainable subtropical farming in terraces.

An ultra-low pressure pneumatic jamming impact device to non-destructively assess cherimoya firmness

The quality of cherimoya fruit is reduced by the rapid deterioration of firmness during ripening. Different methods have been developed for the measurement of firmness. The objective of this study was to use a developed impact prototype for the non-destructive assessment and prediction of cherimoya fruit firmness. The prototype has an ultra-low pressure pneumatic jamming rod used to copy the irregular fruit shape. A sample of 200 cherimoyas from Malaga (Spain) ‘Fino de Jete’ were tested during 4 days. Every day all the fruits were non-destructively tested and a set of 15 were destructively tested. On the fourth day all the remaining fruits were also destructively tested. The prototype was capable of copying the irregularities of the fruit and non-destructively assessing the decrease in cherimoya firmness during ripening without causing damage. A high correlation was found between destructive firmness and non-destructive variables from the prototype. A PLS model was developed to relate destructive firmness from day 4 to non-destructive variables and diameter from day 3, with a R2 of 75.6 and a RMSECV of 0.9885. A calibration set confirmed the prediction with a R2 of 80.2 and a RMSEP of 0.0561. Firmness decay could be non-destructively predicted 24 h in advance using the variables extracted from the prototype device signal.

Comparative study of some fruit quality characteristics of two of <i>Annona cherimola</i> Mill. grown in southern Italy

This work aimed to analyse the differences between fruits obtained by different harvest dates in two cultivars Annona cherimola (Fino de Jete and Campas) planted in Southern Italy. The fruits selected at the fruit-set time were harvested when 1500 Degree Day were accumulated. Fruits were sampled from October to December when 1500 Growing Degree Days (DD) were accumulated from fruit-set. Fruit fresh weight and skin colour were measured at harvest and after storage. The following parameters were also measured: Fruit shape, pulp colour, pulp firmness, number of seeds, total soluble solids, titratable acidity, ascorbic acid, total polyphenol content, total antioxidant capacity and fruit dry weight. An MFA was carried out. In the first phase of the MFA, a PCA was performed for each group of quantitative variables (PPCA). Then, the variables were divided into five groups: Carpological (CR), colourimetric (CL), maturation index (MI), nutraceutical (NU), and Environmental (Env). All relations between the variables and the formation of the factors were affected. The multifactorial factor analysis has allowed evaluating the role that the different groups of variables, taken into consideration, have in defining the time harvest. In order to have fruits of regular shape and size, the harvest must be carried out within the last ten days of October, involving the pollinated flower within the third week of June. About the size and regularity of the fruit, from the third week of June, it appears to be borderline, as the fruits are smaller in size, with fewer seeds, but still, guarantee size and shape that falls within the quality standards of the Annona cherimola. Between the two cultivars, Fino de Jete cultivar is more sensitive to temperature increases during the pollination period than the Campas cultivar.

Yield, pomological characteristics, bioactive compounds and antioxidant activity of <i>Annona cherimola Mill.</i> grown in mediterranean climate

The agronomic and qualitative responses of the cherimoya (Annona cherimola Mill.) fruit grown in Mediterranean climate are not properly studied. Fruits of Fino de Jete, the most diffused worldwide cultivar of cherimoya, and Torre 1 a new genotype obtained by breeding program in Sicily, Italy, were collected at commercial ripening and subjected to productive (yield efficiency, number of fruits, crop load), analytical (fruit weight, transversal diameter, longitudinal diameter, total soluble solid content, titratable acidity, seed weight, seed number, peel and pulp weight, pulp/seed ratio and colorimetric analysis), bioactive compound content (total antioxidant activity, Phenolic and Carotenoid) and sensory evaluations by a semi-trained panel, recorded over two productive seasons. Even if the climatic conditions prevailing in Sicily differ from those of most cherimoya-growing regions, the two observed cultivars generally showed yields and fruit qualitative characteristics comparable with those harvested in other Mediterranean and Tropical areas. Fino de Jete confirmed its quality standard thanks to its yields performance and fruit weight. Despite of this, Torre 1 showed interesting physico-chemical, sensory properties and bioactive compounds, suitable for the consumer needs: less number of seeds and better pulp/seed ratio, better total solid soluble content/tritratable acidity ratio, higher phenolic content and antioxidant activity. These results suggest that cherimoya can be cropped for fresh production in Mediterranean environment with promising yields and good standards of fruit quality.

Effect of fruit-set time on the quality performance of Anona cherimola Mill. fruit in south italy

The aim of this work was to analyse the differences between fruits obtained by different dates of fruit set and identify the proper fruit-set time that allows to obtain the optimum fruit quality in Annona cherimola cv Fino de Jete, planted in Southern Italy. Six fruit-set dates were selected from the first week of June to the second week of July. Fruits were sampled from October to November, when 1500 Growing Degree Days (DD) were accumulated; The DD were calculated using a base temperature of 12 °C. Fruit fresh weight (FW) and skin colour were measured. These parameters were measured also after storage, and in addition, the following parameters were measured: fruit shape (FS), pulp colour, pulp firmness, number of seeds, total soluble solids content (TSSC), titratable acidity (TA), ascorbic acid (AA), total polyphenol content (TPC), total antioxidant capacity (TAC) and fruit dry weight (DW). Moreover, fruit dry weight percentage, fruit fresh weight loss (FWL), and the seed index were calculated after storage.The fruit development period changed from 120 to 146 days with the fruit-set date. The average seed number decreased with fruit set date. A strong correlation between fruit size and seed number occurred and also between the H/D ratio and number seed. FW decreased significantly from the third week of October to the first week of December and FS became progressively less regular in fruit coming from the 4th week of November to the 2nd week of December. From second to five sampling the AA was highest and similar. The lowest values of TAC were measured in the November and early December. The correlation between TAC and AA was stronger compared to TAC and TPC. All quality parameters of Annona cherimola fruit have reached the standards required by the market when 1500 DD have been accumulated from fruit-set. Eventually, the optimal period for fruit set ranged from end of June to the beginning of July.

Allometric models for determining leaf area of 'Fino de Jete' cherimoya grown in greenhouse and in the open field

Allometric models for determining leaf area of 'Fino de Jete' cherimoya grown in greenhouse and in the open field

Identification and quantification of phenolic and other polar compounds in the edible part of Annona cherimola and its by-products by HPLC-DAD-ESI-QTOF-MS

Annona cherimola fruit is native to inter-Andean valleys from Peru and Ecuador. In the Mediterranean region, the main producer of cherimoya is the coast of Granada–Malaga (Spain), also called ‘Costa Tropical’, where the two most important cultivars found are ‘Fino de Jete’ and ‘Campa’.Cherimoya, like most fruits, is an important source of bioactive compounds, such as phenolic compounds. Therefore, the aim of this study was the tentative identification and quantification of phenolic and organic acids in pulp, peel and seed of two cherimoya cultivars (‘Fino de Jete’ and ‘Campa’) using HPLC-DAD-ESI-QTOF-MS.By using the proposed method, 21 phenolic and organic acids were detected in the edible portion of cherimoya, 37 in peel and 22 in seed. Procyanidins were the main phenolic compound family identified in the pulp and peel of the two cultivars, whereas in cherimoya seeds higher quantities of organic acids and flavonoids were detected. Most of the compounds were identified for the first time in cherimoya.According to these results, cherimoya pulp and its by-products are a natural source of procyanidins and other phenolic and polar compounds. In particular, cherimoya peel, with a higher concentration of phenolic and polar compounds in comparison with pulp and seed, represents an interesting food by-product that could be used as an ingredient in the functional food and/or pharmaceutical industry.

Inhibición del bronceado en cáscara de chirimoya ‘Fino de Jete’ por aplicación de 6-bencilaminopurina

The cherimoya (Annona cherimola Mill.) fruit is climacteric and has a very short postharvest life; the symptoms of senescence include peel browning and fruit softening. The objective of this research was to evaluate the effect of application of 6-benzylaminopurine (BAP) in the postharvest life of cherimoya fruit ‘Fino de Jete’. Fruits were randomly selected from the middle and basal part of six trees. BAP was applied at 1.0 mM or 0 mM in every of two dates, that is 8 or 15 days before harvest (DAC). After harvest, fruits were transported for 1.5 h and stored in two different temperatures, refrigerated (TR) (6 °C) or room temperature (TA) (16 ± 2 °C). Every third day, from 1 to 15 day after harvest (DDC), they were analyzed in relation to weight loss, color L*, a* and b*, and fruit firmness and deformation. In TA, the fruits treated with 1 mM BAP in both, 8 or 15 DAC retained peel color L* over 35% (ρ ≤ 0.05) in relation to control.

Biotechnology applied to Annona species: a review

Annonaceae is an ancient family of plants including approximately 50 genera growing worldwide in a quite restricted area with specific agroclimatic requirements. Only few species of this family has been cultivated and exploited commercially and most of them belonging to the genus Annona such as A. muricata, A. squamosa, the hybrid A. cherimola x A. squamosa and specially Annona cherimola: the cherimoya, commercially cultivated in Spain, Chile, California, Florida, México, Australia, Ecuador, Peru, Brazil, New Zealand and several countries in South and Central America. The cherimoya shows a high degree of heterozygosis, and to obtain homogeneous and productive orchards it is necessary to avoid the propagation by seeds of this species. Additionally, the traditional methods of vegetative propagation were inefficient and inadequate, due to the low morphogenetic potential of this species, and the low rooting rate. The in vitro tissue culture methods of micropropagation can be applied successfully to cherimoya and other Annona sp to overcome these problems. Most of the protocols of micropropagation and regeneration were developed using the cultivar Fino de Jete, which is the major cultivar in Spain. First it is developed the method to micropropagate the juvenile material of cherimoya (ENCINA et al., 1994), and later it was optimized a protocol to micropropagate adult cherimoya genotypes selected by outstanding agronomical traits (PADILLA and ENCINA, 2004) and further it was improved the process through micrografting (PADILLA and ENCINA, 2011).At the present time we are involved in inducing and obtaining new elite genotypes, as part of a breeding program for the cherimoya and other Annonas, using and optimizing different methodologies in vitro: a) Adventitious organogenesis and regeneration from cellular cultures (ENCINA, 2004), b) Ploidy manipulation of the cherimoya, to obtain haploid, tetraploid and triploid plants (seedless), c) Genetic transformation, for the genes introduction to control the postharvest processes and the genes introduction to provide resistance to pathogen and insects and d) Micropropagation and regeneration of other wild Annona or related Annonaceae species such as: Annona senegalensis, A. scleroderma, A. montana, A. reticulata, A. glabra, A. diversifolia and Rollinia sp.

FRUIT DEVELOPMENT AND MATURATION PHENOLOGY OF 'FINO DE JETE' CHERIMOYA

Cherimoya is a climacteric that ripens after harvest. It has an ephemeral postharvest life because of high perishability and its limited capacity for cold storage. External morphological changes during maturation are not pronounced and a reliable harvest index does not exist. Farmers, seeking better prices, often harvest under-matured fruits, causing a decrease in quality. It is, therefore, very important to establish an optimum harvest index. In this work we have analyzed development and maturation of ‘Fino de Jete' cherimoya, the main cultivar in Spain. The evolution of size, skin colour, and carpel segments and the peduncle-fruit joint zone appearance, from fruit-set until natural drop, were described. We also have characterized the postharvest evolution and quality parameters of fruits harvested from 9 to 19 weeks after pollination (wap). The most remarkable changes coincided with the most important phases in the fruit-growth-curve, leading to the establishment of four phenological stages: stage 1, young-fruit; stage 2, “green fruit”, fruits at the end of phase I; stage 3, colour-break, at the beginning of phase III; and stage 4, fruit phase III. Fruits in stage 2, harvested before 15 wap did not ripen properly. After 15 wap, at stage 3, fruits reached optimum soluble solids concentration (20-23°Brix) in 6 days at room temperature. Nevertheless, later harvesting, after 17 wap, reduced the seed index. We have estimated that about 1325 growing degree days are necessary for a to be physiologically mature and to reach proper postharvest quality.

Monitoring the pollution risk and water use in orchard terraces with mango and cherimoya trees by drainage lysimeters

Agricultural nonpoint-source pollution is the leading cause of water-quality degeneration of rivers and groundwater. In this context, the coast of Granada province (SE Spain) is economically an important area for the subtropical fruit cultivation. This intensively irrigated agriculture often uses excessive fertilizers, resulting to water pollution. Therefore, a 2-year experiment was conducted using drainage lysimeters to determine the potential risk of nutrient pollution in mango (Mangifera indica L. cv. Osteen) and cherimoya (Annona cherimola Mill. cv. Fino de Jete) orchards. These lysimeters were used to estimate the nutrient budgeting for each crop. NO3-N, NH4-N, PO4-P and K losses according to lysimeters were, respectively, 55.1, 12.4, 3.7, and 0.6 for mango and 61.8, 17.8, 4.9, and 0.5 kg ha−1 yr−1, for cherimoya. NO3, concentrations in the leachates ranged from 1.8 to 44.3 mg L−1, and from 23.0 to 51.0 mg L−1, for mango and cherimoya, respectively, in some cases exceeding the limits for safe drinking water. PO4 also exceeded the permitted concentrations related to eutrophication of water, ranging from 0.07 to 0.5 mg L−1 and from 0.12 to 0.68 mg L−1 from mango and cherimoya lysimeters, respectively. With respect to the nutrient balance, N, P, and K removed by cherimoya fruits was 76.4, 5.5, and 22.6 kg ha−1 yr−1, and for mango fruits 30.2, 3.3 and 27.8 kg ha−1 yr−1, respectively. Nutrient losses in the leachates were surprisingly low, considering total N, P, and K applied during the year, in mango lysimeters 3.8, 0.11, and 12.6%, and in cherimoya lysimeters 7.7, 0.23 and 16.0%, respectively, indicating a potential soil accumulation and eventual loss risk, especially during torrential rains. Crop coefficient (Kc) values of mango trees varied within ranges of 0.35–0.67, 0.55–0.89, and 0.39–0.80 at flowering, fruit set, and fruit growth, respectively. Kc values for cherimoya trees had ranges of 0.58–0.67, 0.61–0.68, and 0.43–0.62 at flowering, fruit set and fruit growth, respectively. In this study, the Kc values of mango and cherimoya were significantly correlated to julian days. Therefore, the estimated WUE in the mango and cherimoya orchards reached 21.2 and 14.0 kg ha−1 mm−1, respectively. Thus, this study highlights the urgency to establish the optimal use of fertilizers and irrigation water with respect to crop requirements, to preserve surface-water and groundwater quality, thereby achieving more sustainable agriculture in orchard terraces.

The use of consecutive micrografting improves micropropagation of cherimoya ( Annona cherimola Mill.) cultivars

Clonal propagation of cherimoya via micropropagation is known to be problematic and its difficulty varies depending on the cultivar used. In order to improve the micropropagation process, the use of successive micrografting was applied to three cherimoya cultivars: ‘Fino de Jete’, ‘Bonita’ and ‘Pazicas’. Grafting nodal tissue onto a rootstock derived from ‘Fino de Jete’ juvenile material improved bud sprouting significantly in all tested cultivars. Rooting of sprouted shoots from non-grafted nodal tissue was extremely poor, however, shoots derived from explants after 1–3 consecutive micrografts displayed enhanced rooting. While ‘Fino de Jete’ and ‘Bonita’ shoots displayed 50% of rooting after two micrografts, Pazicas cultivar shoots required three micrografts to reach this percentage. Rooting was maximum after three micrografts, with 70%, 60% and 50% of rooting for ‘Fino de Jete’, ‘Bonita’ and ‘Pazicas’ shoots, respectively. Rooted plantlets were mycorrhized and acclimatized under greenhouse conditions and displayed a high rate of survival (90–100%) for all cultivars, indicating that the micrografting technique could also have an effect on the acclimation of plants.

DEVELOPMENT OF MICROSATELLITE MARKERS FOR FINGERPRINTING AND BREEDING SUBTROPICAL FRUIT TREE SPECIES

Microsatellites or SSRs are considered as the marker of choice for fingerprinting and breeding in both plant and animal species. However, in most subtropical fruit tree species no SSR sequences are currently available. In this work, we describe the development of SSR sequences in three subtropical fruit tree species: cherimoya (Annona cherimola Mill.), lychee (Litchi chinensis Sonn.) and mango (Mangifera indica L.). In order to develop the SSRs a genomic library enriched in GA/CT repetitive sequences was performed for each species from DNA of standard cultivars: Fino de Jete for cherimoya, Mauritius for lychee and Tommy Atkins for mango. Microsatellite polymorphism was evaluated in germplasm collections of the three species. For cherimoya, 15 polymorphic SSRs were studied in 40 accessions; for lychee, 12 polymorphic SSRs in 21 accessions; and for mango 15 polymorphic SSRs in 30 accessions. For all the three species studied, the microsatellite enrichment procedure was highly successful since over 70% of the clones studied contained the repetitive sequence in cherimoya and mango and over 50% in lychee. The results are discussed in terms of their implications for fingerprinting, germplasm resources management and breeding of subtropical fruit tree species.

Residual effect of atomised water vapour treatment on carbohydrate metabolism during ripening of cv “Fino de Jete” cherimoya fruit

Atomised hot water vapour at between 46 and 54 °C for 60 min was tested as a method of delaying ripening and extending shelf life in cv “Fino de Jete” cherimoya fruit (Annona cherimola Mill.). Heat treatment at 46 °C stimulated the respiration rate and starch degradation, induced ethylene production, increased the accumulation of soluble sugars and α-amylase activity, and moved the onset of ethylene production (OEP) forward. Treatment at 50 °C, and especially at 52 °C, delayed the climacteric peak and the OEP, decreased sugar and organic acid accumulation, and reduced α-amylase and invertase activity. The results obtained indicate that temperatures higher than 48 °C slowed physiological processes and carbohydrate metabolism and extend the shelf life of the cherimoya fruits, while temperatures higher than 52 °C blocked ripening irreversibly.

Early flower initiation allows ample manipulation of flowering time in cherimoya ( Annona cherimola Mill.)

Flower initiation date and readiness to flowering in buds of different age were studied in ‘Fino de Jete’ cherimoya ( Annona cherimola) cultivar in order to establish the limits for the manipulation of its flowering date. Flower initiation was analyzed by light and scanning electron microscopy (SEM) collecting axillary buds from May to the following February, whereas the bud readiness to produce perfect flowers was determined by forcing buds of different age to sprout by means of leaf removal and tipping the new growth. SEM images confirm that cherimoya buds are differentiated into flowers almost a year before blooming. In this regard, axillary buds have already formed the sepals when the subtending leaf has just begun unfolding (week 0), while the petals are clearly visible in 1-week-old buds. Sectioning of paraffin-embedded buds illustrate that cherimoya buds are in fact a bud complex that 1 week after its inception comprises 4–5 buds of different size of which the two largest ones are reproductive, while the 2–3 smallest buds often remain undifferentiated at that time. The high capacity of flowering expressed by young buds that have been forced to grow proves that cherimoya meristems are early competent for flowering. No differences in fertility or in the time needed to reach anthesis after leaf removal were found among buds of different ages. Node position had no effect on bud break and flowering potential. The early flower initiation in cherimoya deduced from this work opens a wide temporal window for the experimental manipulation of flowering and harvest dates in this crop.

PERMANENT GENETIC RESOURCES: Development of 52 new polymorphic SSR markers from cherimoya (Annona cherimola Mill.): transferability to related taxa and selection of a reduced set for DNA fingerprinting and diversity studies

Fifty-two single locus polymorphic microsatellites were developed using two genomic libraries digested with HaeIII and RsaI of cherimoya cv. Fino de Jete enriched in CT/AG repeats. A total of 222 alleles were detected with the selected simple sequence repeats (SSRs). The observed and expected heterozygosities ranged from 0.08 to 0.73 and from 0.20 to 0.84, respectively. Most of the SSRs were transferable to other species in the Annonaceae. A set of 20 microsatellites was selected to facilitate the exchange of data among laboratories.