Duke Cherry Research Articles

Postharvest application of Aloe vera gel and thymol enhances shelf-life of duke cherries via altering physiochemical parameters

BackgroundDuke cherry is a non-climacteric fruit but deteriorates quickly during storage due to thin pericarp and succulent fruit tissue. The application of edible coatings, essential oils, or their combination is an appropriate technique to maintain the quality characteristics and reduce the deterioration of fruits during storage. This research assessed the effect of Aloe vera gel (AVG), thymol, and their combined use on the physicochemical and qualitative properties of duke cherries kept at 5 °C and 80% relative humidity for 28 d.ResultsCompared to the uncoated fruits, duke cherries coated with a combination of AVG and thymol, showed more values of firmness (12.76–100.32%), total phenol (9.99–45.09%), antioxidant activity (7.90–84.56%), and sensory scores(50.15–100.00%), as well as the activity of guaiacol peroxidase (GPX) (12.03–185.11%) and catalase (CAT) (10.20–243.66%) enzymes during cold storage. Moreover, duke cherries coated with a combination of AVG and thymol had remarkably lower values of weight loss (32.57–42.67%), respiration rate (34.96–49.78%), stem browning (24.50–50.53%), spoilage percentage (84.55–100%), anthocyanin (14.21–23.16%), and total soluble solids/titratable acidity (TSS/TA) (35.64–50.15%), as well as hydrogen peroxide (H2O2) (16.66–32.35%) and malondialdehyde (MDA) (15.23–31.05%).ConclusionThe application of AVG and thymol, particularly their combination, can have a high practical potential to extend shelf-life and preserve the quality of duke cherries during cold storage. This treatment has various advantages including natural, edible, cost-effective, and efficient.Graphical

Morphological and pomological characterizations of sweet cherry (Prunus avium L.), sour cherry (Prunus cerasus L.) and duke cherry (Prunus × gondouinii Rehd.) to choose the promising selections

Three domesticated species of Cerasus L. subgenus including sweet cherry (Prunus avium L.), sour cherry (P. cerasus L.) and duke cherry (P. × gondouinii Rehd.) are interesting and increasingly important fruit species in the world. In the current study, morphological and pomological variability of 146 cherry accessions including 45 sweet cherries, 62 sour cherries, and 39 duke cherries was evaluated to select superior selections. Analysis of variance indicated that most of the studied accessions showed high variability for most of the traits. Fruit length ranged from 18.88 to 28.45 mm in sweet cherries, while it was varied from 11.17 to 14.64 mm in sour cherries and 15.37 to 18.60 mm in duke cherries. In addition, fruit weight varied from 4.40 to 8.86 g in sweet cherries, 1.36 to 2.67 g in sour cherries, and 4.40 to 6.04 g in duke cherries. Fruit weight showed positive and significant correlations with leaf length (r = 0.91), leaf width (r = 0.84), and leaf density (r = 0.40). The dendrogram generated using morphological data indicated two different clusters and separated the accessions based on their species. Based on the results obtained here, 20 sweet cherry, 13 sour cherry, and 12 duke cherry accessions can be recommended for cultivation. Furthermore, most of the accessions could substantially contribute to existent cherry breeding programs. The conservation of these autochthonous accessions is highly recommended.

Sour and duke cherry viruses in South-West Europe

This study investigated the phytosanitary status of sour and duke cherry genetic resources in the Iberian Peninsula, and the incidence and leaf symptoms induced by the Prunus necrotic ringspot virus (PNRSV), Prune dwarf virus (PDV) and Apple chlorotic leaf spot virus (ACLSV). Young leaf samples were taken from 204 sour and duke cherry trees belonging to ten cultivars, and were assayed by DAS-ELISA. Samples positive for any of the three viruses were also tested by RT-PCR. To associate the leaf symptoms with virus presence, 50 mature leaves from each infected tree were visually inspected during the summer. The ELISA and RT-PCR results indicated that 63% of the cherry trees were infected by at least one of these viruses. PNRSV occurred in all cultivars sampled and presented the highest infection rate (46%), followed by PDV (31%) and ACLSV (6%). Many trees, (60 to 100%), were asymptomatic while harbouring single and mixed virus infections. The leaf symptoms associated with the viruses included chlorotic and dark brown necrotic ringspots on secondary veins and interveinal regions, for PNRSV, generalized chlorosis around the midveins, for PDV, chlorotic and reddish necrotic ringspots, for ACLSV, and generalized interveinal chlorosis, for mixed PNRSV and PDVinfections.

Phenotypic and genotypic characterization in the collection of sour and duke cherries (Prunus cerasus and ×P. ×gondouini) of the Fruit Genebank in Dresden-Pillnitz, Germany

Phenotypic and genotypic characterization of existing sour and duke cherry cultivars provide information for use by breeders in developing cultivars with improved qualities and for germplasm management to optimise the conserved diversity. This study examined 79 sour and duke cherry cultivars of the Fruit Genebank of the Institute for Breeding Research on Fruit Crops, Dresden-Pillnitz. For morphological analysis, 23 descriptors of the tree, the flower or the fruit, and three phenological characters were recorded to detect similarities and differences among the cultivars. Most of the characteristics exhibited a high degree of variability. Principal component analysis revealed that the first three components were responsible for 48 % of the phenotypic variability. Color descriptors as well as the fruit size and weight, the organoleptic quality and the two descriptors related to the abscission between fruit and stalk were the most effective parameters to discriminate genotypes. The genetic analysis was performed using six microsatellite markers recommended by the European Cooperative Program for Plant Genetic Resources. The average number of the effective alleles was 7.11 and the expected heterozygosity ranged from 0.78 to 0.89. The highest expected heterozygosity was achieved with the primer pairs EMPaS10 and EMPaS12. The tree comparison (‘bipartition distance’) estimated by the two data sets, morphological and genetic, revealed a tree distance of 0.669. Apparently, more research is needed for combining and jointly interpreting phenotypic and genetic marker data in diversity analysis for plant breeding and germplasm management.

Genetic relationships among cherry species with transferability of simple sequence repeat loci.

Sweet and sour cherries are two economically important species in the world. The capability to distinguish among cherry genotypes in breeding, cultivation and germplasm collection is extremely important for scientific as well as economic reasons. In the present research, sixteen simple sequences repeat (SSR) loci were used to estimate the relationships among sweet, sour, duke and wild cherries. All of the SSR markers showed high transferability across the studied species that allowed us to study genetic diversity in them. Totally 96 alleles were generated with SSR loci, of which 93 were found polymorphic with 97.57 % polymorphism. Values of genetic similarity between genotypes varied from 0.16 to 0.97 which indicated high level of genetic diversity. On the basis of their genetic similarities, SSR analysis allowed to group the genotypes into three main clusters according to their species. These results have an important implication for cherry germplasm characterization, improvement, and conservation.

Genetic variation in wild Prunus L. subgen. Cerasus germplasm from Iran characterized by nuclear and chloroplast SSR markers

The selected material of Cerasus subgen. will be useful for conservation and management and important for Prunus breeding programs. Knowledge of relationships among the cultivated and wild species of Cerasus is important for recognizing gene pools in germplasm and developing effective conservation and management strategies. In this study, genetic and phylogenetic relationships of wild Cerasus subgenus species naturally growing in Iran, including P. avium (mazzard), P. mahaleb, P. brachypetala, P. incana, P. yazdiana, P. microcarpa subsp. microcarpa, P. microcarpa subsp. diffusa and P. pseudoprostrata and three commercial species, sweet cherry (P. avium), sour cherry (P. cerasus) and duke cherry (P. x gondouinii) was investigated based on 16 nuclear SSR and five chloroplast SSR. Very high level of polymorphism was detected among the studied species based these molecular markers, indicating high inter and intraspecific genetic variation. Inter and intraspecific genetic similarity coefficients varied from 0.00 to 1.00, indicating high genetic variation in studied germplasm. These two molecular markers types could distinguish differences between all species so that accessions of each species were placed into a single group. Based on molecular markers, a close correlation was observed between intraspecific variation and geographical distribution. Furthermore, based on nuSSR primers, most wild species showed 2–4 alleles and may be tetraploid. In conclusion, the conservation of these highly diverse native populations of Iranian wild Cerasus germplasm is recommended for future breeding activity.

Phenotypic and genotypic variation in Iranian sour and duke cherries

Phenotypic and genotypic variation and structure of 29 sour cherry (P. cerasus) and duke cherry (P. x gondouinii) genotypes from different regions of Iran were identified using random amplified polymorphic DNA (RAPD) markers and morphological characters. Furthermore, one Prunus mahaleb genotype was used as an outgroup for molecular analysis. For morphological analysis, 23 variables were recorded to detect similarities between and among studied sour and duke cherries. Most studied characteristics were showing a high degree of variability. Principal component analysis showed that the first three components explained a total of 73.87 % of the whole phenotypic variability. Based on the morphological cluster analysis, studied sour and duke cherry genotypes were placed into three main clusters. The first main cluster included 16 sour cherry genotypes. The second main cluster contained all duke cherry genotypes and eight sour cherry genotypes, while, only one sour cherry genotype was placed in third main cluster. For RAPD analysis, 17 primers generated a total of 233 discernible and reproducible bands across genotypes analyzed, out of which 214 (91.51 %) were polymorphic with varied band size from 300 to 3000 bp. According to the similarity matrix, the lowest similarity was obtained between P. mahaleb, as an outgroup, and sour cherry. Dendrogram based on molecular data separated genotypes according to their species and geographic origin. Low correlation was observed between the similarity matrices obtained based on morphological and RAPD data. The information obtained here could be valuable for devising strategies for conservation of Iranian sour and duke cherries.

Quality evaluation of sour and duke cherries cultivated in south‐west Europe

The results of many studies describing sour cherry polyphenols and their positive effects on human health have been reported. However, there are no detailed studies concerning the physical quality of fresh fruits of sour and duke cherry. Several physical, chemical and colour fruit-characteristics of 10 sour and duke cherry cultivars cultivated for industrial use in south-west Europe were investigated during a 3-year (2008-2010) period. Some of the cultivars showed distinctive and interesting agronomical characters, such as low susceptibility to fruit cracking and high soluble solids and total polyphenol levels. This was the case with the duke cherry cultivar Guindo Garrafal Negro. Its fruits were quite sweet (18.49°Brix), resistant to cracking (6.34%) and rich in polyphenols (17.16 g gallic acid kg(-1) dry weight). Other relevant cherry cultivars were Guindo Tomatillo and Seixas, which had large and fleshy fruits (4.71 and 3.69 cm(3), respectively) and Guindo Silvestre, for which the lowest fruit cracking values (3.12%) were recorded. Sour and duke cherries are rich in healthy compounds such as polyphenols. Studies including the physical, chemical and colour properties of sour and duke cherry fruits are very interesting to engineers in the design of equipment for harvesting and post-harvest technology.

Dehydrogenase isoenzyme polymorphism in genus Prunus, subgenus Cerasus

Dehydrogenase polymorphism was studied in 36 sour cherry (Prunus cerasus L.), sweet cherry (Prunus avuim L.), mahaleb (Prunus mahaleb L.), ground cherry (Prunus fruticosa Pall.), duke cherry (Prunus gondounii Redh.), Japanese flowering cherry (Prunus serrulata Lindl.) and four iterspecific hybrids (standard cherry rootstocks ?Gisela 5?, ?Gisela 6?, ?Max Ma? and ?Colt?). Inner bark of one-year-old shoots, in dormant stage, was used for enzyme extraction. Vertical PAGE was used for isoenzyme analysis: alcohol dehydrogenase (ADH), formate dehydrogenase (FDH), glutamate dehydrogenase (GDH), isocitrate dehydrogenaze (IDH), malate dehydrogenase (MDH), phosphogluconate dehydrogenase (PGD), and shikimate dehydrogenase (SDH). All studied systems were polymorphic at 10 loci: Adh -1 (3 genotypes) and Adh-2 (5 genotypes), Fdh-1 (2 genotypes), Gdh-1 (3 genotypes), Idh-1 (4 genotypes) i Idh -2 (5 genotypes), Mdh-1 (3 genotypes), Pgd-1 (4 genotypes), Sdh-1 (1 genotype) i Sdh-2 (3 genotypes). Cluster analysis was used to construct dendrogram on which four groups of similar genotypes were separated. Obtained results indicate that studied enzyme systems can be used for determination of genus Prunus, subgenus Cerasus. Among studied enzyme systems ADH, IDH and SDH were the most polymorphic and most useful to identify genetic variability. Polymorphism of FDH and GDH in genus Prunus, subgenus Cerasus was described first time in this work. First results for dehydrogenase variability of Oblacinska indicate that polymorphism of loci Idh-2 and Sdh-2 can be useful for discrimination of different clones.

Multivariate analysis of Prunus subgen. Cerasus germplasm in Iran using morphological variables

Knowledge of relationships among the cultivated and wild species of Cerasus, a subgenus of Prunus L., is important for recognizing gene pools, identifying pitfalls in germplasm collections and developing effective conservation and management strategies. In this study, morphological characterization of wild Cerasus subgenus species naturally growing in Iran, including P. avium L. (mazzard), P. mahaleb L., P. brachypetala Boiss., P. incana Pall., P. yazdiana Mozaff., P. microcarpa Boiss. subsp. microcarpa, P. microcarpa Boiss. subsp. diffusa and P. pseudoprostrata Pojark. and three commercial species, sweet cherry (P. avium L.), sour cherry (P. cerasus L.) and duke cherry (P. × gondouinii Rehd.) was investigated. Twenty-nine variables were recorded in 95 accessions of these species to detect similarities among them. All studied characteristics were showing a high degree of variability, but it was highly pronounced for plant height, leaf characters especially for dimensions and pubescence as well as for petiole and peduncle length. The majority of significant correlation coefficients were found in the characteristics representing plant size and growth habit with leaf size. Principal component analysis was performed for phenotypical diversity determination and grouping of species. Characters with high discriminating values were those related to growth habit, height, compactness, trunk diameter, leaf dimensions, petiole length, leaf tip and serration, flower color, peduncle length, fruit shape and stone shape. Based on the cluster analysis, species included in two main clusters, first those with large structure (sweet, sour and duke cherries, mazzard and mahaleb), second the other species with small structure which might be potentially suitable for rootstock breeding programs. Scatter plot using two first factors also confirmed the grouping by cluster analysis. The conservation of the highly diverse native populations of Iranian wild Cerasus species is recommended.

Agromorphological characterization of traditional Spanish sweet cherry (Prunus avium L.), sour cherry (Prunus cerasus L.) and duke cherry (Prunus x gondouinii Rehd.) cultivars

Thirty-one traditional cultivars (26 sweet cherry (Prunus avium L.), four duke cherry (Prunus x gondouinii Rehd.), and one sour cherry (Prunus cerasus L.)) from Sierra de Francia and Arribes del Duero in Central-Western Spain were surveyed and characterized agromorphologically. A total of 37 descriptors, mainly defined by the International Plant Genetic Resources Institute and the International Union for the Protection of New Varieties of Plants were used to describe flowers, leaves, fruits and the tree itself over a 3 consecutive years. This made possible the unequivocal identification of 25 cultivars. A dendrogram gave a clear separation between the sour, duke and sweet cherry cultivars and showed existing synonymies and homonymies. This work is an important step in the conservation of genetic cherry resources in the province of Salamanca (Spain), which show distinctive and interesting agronomical characters such as low susceptibility to fruit cracking, high levels of soluble solids, early fruit maturity and great rusticity.

Blooming phenology and fertility of sour cherry cultivars selected in Hungary

Experiments were conducted during the period between 1972 and 2002 at three sites in Hungary. At Érd 97, Helvetia 10, and Újfehértó, 3 cultivars were studied in variety collections. Observations were made on the blooming phenology (start, main time, end and length of the bloom period), on the blooming dynamics (the rate of the open flowers counted every day), on the receptivity of sexual organs, on the fruit set following self- and open-pollination and on the effect of association of varieties in the orchards (choice, rate and placement of pollinisers).
 Based on the results the rate of the overlap of the blooming times were calculated and varieties were assigned into five bloom time groups according to their main bloom. Self-fertility conditioned by natural self pollination was studied and good pollinisers were chosen (sweet, sour and duke cherry varieties) for the self-sterile and partially self-fertile varieties.
 The necessity of bee pollination was proved by different pollination methods: natural self-pollination, artificial self-pollination, open pollination. Summary: Experiments were conducted during the period between 1972 and 2002 at three sites in Hungary. At Érd 97, Helvetia 10, and Újfehértó, 3 cultivars were studied in variety collections. Observations were made on the flowering phenology (start, main time, end and length of the bloom period), on the flowering dynamics (the rate of the open flowers counted every day), on the receptivity of sexual organs, on the fruit set following self- and open-pollination and on the effect of association of varieties in the orchards (choice, rate and placement of pollinisers).

The cytology of the Duke cherries and their derivatives

The cytology of the Duke cherries and their derivatives