Mandarin Hybrids Research Articles

Comparative study of the mandarin hybrid fruit characteristics: Nova, Murcott and Ortanique in Capão Bonito SP, Brazil

The Murcott tangor represent 20% of the tangerines trees in São Paulo State being the second more grown. Their fruits have good acceptance in the market cause of the good characteristics presented as: size, attractive internal and external color, transport resistance, high juice rate and industry potential. It is necessary to study the behavior of others varieties, in order to amplify the diversity of tangerine industry, which show suitable characteristics to the fresh fruit market and that make possible different harvest season. Many tangerine varieties, selected from the Citrus Germplasm Bank of the do Centro Avançado de Pesquisa Tecnológica do Agronegócio de Citros "Sylvio Moreira"/IAC, belong to trials carried out in 15 places in São Paulo State. The Capão Bonito area, south-west of the state, is one of this places where the Nova tangelo, the Ortanique and the Murcott tangors are showing quite good results about their fruit qualities. This paper had as an objective to compare the fruit characteristics of the Nova tangelo, the Murcott and the Ortanique tangors grafted on two rootstocks: Rangpur lime and Cleopatra mandarin. Accordingly to the gotten results, is possible to conclude that Nova and Ortanique had shown weight, width, fruit shape and juice percent, similar to the Murcott. In compliance with the harvest season, the Nova present suitable conditions to fresh fruit market in May and June. By the other hand the Murcott fruits can be harvested in July to August and the Ortanique in August to September. For this reason, is possible extend the harvest season of this mandarin-like, from two to five month, occurring inclusive in a period out of the crop at the north hemisphere.

Evaluation of Potential of Mandarin Hybrid 'Shiranuhi' against inoculation of Bacterial Canker Disease Pathogen (Xanthomonas axonopodis pv. citri) in Citrus Field in Jeju Island

This study was carried out to evaluate potential of Shiranuhi cultivar against inoculation of causal pathogen of citrus canker, Xanthomonas axonopodis pv. citri in Jeju Island by comparing degree of susceptibility of fruits and leaves/twigs, and analysis of incidence of canker disease. Progression of symptom, disease incidence, and percent area of lesion were surveyed for evaluation of resistance. In greenhouse condition, symptoms of bacterial citrus canker progressed more rapidly in sweet orange, a moderately susceptible cultivar, than in other four cultivars (satsuma mandarin, `Kiyomi`, `Shiranuhi` and `Yuzu`). At 20 days after inoculation, disease severity was the highest in sweet orange (5.00.0), and all tested leaves were distorted or had dropped. On the other hand, `Yuzu` showed the lowest disease severity (2.60.47), followed by `Kiyomi` (4.00.0), `Shiranuhi` (4.00.82), and satsuma mandarin (4.30.47). Percent area of lesion per leaf 30 days after inoculation was the highest in sweet orange (8.311.78), followed by satsuma mandarin (1.511.25), `Shiranuhi` (1.390.94), and `Kiyomi` (1.10.9), while the lowest was in `Yuzu` (0.260.17). Infield condition, percentage of diseased leaf in `Shiranuhi` was very low, 5.22.9, compared with sweet orange, 71.0 11.5, while that of satsuma mandarin and `Kiyomi` were 6.97.0 and 4.32.0, respectively. Percentages of diseased leaf was higher (17.47.1) than that of diseased fruit (3.22.5) in severely diseased trees of Shiranuhi cultivar, and the disease was not observed on twig in open field condition. Lesion sizes on leaves and fruits in open field condition were 4.12.2 mm2 and 5.15.6 mm2, respectively, while those in greenhouse condition were 8.75.7 mm2, 10.49.2 mm2 and 5.62.6 mm2 on leaves, fruits and twigs, respectively. The disease was observed in 5.6% out of total 107 farmers Shiranuhi fields under polyethylene film house, and average percentages of diseased tree in 31 fields of Shiranuhi cultivar and adjacent satsuma mandarin fields were 0.02% and 14.8%, respectively. Average percentage of diseased fruit was 1.6% in satsuma mandarin which was not observed in anyone of all the 31 Shiranuhi farmers fields. Therefore, it was concluded that `Shiranuhi` cultivar is not potential against causal pathogen of citrus canker disease in Jeju Island because the cultivar has similar resistance as satsuma mandarin which occupies over 95% of total 25,000 ha in Jeju Island in polyethylene film houses protected from outside.

Chromosomal relationships among cultivars of Citrus reticulata Blanco, its hybrids and related species

Karyotypes of 93 individuals belonging to 18 accessions of mandarins, mandarin hybrids and two related species were analysed with the fluorochromes CMA and DAPI, to identify marker chromosomes. The karyotypes revealed highly differentiated banding patterns and could be classified in four groups (I–IV) according to the presence/absence of chromosomes with three bands (type A) or with two bands (one proximal and one terminal, type B, or both terminal, type C). The accessions of group I exhibited the simplest and homozygous karyotypes (lacking chromosome types A, B and C), represented by `Sunki' and `Cleopatra'. Group II (lacking chromosome types A and B) included three accessions of Mediterranean mandarins and `Cravo' mandarin, all of them with very similar and almost completely homozygous karyotypes. All other karyotypes of groups II and III (lacking chromosome type A) were heterozygous for one or more chromosome pairs and most of them seemed to be hybrid derivatives from non-mandarin accessions. Group IV (with chromosome types A and B) was represented only by two heterozygous hybrids (`Murcott' and `King'). The karyotype of most hybrids agrees with one of the possible combinations resulting from chromosome types segregation from their putative ancestor karyotypes, but at least `Orlando' seemed to be a more complex hybrid. Comparing with banding patterns of other Citrus species, those of group I and the Mediterranean mandarins (group II) are the best candidates to represent C. reticulata (sensu Swingle) as a true species.

Analytical Discrimination of the Cold-Pressed Oils of Mandarins and their Hybrids

Volatile compositions of the cold-pressed peel oils of a Satsuma mandarin cultivar, from Japan, and four other cultivars of mandarin hybrids such as Temple, Orlando, Kara and Minneola obtained from Ethiopia and Kenya were analyzed by capillary GC and GC/MS, without prior separation. Satsuma mandarin and Temple were characterized by high concentrations of (E,E)-α-farnesene and linalool, respectively. The enantiomeric distribution of α-pinene, β-pinene, sabinene, limonene, linalool, citronellal and α-terpineol was studied by simple and reliable enantioselective GC methods involving either a chiral capillary column or an on-line coupling of non-chiral and chiral capillary columns. The (+)-enantiomers of most of the components in all of the analyzed oils were present in excess, except for linalool and citronellal in the oils of Satsuma mandarin and Temple, respectively. Cold-pressed oils of Satsuma mandarin were found to contain about 75% enantiomeric excess of (3R)-(-)-linalool instead of (3S)-(+)-linalool excess, as was found in the oils of other mandarin cultivars and hybrids.

The flavor of mandarin hybrids with different coatings

Mandarin hybrids were treated with wax and resin coatings having differing oxygen permeabilities. After storage for 7 days at 21 °C, fruit with coatings having O 2 permeability ≤1.1×10 −16 mol m s −1 m −2 Pa −1 were rated by a sensory panel as markedly less fresh than fruit with higher permeability coatings. These low-permeability coatings were those composed mainly of shellac and wood resin. The flavor changed most for fruit having mean internal O 2 <4%, internal CO 2 >14% at 21 °C and juice ethanol content >1500 ppm after 7 days storage at that temperature. All coatings seemed suitable for storage of specialty citrus fruit for 7 days at 5 °C. It is recommended that for mandarin hybrids, the most suitable are those composed mainly of waxes rather than shellac or wood resin.

Extreme Susceptibility of Primosole Mandarin to Alternaria Fruit Rot in Italy.

Primosole mandarin is a promising mandarin-like hybrid of Satsuma Miho and Carvalhais mandarin that ripens very early, at the beginning of October, in southern Italy (2). During August and September 1999 and 2000 in Sicily, widespread fruit rot, affecting from 80 to 95% of the total production, was observed in a 4-year-old Primosole mandarin orchard. The fruits developed color prematurely and light brown-to-black discoloration of the rind at the stylar end. Internal symptoms consisted of a black rot of the fruit core. Sometimes the exterior of the fruits appeared healthy. No premature fruit drop was observed, and infected fruits became mummified and remained attached on the trees. Alternaria citri Ellis & N. Pierce in N. Pierce was consistently isolated from infected tissues, and the identification of the fungus was based on morphological characteristics of the conidia (1). Pathogenicity tests of single-spore isolates were carried out on surface-sterilized Primosole fruits and were repeated twice. Either a conidial suspension (2 × 104 conidia per ml) was injected into the core of fruits, or fruits were pricked at the stylar end near or through growth cracks in poorly formed navels, and the conidial suspension was placed on the wound. Thirty fruits were used per treatment, and thirty noninoculated fruits were used for controls. Following inoculation, the fruits were placed in plastic bags and kept at 30°C for 15 days. No external symptoms were observed on any of the fruits, but when cut in half, decay of the core was observed in all inoculated fruits. A. citri was reisolated from inoculated fruits, fulfilling Koch's postulates. No symptoms were observed on fruits used as controls. We believe that infection is facilitated by growth cracks at the stylar end and the sensitivity to sunburn of Primosole mandarin. To our knowledge, this is the first report of the extreme susceptibility of Primosole mandarin to Alternaria fruit rot.

The anatomy of the fruit in relation to the propensity of citrus species to split

The anatomy of the fruit has been compared in three prone-to-split mandarin hybrids (Nova, Ellendale and Murcott), several cultivars of clementine mandarin (Fino, Clementina de Nules and Orogrande), and in Owari satsuma mandarin. The fruit of the hybrids is oblate to subglobose and usually presents an open stylar end disrupted by a navel formed by the floral meristem, which is conserved near the apex of the fruit. In the non-prone-to-split clementines as well as in Owari satsuma, the floral axis protrudes inside the style, and the flower meristem is lost through abscission shortly after petal fall. The abaxial side of the carpels fuses with the flower axis forming at the stylar end of the fruit a solid tissue which externally has a small scar at the place of style abscission. Most of the fruits in these cultivars have no navel. In addition, the fruit of clementine is slightly oblate or globose. The relevance of these anatomical characteristics as regards to splitting is supported by the differences between the split and non-split fruits in Nova, the split fruit being more oblate in shape and having a bigger navel than non-split fruit. However, the effect of applied growth regulators on fruit splitting could not be correlated with their effect on the anatomy of the fruit. Additional factors not contemplated in the study also influence fruit splitting.

Tolerance of Selected Orange and Mandarin Hybrid Fruit to Low-dose Irradiation for Quarantine Purposes

Tolerance of many citrus cultivars to low-dose irradiation treatment is not known. Ten citrus cultivars grown in Florida, including the five orange [Citrus sinensis (L.) Osbeck] cultivars, Ambersweet, Hamlin, Navel, Pineapple, and Valencia, and the five mandarin hybrids (Citrus reticulata Blanco), `Fallglo', `Minneola', `Murcott', `Sunburst', and `Temple', were exposed to irradiation at 0, 0.15, 0.3, and 0.45 kGy, and stored for 14 days at 1 °C or 5 °C plus 3 days at 20 °C, to determine dose tolerance based on fruit injury. Softening of `Valencia', `Minneola', `Murcott', and `Temple' was dose-dependent, but that of other cultivars was unaffected. Only `Ambersweet', `Valencia', `Minneola', and `Murcott' did not develop peel pitting at 0.15 kGy or higher. Total soluble solids of `Ambersweet' and `Sunburst' declined slightly with increasing dose. Titratable acidity (TA) of oranges was not affected, but TA of `Sunburst' and `Temple' juice was slightly reduced by irradiation at 0.45 kGy. Juice flavor of `Hamlin', `Navel', `Valencia', and `Minneola', and pulp flavor of `Hamlin', `Valencia', `Fallglo', `Minneola', and `Murcott' was less acceptable after irradiation at 0.3 or 0.45 kGy. The appearance of all cultivars was negatively affected by the loss of glossiness with the 0.45 kGy dose. Less than 1.0% of fruit decayed and irradiation treatment had no effect on decay. Our study indicates that growers and shippers need to be aware that the effects of irradiation on citrus fruits are highly variable and both cultivar-dependent and dose-dependent.

Citrus phylogeny and genetic origin of important species as investigated by molecular markers

Citrus phylogeny was investigated using RAPD, SCAR and cpDNA markers. The genotypes analyzed included 36 accessions belonging to Citrus together with 1 accession from each of the related genera Poncirus, Fortunella, Microcitrus and Eremocitrus. Phylogenetic analysis with 262 RAPDs and 14 SCARs indicated that Fortunella is phylogenetically close to Citrus while the other three related genera are distant from Citrus and from each other. Within Citrus, the separation into two subgenera, Citrus and Papeda, designated by Swingle, was clearly observed except for C. celebica and C. indica. Almost all the accessions belonging to subgenus Citrus fell into three clusters, each including 1 genotype that was considered to be a true species. Different phylogenetic relationships were revealed with cpDNA data. Citrus genotypes were separated into subgenera Archicitrus and Metacitrus, as proposed by Tanaka, while the division of subgenera Citrus and Papeda disappeared. C. medica and C. indica were quite distant from other citrus as well from related genera. C. ichangensis appeared to be the ancestor of the mandarin cluster, including C. tachibana. Lemon and Palestine sweet lime were clustered into the Pummelo cluster led by C. latipes. C. aurantifolia was located in the Micrantha cluster. Furthermore, genetic origin was studied on 17 cultivated citrus genotypes by the same molecular markers, and a hybrid origin was hypothesized for all the tested genotypes. The assumptions are discussed with respect to previous studies; similar results were obtained for the origin of orange and grapefruit. Hybrids of citron and sour orange were assumed for lemon, Palestine sweet lime, bergamot and Volkamer lemon, while a citron × mandarin hybrid was assumed for Rangpur lime and Rough lemon. For Mexican lime our molecular data indicated C. micrantha to be the female parent and C. medica as the male one.

Identification of mandarin hybrids by isozyme and RAPD analysis

A cross between the monoembryonic Clementine MA3 SRA 649 used as seed parent and the polyembryonic Carvalhais mandarin used as pollen progenitor was carried out in the SRA INRA-CIRAD, S. Giuliano, Corsica. Cuttings of 61 plants putatively resulting from this cross were sent to the Centro de Citricultura, Faro, Portugal for further agronomic evaluation under field trials. Isozyme analysis allowed the identification of 59 plants as having sexual origin, however, two plants that showed isozyme patterns identical to their seed parent were impossible to identify as being either of zygotic or of somatic origin. Isozymes confirmed Carvalhais mandarin as the pollen parent of 42 progeny plants, while RAPD analysis confirmed Carvalhais paternity over the remaining 19 plants. A fast and low pollutant method for extraction of Citrus total genomic DNA suitable for RAPD analysis is reported.

Production and cryoconservation of embryogenic cultures of mandarin and mandarin hybrids

Assays were performed to obtain embryogenic callus lines from nine mandarin and mandarin hybrid cultivars by in vitro culture of ovules collected from immature fruits six weeks after anthesis. All cultivars produced embryos and loose friable callus. The small proliferations of nucellar callus from cultured ovules were suitable to recover embryogenic callus lines by periodical subculturing to fresh medium. The embryogenic callus cultures were subjected to cryoprotection with 10% (v/v) (DMSO), freezing by slow cooling, storage in liquid nitrogen and thawing by fast warming. Whole plants from these cryopreserved cultures were recovered through embryogenesis.

Quantitation of Volatile Constituents in Mandarin Juices and Its Use for Comparison with Orange Juices by Multivariate Analysis

Sixteen unpasteurized juices and one pasteurized juice from mandarin and mandarin hybrid fruit were analyzed by headspace gas chromatography (HSGC), and 42 volatile constituents were quantified in ...

Susceptibility and Resistance of Citrus Genotypes to Alternaria alternata pv. citri

AbstractA survey of citrus cultivars in Israel in orchards where Alternaria brown spot was common on Minneola tangelos (mandarin × grapefruit), revealed the occurrence of the disease as typical foliar and fruit lesions on Dancy and Ellendale (mandarins), on Murcott tangor (mandarin × sweet orange), on Nova and Idith (mandarin hybrids), on Calamondin, and on Sunrise and Redblush (grapefruit). Isolates of Alternaria alternata from each of these hosts were proven to be pathogenic to Minneola tangelo.The host range of A. alternata pv. citri from Israel was assayed by inoculating leaves of diverse citrus genotypes. Several mandarins and their hybrids (Dancy, Kara, King, Wilking, Satsuma, Minneola, Orlando, Mikhal, Idith, Nova, Page, Murcott), grapefruit (Marsh seedless), grapefruit × pummelo (Oroblanco), sweet orange (Shamouti, Valencia, Washington navel) Calamondin, and Volkamer citrus were susceptible. Several mandarins and their hybrids (Clementine, Avana, Yafit, Ortanique), Cleopatra, one sweet orange cultivar (Newhall), pummelo (Chandler), lemon (Eureka), Rough lemon, Rangpur lime, sweet lime, citron, limequat, sour orange, Troyer citrange and Alemow were resistant.

Manipulation of fruit set and stylar-end fruit split in ‘Nova’ mandarin hybrid

‘Nova’ mandarin hybrid is prone to stylar-end fruit splitting when produced in solid, isolated blocks. In addition, self-incompatibility and weak parthenocarpy result in poor fruit set. Calcium nitrate application during flowering reduced fruit split, while girdling using a Spanish girdling tool increased fruit set dramatically. A strategy to increase export packout is presented.

Citrus cultivars with high flavonoid contents in the fruits

The flavanone contents of some lesser known citrus cultivars grown in Cuba have been determined in research searching for citrus species/cultivars with high flavanone contents. The cultivar ‘Galleta’ of the mandarin ( Citrus reticulata Blanco) has a higher hesperidin content than the hybrid mandarin ‘Nova’, which is currently being used for the commercial obtainment of this flavanone. The grapefruit cultivar ‘Isaac’ had higher naringin levels than reported in the literature for any citrus species or cultivar. These two species seem potential candidates for the industrial obtainment of flavanones. With regard to neohesperidin, the ‘Afin’ and ‘Bouquet de Fleur’ varieties of Citrus aurantium L. from Spain are the best choices. A preliminary study indicated that the high flavanone contents resulted from the genetic characteristics of the cultivars, rather than from climatic effects.

Some physiological and morphological characteristics of citrus plants for drought resistance

Tolerance and avoidance mechanisms to drought stress were studied in 6-month-old plants of Newhall orange ( Citrus sinensis (L.) Osbeck) and Ellendale tangor (orange × mandarin hybrid) ( Citrus sinensis (L) Osbeck × Citrus reticulata Blanco) during a drought/rewatering cycle under controlled conditions. Drought stress did not promote osmotic adjustment, while elastic adjustment (tissue elasticity increase) was noted in stressed orange and tangor plants. Both citrus plants showed a parallel decrease in leaf conductance ( g 1) and leaf water potential ( Ψ 1) under water stress. Tangor plants had a more efficient water conservative strategy than orange, based on the characteristics of canopy architecture (lower canopy area and a more closed canopy with leaves nearly vertically oriented) together with a significant decrease in cuticular transpiration rates (TRc) under stress.

Fruit splitting in ‘Nova’ hybrid mandarin in relation to the anatomy of the fruit and fruit set treatments

Fruit splitting in the mandarin orange cultivar ‘Nova’ is related to the presence of an open stylar end in the fruit. This opening arises from a cavity present at the base of the style, and is formed in a variable proportion of fruits. The cells at the bottom of this style cavity form a rind-like tissue which develop into a navel structure. The size of this navel is larger in open-stylar end bearing fruits and, accordingly, in split fruit. The number of split fruit per tree is unrelated to the number of fruit set. The application of gibberellic acid (GA 3) has a variable effect on set and splitting depending on its timing. This hormone increases fruit splitting when applied at flowering, but reduces it when applied shortly after the end of the June drop. It has only a minor effect on fruit set.

Volatile Components in Juice from Mandarin and Mandarin Hybrid Fruit

ABSTRACT Twenty-one volatile components of mandarin and mandarin hybrid fruit have been quantified and the amounts were compared to those reported earlier in mandarin and orange fruit.

Citrus Essential Oils of Uruguay. Part I. Composition of Oils of Some Varieties of Mandarin

ABSTRACT The chemical composition of the cold-pressed oils obtained from three mandarin cultivars (“Comun,” “Malvasio” and “Ellendale”) and two mandarin hybrids (“Ortanique” and “Malaquina”) grown in Uruguay were examined using a combination of alumina column chromatography and capillary GC. Forty-five constituents were characterized in the oils with the limonene content varying from 75.26–96.23%. The composition and olfactory characteristics of these oils were compared with those of Italian mandarin oil and Uruguayan sweet orange oil. It was found that the “Ortanique” and “Ellendale” oils were very different from normal mandarin oil, with great similarity in composition and olfactory characteristics to sweet orange oil. The oil of “Malaquina” is also similar more to sweet orange oil than mandarin oil although it is quite rich in aliphatic aldehydes, particularly decanal. The oil of the cv. Malvasio has a composition which is between mandarin and sweet orange oils. The oil of cv. Comun is the only one fou...

Use of Stored Pollen to Hybridize a Mandarin Hybrid and Citrus tachibana

Fresh pollen from Citrus tachibana Macf. was oven-dried (37C), freeze-dried, or placed into anhydrous acetone, and stored at -20C over silica gel. Pollen freeze-dried or stored in anhydrous acetone did not germinate 24 hours after treatment; oven-dried pollen germinated in 1 hour and was comparable to fresh pollen. Pollen that was oven-dried for 12 hours and stored for 1 year was used to pollinate a monoembryonic hybrid of `Temple' (origin unknown) × `Orlando' (C. paradisi Macf. `Duncan' ×C. reticulata Blanco `Dancy'). Glutamate-oxaloacetate transaminase (GOT) isozyme profiles verified progeny hybridity.