Prunus Persica Research Papers - Academia.edu (original) (raw)

Fruit thinning has been practised for thousand of years, and serves a number of purposes. Too many fruits per tree can result in small fruit size and poor quality, breakage of limbs, exhaustion of tree reserves, and can also partially o completely inhibit bud initiation. Hand thinning of the peaches is the most common thinning practice adopted, but it is

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- Profitability, Laboratory experiment, Field Experiment, Low Power

Nitrogen fertilization and winter pruning are commonly used to control crop production in peach [Prunus persica (L.) Batsch] orchards. They are also known to affect the dynamics of Myzus persicae (Sulzer) (Homoptera: Aphididae) aphid populations via bottom-up regulation processes. Interactions between crops and pests can cause complex system behaviour in response to management practices. An integrated approach will therefore improve the understanding of the effects of these two cultural practices on aphid and peach performances.

- by Nadine Hilgert
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- Pest Management, Modeling, Interaction, Population Dynamics

The effect of hot water dipping (HWD) at 40, 44 and 48°C for 6 and 12 min on germination of conidia of brown rot fungus (Monilinia laxa) in vitro and the effect of HWD at 48°C for 6 and 12 min on the fruit quality and development of M. laxa on peach cv. "Roig" and nectarine cv. "Venus" after artificial inoculation in cold storage were studied. Temperature and duration of treatment significantly affected germination of conidia. After HWD at 48°C for 12 min, the lowest germination of conidia (9%) was recorded, which was more than 10 times lower than control (93%). After 3 days from inoculation, there were 80% of inoculated spots with visual symptoms of decay caused by M. laxa on control peaches and 40% of such spots on control nectarines. Successful infections were recorded on only 5% of inoculated spots of nectarine and 10% of inoculated spots of peach after HWD at 48°C for 12 min. HWD at 48°C for 12 min significantly decreased titratable acidity and increased soluble solids concentration/titratable acidity ratio in nectarines. No visual symptoms of heat damage were found on fruits as a consequence of any of the studied treatments. The results show that it is possible to control postharvest brown rot (M. laxa) on peach using HWD at 48°C for 12 min and on nectarine using HWD at 48°C for 6 min without a significant loss of fruit quality.

- by Goran Fruk and +1
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- Heat Treatment, Cold Storage, Fruit Quality, Prunus Persica

In a peach orchard with an initial soil pH of 4.9, preplant application of 0, 13.2, 18.2, 27.3, or 54.2 kg lime/tree site altered soil pH (range after 1 year = 4.8-7.3) but did not affect numbers of Criconemella xenoplax or tree circumference. Liming also failed to reduce the incidence of bacterial canker, which affected 17% of the trees by the sixth year after planting. Four years after planting, numbers of C. xenoplax exceeded 400/100 cm(3) soil, regardless of treatment. Trees with higher densities of C. xenoplax had a higher incidence of canker. The nematophagous fungus Hirsutella rhossiliensis was not detected until the fourth year. Thereafter, the incidence of H. rhossiliensis and percentage C. xenoplax parasitized by H. rhossiliensis increased, but the increases lagged behind increases in numbers of nematodes. In an almond orchard with an initial soil pH of 4.6, preplant application of 0, 6.4, 12.8, or 25.0 kg lime/tree site altered soil pH (range after 1 year = 4.7-7.1). Numb...

- by Michael McKenry and +1
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- Zoology, Nematology, Biological Control, soil pH

Firm-breaker and firm-mature mid-season peaches (Prunus persica L. Batsch cultivar 'Paraguayo') were stored for up to four weeks at 2°C or subjected to intermittent warming cycles of one day at 20°C every six days at 2°C. Several quality parameters were monitored during normal ripening at 20°C and weekly during storage, with and without three days of subsequent ripening at 20°C. After three cycles, intermittent warming avoided or strongly alleviated chilling injuries (particularly woolliness and lack of juiciness) especially in breaker fruit. Low temperature induced abnormal ripening in control fruit, which was detectable when chilling injury was already irreversible. In comparison to sound fruit, injured fruit showed an increased total soluble solids/titratable acidity ratio, a decrease in flesh firmness and in Hue angle flesh color during storage and an excessive loss of acidity in fruit of advanced maturity. Hue angle was a good maturity index only for sound fruit. Intermittent warming appears to maintain the quality of peaches by acclimatizing chilled fruit to subsequent periods of chilling by allowing a gradual ripening of the fruits (softening, enhancement of ground and flesh color, and maintenance of juiciness).

- by Juan Pablo Fernández Trujillo
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- Chemical Engineering, Food, Seasonality, Food Sciences
- by Carlos Martins
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- SHELF LIFE, Phenolic compound, Soil management, Cold Storage

Hujin'' and ''Baihua'' peaches (Prunus persica (L.) Batsch.) were treated at temperatures ranging from 37 to 43°C for 1-3 h with hot water and for 3-48 h with hot moist air, respectively. Heat treatment with hot water caused heat injury... more

- by Judith Zambrano
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- Food Engineering, Heat Treatment, Postharvest, Food Sciences

- by Rachid Senoussi
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- Pest Management, Multidisciplinary, Ecological Modelling, Complex System

The effect of root-zone flooding on mycorrhizal and non-mycorrhizal peach seedlings growing in a low P medium was examined. Mycorrhizal seedlings showed relatively faster development prior to flooding and recorded significantly higher concentrations of shoot P, K and Zn and biomass yield. Ethanol accumulation was significantly higher in the taproots of non-mycorrhizal as compared to mycorrhizal plants after 3 days of flooding. A more rapid decline in plant health was also observed in non-mycorrhizal as compared to mycorrhizal seedlings. The presence or absence of the fungal partner led to significant difference in the ratio of roots that remained viable after extended flooding. Therefore, it is clear that arbuscular mycorrhizal (AM) infection confers limited tolerance to flooding on peach seedlings. This could be due to improved plant nutrition, the suppression of ethanol accumulation in roots and the extension of the duration of root activity in a flooded environment.

- by Laban Rutto
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- Nutrition, Biomass, Symbiosis, Plant Nutrition
- by Nai Ming Lai
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- Food, Pollen, Vicia faba, Prunus Persica

L'influence d'extraits phénoliques de jeunes feuilles de pêcher sur la survie et le gain pondéral des larves de Mj)ziis persicae a été évaluée en les incorporant à une nourriture artificielle. Les feuilles ont été prélevées sur 2 hybrides issus d'un même croisement, l'un sensible, l'autre résistant au puceron. Les fondatrices et les fondatrigènes du puceron ne demeurent pas plus de 24 à 72 heures sur les feuilles de l'hybride résistant. Les extraits phénoliques totaux des 2 hybrides sont défavorables au puceron mais celui provenant de l'hybride résistant est plus défavorable car au 7" jour d'élevage il est létal à 300 mg 1-! contre 600 mg 1 '. L'hybride sensible est plus riche en phénols que l'hybride résistant. Les fractions obtenues à partir des extraits totaux sont moins actives que ces derniers mais une fraction de l'hybride résistant est très active. Différentes substances phénoliques, ou les produits de leur transformation, sont donc défavorables à l'insecte. Les 2 hybrides diffèrent par leur contenu en acides hydroxycinnamiques, notamment les dérivés inconnus des acides p. coumarique et férulique. Ces substances pourraient être associées à la résistance du pêcher au puceron vert du pêcher.

- by Philippe Bastide
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- Agronomy, Environmental Sciences, Agronomie, Myzus persicae

A progeny of 77 hybrids issued from a cross between two heterozygous Prunus, peach [P. persica (L.) Batsch] (variety ‘Summergrand’) and a related species, P. davidiana (clone 1908), was analysed for powdery mildew resistance in five independent experiments. This population was also analysed for its genotype with isoenzyme and RAPD markers in order to map the genes responsible for resistance. A genetic linkage map was generated for each parent. The ‘Summergrand’ linkage map is composed of only four linkage groups including 15 RAPD markers and covering 83.1 centiMorgans (cM) of the peach nuclear genome, whereas the P. davidiana linkage map contains 84 RAPD markers and one isoenzyme assigned to ten linkage groups and covering 536 cM. Significant associations between molecular markers and powdery mildew resistance were found in each parent. For P. davidiana, one major QTL with a very strong effect and five other QTLs with minor effects were located in different linkage groups. For ‘Summergrand’, three QTLs for powdery mildew resistance, with minor effects, were also detected. Consequently, evidence is given here that the powdery mildew resistance of P. davidiana clone 1908 and P. persica variety ‘Summergrand’ is not a monogenic character but is controlled by at least one major gene and several minor genes.

- by Thierry Pascal
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- Technology, Biological Sciences, Molecular Marker, Linkage Group

To determine the effect of electric vibration on the growth, yield and fruit quality of peach electric vibrators that provided intermittent perturbation of 6500 rpm for 15 min every 6 h were firmly attached to the trunks of peach trees. Electric vibration resulted in the reduction of shoot length by 80% but had no significant effect on fruit weight, acid content and Brix. In another experiment, electric vibrators (for 15 min every 2 h) were attached to the branches after summer pruning. The regenerated shoots from the treated branches showed more than 500% reduction in length compared to the untreated ones. Even the regenerated shoots of untreated branches nearby the vibrator showed 60% reduction in length. Ethylene production and ACC content in the shoot tips of treated branches were greater than that from control ones. #

- by Justus Onguso
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- Fruit Quality, Prunus Persica

Sharka, caused by Plum Pox Virus (PPV), is by far the most important infectious disease of peach [P. persica (L.) Batsch] and other Prunus species. The progressive spread of the virus in many important growing areas throughout Europe poses serious issues to the economic sustainability of stone fruit crops, peach in particular. The adoption of internationally agreed-upon rules for diagnostic tests, strain-specific monitoring schemes and spatial–temporal modeling of virus spread, are all essential for a more effective sharka containment. The EU regulations on nursery activity should be modified based on the zone delimitation of PPV presence, limiting open-field production of propagation materials only to virus-free areas. Increasing the efficiency of preventive measures should be augmented by the short-term development of resistant cultivars. Putative sources of resistance/tolerance have been recently identified in peach germplasm, although the majority of novel resistant sources to PPV-M have been found in almond. However, the complexity of introgression from related-species imposes the search for alternative strategies. The use of genetic engineering, particularly RNA interference (RNAi)-based approaches, appears as one of the most promising perspectives to introduce a durable resistance to PPV in peach germplasm, notwithstanding the well-known difficulties of in vitro plant regeneration in this species. In this regard, rootstock transformation to induce RNAi-mediated systemic resistance would avoid the transformation of numerous commercial cultivars, and may alleviate consumer resistance to the use of GM plants.

- by Ignazio Verde and +1
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- Genetic Engineering, PPV, Prunus Persica

The data re vealed that fruit yield of peach in creased with in creas ing ap pli ca tion of zinc sul phate. The max i mum fruit size ( 5.0 cm length and 4.9 cm breadth), fruit weight (89.00g), fruit yield per plant (58.25 kg) and yield per unit area (64.07 q/hect are) were ob served with 800 g ZnSO 4 per plant as soil ap pli ca tion fol lowed by fo liar spray (0.5%) whereas min i mum yield was ob tained with out zinc ap pli ca tion. Zinc ap pli ca tion also im proved to tal sol u ble sol ids (TSS) and TSS: acid ra tio. How ever, acid ity of fruits ob tained from treated and un treated plants was not dif fer sig nif i cantly but the high est acid con tent was ob served in con trol plants, whereas low est was in fo liar ap pli ca tion of 0.50 % ZnSO 4 . Fruits were also more pal at able in Zinc ap plied plants. The high est con cen tra tion of zinc (11.55 ppm) in leaves was ob served at higher doses of soil zinc ap pli ca tion and was in low est in con trol plants.

- by HortFlora Research Spectrum
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- Quality, Peach, Fruit Yield, Prunus Persica

The effects of nitric oxide (NO) on ethylene biosynthesis and lipoxygenase (LOX) activity in a climacteric peach fruit (Prunus persica (L.) Batsch., cv. Feicheng) were studied. It was observed that, in peaches treated with 5 and 10 l l −1 NO, 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase activity, ethylene production and LOX activity were reduced. This led to the accumulation of ACC and 1-malonyl aminocyclopropane-1-carboxylic acid (MACC) during storage. There was no evidence that ACC synthase activity was affected significantly by any concentration of NO. A plausible mechanism is proposed that NO is bound to ACC oxidase to form an ACC oxidase-NO complex, which is chelated by ACC to produce an ACC-ACC oxidase-NO complex, leading to a decrease in ethylene production. The increase in concentration of ACC in NO-treated peaches may result in the redirection of ethylene to MACC production. This is a secondary effect of NO.

- by Mengchen Liu
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- Nitric oxide, Postharvest Biology and Technology, Prunus Persica

Effect of calcium chloride on vacuum osmotic dehydration in peach (Prunus persica) halves in sucrose solution

- by Jesus Rafael Mendez Natera
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- Water Activity, Osmotic Dehydration, Ascorbic Acid, Food Products

Promising new tools for peach fruit quality breeding have been revised in this work. These tools included fruit quality evaluation through physical, chemical and sensorial parameters and post-harvest storage evaluation. The development of a feasible method for an early testing of peach selections generated in breeding programs is also well described together with the discussion of the inheritance of the main fruit quality traits in peach. In addition, non-destructive evaluation methods such as near-infrared, electronic nose and non-destructive impact response were revised. Finally several strategies for the development of molecular marker associated to fruit traits were also revised. Methodologies for the analysis of marker-assisted selection include the use of mapping populations segregating for desired characters. To date, twenty five monogenic genes and QTLs have been mapped in different peach genetic linkage maps. Other markers being used included expressed sequences tags (ESTs) cloned gene analogs (CGAs) and single point mutations (single nucleotide polymorphisms, SNPs). More recent efforts are being oriented to the elaboration of physical maps and the complete sequencing of the peach genome.

The peach (Prunus persica [L.] Batsch) is a tree native to the region known today as Northwest China, where its fruits were known around 2000 BC. Inhabitants of the Mediterranean Area came into contact with the peach probably between the 6th and 4th century BC thanks to the contacts with Persian Empire. In the western part of the Mediterranean Region the peach appeared later (ca. 1st c. AD). In the period under study there were many varieties of the peach, and they were eaten in many different ways – e.g. raw, dried, boiled etc. They could be consumed without any other ingredients, or as an element of more complicated dishes. Ancient and early Byzantine authors, who wrote their treatises between the 1st and 7th c. AD, and dealt with medicine
(Dioscorides, Pliny the Elder, Galen, Oribasius, Aetius of Amida, Paul of Aegina, Athimus and others), described dietetic properties of a peach with details. Moreover, they left some information about a medical use of
this fruit. This aspect of their works is an element of a wider and well-known phenomenon, i.e. an important role of all groups of aliments in the ancient art of healing.

- by Krzysztof Jagusiak
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- Ancient Science, Galen, Food and Nutrition, Ancient Medicine

We examined the population structure of the introduced aphid, Myzus persicae collected mainly from its primary host, Prunus persica, in south-east Australia. Myzus persicae has been present in Australia since at least 1893. Samples were collected in the spring of 1998 from two mainland and three Tasmanian localities and isofemale lines were established in the laboratory. The reproductive mode (life cycle), karyotype and 17-locus microsatellite genotype of each clone were determined. All populations showed significant population differentiation (F ST 0.058-0.202) even over small geographic distances (Ͻ50 km). All clones were karyotypically normal except for a subset of clones from one site that was exposed to the carbamate insecticide, Pirimor,

- by Paul Sunnucks
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- Evolutionary Biology, Genetics, Population Genetics, Reproduction

Peaches and nectarines ripen and deteriorate quickly at ambient temperature. Cold storage is used to slow these processes and decay development. However, low temperature disorders, chilling injury classified as internal breakdown, limit the storage life of peaches and nectarines under refrigeration. The onset of chilling injury symptoms determines the postharvest storage/shipping potential because their development reduces consumer acceptance. Chilling injury is genetically influenced and triggered by a combination of storage temperature and storage period. It manifests itself as fruit that are dry and have a mealy or woolly texture (mealiness or woolliness), or hard textured fruit with no juice (leatheriness), fruit with flesh or pit cavity browning (internal browning), or with flesh bleeding (internal reddening). In this review, we describe what is known about the etiology of each of these types of chilling injury symptoms as well as the biochemical processes in the fruit tissue responsible for their development. We also report on pre-and postharvest manipulations or treatments that can affect the time of appearance or severity of chilling injury symptoms.

- by Susan Lurie
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- Genetics, Postharvest Biology and Technology, Ambient Temperature, Low Temperature
- by Maria Gil
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- Engineering, Mass Spectrometry, Food Chemistry, Multidisciplinary

In clayey and calcareous soils without a stable irrigation and fertilization system, the type of rootstock can particularly affect both the vegetative and productive properties of 'Suncrest' peach (Prunus persica L. Batsch) plants, and the qualitative and nutritional attributes of their fruit. The GF677 rootstock (P. persica Â Prunus amygdalus) promoted the highest vegetative development, followed by Julior (Prunus insistitia). The 'Suncrest' on Ishtara [(Prunus cerasifera Â P. persica) Â (P. cerasifera Â Prunus salicina)] and Barrier1 (P. persica Â Prunus davidiana) had lower, but similar, plant vigour, but the latter rootstock differed in its higher production of pruned wood. The lowest adaptability to these cultivation conditions was observed for 'Suncrest' grafted onto Citation (P. persica Â P. salicina), which showed the lowest plant development and production. For the plant yield, the 'Suncrest' grafted onto GF677, Julior, Ishtara, and Barrier1 were all similar. The fruit yield and both the canopy volume and pruned wood of 'Suncrest' grafted onto Ishtara showed a particular relationship, giving the best indices of yield efficiency and plant physiological equilibrium. Moreover, the same rootstock promoted the largest fruit size, while the smallest fruit were found on GF677 rootstock. The fruit from the Citation 'Suncrest' ripened 3 days early, while those from Barrier1 had a late fruit ripening. Firmness, soluble solids and the soluble solids to total acidity ratio were only affected slightly by the different rootstocks, while the total acidity of the fruit varied significantly according to rootstock; the fruit from 'Suncrest' grafted onto Barrier1, Julior, and Citation had the highest total acidities. The rootstock effects on the nutritional attributes of the fruit were relevant. The 'Suncrest' on Julior and GF677, followed by Ishtara, produced fruit with the greatest antioxidant activities and total phenolic contents. The 'Suncrest' on Citation and, especially, Barrier1 had reduced nutritional values of the fruit. The variations in antioxidant activities and total phenolic contents showed a positive correlation. #

- by B. Mezzetti and +1
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- Antioxidant Activity, Nutritional Value, Plant Development, Fruit Ripening

This research was conducted to evaluate the potential and limitations of hyperspectral remote sensing to detect iron deficiency in capital-intensive multi-annual crop systems, e.g. peach orchards. The noted deficiency can be regarded as a proxy for deviations from optimal plant functioning, while detection of such deviations is in turn of significant importance to monitoring and modelling efforts of orchards as production systems. Hyperspectral leaf, canopy, and airborne reflectance measurements were acquired in a peach (Prunus persica L.) orchard in Zaragoza, Spain. Leaf-and canopy-level data were collected with a handheld spectroradiometer (ASD, Inc.), while the AHS-160 hyperspectral sensor provided airborne data. Blocks of trees were treated with different amount of iron chelates (Sequestrene) which created a dynamic range of chlorophyll concentration as measured in leaves. Hyperspectral measurements at leaf-level were carried out to characterize the physiological aspects of nutrient stress, as opposed to the evaluation of plant nutrient status at the complete plant-level. Stressinduced physiological changes make stress detection at the leaf-level possible at an early stage of suboptimal photosynthetic functioning. Airborne imagery, however, is difficult to interpret due to altering illumination angles, BRDF effects, and intervening atmospheric light interactions resulting in an alteration of the vegetative reflectance spectrum. Although many studies have implemented hyperspectral analysis of nutrient status at large scales, this research field is still in its infancy phase, since the link between airborneand leaf-level measurements is lacking. This inevitably makes the physiological interpretation of existing hyperspectral research more complex. The multi-level (leaf, canopy, and airborne) approach presented here enabled the assessment of vegetation indices and their relationship with pigment concentration at each monitoring level. Pertinent classical chlorophyll-related vegetation indices were tested and new indices were extracted from the spectral profiles by means of band reduction techniques and narrow-waveband rationing, which involved all possible 2-band combinations. Robustness was evaluated by studying the index performance for datasets of increasing complexity, from leaf-to canopy-and airborne-level. Physiological interpretations extracted from leaf-level experiments were extrapolated to canopy-and airborne level. The measured spectra and estimated biochemical parameters were related via inversion of a linked directional homogeneous canopy reflectance model (ACRM) and the PROSPECT leaf model. Numerical model inversion was conducted by minimizing the difference between the measured reflectance samples and modelled reflectance values. An improved optimization method is presented. Results are compared with a simple linear regression analysis, linking chlorophyll to the reflectance measured at the leaf level and at the Top of Canopy (TOC), while optimal band regions and bandwidths also were analyzed.

- by Steve Backer
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- Hyperspectral remote sensing, Iron, Spectrum, Vegetation indices

A previous model developed by the authors for chemical peeling of spherical foods was applied to peaches, which were assimilated to that geometry. Equations for the prediction of chemical peeling time as a function of temperature; alkali concentration and peeled thickness; and texture changes due to the cooking effect during peeling were established. Likewise, weight loss associated to peeling was determined. A total of 128 experiments were performed, involving caustic soda concentration of 1.6, 3.2, 5.6 and 7.3 (g/100 ml) and temperatures of 70, 80, 90 and 97 °C for peeling times from 0 to 8 min at 1-min intervals. Peeling maps to estimate peeling time for practical peeling conditions, including alkali temperature (70–97 °C), alkali concentration (1.6–7.3 g/100 ml), and peel thickness (0.02–0.05 cm) were developed.

- by riva rinaldy
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- Animal Production, Weight Loss, Texture, Model development

Cell wall changes were examined in fruit of a melting flesh peach (Prunus persica L.) allowed to ripen on the tree. Three phases to softening were noted, the first of which began prior to the completion of flesh colour change and an increase in ethylene evolution. Softening in young mature fruit, prior to ripening, was associated with a depolymerization of matrix glycans both loosely and tightly attached to cellulose and a loss of Gal from all cell wall fractions. After the initiation of ripening, but before the melting stage, softening was associated with continuing, progressive depolymerization of matrix glycans. A massive loss of Ara from the loosely bound matrix glycan fraction was observed, probably from side chains of glucuronoarabinoxylan, pectin, or possibly arabinogalactan protein firmly bound into the wall and solubilized in this extract. An increase in the solubilization of polyuronides also occurred during this period, when softening was already well advanced. The extensive softening of the melting period was marked by substantial depolymerization of both loosely and tightly bound matrix glycans, including a loss of Ara from the latter, an increase in matrix glycan extractability, and a dramatic depolymerization of chelator-soluble polyuronides which continued during senescence. Depolymerization of chelator-soluble polyuronides thus occurred substantially after the increase in their solubilization. Ripening-related increases were observed in the activities of exo-and endo-polygalacturonase (EC 3.2.1.67; EC 3.2.1.15), pectin methylesterase (EC 3.1.1.11), endo-1,4-b-glucanase (EC 3.2.1.4), endo-1,4-b-mannanase (EC 3.2.1.78), a-arabinosidase (EC 3.2.1.55), and b-galactosidase (EC 3.2.1.23), but the timing and extent of the increases differed between enzymes and was not necessarily related to ethylene evolution. Fruit softening in peach is a continuous process and correlated closely with the depolymerization of matrix glycans, which proceeded throughout development. However, numerous other cell wall changes also took place, such as the deglycosylation of particular polymers and the solubilization and depolymerization of chelator-soluble polyuronides, but these were transient and occurred only at specific phases of the softening process. Fruit softening and other textural changes in peach appear to have a number of stages, each involving a different set of cell wall modifications.

- by Carlos Crisosto
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- Metabolism, Plant Biology, Aging, Experimental Botany

Cultivar segregation according to the sensory perception of their organoleptic characteristics was attempted by using trained panel data evaluated by principal component analysis of four sources per cultivar of 23 peach and 26 nectarine cultivars as a part of our program to develop minimum quality indexes. Fruit source significantly affected cultivar ripe soluble solids concentration (RSSC) and ripe titratable acidity (RTA), but it did not significantly affect sensory perception of peach or nectarine flavor intensity, sourness or aroma by the trained panel. For five out of the 49 cultivars tested, source played a role in perception of sweetness. In all of these cases when a source of a specific cultivar was not classified in the proposed organoleptic group it could be explained by the fruit having been harvested outside of the commercial physiological maturity (immature or over-mature) for that cultivar. The perception of the four sensory attributes (sweetness, sourness, peach or nectarine flavor intensity, peach or nectarine aroma intensity) was analyzed by using the three principal components, which accounted for 92 and 94% of the variation in the sensory attributes of the tested cultivars for peach and nectarine, respectively. Season did not significantly affect the classification of one cultivar that was evaluated during these two seasons. By plotting organoleptic characteristics in PC1 and PC2 (∼76%) for peach and nectarine, cultivars were segregated into groups (balanced, tart, sweet, peach or nectarine aroma and/or peach or nectarine flavor intensity) with similar sensory attributes; nectarines were classified into five groups and peaches into four groups. Based on this information, we recommend that cultivars should be classified in organoleptic groups and development of a minimum quality index should be attempted within each organoleptic group rather than proposing a generic minimum quality index based on the ripe soluble solids concentration (RSSC). This organoleptic cultivar classification will help to match ethnic preferences and enhance current promotion and marketing programs.

- by Carlos Crisosto
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- Principal Component Analysis, Panel Data, Seasonality, Pca

The effects of postharvest calcium applications on cell wall properties and quality attributes of peach fruits (Prunus persica L. Batsch, cv. 'Andross') after harvest or cold storage up to 4 weeks were determined. The fruits were immersed in deionised water or in different calcium sources (calcium chloride, calcium lactate and calcium propionate) at two calcium concentrations (62.5 and 187.5 mM Ca). Calcium concentration profiles in fruits (peel and flesh), in cell wall and in pectin fractions were determined. The calcium content in the peel increased up to 2.7-fold, whereas flesh calcium increased up to 74%, 1 day after immersion. The increase of flesh calcium was accompanied by increase of cell wall calcium, which corresponded to a significant increase of calcium in the water-insoluble pectin fraction. However, calcium became saturated in the water-insoluble, but not water-soluble, pectin fraction with 62.5 mM Ca treatment. Treatment with 62.5 mM Ca salts was as effective as higher concentrations of calcium chloride maintaining tissue firmness during storage. Inversely, calcium lactate and calcium propionate at high concentrations (187.5 mM Ca) caused toxicity symptoms on the fruit surface, expressed as skin discoloration and superficial pitting, leading to additional chemical changes and reduced tissue firmness. Postharvest calcium applications limited the intense of chilling injury symptoms, expressed as flesh browning after 4 weeks cold storage. Peach fruits with severe flesh browning symptoms were characterized by reduced ethylene production, and reduced activities of the pectin modifying enzymes poly-galacturonase and pectin-methyl-esterase.

- by I. Mignani
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- Food Chemistry, Multidisciplinary, Quality Attributes, Enzyme

Background: Carotenoids are plant metabolites which are not only essential in photosynthesis but also important quality factors in determining the pigmentation and aroma of flowers and fruits. To investigate the regulation of carotenoid metabolism, as related to norisoprenoids and other volatile compounds in peach (Prunus persica L. Batsch.), and the role of carotenoid dioxygenases in determining differences in flesh color phenotype and volatile composition, the expression patterns of relevant carotenoid genes and metabolites were studied during fruit development along with volatile compound content. Two contrasted cultivars, the yellow-fleshed 'Redhaven' (RH) and its white-fleshed mutant 'Redhaven Bianca' (RHB) were examined.

- by Efraim Lewinsohn and +2
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- Microbiology, Pigmentation, Principal Component Analysis, Plant Biology

Stark Red Gold" nectarines were harvested at 30 N of flesh firmness (FF) and 1 nl g −1 h −1 of ethylene production, and treated in sealed plastic containers with 1 l l −1 (1 ppm) 1-methylcyclopropene (1-MCP) for 12 h at 25 • C. Treated and control fruit were then transferred either to a growth chamber at 25 • C or to a cold room at 4 • C for 3 days. At the end of treatment with 1-MCP; ethylene production in control fruit had increased relative to production at harvest, and this rise was abolished by the presence of the chemical. Moreover, treated fruit showed lower soluble solids content (SSC) and higher FF and titratable acidity (TA) compared to control ones, and putrescine and spermine levels were moderately enhanced in the mesocarp at the end of treatment. In contrast with the inhibition of ethylene production, 1-aminocyclopropane-1-carboxylate synthase (ACS) and especially 1aminocyclopropane-1-carboxylate oxidase (ACO1 and ACO2) transcript levels were enhanced relative to controls. During storage, 1-MCP affected ethylene production and biosynthetic gene expression, fruit softening and other quality parameters in a temperature-dependent manner: in fruit held at 25 • C a strong decrease in ethylene production, a delay in ripening and lower ACS and ACO1/ACO2 levels were recorded, while in fruit held at 4 • C an opposite trend was observed. Results suggest that 1-MCP application followed by storage at 25 • C appears effective in controlling postharvest ripening. The lack of efficacy of the chemical in cold-stored fruit is discussed in relation to changes in SAMDC gene expression and putrescine accumulation in treated fruit relative to controls, which may be part of a stress response.

The contents of sugars and organic acids in fruits were studied among 19 different peach and nectarine cultivars. The fruits were obtained from the Fruit Growing Centre Bilje near Nova Gorica in the time of technological maturity. Sugars (glucose, fructose, sucrose and sorbitol) and organic acids (citric, malic, shikimic and fumaric acid) in fruits were identified and measured by high

- by Metka Hudina
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- High Performance Liquid Chromatography, Prunus Persica, Citric Acid, Organic Acid

Background: Prunus fruit development, growth, ripening, and senescence includes major biochemical and sensory changes in texture, color, and flavor. The genetic dissection of these complex processes has important applications in crop improvement, to facilitate maximizing and maintaining stone fruit quality from production and processing through to marketing and consumption. Here we present an integrated fruit quality gene map of Prunus containing 133 genes putatively involved in the determination of fruit texture, pigmentation, flavor, and chilling injury resistance.

- by Carlos Crisosto
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- Genetics, Biological Sciences, Gene Mapping, Expressed Sequence Tags

This research was conducted to assess the potential of hyperspectral indices to detect iron deficiency in capital-intensive multi-annual crop systems. A well-defined hyperspectral multi-layer dataset was constructed for a peach orchard in Zaragoza, Spain, consisting of hyperspectral measurements at various monitoring levels (leaf, crown, airborne). Trees were subjected to four different treatments of iron application (0 g / tree, 60 g / tree, 90 g / tree, and 120 g / tree). Groundbased measurements were used to characterise the on-site peach (Prunus persica L.) orchard in terms of chlorophyll, dry matter, water content, and leaf area index (LAI). Indices were extracted from the spectral profiles by means of band reduction techniques based on logistic regression and narrow-waveband ratioing involving all possible two-band combinations. Physiological interpretations extracted from leaf-level experiments were extrapolated to crown-and airborne level. It was concluded from leaf level measurements that a decrease in leaf chlorophyll concentration resulted due to iron deficiency. The results suggested that spectral bands and narrow waveband ratio vegetation indices, selected via multivariate logistic regression classification, were able to distinguish iron untreated and iron treated trees (C-values>0.8). Moreover, the most appropriate indices obtained in this manner fulfilled the expectations by being highly correlated (R 2 >0.6) to the measured chlorophyll concentrations. The visible part of the spectrum, mostly dominated by the amount of pigments (e.g. chlorophyll, carotenoids), provided the most discriminative spectral region (505 -740 nm) in this study. The discriminatory performance of a combined chlorophyll and soil-adjusted vegetation index was compared to the results of the selected vegetation indices to estimate the effects of soil background and LAI on those indices.

- by Stephanie Delalieux
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- Logistic Regression, Iron, Leaf Area Index, Spectrum

Reduction in the amount of light supphed during the mid-rest period caused a hetter leaf bud opening in the peach as compared with natural winter daylight; this includes darkness, short photoperiod and reduced light intensity. The quantitative nature of this light effect was shown. The role of light as a factor regulating dormancy is discussed.

- by A. Erez
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- Plant Biology, Prunus Persica, Biochemistry and cell biology

Buds are specialized structures that protect fragile meristematic regions during dormancy and are part of the mechanism that plants use to survive unfavorable environmental conditions such as low temperature or dessication stress. The evergrowing (evg) mutant of peach [Prunus persica (L.) Batsch] does not form terminal vegetative buds in response to dormancy-inducing conditions such as short days and low temperatures, and the terminal meristems maintain constant growth (leaf addition and internode elongation). We genetically mapped the evg trait and identified the corresponding genomic region in a wild-type genome. We sequenced and annotated the 132-kb region. Nineteen genes were predicted to be in the sequenced region. Ten of the predicted genes were demonstrated to be expressed in the wild-type germplasm but six of these were not expressed in mutant tissues. These six genes are a cluster of MIKC-type MADS-box transcription factors similar to genes from Ipomoea batatas and Solanum tuberosum MADS-box, which also regulate meristem growth in vegetative tissues. A 41,746-bp deletion is present in this region of the mutant genome which results in the loss of all or part of four of the six MADS-box genes. The six MADS-box genes that are not expressed in the mutant are candidates for the regulation of growth cessation and terminal bud formation in peach in response to dormancy-inducing conditions and have been named dormancy-associated MADS-box (DAM) genes.

- by Douglas Bielenberg
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- Genetics, Agricultural Biotechnology, Genetic Map, Transcription Factor

Putrescine (5, 10 and 20mM), spermidine (0.5, 1 and 2mM) and aminoethoxyvinylglycine (AVG; 0.32, 0.64 and 1.28mM) were applied to peach trees (Prunus persica L. Batsch cv Stark Red Gold) under open field conditions. Treatments were performed 28 (polyamines; PAs) and 21 or 7 (AVG) days before harvest at 115dAFB. Both PAs and AVG reduced ethylene production of fruit, delayed

Firm-breaker (FB) and firm-mature (FM) peaches cv. 'Paraguayo' were either stored for 4 weeks at 2°C or subjected to three cycles of 1 day of intermittent warming (IW) at 20°C every 6 days at 2°C. Normal postharvest ripening and post-storage ripening at 20°C were also studied in order to relate postharvest physiology with the onset of chilling injuries (CI) (woolliness, gel breakdown and scald). As far as we know, both gel breakdown and scald have been described and reported on peaches for the first time. FB peaches were more sensitive to CI than FM ones. A high respiration rate and ethylene production in conventionally stored fruit after 2 weeks of storage, followed by a drop in ethylene production, was accompanied by the development of CI in fruit of both maturity stages. IW strongly reduced CI during storage. Periodic warming acclimatised chilled fruit to subsequent periods of chilling by allowing them to ripen due to the production of a suitable amount of ethylene, depending on their maturity stage at harvest. The increase in ethylene production during post-storage ripening could be related to the development of over-ripeness.

- by Antonio Cano
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- Postharvest biology, Postharvest Biology and Technology, Enzyme, Chilling Injury
- by Semra Demir
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- New Zealand, Prunus Persica, Stone Fruit, Fusarium Spp

Atributos como coloração da epiderme, tamanho da fruta, sabor e aroma são referências importantes para o consumidor, pois têm impacto direto na percepção de qualidade. O trabalho teve como objetivo avaliar a qualidade, através da análise sensorial, de pêssegos submetidos a diferentes manejos fitotécnicos. Na cultivar Maciel foi avaliado o efeito dos seguintes tratamentos: testemunha; poda verde; plástico de ráfia e poda verde; plástico metalizado e poda verde; 800 g de cloreto de potássio incorporado ao solo, mais 6 g via foliar e poda verde; 1200 g de cloreto de potássio incorporado ao solo, mais 10 g via foliar e poda verde; 1600 g cloreto de potássio incorporado ao solo, mais 14 g via foliar e poda verde; 1600 g cloreto de potássio incorporado ao solo e poda verde; antitranspirante e poda verde. As aplicações dos tratamentos tiveram início em setembro de 2002, finalizando em novembro desse ano. Pela análise sensorial foi possível verificar que o tratamento 1200 g de potássio incorporado ao solo, seguido da pulverização de 10 g do nutriente na folha, proporcionou melhor aspecto visual no que se refere à coloração vermelha, intensidade de odor característico, sabor, gosto doce e suculência das frutas. Desta forma, conclui-se que práticas de manejo bem aplicadas permitem incrementar a qualidade visual e sensorial de pêssegos que possuem deficiência nesses atributos. Palavras-chave: cor da epiderme, sabor característico, odor característico. ABSTRACT Attributes as color of epidermis, fruit size, taste and flavor are important references to the consumer, since they have direct impact on quality perception. This work aimed to evaluate fruit quality through the sensory analysis of peaches (cv. Maciel) submitted to different cultural practices. The following treatments were studied: control; green prunning; raffia plastic and summer prunning; metallized plastic and summer prunning;

- by Renato Trevisan
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- Cultural Practice, Sensory Analysis, Fruit Quality, Prunus Persica

The ESTree db http://www.itb.cnr.it/estree/ represents a collection of Prunus persica expressed sequenced tags (ESTs) and is intended as a resource for peach functional genomics. A total of 6,155 successful EST sequences were obtained from four in-house prepared cDNA libraries from Prunus persica mesocarps at different developmental stages. Another 12,475 peach EST sequences were downloaded from public databases and added to the ESTree db. An automated pipeline was prepared to process EST sequences using public software integrated by in-house developed Perl scripts and data were collected in a MySQL database. A php-based web interface was developed to query the database. The ESTree db version as of April 2005 encompasses 18,630 sequences representing eight libraries. Contig assembly was performed with CAP3. Putative single nucleotide polymorphism (SNP) detection was performed with the AutoSNP program and a search engine was implemented to retrieve results. All the sequences and all ...

- by Andrea Caprera and +1
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- Programming Languages, Genomics, Computational Biology, Functional Genomics

The loss of quality in peach (Prunus persica) after harvest is associated with metabolic changes, mechanical damage, loss of pulp firmness, physiological disorders and decay. In the 'Chiripá' cultivar, woolliness is a major physiological process that affects the postharvest quality. For a better understanding of the development of woolliness in 'Chiripá' peach and to identify conditions that can prevent it, we devised several postharvest treatments consisting of cold storage (CS) either alone or in combination with the application of ethylene or 1-methycyclopropene (1-MCP), intermittent warming or controlled atmosphere (CA) storage. We evaluated the effects of these treatments on postharvest preservation, the occurrence of woolliness and the activities of endo-polygalacturonase (endo-PG), exo-polygalacturonase (exo-PG) and pectin methylesterase (PME). Our results indicated that these treatments could modify the activities of the three enzymes, and that the induction of endo-PG and exo-PG activity and/or the repression of PME activity reduced the occurrence of woolliness. CS alone had a major effect on endo-PG and exo-PG activity but less impact on PME activity. The application of 1-MCP exacerbated this difference. Either ethylene application or intermittent warming increased endo-PG and exo-PG activities without reducing PME activity, resulting in the loss of pulp firmness and decay. Under CA storage, PME activity was effectively reduced and the activities of endo-PG and exo-PG, which were low during the treatment, dramatically increased 5 days after the end of the treatment. The overall quality of the peaches was better preserved under CA storage alone. With this treatment, the difference between PG and PME activity narrowed and the activity of both enzymatic groups decreased. As a result, the firmness of the pulp was better preserved and the incidence of decay and woolliness decreased.

- by Leonardo Nora
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- Postharvest biology, Postharvest Biology and Technology, Enzyme, Postharvest

... Monika Kałużna & Joanna Puławska & Piotr Sobiczewski ... Recently, the PCR melting profile (PCR MP) method appeared to be very useful in genetic diversity studies of several bacterial genera, mainly Enterobacteriaceae (Masny... more

- by Piotr Sobiczewski and +1
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- Microbiology, Plant Biology, Genetic Diversity, Pseudomonas Syringae

Se realizó un experimento durante tres años (2004/05 a 2006/07) sobre un monte de duraznero recién implantado en el sur de Uruguay. Se aplicaron cinco tratamientos de riego: secano (T1), goteros de 1,6 L h-1 a 0,4 m (T2), goteros de 4 L h-1 a 1 m (T3), microjets de 21 L h-1 a 5 m (T4) y goteros de 2 L h-1 a 1 m, dos líneas por fila (T5), en un diseño experimental en cuadro latino. Las parcelas eran de siete plantas en un marco de plantación de 2,5 x 4,5 m. En todos los tratamientos con riego se aplicó la misma dosis de agua, de forma de cubrir el 100% de la ETc. El porcentaje de volumen de suelo mojado fue de 16, 18, 22 y 44% para los tratamientos T2, T3, T4 y T5 respectivamente. En las variables peso de poda, potencial hídrico foliar y xilemático, conductancia estomática, crecimiento de frutos, rendimiento y tamaño promedio de los frutos, los tratamientos que recibieron riego no se diferenciaron estadísticamente entre sí, pero todos presentaron valores significativamente superiores al secano (p < 0,05). No se evidenció ninguna respuesta entre los tratamientos regados al porcentaje de suelo mojado, para todas las variables analizadas. Se plantea la hipótesis que los efectos de estos tratamientos, en un cultivo perenne, serían acumulativos y se podrían expresar en años sucesivos. Palabras-clave: patrones de mojado, Prunus persica, riego localizado, volumen de suelo mojado Peach trees response to different water application patterns ABSTRACT An experiment was carried out for three years (2004/05 to 2006/07) on a just implanted peach grove, in the south of Uruguay. Five irrigation treatments were applied: without irrigation (T1), drippers of 1.6 L h-1 at 0.4 m (T2), drippers of 4 L h-1 at 1 m (T3), microjets of 21 L h-1 at 5 m (T4) and drippers of 2 L h-1 at 1 m, two lines by row (T5), following a Latin square experimental design. The experimental plots had seven trees in a plantation frame of 2.5 x 4.5 m. In all treatments with irrigation, the same water dose was applied, in order to fulfill 100% of the ETc. The percentage of wetted soil volume was 16, 18, 22 and 44% for treatments T2, T3, T4 and T5 respectively. Regarding variables, prune weight, foliar and xilematic water potential, stomata conductance, fruit growth, yield and average size of the fruits, the treatments with irrigation were not statistically different, but all of them were significantly different from the treatment without irrigation (p < 0.05). No response to the percentage of wet soil among the irrigated treatments was detected, for all the analyzed variables. The hypothesis that the effects of these treatments, upon a perennial crop would be cumulative, and would possibly show up in the following years, is considered.

- by Raquel Hayashi
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- Experimental Design, Prunus Persica, Cumulant, Water Potential

Agronomic and fruit quality traits were evaluated and compared for three consecutive years on 1,111 seedlings coming from 15 peach and nectarine breeding crosses, grown under a Mediterranean climate. Significant differences among and within the different progenies were found for most of the traits analyzed. The breeding population segregated for several Mendelian characters such as peach or nectarine fruit, round or flat fruit, yellow or white flesh and freestone or clingstone. In addition, aborting fruit and flat fruit trees were found in our progeny, and our data seem to support multi-allelic control of both flat shape and aborting fruit. The variation within the progenies of some traits such as blooming and harvesting date, yield, fruit weight and SSC was continuous, suggesting a polygenic inheritance. Relationships between qualitative pomological traits and these agronomic and fruit quality parameters were also found. Valuable correlations among agronomic and fruit quality parameters were found, although coefficients of variation depending on the progeny should be considered. In addition, principal component analysis (PCA) revealed several relationships among quality traits in the evaluated progenies. Based on this evaluation, 26 outstanding genotypes were pre-selected from the initial breeding population for further studies.

Effects of partial bark ringing and complete ringing on peach (Prunus persica Batsch cv. ‘Hikawahakuho’) trees grafted on vigorous peach seedling rootstocks (wild form) were studied. Ring of bark 2cm length was peeled from trunk leaving (or not) a connecting 2mm bark strip (a bridge) on the trunk. The treatment was done partial ringing once, weekly, fortnightly and monthly. Shoot

- by Ali El-Shereif
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- Prunus Persica, Scientia

Foraging behaviour of four honeybee species (Apis mellifera A. cerana, A. dorsata and A. jlorea) was studied in relation to energy production rates of Prunus persica and a simultaneously blooming weed, Lepidagathus incurva. Energy produced ranged from a minimum of O.642±O.Ol joules (L. incurva)/flowerl day to a maximum of 1.49±O.14 joules/day (P. persica). The weed having higher nectar sugar concentration and high flowering density attracted more number of bees as compared to peach. The foraging rates of bees were much higher on the weed and they could harvest more energy per unit time from the weed flowers. Evidently, food acquisition efficiency and quality of food determines the foraging decision of bees.

- by Dharam Abrol
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- Zoology, Foraging behaviour, Energy Production, Prunus Persica

A toxigenic property has been demonstrated in a Pseudomonas syringae pv. persicae/Prunus persica isolate. Several substances, which are named persicomycins, have been purified in variable quantities from cultures. The structures of four of them were established by NMR and chemical ionization mass spectrometry. These compounds are 3-(3'-hydroxy)hydroxy fatty acids and thus represent a new family among the phytobacterial toxins. Other minor substances have also been isolated and have been shown to belong to the same family on the basis of their 7H-NMR spectra. All of them cause necrosis of peach tree tissues, a symptom similar to the one obtained after bacterial infection and antibiosis of microorganisms such as Bacillus thuringiensis. These results provide evidence that necrosis-inducing toxins are not restricted to the pathovar syringae. Furthermore, similar substances were purified from necrosed tissues of inoculated and diseased peach trees. 3-(3'-Hydroxydecanoyloxy)hexade...

- by Eric Guittet
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- Mass Spectrometry, Magnetic Resonance Spectroscopy, Fatty acids, Pseudomonas

The peach tree (Prunus persica) produces gum exudates on its trunk and fruit. The former was extracted with water to give polysaccharide (PPN) and residual material was extracted with alkali giving structurally similar PPNA (NMR examination), which was formed in a slightly higher yield (42% compared with 37%). PPNA consisted of Ara, Xyl, Man, Gal, and uronic acids in a

- by Marcello Iacomini
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- Organic Chemistry, Inner Core, Spectrum, Food Sciences

Twenty peach and nectarine (Prunus persica [L.] Batsch) varieties (Morettini No. 1, Coronet, Dixired, Jerseyland, Gialla Precoce Morettini, Cardinal, Golden Jubilee, Red Haven, Belle di Georgia, Early Elberta, Elberta, J.H. Hale, Rio Oso Gem, Desert Gold, Spring Time, June Gold, Red Cup, Flavor Top, Fantasia, Flame Kist) grafted on wild peach seedlings were evaluated for 10 years in the Greek island Kos. The results showed that some peach and nectarine varieties with high chilling requirements such as Red Haven (950 hrs) gave satisfactory yield in the soil and climatic conditions of Kos, where the mean duration of temperatures below 7°C was found to be about 150 hr. Bloom and maturity dates were different in the same varieties in Kos compared to their standard bloom and maturity dates in Naoussa. Regarding a response to Plum pox virus the varieties Jerseyland, Gialla Precoce Morettini, Desert Gold and Spring Time were the most resistant whereas Dixired, Red Haven, Belle Di Georg...

- by Thomas Thomidis
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- Horticultural Science, Fruit Quality, Prunus Persica, Plum Pox Virus