scholarly journals Genomic, Morphological and Biological Traits of the Viruses Infecting Major Fruit Trees

Viruses ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 515 ◽  
Author(s):  
Muhammad Umer ◽  
Jiwen Liu ◽  
Huafeng You ◽  
Chuan Xu ◽  
Kaili Dong ◽  
...  
Keyword(s):  
Citrus Fruit ◽  
Fruit Trees ◽  
Fruit Production ◽  
Cross Infection ◽  
Stone Fruit ◽  
Biological Traits ◽  
Virus Species ◽  
Pome Fruit ◽  
Wide Range ◽  
Yield Quality

Banana trees, citrus fruit trees, pome fruit trees, grapevines, mango trees, and stone fruit trees are major fruit trees cultured worldwide and correspond to nearly 90% of the global production of woody fruit trees. In light of the above, the present manuscript summarizes the viruses that infect the major fruit trees, including their taxonomy and morphology, and highlights selected viruses that significantly affect fruit production, including their genomic and biological features. The results showed that a total of 163 viruses, belonging to 45 genera classified into 23 families have been reported to infect the major woody fruit trees. It is clear that there is higher accumulation of viruses in grapevine (80/163) compared to the other fruit trees (each corresponding to less than 35/163), while only one virus species has been reported infecting mango. Most of the viruses (over 70%) infecting woody fruit trees are positive-sense single-stranded RNA (+ssRNA), and the remainder belong to the -ssRNA, ssRNA-RT, dsRNA, ssDNA and dsDNA-RT groups (each corresponding to less than 8%). Most of the viruses are icosahedral or isometric (79/163), and their diameter ranges from 16 to 80 nm with the majority being 25–30 nm. Cross-infection has occurred in a high frequency among pome and stone fruit trees, whereas no or little cross-infection has occurred among banana, citrus and grapevine. The viruses infecting woody fruit trees are mostly transmitted by vegetative propagation, grafting, and root grafting in orchards and are usually vectored by mealybug, soft scale, aphids, mites or thrips. These viruses cause adverse effects in their fruit tree hosts, inducing a wide range of symptoms and significant damage, such as reduced yield, quality, vigor and longevity.

scholarly journals Dieback of apricot plantations caused by 'Ca. Phytoplasma prunorum' in Borsod-Abaúj-Zemplén county (Northern-Hungary)

2010 ◽  
pp. 34-41
Author(s):  
Gábor Tarcali ◽  
Emese Kiss ◽  
György J. Kövics ◽  
Sándor Süle ◽  
László Irinyi ◽  
...  
Keyword(s):  
Sour Cherry ◽  
Fruit Trees ◽  
Fruit Production ◽  
Plant Diseases ◽  
Stone Fruit ◽  
Stone Fruits ◽  
The North ◽  
Long Run ◽  
The World ◽  
Fruit Plantations

Plant diseases caused by phytoplasmas have increasing importance in all over the world for fruit growers. Lately, phytoplasma diseases occur on many fruit varieties and responsible for serious losses both in quality and quantity of fruit production. In the long-run these diseases cause destruction of fruit trees. The apricot phytoplasma disease (Ca. Phytoplasma prunorum) was first reported in Europe in 1924 from France. In 1992 the disease has also been identified in Hungary. On the base of growers' signals serious damages of "Candidatus Phytoplasma prunorum" Seemüller and Schneider, 2004 (formerly: European stone fruit yellows phytoplasma) could be observed in different stone fruit plantations in the famous apricot-growing area nearby Gönc town, Northern-Hungary. Field examinations have been begun in 2009 in several stone fruit plantations in Borsod-Abaúj-Zemplén County mainly in Gönc region which is one of the most important apricot growing regions in Hungary, named “Gönc Apricot Growing Area”. Our goals were to diagnose the occurrence of Ca. Phytoplasma prunorum on stone fruits (especially on apricot) in the North-Hungarian growing areas by visual diagnostics and confirm data by laboratory PCR-based examinations. All the 28 collected samples were tested in laboratory trials and at 13 samples from apricot, peach, sour cherry and wild plum were confirmed the presence of phytoplasma (ESFY). On the base of observations it seems evident that the notable losses caused by "Ca. Phytoplasma prunorum" is a new plant health problem to manage for fruit growers, especially apricot producers in Hungary. 

scholarly journals Use of Flying Dragon Trifoliate Orange As Dwarfing Rootstock for Citrus Under Tropical Climatic Conditions

HortScience ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 11-17 ◽  
Author(s):  
François Mademba-Sy ◽  
Zacharie Lemerre-Desprez ◽  
Stéphane Lebegin
Keyword(s):  
New Caledonia ◽  
Citrus Fruit ◽  
Tree Height ◽  
Fruit Trees ◽  
Fruit Production ◽  
Climatic Conditions ◽  
Poncirus Trifoliata ◽  
Trifoliate Orange ◽  
Gross Margin ◽  
Trunk Diameter

Citrus fruit trees grown under tropical climatic conditions have a high level of vigor and, consequently, late fruit-bearing and low productivity. The use of Flying Dragon trifoliate orange [Poncirus trifoliata var. monstrosa (T.Itô) Swing.] (FD) rootstock could overcome these negative effects by inducing small trees with early production. Trials including eight commercial cultivars began in Dec. 1992 on an irrigated plot on the main island of New Caledonia (South Pacific). Growth of the trees was observed over a 13-year period through twice-yearly measurements of tree height, canopy between and in the rows, and trunk diameter. Fruit production was recorded beginning 2 years after planting. According to the climatic and pedological conditions of the experimental site, trees grafted on FD could, depending on cultivar, be planted in densities from 519 to 1111 trees/ha. Over the 13 years, yields were 0.5 to 2.8 times greater than those of the same cultivar on the standard rootstock. ‘Tahiti’ lime cumulative planting and maintenance costs were only 1.5 times higher for a density five times as great, and the level of productivity per hectare (gross margin/ha) was 3.3 times that of traditional orchards. Grafting citrus cultivars on FD, which is seldom used in the Mediterranean zone as a result of its excessive dwarfing effect in relation with the climatic conditions, could prove, on the other hand, promising in tropical areas.

scholarly journals Evaluation of the Prunus interspecific progenies for resistance to Plum pox virus

2013 ◽  
Vol 49 (No. 2) ◽  
pp. 65-69 ◽  
Author(s):  
J. Salava ◽  
J. Polák ◽  
I. Oukropec
Keyword(s):  
Interspecific Hybrids ◽  
Agronomic Traits ◽  
Fruit Trees ◽  
Fruit Production ◽  
Stone Fruit ◽  
Plum Pox Virus ◽  
Prunus Amygdalus ◽  
Prunus Species ◽  
Sources Of Resistance ◽  
Resistance Transfer

Sharka disease caused by the infection with the Plum pox virus (PPV) in stone fruit trees is worldwide the most devastating for stone fruit production. Until now, good sources of resistance to PPV within the peach group have not been available. There are no commercial cultivars of peach that are resistant to PPV. Other Prunus species are known to show varying levels of resistance. Interspecific hybrids GF 677 (Prunus amygdalus × P. persica) and Cadaman (P. davidiana × P. persica) were revealed to be resistant to PPV. The resistance to a Dideron isolate of the descendants of Cresthaven × GF 677 and Cresthaven × Cadaman and their progenitors was evaluated after inoculation by chip-budding in a sealed screenhouse. Results demonstrate a certain level of resistance in both progenies of interspecific hybrids and indicate a potential for PPV resistance transfer to commercial peach cultivars but it will be necessary to perform backcrosses with peach cultivars of agricultural interest in order to return pomological and agronomic traits. For the definitive confirmation of resistance/susceptibility it will be necessary to wait until the adult stage of hybrids.

scholarly journals Reducing Flowering with Gibberellins to Increase Fruit Size in Stone Fruit Trees: Applications And Implications in Fruit Production

2000 ◽  
Vol 10 (4) ◽  
pp. 744-751 ◽  
Author(s):  
Stephen M. Southwick ◽  
Kitren Glozer
Keyword(s):  
Fruit Set ◽  
Relevant Literature ◽  
Fruit Size ◽  
Fruit Trees ◽  
Fruit Production ◽  
Prunus Armeniaca ◽  
Climatic Conditions ◽  
Stone Fruit ◽  
Labor Costs ◽  
Floral Buds

Many commercially grown stone fruit including apricots (Prunus armeniaca L.), peaches and nectarines [P. persica (L.) Batsch], plums (P. salicina Lindl., P. domestica L.), prunes (P. domestica L.), and pluots (P. salicina × P. armeniaca) have a tendency to produce high numbers of flowers. These flowers often set and produce more fruit than trees can adequately size to meet market standards. When excessive fruit set occurs, removal of fruit by hand thinning is necessary in most Prunus L. species to ensure that remaining fruit attain marketable size and reduce biennial bearing. Over the years there have been numerous attempts to find chemical or physical techniques that would help to reduce the costs associated with and improve efficiencies of hand thinning, however, alternate strategies to hand thinning have not been widely adopted for stone fruit production. In the past 10 years, several chemical treatments have shown promise for reducing hand thinning needs in stone fruit. Management of flowering by chemically reducing the number of flowers has been particularly promising on stone fruit in the Sacramento and San Joaquin Valleys of California. Gibberellins (GAs) applied during May through July, have reduced flowering in the following season in many stone fruit cultivars without affecting percentage of flowers producing fruit. As a result, fruit numbers are reduced, the need for hand thinning is reduced and in some cases eliminated, and better quality fruit are produced. There are risks associated with reducing flower number before climatic conditions during bloom or final fruit set are known. However, given the changes in labor costs and market demands, the benefits may outweigh the risks. This paper reviews relevant literature on thinning of stone fruit by gibberellins, and summarizes research reports of fruit thinning with GAs conducted between 1987 and the present in California. The term thin or chemically thin with regard to the action of GA on floral buds is used in this paper, consistent with the literature, although the authors recognize that the action of GA is primarily to inhibit the initiation of floral apices, rather than reduce the number of preformed flowers. At relatively high concentrations, GA may also kill floral buds. Chemical names used: gibberellic acid, potassium gibberellate.

scholarly journals Less Common Phytoplasmas Infecting Stone Fruit Trees

2011 ◽  
Vol 51 (4) ◽  
pp. 435-440 ◽  
Author(s):  
Mirosława Cieślińska
Keyword(s):  
New Species ◽  
Geographic Distribution ◽  
Fruit Trees ◽  
Fruit Production ◽  
Stone Fruit ◽  
Insect Vectors ◽  
Taxonomic Groups ◽  
And Control ◽  
Control Management

Less Common Phytoplasmas Infecting Stone Fruit TreesPrunusspecies plants can be infected by eight ‘CandidatusPhytoplasma’ (‘Ca.P.’) species classified to eight distinctive taxonomic groups: ‘Ca.P. prunorum’ (16SrX-B), ‘Ca.P. mali’ (16SrX-A), ‘Ca.P. pyri’ (16SrX-C), ‘Ca.P. asteris’ (16SrI), ‘Ca.P. aurantifolia’ (16SrII), ‘Ca. P. ziziphi’ (16SrV), ‘Ca.P. fraxini’ (16SrVII), ‘Ca.P. phoenicium’ (16SrIX) and two potentially new species: ‘Ca.P. pruni’ (16SrIII) and ‘Ca.P. solani’ (16SrXII). These agents occur incidentally in orchards and their impact on stone fruit production is lower than ‘CandidatusPhytoplasma prunorum’. Hosts, geographic distribution, symptoms and insect vectors of these ‘Ca.P.’ species, methods of their identification, and control management are reviewed.

scholarly journals Susceptibility of Austrian apricot and peach cultivars to

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 281-284 ◽  
Author(s):  
S. Richter
Keyword(s):  
Peroxidase Activity ◽  
Plant Pathogen ◽  
Defense Mechanisms ◽  
Fruit Trees ◽  
Fruit Production ◽  
Stone Fruit ◽  
Plant Pathogen Interaction ◽  
Sieve Tubes ◽  
Cultivar Susceptibility

1548 stone fruit trees (1435 trees of P. armeniaca, 113 trees of P. persica) were examined by PCR for ESFY to get information on spread and susceptibility of cultivars and rootstocks used in Austrian stone fruit production. Cultivar susceptibility seems to be less important for tolerance to ESFY than rootstock resistance. Apricot cultivars on rootstocks of myrobalan, commonly used in Austria, are more infected than cultivars on plum rootstocks. Data on peach and apricot rootstocks are not representative as both are not commonly used in Austrian apricot production. In addition, the presence of peroxidase activity in shoot sieve tubes of infected apricot trees (Hungarian Best) reveals that peroxidase is involved in defense mechanisms in plant-pathogen interaction.

scholarly journals 567 Effects of Mancozeb, NOVA, GA, and Yeast-like Fungi on Stylar-end Russeting of Navel Orange

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 544B-544
Author(s):  
E.W. Stover ◽  
M. Myers ◽  
R.M. Sonoda ◽  
Z. Guo
Keyword(s):  
Citrus Fruit ◽  
Rhodotorula Glutinis ◽  
Navel Orange ◽  
Pome Fruit ◽  
Liquid Suspension ◽  
Wide Range ◽  
History Of ◽  
Repeated Applications ◽  
Florida Citrus ◽  
Orange Trees

Stylar-end russetting (SER) is a cosmetic defect of Florida citrus fruit most frequently associated with navel orange. SER is evident as spots or streaks of corky tissue that often form a network of intersecting lines. Occurrence of SER is reported to vary widely from year to year, but some orchards have a history of severe SER, with fruit culled annually for this defect. Growers report that SER is typically first evident in August. The cause of SER has not been determined. Reports of yeast-like fungi inducing russet in pome fruit suggest that similar organisms may be implicated in SER. Yeast-like fungi were isolated on acid PDA from navel oranges in an orchard with frequent severe SER. Strains were selected with a wide range of colony morphology, but were not identified taxonomically. These strains, and strains of Aureobasidium pullulans and Rhodotorula glutinis that caused russetting in pome fruit, were grown in liquid suspension and sprayed on navel orange trees with three repeated applications during July and Aug. 1998. No increase in SER was observed on strain-inoculated trees compared to controls. Two broad-spectrum fungicides were sprayed on other navel orange trees to further explore the possibility that fungi may be involved in SER. GA (gibberellic acid) was also applied in this experiment because it can reduce russetting in apples. All applications were made five times at 3-week intervals in June through Sept 1998. SER was assessed in fruit harvested late Sept. 1998. The proportion of fruit with less than 10% of the surface exhibiting SER was 51% for controls, increased to 69% where myclobutanil was applied at 74 mg a.i./L and increased further to 93% where manganese ethylenebisdithiocarbamate was applied at 1775 mg a.i./L. GA did not significantly influence SER.

scholarly journals 659 Reducing Floral Initiation and Return Bloom in Fruit Trees— Applications and Implications in Fruit Production: Pome Fruit

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 561E-561
Author(s):  
Duane W. Greene
Keyword(s):  
Fruit Set ◽  
Fruit Size ◽  
Fruit Trees ◽  
Fruit Production ◽  
Alternative Methods ◽  
Pome Fruit ◽  
Flower Bud ◽  
Bud Formation ◽  
Biennial Bearing ◽  
Flower Bud Formation

Pome fruit display a biennial bearing tendency that is characterized by heavy flowering and fruit set one year followed by a year with reduced bloom and fruit set. This tendancy results in a year with heavy cropping with small fruit, and a subsequent year with large fruit and a small crop. Both situations are undesirable. Chemical thinners in the “on” year are frequently used to modify this cropping behavior. Alternative methods to control cropping by flower bud inhibitions will be discussed. Gibberellin application in the “off” year at or soon after bloom will inhibit flower bud formation and encourage moderate flowering. This method of crop regulation has been used infrequently. Gibberellins differ in their ability to inhibit flowering. Therefore, selection of a specific gibberellin and an effective concentration range may provide greater flexibility in controlling flowering. The cytokinins CPPU and thidiazuron inhibit flower bud formation, increase fruit size, and also thin fruit. Appropriate application of these cytokinins will be discussed where beneficial effects on fruit size may be achieved while maintaining a moderate level of flower bud formation.

scholarly journals Ideas on the European stone fruit yellows – as an entomologist can see them

2014 ◽  
pp. 30-34
Author(s):  
András Bozsik
Keyword(s):  
Population Dynamics ◽  
Fruit Trees ◽  
Fruit Production ◽  
Stone Fruit ◽  
Mediterranean Countries ◽  
Main Host ◽  
Cacopsylla Pruni ◽  
Prunus Spp ◽  
Propagation Material

The European stone fruit yellows (ESFY) is an important endemic disease in Europe which causes in both, the Mediterranean countries and Central Europe serious damage. Its pathogen is the ‘Candidatus Phytoplasma prunorum’. The treatment and healing of the diseased trees and plantations with chemicals do not promise success. Thus, prevention may be the only solution. The transmission and spread of the pathogen happen by infected propagation material (grafting) or a vector (the psyllid, Cacopsylla pruni). Mechanism of the pathogen’s transmission and population dynamics of the vector have been extensively investigated in several European countries, which may allow by the control of C. pruni even to hold back the disease. Diseased stone fruit trees and wild Prunus spp. as main host species play an important role in maintaining and spreading the pathogen. C. pruni collects the pathogen by feeding on these plants and it carries persistently ‘Ca. P prunorum’. Researchers in Hungary have been characterized the disease only in terms of plant pathology, but neither the significance of the vector nor the role of wild Prunus spp. have been studied. This summary intends to give clues to these researches, that not only axe and saw should be the instruments of national control, but knowing the role and population dynamics of the vector the stone fruit production should be more successful.

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