Plant Pathology Science

Review of Shot-Hole Disease of Stone-Fruit Trees

Abdollah Ahmadpour

Ahmadpour A. 2018. Review of shot-hole disease of stone-fruit trees. Plant Pathology Science 7(2):1-13. DOI: 10.2982/PPS.7.2.1

Shot-hole caused by Stigmina carpophila , is an important disease of stone fruit trees worldwide including Iran. The pathogen produces sporodochia bearing sympodial conidiophores, bearing conidia which have often 3-5 cells. Pathogen has wide host range and can infect almost all species of the genus Prunus. The pathogen overwinters as mycelium in twig cankers and blighted buds or in it is associated with dormant buds. Temperature and duration of wetness are important factors on disease incidence and its severity. The pathogen penetrates the plant indirectly through stomata or directly with its appressoria. Because of the importance of shot hole disease in Iran, symptoms, morphological characteristics of the pathogen, epidemiological factors and methods of disease management are discussed in this review.

Bacterial Canker of Tomato, Bacterial Canker of Tomato

AZIZ BAGHERI

Bagheri A. 2018. Bacterial canker of tomato. Plant Pathology Science 7(2):14-21.
DOI: 10.2982/PPS.7.2.14

Bacterial canker of tomato caused by Clavibacter michiganensis subsp. michiganensis is one of the most important and economical diseases of tomato. Pale, yellow, dry leaves and shoots with colorless strips are the main symptoms on infected plants. The canker is formed in the last stages of the disease. Use of pathogen-free seeds or seedlings, implementation of quarantine regulations in infected areas‎, fallow and rotation with plants out of the Solanaceae family, plowing after tomatoes harvesting and drip irrigation are the main management strategies for disease control. Spraying copper chemicals can also help disease control.

Review of Aflatoxin in Pistachio and its Control Strategies

Mohammad Moradi

Moradi M. and Fani S. R. 2018. A review of aflatoxin in pistachio and control strategies. Plant Pathology Science 7(2): 22-33. DOI: 10.2982/PPS.7.2.22

Aflatoxin contamination of pistachio nut is a health challenge that can affect the economic value of the largest Iranian non-oil exports. This potent hepatocarcinogen mycotoxin is produced by some species of Aspergillus, particularly by A. flavus, under certain conditions during fruiting, harvesting, transportation and storage. Infection of pistachio to the fungus in the orchard is the key factor in its contamination with aflatoxin. This situation occurs with the formation of early splited pistachios and mechanical damages that caused by biotic and abiotic factors. The environmental temperature and relative humidity and the moisture content of pistachio, during the different stages of pistachio production and processing, have significant roles in the incidence and distribution of fungal contamination as well as the increasing of aflatoxin production. The inhibition of these factors is possible with applying of some agronomic, mechanical, physical and biological methods. Orchard establishment based on principles of gardening like optimal plant spacing, uniformity of cultivars, good pruning, proper irrigation method and nutrition along with on time harvesting, proper processing and storage, can guarantee the production of a healthy and valuable product. Biological controls using nontoxinogenic strains of A. flavus and yeasts are also recorded as successful strategies for reducing the pistachio aflatoxin.

Characteristics of Ourmia melon virus (OuMV)

Mina Rastgou

Rastgou M. 2018. Characteristics of Ourmia melon virus (OuMV). Plant Pathology Science 7(2): 34-46. DOI :10.2982/PPS.7.2.34

Ourmia melon virus (OuMV) is one of the viruses that cause mosaic disease in melon (Cucumis melo L.), in West-Azerbaijan Province and some other parts of Iran including Guilan, Fars and Alborz Provinces. This virus was first detected in diseased cucurbits with mosaic and ring spot symptoms, in Urmia in 1978. The virus has unique characteristics that differentiate it from other viruses that infect cucurbits. The virus particles are bacilliform with conical ends. Genome consists of three linear positive-sense single-stranded RNAs, each encoding one protein. Host range mostly limited to Cucurbitaceae and Solanaceae families. Ourmia melon virus, Epirus cherry virus and Cassava virus C are three species those are placed in the genus Ourmiavirus.

The Biosensors and Their Application in Plant Pathology

Davoud Koolivand

Abadkhah M. and Koolivand D. 2018. The biosensors and their application in plant pathology. Plant Pathology Science 7(2):47-59. DOI:10.2982/PPS.7.2.47

Preventing plant disease damage requires the use of new, powerful, simple and portable tools to quickly diagnose pathogens. Today, biosensor technology known as a powerful tool for evaluating conventional methods in agricultural sciences. Sensitivity, selectivity and portability of biosensors made it possible to develop them as special tools for rapid analysis of compounds in samples with low concentration. Biosensors have three main components, biological element, transducer and readout system. The most important application of biosensors in plant pathology is rapid detection of plant pathogens, in order to reduce the use of expensive and environmentally-damaging chemicals. This article introduces different types of biosensors and their applications in plant pathology.

Protease Inhibitors and Their Application Against Plant Pathogens

Mahdi Davari

Erfani M. and Davari M. 2018. Protease inhibitors and their application against plant pathogens. Plant Pathology Science 7(2):60-72. DOI: 10.2982/PPS.7.2.60

Proteases cleave the peptide bonds in proteins and in this way prevent protein activity by degrading them. Proteases are classified into four categories: serine proteases, cysteine proteases, aspartic proteases and metalloproteases. Plant pathogens utilize these vital molecules in plant infecting process. In the other hand, the activity of proteases is inhibited by protease inhibitors of plants. Serine is one of the protease inhibitors. The plants produce the materials inhibiting pathogenic proteases. These molecules are produced in plant cells during pathogenic microorganisms and viruses attack. Protease inhibitors are divided into several families based on sequence similarity and structure. Because the risk of pathogen resistance to this defense strategy is low, it seems these molecules could be use for biological control against plant pathogens.