Plant Pathology Science

Optimal method for production of mycelia biomass of Ganoderma lucidum in sugarcane molasses

Ebrahim Mohammadi Goltapeh

Ahmadifar S , Hosseini SM, MohammadiGoltapeh E, Jahedi A (2020) Optimal method for production of mycelia biomass of Ganoderma lucidum in sugarcane molasses. Plant Pathology Science 9(1):1-14. DOI: 10.2982/PPS.9.1.1.

Introduction: Ganoderma lucidum, medicinal mushroom, is one of the most effective traditional medicine in East Asia. The mycelium, the spore and the basidiocarp contain about 400 different bioactive compounds with polysaccharides, peptidoglycans and triterpenes as active ingredient groups of medical value. Underwater cultivation is one of the most reliable technologies to produce the industrial biomass of this mushroom, which contains anti-tumor and anti-cancer polysaccharides. Regarding the growth of fungal mycelium, it is related to various environmental factors such as pH, temperature and available nutrients. The aim of this study was to determine the influence of pH, temperature and different concentrations of the carbon and nitrogen sources on the growth rate of fungal biomass in sugar cane molasses. Materials and Methods: The first part of the study dealt with the morpHological and molecular identification of an Iranian isolate from G. lucidum. Then the effects of carbon sources of arabinose, maltose, cellulose and xylose at concentrations of 0.1, 0.2 and 0.3%, and nitrogen sources of yeast extract, MgSo₄.7H2O, peptone and K₂Hpo₄ at concentrations of 0.2, 0.3 and 0.4%, pH 4, 4.5, 5 and 5.5, and a temperature of 25° C, 28° C, 32 ° C and the number of 2, 3, and 4 inoculum particles of 5 mm² for the production of mycelium biomass of G. lucidum, in sugarcane molasses was studied, in completely randomized design experiments with four replicates for each treatment in vitro. Results: A comparison of the mean dry weight mycelium of G. lucidum produced with different treatments showed the significant differences between the treatments with a probability of 5%. The highest yield of G. lucidum was obtained in peptone with concentration of 0.3%, maltose with concentration of 0.2%, pH=5, 3 inoculum particles with 5mm² diameter, at 28°C. Conclusion: Sugar cane molasses can be used as a cheap and inexpensive medium for the biomass production of G. lucidum. For the first time this study showed that by adding peptone with concentration of 0.3%, maltose with concentration of 0.2%, to sugarcane molasses, with 3 particles of inoculum with 5mm² diameter, in pH=5, and 28°C, the highest biomass of this medicinal mushroom could be produced.

Report of five species of plant parasitic nematodes associated with hawthorn forest trees in western Iran

eadi bazgir

Z, Bazgir E, Naghavi A (2020) Report of five species of plant parasitic nematodes associated with hawthorn forest trees in western Iran. Plant Pathology Science 9(1):15-29. DOI: 10.2982/PPS.9.1.15

Introduction: The Hoplolaimidae family is one of the largest and economically most important families of the order/ infraorder Tylenchida / Tylenchomorpha. The members of this family spread all over the world and can be found under different climatic conditions. Some species in this family are serious plant parasites and significantly reduce crop yields. Materials and Methods: In the forests of Khorramabad city in western Iran 70 samples were collected from the soil around the roots of hawthorn trees in the period of 2017-2019. After recording the properties of each sample, they were transferred to a laboratory and cooled at 4 °C. The nematodes were extracted from the soil using the tray method, then fixed and transferred to pure glycerin, and permanent slides were made. The morphological and morphometric properties of the nematodes were examined using a light microscope equipped with a Dino Capture camera. The nematode species were identified using scientific identification keys. Results: Five species of plant parasitic nematodes belonging to two genera of Hoplolaimidae were identified in this study, including Rotylenchus goodeyi, Helicotylenchus canadensis, H. digonicus, H. vulgaris and H. tunisiensis. Conclusion: R. goodeyi is reporting as a new record for the nematode fauna of Iran. Morphometrical and morphological characteristics of these nemadodes are described here.

Effect of eight essential oils on bacterial canker disease in citrus

Rasool Rezaei

Rezaei R (2020) Effect of eight essential oils on bacterial canker disease in citrus. Plant Pathology Science 9(1):30-39. DOI: 10.2982/PPS.9.1.30.

Introduction: Citrus bacterial canker caused by Xanthomonas citri subsp. citri is an economically important disease in many tropical and subtropical countries. Several pathotypes of this pathogen have been described which, in addition to certain genotypic features, are distinguished above all by their geographical origin and their host range. Citrus bacterial canker disease is wide spread in Iran and a major threat to the production of Mexican lime (Citrus aurantifolia). Therefore, management of citrus canker is inevitable in citrus growing areas where citrus canker has been established. Application of copper-based bactericides is a standard control measure for management of citrus canker worldwide. Therefore, their long-term use leads to the development of resistant isolates. Plant extracts and essential oils with an antimicrobial effect have become particularly important as an environmentally friendly method for the treatment of plant diseases. Many researchers have recently focused on studying plant extracts and essential oils that contain antimicrobial compounds. Material and Methods: The present study was carried out on the antibacterial effect of Common yarrow (Achillea millefolium), Ginger (Zingiber offcinale), Golden marguerite (Anthemis tinctoria), Fennel (Foeniculum vulgare), Common sage (Salvia officinalis), Gum tragacanth (Astaragalus gossypinus), Summer savory (Satureja hortensis) and True cardamom (Elettaria cardamomum) against two pathotype of Xanthomonas citri subsp. citri under laboratory and greenhouse conditions. Results: All essential oils have an inhibitory effect on multiplication of Xanthomonas citri subsp. citri. The antibacterial test results showed that the essential oils of Ginger and True cardamom strongly inhibited the growth of Xanthomonas citri subsp. citri pathotype, especially the pathotype A*, whereas other essential oils showed moderate to weak activities. Conclusion: The essential oils of these eight plants, especially ginger and cardamom, have good potential for the management of citrus bacterial canker.

Frocasting and monitoring system of date palm bunch feding in Khozestan province

Masoud Latifian

Latifian M , Rahkhodaei E (2020) Frocasting and monitoring system of date palm bunch feding in Khozestan province. Plant Pathology Science 9(1):40-56. DOI: 10.2982/PPS.9.1.40.

Introduction: Bunch feding is an important injurious disease of date palm. Materials and Methods: This research was carried out to its descsion making system in Abadan-Khoramshhar, Shadegan, Ahwaz, Mahshar and Behbehan regions of Khozestan province by climatic and geoststistical models from 2012 to 2016. Samples were taken randomly from 10 trees located in one date palm orchards of any villages Results:Results showed that the disease damage reached to the peak values in September. Forecasting model of damage factors have been significant at level 1 and 5 percent. Variography of distributions on different sites were calculated that the model nuggets for date palm bunch feding in Abadan - Khoramshhar, Shadegan, Ahwaz, Mahshar and Behbehan regions were 1.6, 1.7, 0.15, 0.51 and 2.5 kilometers respectively. These results show that errors of the damage estimation were low at the distances less than whithin sampling sapace. Effective ranges of variograms were 4.1. 12.9, 4.7, 1.9 and 11.06 respectively which indicated the date palm bunch feding distribution in region. Sill of models were 0.49, 0.76, 0.37, 0.31, and 0.51 respectively that at the distances more than these thresholds, correlations between the injury data were at the lowest level and could be monitored. Conclusion: The results of this study

were the basic steps in creating a decision making system in date palm protection network. According to the results of this research, the bunch feding damge can be properly monitored, forecasted and controlled before the maximum damage occurs.

Scab diseases of apple and pear

Leila Ebrahimi

Ebrahimi L (2020) Scab diseases of apple and pear. Plant Pathology Science 9(1):57-67. DOI: 10.2982/PPS.9.1.57

Apple and pear scab diseases caused by Venturia inaequalis and V. pyrina are the most important economical diseases on these plants. These pathogens overwinter in the form of spherical pseudothecia on the remnants of infected leaves. However, in areas with mild winters, they remain as mycelium or conidia in buds and branches. Symptoms of the disease on the leaves are black spots with a velvety surface. In severe and early infections on fruits, deformity and cracks occur. Humidity and temperature are important and influential factors in the prevalence and severity of this disease. The disease will be severe in areas where the weather is cool and humid in spring and early summer. Symptoms of diseases, morphological characteristics of pathogens, disease cycles and disease management methods including resistant cultivars, horticultural sanitation, biological control, chemical control and their forecasting program are illustrated and discussed.

Review of durable management of soil-borne plant pathogens

Mousa Najafiniaya

Najafiniya M , Azadvar M (2020) Review of durable management of soil-borne plant pathogens. Plant Pathology Science 9(1):68-77. DOI: 10.2982/PPS.9.1.68.

Plant diseases play a critical and limiting role in crop production and their control by using pesticides cause serious problems regarding food safety and environmental health and increase the need for other sustainable disease management techniques. Some of plant pathogens may infect the aerial parts of plants, but spent part of their life cycle in the soil and maintained their survival. In such cases, part of the life cycle of the plant pathogen in soil may be very important, even if that microorganism does not infect the roots. Mono culturing and cultivation of crops belonging to the same family increase the potential of disease incidence. Using and applying the suitable and correct cultural practices that limit damage of root diseases is necessary for sustainable management of soil-borne pathogens. Cultural operations, including the use of cover green crops, crop rotation, organic composts, certified seeds and propagative materials, amended organic material to soil, proper tillage systems, soil solarization, resistant cultivars, mycorrhizal fungi, all are reported and confirmed as management options for long time saving soil quality and good sustainable management of soil borne diseases.

Role of betasatellites in interaction of viruses with plants

Saeid Tabein

Mosharaf N, Tabein S, Behjatnia SAA, Safi A (2019) Role of betasatellites in interaction of viruses with plants. Plant Pathology Science 9(1):78-90. DOI: 10.2982/PPS.9.1.78.

Betasatellites, as begomovirus-dependent small circular single-stranded DNAs, are multifunctional agents that trigger disease symptoms, suppress gene silencing pathways and also interact with various cellular pathways and factors. These subviral elements have a conserved genome organization that encodes only a functional open reading frame on the complementary sense strand βC1. The encoded beta satellite protein affects only the helper begomovirus cycle factor. The small size with a strong promoter sequence and the ability to replace βC1 with foreign genes made beta satellites suspected tools for the investigation of functional genes. As we expand our knowledge of begomovirus / beta satellite complexes and their interactions with host plants, we develop management approaches for the expansion of begomoviral destructive diseases.

Dutch elm disease

Mahdi Arzanlou

Mehrabioun Mohammadi M, Ahmadi N, Arzanlou M (2020) Dutch elm disease. Plant Pathology Science 9(1):91-100.         DOI: 10.2982/PPS.9.1.91.

Elm trees are one of the most important ornamental trees and are widely used in the design of urban green spaces. Dutch elm disease is recognized as one of the most important elm diseases in the world. The disease has become an epidemic worldwide and at least three species of Ophiostoma including O. ulmi, O. novo-ulmi and O. Himal-ulmi that differ in geographical distribution and invasion power, are involved in this disease. In Iran, O. ulmi and O. novo-ulmi are known to involve in this disease, with O. novo-ulmi being more virulent. Management of the disease is mainly achieved through preventive and quarantine methods, health measures, resistant cultivars and the use of chemical compounds. Various aspects of the disease, including disease symptoms and signs, pathogen biology and ecology, disease management methods are reviewed in this paper.

Application of seaweeds in plant disease management

Reza Ghaderi

Dehghan AA, Ghaderi R (2020) Application of seaweeds in plant diseases management. Plant Pathology Science 9(1):101-107. DOI: 10.2982/PPS.9.1.101.

Algae are the most important plant growth stimulants due to their high content of minerals, amino acids, vitamins and growth regulators such as auxin, cytokinin and gibberellin. Use of these stimuli in crops can improve rooting, yield, photosynthetic capacity and their resistance to pathogens. Application of algae (mainly seaweeds) against various plant diseases including bacterial, fungal, viral and nematode diseases as well as pests has been proven. Seaweeds are used as a powder or extract mixed with soil, or foliar spray to control of plant diseases. They are usually involved in controlling plant pathogens by inducing plant resistance, antagonistic activity by induced activity of other microorganisms, and enhancing plant growth. In general, seaweeds can be applied as biofertilizers, biostimulators and soil amendments in integrated plant diseases management programs.

Induced resistance, Phytophthora, Pseudomonas, Verticillium

Aminallah Tahmasebi

Tahmasebi A, GhodoumParizipour MH (2020) The role of brassinosteroid hormones in plant response to pathogens. Plant Pathology Science 9(1):108-117. DOI: 10.2982/PPS.9.1.108.

Plants are usually attacked by several pathogens. Different defense pathways in plants have evolved in reaction to pathogens. Plant defense responses have been shown to be regulated by various plant hormones. Brassinosteroids are plant-specific steroid hormones that play important roles in regulating growth and developmental processes. In addition to acting as a regulator of plant growth, they also play a role in defense responses to pathogens. Many researches have been done on their role in plant resistance to fungi, bacteria and viruses, which are described in this article. Further understanding of the role of these hormones in plant defense responses can be useful in inducing resistance or producing plants resistant to pathogens.

Oak charcoal rot disease in Iran

Fariba Ghaderi

Ahmadi S, Ghaderi F, Safaee D (2020) Oak charcoal rot disease in Iran. Plant Pathology Science 9(1):118-128. DOI: 10.2982/PPS.9.1.118.

Oak charcoal rot is caused by two fungi, Biscogniauxia mediterranea and Obolarina persica. These fungi, which are opportunistic or secondary invaders and attack stressful trees, are one of the main problems of oak forests in Iran. The disease was first reported in 2011 in the northern forests on Quercus castaneifolia and Zelkova carpinifolia trees and then in the Zagros forests on Q. brantii tree. The disease has spread rapidly in the forests of the Zagros over the years. Symptoms of the disease include decay and death of trees, browning of leaves and early fall. Gum secretion on the branches and trunks of old trees and browning of wood texture and woody vessels can be seen up and down the height of the trunk. The morphological characteristics of pathogens, the spread and survival of pathogens, and disease management methods are described in this article.

Impact of six essential oils on strawberry gray mold

Nasser Beikzadeh

Beikzadeh N, Afzali H (2020) Impact of six essential oils on strawberry gray mold. Plant Pathology Science 9(1):129-140. DOI: 10.2982/PPS.9.1.129.

Introduction: Gray mold caused by Botrytis cinerea is the most important disease after strawberry fruit harvest. The use of chemical fungicides can have a negative effect on the health of consumers, so the use of plant essential oils for disease management has been considered. The effect of six plant essential oils on the pathogen and the contamination of strawberry fruits was investigated in this research to identify suitable essential oil to control the disease. Materials and Methods: The pathogen was isolated from infected strawberry fruits in northeastern Iran. The inhibitory effect of different concentrations of peppermint, savory, caraway, cumin, eucalyptus and thyme essential oils on mycelial growth and germination of the pathogen spores was tested by mixing them with culture medium. Then, the effect of these essential oils in liquid and vapor phases on the contamination of strawberry fruits was tested. After normalization, the data of these experiments were analyzed by analysis of variance with MSTAT-C software and the means were compared with Duncan test. Results: Essential oils of caraway and eucalyptus had the greatest effect in inhibiting the growth of pathogen mycelium. Essential oils of caraway, cumin, savory, thyme and peppermint had the greatest effect in inhibiting the germination of pathogen spores. The essential oils of caraway, cumin, savory, thyme and peppermint in the vapor phase, the essential oils of caraway and eucalyptus in the liquid phase, prevented further contamination of the fruit. Conclusion: The findings of this study show that all of these plant essential oils can significantly prevent the growth of mycelium and germination of pathogen spores and contamination of strawberry fruits, but the effect of caraway essential oil in most cases is better than others. Thus, it can be used as an alternative to fungicides on strawberry fruit.