Papers by Farnaz Abed-Ashtiani
Mycologia Iranica, Dec 1, 2019
During the study of fungal species associated with canker and dieback diseases of walnut trees (J... more During the study of fungal species associated with canker and dieback diseases of walnut trees (Juglans regia L.) in East Azerbaijan province, Iran, eight fungal isolates with similar characteristics resembling asexual stage of the genus Juglanconis were isolated from trees showing canker, dieback, and dead skin symptoms in Osko and Horand regions. Conidiomata on the host tissue were acervular and stromatic, 1 -2.5 mm diam, blackish, scattered or confluent, covered with black conidial masses when mature. Conidiophores were unbranched or rarely branched at the base. Conidiogenous cells were cylindrical and annellidic. Conidia elliptic to ovate, truncate with distinct scar at the base, thick-walled and with distinct ornamentation on the inner side of the wall consisting of irregular confluent verrucae, hyaline when immature, brown to blackish when mature, covered with gelatinous sheath, (11) 14 -16 (-18) × (15 -) 22 -25 (-28) µm. Fungal isolates were identified as J. juglandina based on morphological characteristics and host association. Identification of the species was further confirmed by sequence analysis of the elongation factor (tef1-α) gene. Present study is the first report of J. juglandina for the mycobiota of Iran.
Journal of Phytopathology, Jul 23, 2015
Pepino (Solanum muricatum var. pepino) plants were found affected by an extensive leaf spot cause... more Pepino (Solanum muricatum var. pepino) plants were found affected by an extensive leaf spot caused by plant pathogenic fungi during a survey in the Cameron highlands, Pahang state, Malaysia. Symptomatic leaf samples were collected from infected pepino plants and cultivated on PDA medium, and the pathogen was isolated and purified; then, consequently, all isolates were identified as Stemphylium lycopersici on the basis of their cultural and morphological characteristics and combined sequences of the internal transcribed spacer (ITS) and glyceraldehyde-3-phosphate dehydrogenase (gpd) regions. A pathogenicity assay on detached leaves further confirmed that S. lycopersici causes leaf spot disease. To the best of our knowledge, this is the first report of S. lycopersici causing leaf spot on pepino in Malaysia and worldwide.
Journal of Phytopathology, May 17, 2022
Journal of Phytopathology
During the study of fungal species associated with canker and dieback diseases of walnut trees (J... more During the study of fungal species associated with canker and dieback diseases of walnut trees (Juglans regia L.) in East Azerbaijan province, Iran, eight fungal isolates with similar characteristics resembling asexual stage of the genus Juglanconis were isolated from trees showing canker, dieback, and dead skin symptoms in Osko and Horand regions. Conidiomata on the host tissue were acervular and stromatic, 1 – 2.5 mm diam, blackish, scattered or confluent, covered with black conidial masses when mature. Conidiophores were unbranched or rarely branched at the base. Conidiogenous cells were cylindrical and annellidic. Conidia elliptic to ovate, truncate with distinct scar at the base, thick-walled and with distinct ornamentation on the inner side of the wall consisting of irregular confluent verrucae, hyaline when immature, brown to blackish when mature, covered with gelatinous sheath, (11)14–16 (–18) × (15–) 22–25 (–28) µm. Fungal isolates were identified as J. juglandina based on ...
Czech Journal of Genetics and Plant Breeding, 2016
The genus Pyricularia (anamorph)/Magnaporthe (teleomorph) includes important destructive pathogen... more The genus Pyricularia (anamorph)/Magnaporthe (teleomorph) includes important destructive pathogens causing blast disease on various species from the family Poaceae. Thirty-five Magnaporthe isolates were collected from diseased rice plants (variety MR219) in different rice-growing regions of Malaysia, including the five states of Selangor, Penang, Kedah, Kelantan, and Perak between 2010 and 2014. DNA sequence analyses of the internal transcribed spacer (ITS), actin, β-tubulin and calmodulin gene regions, random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) analyses were conducted to analyse 35 Magnaporthe isolates. Phylogenetic analysis of the combined dataset confirmed the identification of all isolates as M. oryzae with a high distance from other Magnaporthe (Pyricularia) species. RAPD and ISSR analyses indicated the existence of a relatively low similarity index value among M. oryzae isolates through identification of four main clades. The clustering of RAPD and ISSR analyses demonstrated that there was a correlation between the isolates and their geographical origins.
The Plant Pathology Journal, 2012
Rice blast disease caused by Magnaporthe grisea (Hebert) Barr [teleomorph] is one of the most dev... more Rice blast disease caused by Magnaporthe grisea (Hebert) Barr [teleomorph] is one of the most devastating diseases in rice plantation areas. Silicon is considered as a useful element for a large variety of plants. Rice variety MR219 was grown in the glasshouse to investigate the function of silicon in conferring resistance against blast. Silica gel was applied to soil while sodium silicate was used as foliar spray at the rates of 0, 60, 120, 180 g/5 kg soil and 0, 1, 2, 3 ml/l respectively. The treatments were arranged in a completely randomized design. Disease severity and silicon content of leaves were compared between the non-amended controls and rice plants receiving the different rates and sources of silicon. Silicon at all rates of application significantly (α = 0.05) reduced the severity of disease with highest reduction (75%) recorded in treatments receiving 120 g of silica gel. SEM/EDX observations demonstrated a significant difference in weight concentration of silicon in silica cells on the leaf epidermis between silicon treated (25.79%) and non treated plants (7.87%) indicating that Si-fertilization resulted in higher deposition of Si in silica cells in comparison with non-treated plants. Application of silicon also led to a significant increase in Si contents of leaves. Contrast procedures indicated higher efficiency of silica gel in comparison to sodium silicate in almost all parameters assessed. The results suggest that mitigated levels of disease were associated with silicification and fortification of leaf epidermal cells through silicon fertilization.
Canadian Journal of Plant Pathology, 2014
European Journal of Plant Pathology, 2014
Archives of Phytopathology and Plant Protection, 2022
Abstract In this study, PLANT TONIC9 (EOX-SOV) was screened for its in vitro efficacy against som... more Abstract In this study, PLANT TONIC9 (EOX-SOV) was screened for its in vitro efficacy against some fungal species. PLANT TONIC9 significantly inhibited the mycelial growth and conidial germination of all tested species as compared with untreated control. The highest mycelial growth and conidial germination inhibition percentage was recorded for Monilinia species while the lowest inhibition percentage was recorded for Rosellinia sp. The lowest minimum inhibitory concentration (MIC) value was observed against Monilinia fructigena and Monilinia fructicola followed by Monilinia laxa and Botrytis cinerea. Also the in vivo efficacy of PLANT TONIC9 against M. laxa was investigated. Application of PLANT TONIC9 significantly reduced the severity and incidence of brown rot disease on apple as compared with the control. PLANT TONIC9 treatments were also successful to retain the size, specific gravity, and shelf life of tested fruits and to decrease their spoilage percentage over the experimental period as compared with the control.
Mycological Progress, 2014
A new species of Alternaria causing leaf spot of pepper (Capsicum annuum) obtained from the Camer... more A new species of Alternaria causing leaf spot of pepper (Capsicum annuum) obtained from the Cameron highlands, Pahang, Malaysia, was determined based on phylogenetic analyses, morphological characteristics, and pathogenicity assays. Phylogenetic analyses of combined dataset of the glyceraldehyde-3-phosphate dehydrogenase (gpd), Alternaria allergen a 1 (Alt a1) and calmodulin genes revealed that the new isolates clustered into a subclade distinct from the closely related Alternaria species A. tomato and A. burnsii. The solitary or short chains of conidia resemble those of A. burnsii. However, conidia with long beaks are morphologically similar to A. tomato. Hence, the pathogenic fungus is proposed as Alternaria capsicicola sp. nov. Pathogenicity assays indicated that A. capsicicola causes leaf spot on pepper.
Silicon is the second most plentiful element in soil and is beneficial for a large variety of pla... more Silicon is the second most plentiful element in soil and is beneficial for a large variety of plants. It is concentrated in plant tissues in quantities similar to that of macronutrients. Considerable damages to plants caused by abiotic stresses such as drought stress, salinity stress, heavy metal stress and nutrient imbalance, as well as biotic stresses like insect pests and pathogens and even herbivorous attacks, have been reported to be reduced significantly by silicon application. Among rice diseases, blast is recognized as the most devastating one. Silicon fertilization has been reported to be efficacious in controlling and mitigating rice blast severity. Two different hypotheses are proposed for the ability of silicon to lessen disease severity. The first hypothesis emphasizes on silicon function as a mechanical barrier against appressorial penetration, while the second hypothesis is based upon the belief that silicon has some physiological roles in disease resistance.
Barr [teleomorph] is one of the most devastating di-seases in rice plantation areas. Silicon is c... more Barr [teleomorph] is one of the most devastating di-seases in rice plantation areas. Silicon is considered as a useful element for a large variety of plants. Rice variety MR219 was grown in the glasshouse to investigate the function of silicon in conferring resistance against blast. Silica gel was applied to soil while sodium silicate was used as foliar spray at the rates of 0, 60, 120, 180 g/5 kg soil and 0, 1, 2, 3 ml/l respectively. The treatments were arranged in a completely randomized design. Disease severity and silicon content of leaves were compared between the non-amended controls and rice plants re-ceiving the different rates and sources of silicon. Silicon at all rates of application significantly (α = 0.05) reduced the severity of disease with highest reduction (75%) recorded in treatments receiving 120 g of silica gel. SEM/EDX observations demonstrated a significant difference in weight concentration of silicon in silica cells on the leaf epidermis between silicon trea...
Phytopathologia Mediterranea, 2018
Grapevines exhibiting general decline symptoms were observed in July 2012 in Arbatan, a region in... more Grapevines exhibiting general decline symptoms were observed in July 2012 in Arbatan, a region in Marand county, north-western Iran. Leaf necrosis symptoms were also observed in affected grapevines. Dark brown necrotic lesions and wood discoloration were observed in the vascular tissues of affected cordons. Fungal isolates, all with similar cultural and morphological features, were obtained from symptomatic tissues. Morphological characteristics indicated that the isolates were Macrophomina phaseolina . Sequence analysis of the elongation factor (EF-1α) gene from isolates confirmed this identification, with 100% similarity to the reference M. phaseolina sequences obtained from GenBank. Pathogenicity assays of two M. phaseolina isolates on 2-year-old potted vines (cv. ‘Keshmeshi’) demonstrated that M. phaseolina was pathogenic on grapevine. This study confirmed the association of M. phaseolina with grapevine decline symptoms, and represents the first report of this fungus associated ...
Journal of Phytopathology, 2021
Rice blast caused by fungus Magnaporthe grisea (Hebert) Barr [teleomorph]Pyricularia oryzae Cavar... more Rice blast caused by fungus Magnaporthe grisea (Hebert) Barr [teleomorph]Pyricularia oryzae Cavara is among the most devastating diseases of rice worldwide. In modern agricultural practices it is highly important to manage diseases and pests using efficient methods with minimum harm to the environment. Although silicon has been reported to significantly reduce foliar diseases in crops, its application has not been widely adopted in Malaysia. Hence studies were conducted to determine the effects of silicon on Pyricularia oryzae. Rice variety MR219 was grown in the glasshouse and the function of silica gel and sodium silicate in conferring resistance against blast was investigated. Silica gel was applied to soil prior to planting (0, 60, 120, 180 g/5 kg of soil) while sodium silicate was used as foliar spray (0, 1,2, 3 mL/L). The treatments were arranged in a completely randomized design with three replications. The severity of disease and silicon content of leaves were compared betwe...
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Papers by Farnaz Abed-Ashtiani