Hamid Alvanipour; Heshmatolah Aminian; Khalil Alami-Saeid; Karim Sorkheh; Reza Farrokhinejad; Mohammad Javan-Nikkhah
Abstract
khamedj is one of the most important fungal diseases that in a favorable condition can lead to severe outbreaks and causing an 80% loss of the annual harvest. 30 isolates of Mauginiella scaettae, the causative agent of this disease including 27 isolates from different locations of the Iran, two isolates ...
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khamedj is one of the most important fungal diseases that in a favorable condition can lead to severe outbreaks and causing an 80% loss of the annual harvest. 30 isolates of Mauginiella scaettae, the causative agent of this disease including 27 isolates from different locations of the Iran, two isolates from Iraq and one isolate from Kuwait were collected from different palm cultivars during 1397-1397 and used in the present study. Seven EST-SSRs markers were applied to show the genetic diversity among these 30 isolates. Five loci including, SNOD1, SNOD26, SNOD22, SNOD17, and SNOD21 were polymorphic among the species and revealed a total of 16 alleles. Also, two microsatellite markers, including SNOD5 and SNOD16, did not amplify and showed no amplification. The dendrogram constructed based on the similarity index resulted in five major clusters so that two clusters were divided into sub-clusters. The highest similarity value was observed between isolates Ilam-sa and Behb-kh2 (0.75) and followed by isolates abad-ma1 and ramh-sa1 (0.57). On the other hand, two isolates Kheshbid-za and Abad-sa1 have the highest genetic distances with other isolates. Thirteen isolates were selected from the identified genetic groups to study pathogenic groups on the sayer cultivar. The results indicated that there were significant differences among isolates used. The results revealed that Behb-ma1 isolate and Mehr-sa isolate showed the lowest and highest pathogenicity, respectively.
Farshad Karamian; Mohammad Salari; Mahdi Pirnia; Abdollah Ahmadpour; Mohammad Javan Nikkhah
Abstract
Root and crown common rotdisease caused by Bipolaris sorokiniana, has caused severe losses of wheat products worldwide. A collection of 147 monoconidial isolates was made from cultivated wheat in West Azerbaijan (Miyandoab), Golestan (Gorgan), Alborz (Karaj), Kermanshah (Kermanshah) and Fars (Shiraz) ...
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Root and crown common rotdisease caused by Bipolaris sorokiniana, has caused severe losses of wheat products worldwide. A collection of 147 monoconidial isolates was made from cultivated wheat in West Azerbaijan (Miyandoab), Golestan (Gorgan), Alborz (Karaj), Kermanshah (Kermanshah) and Fars (Shiraz) provinces in 2017-2018. After morphological and molecular identification, mating type primers were designed based on a conserved DNA binding (alpha domain) in MAT-1 and the high mobility group (HMG) domain in MAT-2. Frequency of mating type idiomorphs of B. sorokiniana isolates were done by multiplex PCR. Among 147 isolates of five population, 86 isolates amplified by MAT-1 primer and 61 isolates by MAT-2 primer. Frequencies of MAT-1 alleles in Shiraz and Gorgan populations was more than the MAT-2 alleles. According to the results of the Chi-square test (X2), Karaj, Kermanshah and Miyandoab populations had not significant difference (P<0.05). Therefore, these three populations have the highest potential for sexual reproduction than the otherthreepopulations. In addition, isolates from all of the populations were studied to evaluate the sexual fertility in vitro. After two months, pseudothecia without mature asci and ascospores formed in media.
habibullah bahlolzada; Hossein Saremi; Mohammad Javan Nikkhah; Maryam Fallahi; seyed mohammad bagher Hosseini
Abstract
The members of Fusarium is one of the important causal egent of soil borne diseases which cause serious damage in the agricultural and horticultural crops in the world. In order to investigate Fusarium destributions in agricultural soils in the Bamyan and Daikundi with semi desert climates, Kandahar ...
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The members of Fusarium is one of the important causal egent of soil borne diseases which cause serious damage in the agricultural and horticultural crops in the world. In order to investigate Fusarium destributions in agricultural soils in the Bamyan and Daikundi with semi desert climates, Kandahar and Helmand with desert climates, sampling was performed in Afghanistan in 2018-2019. The PPA medium (Pepton PCNB Agar) was used for Fusarium isolations. For morphological characterisation, pure cultures were transferred to CLA (Carnation Leaf-piece Agar), SNA (Synthetic Nutrient Agar ) and PDA (Potato Dextrose Agar) mediums and gene sequencing of tef-lα regions were performed for molecular identification. Totally 134 Fusarium isolates were obtained and grouped in 11 different species. The presence of F. incarnatum-equiseti species complex (FIESC) (28%), F. solani (16%), F. acuminatum (6%), F.verticillioides (5%), F. oxysporum (3%), F. coeruleum (1%) and F. compactum (1%) with different frequency were detected in both regions of the sampling areas. F. sambucinum (1%) was detected in semi-desert climates (Bamyan and Daikundi provinces), While F. proliferatum (18%), F. culmorum (13%) and F. Pseudograminearum (1%) were isolated and identified in areas with desert climates (Helmand and Kandahar provinces). The results this study, geographical distribution of various species of Fusarium in Afghanistan, provide useful information about management of soil borne Fusarium pathogens.
Saadi Karami; Mohammad Javan Nikkhah; Khalil-Berdi Fotouhifar; Vahid Rahjoo; Abdollah Ahmadpour; Amin Alidadi
Abstract
In order to study the Bipolaris and Curvularia species associated with corn, sorghum and sugarcane, sampeling were performed from different regions of Iran (including Alborz, Ardabil, Fars, Gilan, Golestan, Khuzestan, Mazandaran and Zanjan provinces) during the summer of 2011 and 2012. Fungal species ...
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In order to study the Bipolaris and Curvularia species associated with corn, sorghum and sugarcane, sampeling were performed from different regions of Iran (including Alborz, Ardabil, Fars, Gilan, Golestan, Khuzestan, Mazandaran and Zanjan provinces) during the summer of 2011 and 2012. Fungal species were identified based on morphological features and molecular data of ITS regions of ribosomal DNA. Eleven species including Viz. Bipolaris cynodontis (48 isolates), B. sorghicola (16 isolates), B. maydis (17 isolates), B. sorokiniana (seven isolates), B. bicolor (four isolates) and B. oryzae (two isolates), Curvularia spicifera (19 isolates), C. papendorfii (ten isolates), C. ellisii (two isolates), and C. hawaiiensis (one isolate) were identified. Pathogenicity test of the species were performed on four to six leaf stage of corn, sorghum and sugarcane seedlings. Finally, pathogenicity of B. maydis, B. sorokiniana and B. oryzae on corn and B. sorghicola on sorghum seedlings were confirmed. This is the first report of occurrence and pathogenicity of B. sorokiniana and B. oryzae on corn leaves in Iran.
Vahid Khosravi; Mohammad Javan Nikkhah; Hossein Saremi; Shahram Naeimi; Rasoul Zare
Abstract
During survey of rice fields in Fars and Khuzestan provinces at mature grain stage, 42 seed samples were collected. Fusarium isolates were obtained from these samples by planting seeds on selective Fusarium medium (Pepton-PCNB-Agar, PPA) by two methods i.e.; surface sterilization by sodium hypochlorite ...
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During survey of rice fields in Fars and Khuzestan provinces at mature grain stage, 42 seed samples were collected. Fusarium isolates were obtained from these samples by planting seeds on selective Fusarium medium (Pepton-PCNB-Agar, PPA) by two methods i.e.; surface sterilization by sodium hypochlorite (NaClO 1%) and without disinfection. Cultivated samples were kept in incubator at 25±1° C and intermittent light (12 hours of light and 12 hours of darkness). Morphological identification of 26 purified Fusarium isolates was performed on the WA, PDA, CLA and SNA. Phylogenetic relationships of 18 isolates on the basis of TEF1-α gene region and ITS1-5.8S-ITS2 region sequences were investigated. The results revealed that Fusarium isolates belonged to two species complexes FIESC (Fusarium incarnatum-equiseti species complex, 50%) and GFSC (Gibberella fujikuroi species complex, 46%). Fusarium fujikuroi species in Fars and F. semitectum species in Khuzestan were most frequent. Two species F. fujikuroi and F. andiyazi belonging to the GFSC species complex were identified in two separate clades in phylogentic tree based on TEF1-α. On the basis of TEF1-α gene, F. merismoides was not identified, but the ITS region sequence was identified as Fusicolla acetilerea and differentiated this species from Fusarium species in the phylogenetic tree.
Fatemeh Salimi; Mohammad Javan Nikkhah; Fereydon Padasht Dehkayi; Alireza Alizadeh; Hasan Soltanloo; Sareh Yosefirad
Abstract
In order to assess the dynamic of Pyricularia oryzae at leaf and panicle neck blast stages, population genetic structures of the 142 isolates were investigated in a rice field and at three levels using SSR markers and five primer pair combinations. All the isolates were collected from the two-leaf and ...
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In order to assess the dynamic of Pyricularia oryzae at leaf and panicle neck blast stages, population genetic structures of the 142 isolates were investigated in a rice field and at three levels using SSR markers and five primer pair combinations. All the isolates were collected from the two-leaf and panicle stages at three levels. In the first level, isolates collected from leaf and panicle neck blast stages in the rice field were analyzed. In the second level, isolates belonged to the leaf and panicle neck populations were collected from tillers of the same rice hill and analyzed. In the third level, the ienvestigated isolates belonged to three populations and were obtained from three distinct leaf spots from the same rice leaf in a rice tiller. Based on constructed dendrogram for all of the 142 isolates, genetic similarity varied from 89 to 100% among the isolates. Population genetic estimations at the three studied levels showed that the amount of gene flow was 57.62, 10.68, and 4.783, respectively between the isolates. Detection of mating type idiomorphs of the studied isolates using multiplex PCR showed that all the isolates had Mat1-1 idiomorph. This indicates the absence of sexual reproduction within the M. oryzae populations in rice fields in Guilan province and the fungus reproduces only in an asexual way. Low genetic variation and high genetic similarity among the populations of the causal agent of rice blast disease in Guilan province confirm this result.
Leila Ebrahimi; Khalil-Berdi Fotouhifar; Mohammad Javan Nik Khah; Mohammad-Reza Naghavi
Abstract
Apple scab disease caused by Venturia inaequalis is the most important economic disease worldwide where the apple is grown and causes annual epidemics. It reduces the quality and quantity of the yields in different regions of Iran. In this study, diversity and population genetic structure of V. inaequalis ...
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Apple scab disease caused by Venturia inaequalis is the most important economic disease worldwide where the apple is grown and causes annual epidemics. It reduces the quality and quantity of the yields in different regions of Iran. In this study, diversity and population genetic structure of V. inaequalis were surveyed on different apple cultivars using 18 microsatellite markers. 51 isolates were obtained from infected leaf and fruit specimens from wild apple, Iranian endemic and commercial apples from Northern provinces of Iran (Mazandaran, Golestan and Guilan). 28 SSR primers were used to investigate the genetic diversity of this pathogen. Among them, 18 primers showed polymorphism between isolates and populations. AMOVA analyses revealed that 97% of the variation was distributed among individuals within populations, and 3% was attributable to the differences among populations. Gene diversity indexes including Nei’s gene diversity, Shannon index and allele numbers in every population showed that diversity within the population on endemic cultivars is more than the diversity in the population of wild and commercial cultivars. Also, the population of commercial cultivars has more diversity in comparison with the wild population. High genetic diversity within the populations is caused by annual sexual reproduction, gene flow between populations and probably the existence of this fungus for a long time in this region.
Reza Heidarian; Khalil-Berdi Fotouhifar; Amir-Hossein Mohammadi; Mohammad Javan Nik Khah
Abstract
Pistachio die-back disease is an important disease in Iranian pistachio orchards. One of the most important fungal agents of the disease is Paecilomyces which has been recently identified as P. formosus based on phylogenetic and physiologic studies. In this study, four pairs of primers designed using ...
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Pistachio die-back disease is an important disease in Iranian pistachio orchards. One of the most important fungal agents of the disease is Paecilomyces which has been recently identified as P. formosus based on phylogenetic and physiologic studies. In this study, four pairs of primers designed using mating type idiomorph sequences of P. variotii deposited in GenBank (NCBI). Designed primers were tested in some isolates of P. formosus and finally two primer pairs including; Mat1-1f224 and Mat1-1r224 for amplification of Mat1-1 and Mat1-2f165 and Mat1-2r165 primers for amplification of Mat1-2 idiomorphs were selected. Mating type idiomorphs were amplified in 124 isolates of P. formosus which have been obtained from pistachio trees and eight other species including; Pistacia mutica, Punica granatum, Prunus amygdalus, Caesalpinia gilliesii, Nerium oleander, Tamarix aphylla, Tamarix hispida, Haloxylon sp. and air of pistachio orchards. In 50 isolates (40.3%) Mat1-1, in 59 isolates (47.6%) Mat1-2 and in 15 isolates (12.1%) both idiomorphs were identified. 16 isolates from each mating type and three isolates which had both idiomorphs were selected and crossed in all of the possible combinations on PDA culture medium and cultures were incubated at 25 °C in continuous dark condition. After eight months, sexual reproduction was not observed in crosses.
Saeideh Jafarpour; Khalil-Berdi Fotouhifar; Mohammad Javan-Nik Khah; Mohhamad Reza Asef
Abstract
During September to November 2010-2012, 17 fruiting body specimens of Armillaria were collected from diverse forest sites in Guilan, Mazandaran and Golestan Provinces (Iran) and 24 basidiocarp derived isolates were obtained. Mating tests were performed using 10 Iranian representative isolates and 12 ...
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During September to November 2010-2012, 17 fruiting body specimens of Armillaria were collected from diverse forest sites in Guilan, Mazandaran and Golestan Provinces (Iran) and 24 basidiocarp derived isolates were obtained. Mating tests were performed using 10 Iranian representative isolates and 12 European tester strains of European species including A. mellea, A. gallica and A. cepistipes. Crossing tests were also used for identification of interspecific and intraspecific separation criteria. In the mating test of a total number of 360 interspecific crosses, Iranian isolates were divided into two A. mellea and A. gallica groups. Hemi-compatible and compatible reactions were found in 126 interspecific crosses. Analysis of crosses demonstrated clear separation for both MFF (mycelial fusion frequency) and BLF (black line frequency) and also change in culture morphology. Mating data clearly distinguished three species including A. mellea, A. gallica and A. cepistipes and defined sexual compatibility of Iranian species with their European counterparts. In spite of close phylogenetic relationship between Iranian A. gallica and A. cepistipes, it also represented a significant clear cut based on the sexual fertility. The results suggest that biological species concept in these fungi consist of using both somatic and sexual compatibilities that still can be used in case of selection of a proper pattern of isolates.
Hossein Taheri; Mohammad Javan Nikkhah; Seyed Ali Elahinia; Seyed Akbar Khodaparast; Morteza Golmohammadi
Abstract
Citrus dieback and postbloom fruit drop caused by Colletotrichum gloeosporioides are common diseases of citrus trees in North of Iran. According to increasing of disease damage in recent years, which can be due to the genetical alteration of pathogen, genetic structure of the fungus population in North ...
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Citrus dieback and postbloom fruit drop caused by Colletotrichum gloeosporioides are common diseases of citrus trees in North of Iran. According to increasing of disease damage in recent years, which can be due to the genetical alteration of pathogen, genetic structure of the fungus population in North of Iran was studied. So, four citrus orchards in Rahim Abad (Guilan), Ramsar, Sari and Gorgan were surveyed and. symptomatic tissues were sampled. After identification of fungal Isolates, DNA fingerprinting for144 Isolates were done by seven ISSR markers and PCR method. Acording to cluster analyses by UPGMA method and Jacard coeficient, thirteen groups were found. The mean of gene and genotype diversities across all populations were 0.33 and 0.49 respectively. There were low genetic differentiation (0.127) among populations and high gene flow (3.437) proved the low genetic differentiation. Maximum genetic identity observed between Guilan and Gorgan and the minimum observed between Ramsar and Sari populations. Distance between Rahim Abad and Ramsar is less than between Ramsar and Sari. So, genetic distance between Guilan and Ramsar and between Ramsar and Sari populations correlated to their geographical distance, but it was irregular for Guilan and Gorgan isolates. According to this study C. gloeosporioides populations derived from citrus orchards in North of Iran have genetic diversity and low genetic differentiation and Genetic distance among populations confirm the high gene flow among them.
Sudabeh Bozorgmanesh; Khalil-Berdi Fotouhifar; Mohammad Javan Nik Khah
Abstract
In order to study of mycelial compatibility of Valsa sordida isolates on two culture media including potato dextrose agar and oat meal agar, 91 isolates that were collected from different provinces in 2004 and 2011 were used. In the prepared test, each isolate was paired with itself and with any of the ...
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In order to study of mycelial compatibility of Valsa sordida isolates on two culture media including potato dextrose agar and oat meal agar, 91 isolates that were collected from different provinces in 2004 and 2011 were used. In the prepared test, each isolate was paired with itself and with any of the other isolates. Dark barrage zone that shows incompatibility between two isolates, were observed seven days after parings. According to the results, thirty-eight single mycelial compatibility (MC) groups and eight multi-merge groups were identified on PDA culture medium and twenty-five single m-c groups and ten multi-merge groups on OMA culture medium were detected, showing the existence of high genetic diversity among the fungal isolates. In this study, no relationship between obtained MC groups on two culture media with geographic distribution and host plant origins of the fungal isolates was observed.
Bahar Karimian; Mohammad Javan Nikkhah; Doostmorad Zafari; Khalil Fotoohifar; Shahram Naiemi
Abstract
Strains of Trichoderma harzianum s. l. have a great importance because of affecting mankind by being used as biological control agents against plant pathogens. In the present study, we planned to characterize the phylogenetic structure of T. harzianum recovered from different geographical origins and ...
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Strains of Trichoderma harzianum s. l. have a great importance because of affecting mankind by being used as biological control agents against plant pathogens. In the present study, we planned to characterize the phylogenetic structure of T. harzianum recovered from different geographical origins and various habitats in some climates of Iran (NC, SCD, CSW). In order to screen 239 collected Trichoderma isolates, the strains were pre-screened by RAPD-PCR, and representatives were selected for sequencing of ITS1-5.8 s-ITS2 genomic region. Totally, 176 T. harzianum isolates were obtained. Fourteen phylotypes were found as a result of maximum parsimony analysis of 76 ITS1 and ITS2 sequences related to T. harzianum, including one single-member phylotype representing a novel ITS allele for T. harzianum, endemic to Iran. Finding a unique ITS allele of T. harzainum in climate CSW may be an indicative of the effective role of this kind of climatic conditions on arising this new ITS allele.
Hasan Momeni; Mohammad Javan-Nikkhah; Mohammad Razavi; Mohammad Reza Naghavi
Abstract
Tan spot disease of wheat with the causal agent of Pyrenophora tritici-repentis is a very serious disease throughout the world causing severe yield losses. Out of 163 isolates of the pathogen, collected from Golestan and Mazandaran provinces, 58 were selected for a study of population genetic structure. ...
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Tan spot disease of wheat with the causal agent of Pyrenophora tritici-repentis is a very serious disease throughout the world causing severe yield losses. Out of 163 isolates of the pathogen, collected from Golestan and Mazandaran provinces, 58 were selected for a study of population genetic structure. Selecting the real representatives from the whole population was carried out according to the results of the rep-PCR with BOX primers, and as well the locations of the isolates and the fields where the isolates had been collected. Population genetic structure of the pathogen was evaluated using rep-PCR as a molecular marker with three primers namely BOX, ERIC and REP. Three softwares of POPGENE, NTSYS-pc and GenALEx6 were utilized for data analysis. Population structure study among six sub-populations of the Iranian isolates revealed that 73% of the total variance was related to the variations within sub-populations while 27% of that related to the variance among sub populations. Mean gene diversity of the population was estimated as 0.3147. A dendrogram, based upon genetic similarity with Dice coefficient and UPGMA method showed no clear separations among isolates belonging to different races 1 and 2, so racial distribution of isolates is not found consistent with rep-PCR classification of the isolates in the dendrogram. There exists some consistency between geographical origin of the isolates and their genetic similarity. This is the first study covering population genetic structure of P. tritici-repentis in Iran. An evaluation of telemorph production regarding the pathogen, showed that pseudothecia (with asci and ascospores) were produced for 54% of the isolates while 17% of the isolates produced pseudothecia without asici and 29% while produced no sexual structures. It seems that beside the MAT gene and some other independent genetic factors, some macronutrients as well as humidity effect telemorph production.
Mansoureh Rahimi; Seyed Kazem Sabbagh; Mohammad Javan Nikkhah; Hasan Soltanloo; Mohammad Salari; Naser Panjehkeh
Abstract
Ascochyta blight caused by Ascochyta rabiei is one of the most destructive diseasesaffecting chickpea (Cicer arietinum). To study the genetic diversity of the fungus, fifty threeisolates were rendomly collected from chikpea fields in eight different regions of LorestanProvince namely Azna, Aleshtar, ...
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Ascochyta blight caused by Ascochyta rabiei is one of the most destructive diseasesaffecting chickpea (Cicer arietinum). To study the genetic diversity of the fungus, fifty threeisolates were rendomly collected from chikpea fields in eight different regions of LorestanProvince namely Azna, Aleshtar, Broujerd, Poldokhtar, Chegeni, Khoorramabad, Koohdasht,Noorabad.The isolates were cultured and purified on specific chickpea seed meal dextrose agarmedium. Genetic diversity among the population was assayed, employing SSR marker andusing five specific primer pairs. Similarity of the isolates was determined using Dice'scoefficient and UPGMA clustering method. Cluster analysis of data revealed that isolates withgenetic similarity distance equal to 3% were placed in 9 distinct genetic groups. PCoA analysisof data was done employing Jaccard similarity matrix in NTSYS software. According to theacquired data, from among 53 components, 15 components stood within an Eigenvalue greaterthan 1 with 90.49 % of variation being justified. Analysis of molecular variance (AMOVA)revealed the highest genetic variation (96%) within populations while distributed amongpopulations by 4%.The results finally indicated that there is considerable genetic diversityamong and between the isolates collected from different regions of the province.
minoo bargnil; mohammad javan nikkhah; seyed mahmood okhovat; keyvan ghazanfari
Abstract
A determination of the genetic variation of the fungus isolated from graminous weeds which is highly beneficial to know probable genetic recombination in the fungus populations was done for the first time in Iran through PCR reaction. The isolates of fungus “Magnaporthe grisea” from graminous weed ...
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A determination of the genetic variation of the fungus isolated from graminous weeds which is highly beneficial to know probable genetic recombination in the fungus populations was done for the first time in Iran through PCR reaction. The isolates of fungus “Magnaporthe grisea” from graminous weed hosts and from rice were analyzed through RAPD-PCR to assay the mating type and genetic diversity.Using three random primers of: I, D and H, DNA fragments of 42 isolates were amplified from 220bp to 2500bp. Using cluster analysis and data comparison as based on Dice coefficient four clonal lineages and 20 haplotypes were identified. Similarity of 20% “A” clonal lineage including 29 isolates recovered from Digitaria sp. as well as isolates recovered from unknown weed hosts with “B”,“C” and “D” clonal lineages (including isolates recovered form Setaria sp. Echinocloa sp. of rice isolates) indicates distant relationship of “A” clonal lineage with the other clonal lineages. Forty-eight single-spored isolates of weeds and of rice were crossed with eight fertile hermaphrodite standard isolates on medium culture assay the mating type. Among Echinochloa sp. and Setaria sp. isolates Mat1-1 and among isolates of Digitaria sp. Mat1-2 were the dominant ones. Mating type of isolates recovered from rice was determined as Mat1-1. Weed isolates especially isolates obtained from Setaria sp. had high fertility as all Setaria sp. isolates produced ascospores in crosses. Mating type of 34 isolates was determined using PCR technique and two pairs of specific primers by the names of L1, L2,T1 and T2 verified the results of the mating experiments.
Mohsen Farzaneh; Masoud Ahmadzadeh; Alireza Ghasempour; Mansoureh Mir-Abolfathi; Mohammad Javan Nikkhah; Abbas Sharifi-Tehrani
Abstract
Aflatoxin is one of the most hazardous mycotoxins injurious to both humans and animals. Aflatoxin contamination of crops is a serious economic loss inflicted upon agriculture, food and animal industry throughout the entire world. In nature, there are microorganisms able to alleviate aflatoxin contamination ...
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Aflatoxin is one of the most hazardous mycotoxins injurious to both humans and animals. Aflatoxin contamination of crops is a serious economic loss inflicted upon agriculture, food and animal industry throughout the entire world. In nature, there are microorganisms able to alleviate aflatoxin contamination in crop products. In this work, the effects of four strains of Bacillus subtilis in reducing aflatoxin, induced by Aspregillus flavus, were investigated under in vitro conditions. The results indicated that strain BsP1 could completely inhibit the mycelial growth of A. flavus in PDB liquid medium. Strains BsP4, BsP5 and BsP38 caused a mass reduction of 58.88, 27.41 and 29.03% of fungal biomass, followed by 86.85, 21.80 and 26.16% reduction of aflatoxin B1 (AFB1), respectively. There also was a negative significant correlation observed between the decrease in fungal biomass and AFB1 production. Bioremediation studies revealed that the bacteria didn’t have the ability to remediate AFB1 after 3 days of incubation. However, the strain BsP1 could completely remediate AFB1 even after 5 days of incubation. Cell walls of these bacterial strains showed no sign of an ability for binding and removing of AFB1. The supernatant fluid of strain BsP1 was considerably able to degrade AFB1. The results finally suggest that the promising isolate of B. subtilis is of the potential to reduce aflatoxin in susceptible crops, possibly through antibiosis and degradation mechanisms.
Parastou Motalebi; Mohammad Javan-Nikkhah; Seyed Mahmoud Okhovat; Khalil Berdi Fotouhifar
Abstract
Thirty five monoconidial isolates of the fungal culture collection Pyricularia grisea were examined, to identify the vegetative compatibility groups and characterize the genetic diversity of isolates as through rep-PCR genomic fingerprinting. The isolates were collected from ricefields during 1997-1999. ...
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Thirty five monoconidial isolates of the fungal culture collection Pyricularia grisea were examined, to identify the vegetative compatibility groups and characterize the genetic diversity of isolates as through rep-PCR genomic fingerprinting. The isolates were collected from ricefields during 1997-1999. Genetic diversity of P. grisea isolates was studied as based on DNA fingerprinting through rep-PCR using two primers previously designed based on the nucleotidal sequence in ERIC and BOX regions. They generated variable length fragments ranging from 400 to 2500 bp. Phenetic analysis let to differentiation of four distinct clonal lineages designated as A to D. Clonal lineage A with 74.28% frequency, constituted the largest fingerprinting group. For VCG analyses nit mutants were obtained from fast growing sectors on Minimal Medium (MM) containing 5% potassium chlorate. Complementation between nit mutants of isolates was tested on MM. Four vegetative compatibility groups were determined including VCG1, VCG2, VCG3 and VCG4. Group VCG3 comprised of 14 isolates was the dominant VC group among others. This study revealed that isolates obtained from rice were designated in the four VC groups forming heterokaryon with each other; however these isolates were separated with more than 80% similarity from each other using rep-PCR marker with most of isolates being VCG3 were determined in A clonal lineage. Both VCGs and rep-PCR analyses determined low genetic diversity in P. grisea population from rice.
Abd-allah Ahmadpour; Youbert Ghosta; Mohammad Javan-Nikkhah; Mohammadreza Fattahi; Keyvan Ghazanfari
Abstract
To determine the specificity and host range of Wilsonomyces carpophilus isolates, some stone fruit seedlings (Prunus armeniaca, Prunus dulcis, Prunus reuteri, P. vulgaris, P. domestica, P. persica, P. avium and P. cerasus), pome fruits (Malus communis, Pyrus communis, Crataegus azarollus and Crataegus ...
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To determine the specificity and host range of Wilsonomyces carpophilus isolates, some stone fruit seedlings (Prunus armeniaca, Prunus dulcis, Prunus reuteri, P. vulgaris, P. domestica, P. persica, P. avium and P. cerasus), pome fruits (Malus communis, Pyrus communis, Crataegus azarollus and Crataegus monogyna) as well as ornamental plants (Rosa persica, Rosa sp. and R. damascena) were selected for pathogenicity tests under greenhouse conditions. Five isolates from five different hosts (apricot, almond, plum, peach and sweet cherry) were taken for pathogenicity tests on ten leaf-seedlings under 20±2?C and relative humidity of more than 75%, using atomized 105 conidial suspensions. The results showed that all isolates caused disease on Prunus seedlings. No specificity was observed between isolates and hosts. Pale brown to black lesions were observed on some of the pear leaves and twigs, and as well on apple and hawthorn leaves after 4 days past of inoculation. Lesions did not expand or abscise and there was no sporodochium observed on leaves even after 20 days past, so that, pear, apple and hawthorn were not determined as important hosts of the fungus. In addition, symptoms were not observed on the ornamental plants and on whitethorn, raising the expectation that the fungus is limited to stone fruits. Appearance of disease symptoms on almond, plum, peach and nectarine, and on apricot twigs in orchards, infection of plum and apricot twigs in greenhouse and isolation of fungus from these are the first reports from Iran. To evaluate the relative resistance of nine peach cultivars to tree fungus isolates, as based on the number of lesions per 10 cm2 of leaf surfaces, tests were carried out under greenhouse conditions (20±2?C and relative humidity of more than 75%). The results indicated that there were significant differences among relative resistance of cultivars and among isolates' pathogenicity. Redtop, Springcrest and Early Elberta cultivars were resistant, whereas, Dixired cultivar was recorded as highly susceptible.
Fariborz Lotfi miri; Mohammad Javan Nikkhah; Hamdireza Zamanizadeh; Fereydoun Padasht Dehkaei
Volume 42, Issue 1 , June 2011, , Pages 61-74
Abstract
To study the population structure of Gibberella fujikuroi species complex, the causal agent of rice foot rot, samples were taken from different rice growing regions of Guilan province in 2004. Among fourty-one isolates recovered from different cultivars; three isolates did not produce microconidial chain. ...
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To study the population structure of Gibberella fujikuroi species complex, the causal agent of rice foot rot, samples were taken from different rice growing regions of Guilan province in 2004. Among fourty-one isolates recovered from different cultivars; three isolates did not produce microconidial chain. In order to study the sexual fertility and determine the mating type as well as mating population among isolates, each isolate was crossed with six female tester isolates from three known mating populations of A, C and D on Carrot Agar (CA) medium. Two tester isolates from two opposite mating types including MATA-1 and MATA-2 for mating population A, MATC-1 and MATC-2 for mating population C as well as MATD-1 and MATD-2 for mating population D were taken to pair with Iranaian isolates. As a result, ten isolates in mating population A (Fusarium verticillioides), two isolates in mating population C (F. fujikuroi) and twenty-nine isolates in mating population D (F. proliferatum), were grouped. All the F. verticillioides and F. fujikuroi isolates belonged to MATA-1 and MATC-1 mating type, while both MATD-1 and MATD-2 mating types were identified among F. proliferatum isolates. Because of the presence of both mating types among mating population D isolates, mating possibility was studied among them. Among thirty-six crosses between these isolates, only two led to formation of perithecium containing ascospores. Vegetative compatibility tests revealed that ten F. verticillioides isolates belonged to nine Vegetative Compatibility Groups (VCGs), two F. fujikuroi isolates were grouped in two distinct VCGs each with one member and twenty-nine isolates which belonged to F. proliferatum were divided into twenty VCGs. In complementation tests among nit mutants of isolates the isolates belonging to three mating populations failed to form heterokaryons. Pathogenicity test related to fourty-one isolates was done on the susceptible cultivar Khazar in which all the isolates caused disease symptoms with white colonies on the stems. In this investigation it was demonstrated that all the three mating populations A, C and D from G. fujikuroi species complex were the causal agents of rice foot rot in Guilan paddy fields. Moreover, based on vegetative compatibility tests, each of the mating populations A and D showed high genetic diversity, the existence of several single-member VC groups confirming this conclusion.
Vahid Zarrinnia; Mohammad Javan Nikkhah; Hamdireza Zamanizadeh; Rahim Mehrabi; Vahid Khosravi
Volume 42, Issue 1 , June 2011, , Pages 179-190
Abstract
Thrity seven isolates of Magnaporthe grisea collected from several host plants from family of Poaceae namely Digitaria singuinalis, Setaria italica, and Echinochloa sp.were tested for their pathogenecity against two susceptible rice cultivars. Conidial suspensions were prepared by the surfaces of 14-day-old ...
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Thrity seven isolates of Magnaporthe grisea collected from several host plants from family of Poaceae namely Digitaria singuinalis, Setaria italica, and Echinochloa sp.were tested for their pathogenecity against two susceptible rice cultivars. Conidial suspensions were prepared by the surfaces of 14-day-old cultures being washed with sterile water and adjusting the final concentrations to approximately 5×104 conidia per ml with the aid of hematocytometer. Inoculums were applied to the leaves of 3 week-old plants and symptoms scrutinized 10 to 12 days following inoculation. Moreover, to confirm the outcomes of the test, the survey of the infection of the leaves was recapitulated after a 5 days interval. Pots each containing sixty seedlings of either Binam or Tarom rice cultivars were sprayed with 50 ml suspension of 5×104 conidia per ml from either pure cultures of the M. grisea or water, with a hand-held mist sprayer (until runoff) onto rice plants that were at a four-to-five-leaf stage. Inoculated plants were incubated in a humidity chamber and maintained at 100% relative humidity (RH) for 48 h and then reincubated in a greenhouse (20 to 24°C). Also negative and positive control plants were sprayed with distilled water and with rice infecting isolate respectively in the same manner. After 10 to 12 days past, leaf spot symptoms appeared on some inoculated plants. Then five virulent and semi virulent isolates as based upon their interaction with rice were analyzed for pathogenic races. In total 13 cultivars and lines (eight varieties differentiated through international standard cultivars and five through Near Isogenic Lines (NILS)) were examined. The last five isolates were classified in four pathogenic races IB-58 ,IA-27, IA-127, IA-17 that belonged to two race groups IA and IB as based on their virulence on eight international differential varieties, and in A, B, C, D as based on their virulence on five Near Isogenic Lines (NILS).
Khoshnoud Noorolahi; Mohammad Javan Nikkhah; Mohammadreza Naghavi; Seyed Mahmoud Okhovat
Volume 41, Issue 2 , March 2011, , Pages 187-193
Abstract
Pathogenic diversity in Didymella rabiei in Ilam and Kermanshah provinces was assessed with the objective of finding out about the existence of pathotypes. One hundred isolates from different farms of chickpea growing regions in these provinces were collected in 2007. Isolates were arranged into ten ...
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Pathogenic diversity in Didymella rabiei in Ilam and Kermanshah provinces was assessed with the objective of finding out about the existence of pathotypes. One hundred isolates from different farms of chickpea growing regions in these provinces were collected in 2007. Isolates were arranged into ten different groups based upon their sampling regions. One isolate was chosen from anyone of the ten groups as the representative isolate one. Pathogenecity of the selected isolates was conducted on a set of seven chickpea differential hosts in glasshouse conditions. Reaction types of the ten isolates were studied one month past inoculation and on the basis of a 9 point scale. Based on disease reaction on differential hosts in accordance with disease reaction pattern on differential lines in ICARDA, three pathotypes were identified. The pathotypes included: pathotype 1 from Mehran, Ivan in Ilam province, Gilanegharb, Ghasrshirin, Sararoud and Sahneh in Kermanshah province; pathotype 3 from only Darahshahr in Ilam province, and finally pathotype 6 from Abdanan, Shirvan Chardavol in Ilam province and from Sarpolezahab in the province of Kermanshah.
Mona Khansari Atigh; Mohamad JavanNikkhah; Akbar Khodaparast; Mariyeh Babri; Keyvan Ghazanfari
Volume 41, Issue 1 , September 2010
Abstract
Glomerella cingulata is the causal agent of anthracnose disease on citrus that attacks weakened trees. The sexual stage is rare in nature but can be produced in laboratory under certain conditions. Sixty-seven single-spore isolates were selected from citrus in Mazandaran province to be used in this study. ...
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Glomerella cingulata is the causal agent of anthracnose disease on citrus that attacks weakened trees. The sexual stage is rare in nature but can be produced in laboratory under certain conditions. Sixty-seven single-spore isolates were selected from citrus in Mazandaran province to be used in this study. Isolates were cultured on YPSS for investigating heterothallism and homothallism. To understand homothallism of isolates, they were cultured on YPSS alone and then placed at 21?C with 12h dark and 12h light for 15-21 days. An 8.8% of isolates were homothallic, while others were paired in YPSS of the above conditions to be investigated for heterothallism. 25% of the isolates were found as heterothallic. Perithecia of smooth walls along with necks were produced. Asci were in groups with any ascus containing 8 one celled ascospores. For VCG determination, forty one isolates were employed. Isolates were cultured on 5% MMC for selecting nit mutants. Two isolates could not grow on MMC and were found as wild types. After selecting nit mutants, they were cultured in media of different nitrogen sources for detecting phenotypes of nit mutants. The maximum percentage of nit occurred in the case of nit 1 (66%). Nit 3 was 56% and nit M 53%. The inter-isolate combinations started in MM among different nits of any isolate with two HSI isolates being found. Other 37 isolates were crossed together with different nits on MM with all the cultures being placed at 25?C in the dark. Thirty five VCGs were identified. The isolates that produced perithecium were different from the ones producing heterokaryons. Sexual stage along with sexual fertility is one of the factors of diversity that ended up with many groups in vegetative compatibility.
Elham Mohamadian; Mohamad JavanNikkhah; Seyed Mahmoud Okhovat; Keyvan Ghazanfari
Volume 41, Issue 1 , September 2010
Abstract
Fertility status and distribution of mating type alleles of Gibberella moniliformis and G. intermedia, both the causal agents of the foot rot and bakanae of rice, as well as stalk and root rot of corn were studied using specific primers. One hundred and twenty eight single-spore isolates were collected ...
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Fertility status and distribution of mating type alleles of Gibberella moniliformis and G. intermedia, both the causal agents of the foot rot and bakanae of rice, as well as stalk and root rot of corn were studied using specific primers. One hundred and twenty eight single-spore isolates were collected from rice growing areas of Guilan and Mazandaran and from various corn-growing areas of Iran. Sixteen isolates of G. moniliformis from rice and 54 isolates from corn, 28 isolates of G. intermedia from rice and 30 isolates from corn were taken into account for the study. Also 30 isolates of G. intermedia from corn and 12 isolates from rice, 5 isolates of G. moniliformis from rice were paired with standard tester isolates. A multiplex PCR technique was employed to distinguish idiomorphs MAT-1 and MAT-2 by using two pairs of specific primers GFmat1a, GFmat1b, and Gfmat2c, Gfmat2d. Among 68 isolates of G. moniliformis, 47 (69%) were identified as MAT-1 and 21 isolates (31%) belonged to MAT-2. Among 53 isolates 0f G. intermedia, 33 (62%) were identified as MAT-1 and 20 isolates (38%) belonged to MAT-2. Among 42 isolates of G. intermedia which were crossed with tester isolates, 26 (62%) were MAT-1 and 16 (38%) were MAT-2. The results of PCR were similar to those predicted as based on the results of crosses. Field isolates belonging to MAT-1 and MAT-2 were crossed with each other but no perithecium was formed. This indicated that all the isolates are female-sterile or male-fertile. The existence of both opposite mating type alleles with favorable frequency and different parents is an important occurrence of genetic diversity in the population of fungi. With regard to that, two mating type alleles found in the studied populations were of relatively high frequency of MAT-1 but because of the low level of female-fertile, occurrence of genetic diversity in the populations of G. moniliformis and G. intermedia coming from rice and corn could be attributed to other mechanisms of variability.
Mariyeh Babari; Mohammad JavanNikkhah; Hosein Taheri; Yaghub Aliyan
Volume 40, Issue 2 , February 2010
Abstract
In recent years, anthracnose disease of citrus has caused and contiunes to cause heavy losses to some citrus commercial tree varieties in Mazandaran Province. This disease is deeply spread out in the citrus orchards of the province. In order to isolate and identify the causal agent or agents of the disease, ...
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In recent years, anthracnose disease of citrus has caused and contiunes to cause heavy losses to some citrus commercial tree varieties in Mazandaran Province. This disease is deeply spread out in the citrus orchards of the province. In order to isolate and identify the causal agent or agents of the disease, random sampling was done from infected trees during 2004-2005. In lab, samples were cultured on PDA medium. From among 119 samples cultured, 96 Colletotrichum isolates were isolated. Based upon morphological and some physiological characteristics as well as on growth optimal temperature, all the isolates were identified as Colletotrichum gloeosporioides. Pathogenicity severity tests with selected isolates were done on detached branches and as well on two-year old Valencia orange (Citrus sinensis (L.) Osbeck), Unshio mandarin (Citrus unshio Marcow) scions in laboratory and in greenhouse, respectively. The results showed that all isolates were pathogenic on two original cultivars. There were significant virulencedifferences observed (at ? = %1) among the isolates. On the basis of virulence, the lab Valencia and Unshios were respectively divided inot 17 and 15 groups, wherease the greenhouse ones (Valencia and Unshios) divided into 7 and 8 (groups) respectively.
Shahram Naeimi; Mahmoud Okhovat; Mohammad JavanNikkhah; Laslou Kredics; Vahid Khosravi
Volume 40, Issue 2 , February 2010
Abstract
Samples were collected from soil and as well from phyllosphere of rice plant and subjected to dilution plate technique on RBSF Trichoderma selective medium. A total of 202 Trichoderma isolates were obtained from rice fields at different geographical locations distributed all over Mazandaran Province. ...
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Samples were collected from soil and as well from phyllosphere of rice plant and subjected to dilution plate technique on RBSF Trichoderma selective medium. A total of 202 Trichoderma isolates were obtained from rice fields at different geographical locations distributed all over Mazandaran Province. Single spore isolates were obtained and genomic DNA extracted from all the isolates using DNA extraction kit. For an identification of isolates, morphological as well as molecular characteristics were studied. Morphological identifications were accomplished through morphological keys and subsequent descriptions. For molecular identification, the Internal Transcribed Spacer (ITS) region of the rDNA gene complex, including ITS1, the 5. 8S rRNA gene and ITS2 was amplified using primers ITS1 and ITS4. To identify the isolates at the species level, ITS sequence analysis was carried out for all isolates with the aid of the program TrichOKEY 2. The identified isolates belonged to six species of: Trichoderma harzianum, T. virens, T. atroviride, T. hamatum, T. brevicompactum and
T. asperellum. More than 90 percent of the isolates belonged to species T. harzianum and
T. virens. Therefore, these two important biocontrol agent species of plant diseases, are the most common ones occurring in the rice (paddy) fields. T. harzianum is the most dominant Trichoderma species observed in rice phyllosphere while T. virens being more abundant in soil. None of the isolates of the four remaining species were isolated from phyllosphere. In addition, all T. atroviride isolates, except for one, originate from the eastern part of the Mazandaran province.
