فهرست مطالب ناصر امانی فر

Strains of Pseudomonas syringae pv. syringae (Pss) are pathogenic in various types of plants, sometimes causing economic damage that requires chemical control. In Chaharmahal va Bakhtiary province, this pathogen damages stone fruit trees, wheat, beans, and greenhouse plants like cucumber. This study investigated the resistance of 62 Pss strains from different hosts to copper ions (copper sulfate) in a culture medium. Results showed that 37.1% and 32.3% of the strains were resistant to 100 and 200 µg/ml copper sulfate concentrations, respectively. Five copper-resistant strains from peach, almond, cherry, wheat, and beans and one sensitive strain from cucumber, were selected for further evaluation. The effect of various formulations containing copper compounds on inhibiting the growth of these strains in the culture medium was assessed. All five isolates showed varying resistance to copper compounds (copper oxychloride, copper oxide, copper carboxylate, and Bordeaux mixture). Doubling the concentration of these compounds did not significantly affect bacterial growth. However, adding mancozeb, zinc sulfate, or iron sulfate to each copper compound significantly inhibited bacterial growth on the culture medium. The copper carboxylate formulation combined with mancozeb was the most effective inhibition. The CopA gene, responsible for copper resistance, was detected in the five resistant strains and other Pss strains, confirming the results of the experiments. In conclusion, there is resistance to copper compounds in various Pss strains. For effective chemical control, compounds with a synergistic effect on bactericidal activity should be added to copper compounds. The most influential formulation identified in this study for reducing the population of copperresistant Pss strains and controlling diseases caused by them is a combination of copper carboxylate or copper oxide with mancozeb and urea.

Bacterial canker of stone fruit trees caused by Pseudomonas syringae pv. syringae (Pss) interacts with several factors such as ring nematodes. The effect of infection of Mesocriconema xenoplax (Mx) and Pss and co-infection in pot conditions in the greenhouse on peach bacterial canker was investigated on GN and GF677 rootstocks, tolerant and susceptible to Mx, respectively. One-year peach seedlings (cv. Zaafarani), susceptible to Pss, grafted on these rootstocks were used. Infection treatments included nematode inoculation, bacterial inoculation, and inoculation with both pathogens. The experiment was conducted as a factorial in a completely randomized design with five replications. The results were evaluated and compared statistically based on disease severity, bud death, seedling height, root weight, total plant weight, and population of Mx in soil. The results showed a significant difference between GN and GF677 in terms of response to pathogen inoculation (s) based on evaluation indexes. In both vegetative rootstocks, canker severity and dead bud in seedlings co-inoculated with Mx and Pss were more than those only inoculated with Pss alone. In seedlings with GF677 rootstock, in infection with both pathogens, the rate of canker progression up to about 30 cm was measured and dieback was observed. In inoculation with only Mx and Pss, there was a significant difference in plant growth indexes (in both treatments) and nematode population and disease severity between the two rootstocks for inoculation with nematode and bacteria. Therefore, it can be concluded that Mx is a synergistic factor for peach trees (especially at a susceptible rootstock) to aggravate bacterial canker disease caused by Pss.

The lateral bud death disorder in almond (cv. Shahroud 12) is observed in some replanted orchards in Chaharmahal and Bakhtiary province. The abundance of plant parasitic nematodes, phytophthora species and zinc deficiency were more in trees with symptoms than the asymptomatic trees. Experiment was performed in a randomized complete block design with seven treatments including pesticides like fluopyram (Velum Prime®; EC, 41.5%), Abamectin (Vertimec®; EC, 1.8%), Fosetyl-Al + Propamocarb (Previcur Energy®; SL, 840), Fosetyl-Al (Elite®; WDG, 80%), Diazinon (Bazodin®; EC, 60%) , Zinc sulfate (ZnSO4H2O, 33%) and control with five replications on Shahroud 12 cultivar almond trees along Zayandehrood during 2018-2020. A week before the application of chemical treatment and three months later, soil and root samples were collected for the measurement of plant-parasitic nematode population and isolation of Phytophthora species and the zinc content. Four branches per tree were selected from different directions, a week before the chemical treatment and five months later, and  healthy (containing leaf and fruit) and dead buds were counted. The results show the treatments of Velum Prime, Abamectin, Diazinon, Zinc sulfate, Previcor and Elite reduced the bud death and improved the disorder of the almond trees by 66.1%, 53.2%, 36.3%, 33%, 19.3% and 16.9%, compared with the control, respectively. Although compounds with nematicidal properties were more effective in improving this disorder; other treatments were also significantly different compared with control in terms of reducing the symptoms of bud death. The role of other factors in causing this disorder can not be ignored; therefore, the interactional effects of these factors in causing or exacerbating  the symptoms of  bud death of almond (Shahroud 12 cv.) may be more effective than a single cause alone.

Bacterial canker caused by Pseudomonas syringae pv. syringae (Pss) is one of the most important diseases of peach and the use of  chemical pesticides in the control of the disease is inevitable. To determine the most effective formulation of copper bactericides, an experiment was conducted, during 2018-2020, in the form of a randomized complete block design with 20 treatments and 4 replications along the Zayanderood river. The treatments  used included copper oxychloride, copper oxide, copper carboxyl, bordeaux mixtures, fosetyl aluminium, urea and Zinc sulfate. Some treatments included a mixture of the above copper bactericides with urea or zinc sulfate, or both. The effect of the treatments on the incidence and severity of the disease was assessed by scaling the size of the canker in early June.. The first spraying was done in autumn after leaf fall and the second spraying was done before swelling of flower buds in winter. Three weeks after the second spraying, the population of Pss in peach buds was counted by isolation of the bacteria on the culture medium. The best formulations for chemical control of of peach bacterial canker were copper carboxyl or copper oxide plus urea and zinc sulfate compared witht copper bactericides alone. the highest efficacy was observed by copper carboxyl (78.7%), copper oxide (76%), copper oxychloride (48.1%) and Bordeaux mixture (45.6%), respectively, in terms of reducing disease severity. Fosetyl aluminium like copper oxychloride and Bordeaux mixtures, reduced disease severity level. Also, there was a statistically significant difference between application of urea and Zinc sulfate in comparison with the control (P = 0.05).

Persian oak (Quercus branti Lindl) is the most important forest tree of the Zagros mountains. During the recent drought conditions, the oak decline has widely been observed in the areas of Chaharmahal and Bakhtiari Province, especially the town Lordegan. Symptoms include early fall coloration, early leaf drop, vascular discoloration in the twigs (Fig. A-1), drying of the branches, discoloration of the main trunk and branches, cracks and splitting of the trunk, the presence fungal organs as black and olive powdery under the bark (Fig. B-1) and death of the trees. While up to 70% of the trees may suffer from the disease on south-facing slopes (Fig. D-1), north-facing slopes are normally unaffected(Fig. C-1). In 2018, samples of bark, main trunk, and a branch of trees with symptoms (16 specimens) and some specimens (7 specimens) of apparently healthy trees were collected in Lordegan town and isolated by standard methods of isolation of pathogenic fungi on malt agar and potato-dextrose-agar media. The fungal isolates were purified after growth and sent to Botany Research Department of Iranian Research Institute of Plant Protection for identification. Identification results showed that isolates of Biscogniauxia Mediterranea, Paecilomyces cf variotii and Paraconiothyrium sp. are fungi associated with charcoal rot and oak decay in Chaharmahal va Bakhtiari province. From 16 samples with described symptoms, 9 samples of Paraconiothyrium sp, 5 samples of B. mediterranea and 4 samples of Paecilomyces cf variotii were isolated. Two samples of asymptomatic samples were also isolated Paraconiothyrium sp and B. mediterranea.

Winter sunscald is a physiological disorder that causes damage to almond and peach trees in some orchards of Chaharmahal va Bakhtiary province. In orchards with favorable conditions for this disorder bacterial canker was more severe observed. Early symptoms consist of discolored bark, similar to a canker, and some small vertical cracking in the bark. As time progresses, bark will begin to slough off, the death of the trunk and dieback. Symptoms can be seen on the south and southwest sides of the trees. The relationship between winter sunscald and bacterial canker of almond and peach in Chaharmahal va Bakhtiary province was investigated during 2016-2019. This study was conducted in 12 selected peach and almond orchards in different areas of the province. In almonds, disorder index on the southwest side of the trees increased by 83% compared to the northeast side of the trees, while in peaches the increase was about 82.7%. Frequency of isolation of Pseudomonas syringae pv syringae (bacterial canker agent) on the southwest side of the trees was about 78.4% and 75% higher for almonds and peaches, respectively. The southwestern white painting treatment of the trunk compared to the control showed that in almonds it decreased sunscald and canker symptoms in almonds70 to 81% and for peaches56.3 to 86%. So, it can be said that winter sunscald is causes of decline and plays role as a predisposing factor for e bacterial canker of almond and peach trees in Chaharmahal va Bakhtiary province.

Pierce's disease (PD) has been recently reported of Iran. To determine the distribution pattern of this disease, during 2013-2018 years, 365 samples of leaf and stem of grapes of 88 vineyards were collected with PD symptoms. Samples obtained of Iranian grape growing provinces of Fars, Khorasan Razavi, North Khorasan, South Khorasan, Semnan, Alborz, Tehran, Qazvin, Zanjan, West Azarbaijan, East Azarbaijan, Kurdistan, Kermanshah, Lorestan, Kohgiluyeh va BoyerAhmad, Markazi, Hamedan and Chahar Mahal va Bakhtiary. Samples were tested for the presence of Xylella fastidiosa by culturing, DAS-ELISA and PCR assay with X. fastidiosa-specific primers. Pathogenicity tests, for some isolates, were conducted on grapevine (cv. Bidaneh Qazvin) under greenhouse conditions. Early symptoms is leaf scorched, while adjacent tissues turned yellow or red. Some grapes showed “matchstick” symptoms in which the leaves dropped from the plant, while petioles remained attached. Approximately 56%, 44.8% and 7.1% of the samples, by DAS-ELISA, PCR and culturing, were infected to X. fastidiosa, respectively. Although based on DAS-ELISA all of the sampled provinces showed infected to X. fastidiosa, there were by the results of culturing and PCR infected to X. fastidiosa is definitive for some vineyards provinces of Fars, Khorasan Razavi, Alborz, Qazvin, Zanjan, Lorestan, Hamedan and Chahar Mahal-va-Bakhtiary. This mapping obtained the dispersion of PD in vineyards of Iran, and can be used as a distribution guide map of X. fastidiosa for plant protection organization of Iran.

During 2010-2017, samples of different plants grown in greenhouses and crops with sprinkler irrigation systems, in Chaharmahal va Bakhtiary province, showing symptoms of necrotic spots, marginal leaf blight, fruit rot, and wilting were collected and tested for the presence of bacteria associated with those symptoms. The isolated bacteria were identified based on standard methods for the identification of plant pathogenic bacteria. Pathogenicity of strains was tested on appropriate hosts under greenhouse conditions. Although various genera of bacteria were isolated, isolation frequency of fluorescent pseudomonads was more than other genera of bacteria. Fifty-three and a half percent of pseudomonads was identified as Pseudomonas marginalis and 18.2% as P. syringae pv syringae. The isolates of P. marginalis from cucumber, potato, tomato, pepper, wheat, beet, and dieffenbachia and strains of P. syringae pv syringae from cucumber, sugar beet, wheat, and tomato were pathogenic on their respective hosts. Polymerase chain reaction with universal primers 16Sf / 16Sr and R1378 / PO27F, designed for detection of γ-Proteobacteria, confirmed the identity of the isolated bacteria based on biochemical and physiological tests by the alignment of nucleotide sequences in the GeneBank. Phylogenetic analysis based on 16SrDNA gene sequences of 10 isolates of  P. marginalis were differentiated from each other. This investigation showed that strains of P. marginalis can  bepotential pathogens for greenhouse plants and field crops  with sprinkler irrigation.

At present, replant disorder and peach (Prunus persica (L.) Batsch) short life has become an important problem in peach production, and it has seriously restricted the development of the peach industry in Chahar Mahal va Bakhtiary province. During 2014-2017, 108 samples of plant tissues and rhizosphere were collected from the peach orchards of this province. Samples were investigated to isolation and identification microorganisms and pathogens associated with symptoms of peach replant problem. Symptoms including: yellowing, stunting, abscission of leaf, leaf discoloration and chlorosis, crown and root rot, canker and death of young trees. From plant and soil samples, the frequency respectively, isolates of Bacillus sp, Fusarium sp, Pseudomonas flourescens, Mesocriconema xenoplax, Aspergillus sp, Alternaria sp, Pantoea agglomerans, Arthrobacter sp, Phytophthora sp, Pseudomonas syringae, Pseudomonas putidae, Verticillium dahliae, Dematophora necatrix, Trichoderma sp, Streptomyces sp, Meloidogyne sp, Pratylenchus sp, Paratylenchus sp, Stenotrophomonas maltophilia, Pythium spand Rhizoctonia spwere isolated and identified. About 11% of isolates were unknown. The amount of replant disorder and isolation of these microorganisms in orchards that were planted immediately after the destruction of previous trees or planted the same previous species was about 30% more than the orchards that had not been cultivated (fallow) for at least one year. On this basis canbe say these microorganisms are the most important agents associated with replant problem and life short in peach orchards in Chahar Mahal va Bakhtiary province. Koch's postulates investigations are necessary to determine the role of these microorganisms in this replant disease

Viral diseases are among the most important diseases of wheat in Chahar Mahal Va Bakhtiari province. During 2005-2008 growing seasons, the efficacy of seed treatment with imidacloprid and thiamethoxam on three cultivars of wheat were tested for the control of viral diseases, including: Barley yellow dwarf virus (BYDV-PAV and BYDV-MAV serotypes), Cereal yellow dwarf virus (CYDV-RPV serotype), Wheat dwarf virus (WDV), Iranian maize mosaic virus (MIMV), Barley yellow striate mosaic virus (BYSMV) and Wheat streak mosaic virus (WSMV), with natural vectors under field condition in Shahrekord. The experimental design was a split plots arrangement of a randomized complete block with four replications. Disease incidence was determined based on the percentage of plants exhibiting symptoms and ELISA test. At harvest, data was collected on yield and yield components. Results showed that seed treatment insecticides increased grain yield and yield components, with significant reduction occur BYDV-PAV, BYDV-MAV, CYDV-RPV, WDV, IMMV and BYSMV in wheat plants compare with untreated control, while occur WSMV was not affected. “Shahriar” wheat cultivar treated with imidacloprid was the most effective treatment for control of viral diseases. The effect of seed treatment with imidacloprid was higher than thiamethoxam. Occurrence virus diseases on Alvand cultivar was more than other cultivars. The amounts of infection to WSMV, BYDV-PAV, CYDV-RPV, WDV, BYSMV, BYDV-MAV and MIMV in seed treatment plots were from highest to lowest (in descending order).

Fusarium root rot of common bean, caused by Fusarium solani f. sp. phaseoli (Fsp), is a major disease of this crop in Iran. In this study 13 commercial cultivars and genotypes in 3 types of common bean were evaluated for resistance to Fusarium root rot under greenhouse conditions. The investigation was conducted as a factorial experiment in a completely randomized design with three replications under conditions with and without drought stress. The reaction of cultivars and genotypes were evaluated based on measuring disease severity (root necrosis) and some growth parameters. Results showed a significant difference in yield components of different cultivars and the impact of Fsp on evaluated parameters. Cultivars in response to Fsp without drought stress were divided into three groups: 1. Weak infection: Sadri, Joneghan, Kosha, Sayad, 2. Moderate infection: Talash, Akhtar, D81083, Ghafar, Lordegan, Dorsa and 3. Severe infection: Pak, Shekofa, Daneshkadeh. Generally, the most, moderate and least sensitive varieties were belonged to white bean, pinto (Chiti) bean and red kidney bean cultivars, respectively. Under drought stress conditions except for Sadri and Sayad which showed moderate of disease severity, other cultivars showed severe infection resulting in plant death. These results indicated that drought stress is a predisposing factor in pathogenicity of Fsp on common bean.

Polystigma amygdalinum Sacc (Cannon sp nov.) causes almond leaf blotch and is reported from various countries. The pathogen is widely distributed in the Mediterranean region and often causes premature defoliation of its host. Based on morphology, P. amygdalinum has been assumed to be a member of the order Phyllachorales and is consid¬ered to be a close relative of the genus Phyllachora, but phylogenetic analyses indicated that P. amygdalinum did not group with Phyllachora species (Phyllachorales) which have been thought to be its close relative. Polystigma amygdalinum show to be a relative of Trichosphaeriales and Xylariales and placed in the Xylariomycetidae. Almond leaf blotch is the most important disease on the leaf in almond (Prunus dulcis) in Iran. Ascospores are believed to be the only inoculum of this pathogen. Ascocarp initials develop in infected leaves in contact with, or in close proximity to, filamentous spore-bearing bodies, which are the first to appear. Environmental factors were affected ascocarp formation and development in P. amygdalinum. Mature ascocarps were formed in leaves from July to October (leaf fall). Ascocarps were produced under field conditions in infected leaves buried in soil at the depths of 0 to 40 cm with maximum mature ascocarp formation at 5 cm and minimum at the soil surface. Based on the appearance of disease symptoms under natural and greenhouse conditions the incubation period was estimated about to be 40-45 and 35-40 days respectively. The peak of ascospore discharge was 2-3 weeks after petal fall and was dependent on rain fall. Various chemicals were applied to control P. amygdalinum on almond. Spraying with Mancozeb and Bordeaux mixture is the most effective with four applications after petal fall in East Azerbaijan. Over a 4-year study period, it was found that ascospore discharge began at flowering and continued for 4-5 weeks in Maharloo of Fars Province. The maximum discharge occurred at petal fall. The incubation period was estimated to be 4-5 weeks under experimental conditions. Although the mature ascospores could produce short germ tubes in distilled water or water agar, the fungus could not be cultured or grown on conventional media from either ascospores, pycnidiospores or stromatic tissues under laboratory conditions. Of several systemic and non-systemic fungicides evaluated under field conditions, triforine at 100-400 µg /ml was most effective. Other fungicides which significantly reduced leaf infection were, in order of efficacy, copper oxychloride (2000µg/ml), copper hydroxide (2000 µg/ml), Bordeaux mixture (10000 µg/ml) and mancozeb (2000 µg/ml). Carbendazim and thiophanate methyl (500 µg/ml) increased the level of infection. One application of the fungicide at petal fall and then at two at 14-day intervals were found to be effective in reducing the disease. Two applications of Bordeaux mixture at 2 and 4 weeks after petal fall was found to be the most efficient control treatment in Chahar Mahal and Bakhtiari. A single spray two weeks after petal fall also reduced the disease significantly.
During 2012-13, the efficiency triforin (Saprol® 30%) (500 µg /ml) with three timing of applications, in comparison with Bordeaux mixture (10000 µg /ml) on two local cultivars (Sefid and Mamaee), was tested in a completely randomized block design, in along Zayanderood of Chahar Mahal and Bakhtiari province.
According to the results, two applications of triforin at two and four weeks after petal fall, a single spray four weeks after petal fall and two applications of Bordeaux mixture were found to be the most efficient control treatment in both cultivars, respectively. All applications of fungicides on both cultivars reduced the disease significantly. Infectivity percent and disease severity on Mamaee cultivar were more than Sefid. In general, it can be said Triforin was more effective in terms of decreasing infectivity percent and disease severity in comparison with Bordeaux mixture.
The results of this study, previous researches and surveys in Chahar Mahal and Bakhtiari province and other parts of Iran show that some of the almond cultivars cultivated in the country are susceptible to P. amygdalinum, so the only method to manage this disease is using the chemical control on these cultivars. Two applications of fungicides at two and four weeks after petal fall was found to be the most efficient control treatment in Chahar Mahal and Bakhtiari, these results are recommended for all regions of Iran.

Field studies were conducted in Shahrekord and Lordegan towns of Chahar Mahal va Bakhtiari province, in two growing seasons from 2009 through 2011, to evaluate the effect of planting date, with and without a seed- treatment insecticide (Imidacloprid), on yield (biomass), yield components and control of maize Iranian mosaic disease (MIMD) with natural vectors in maize (Zea mays L.) Single cross 704 cultivar. The experimental design was a split plot arrangement of a randomized complete block with four replications. Main plots consisted of four planting dates, approximately 15 days apart from 10 May through 25 June. Sub plots consisted of a seed-treatment systemic insecticide application. In each of the two years, yields and yield components of plots planted in 10 May were reduced significantly by MIMD infection. Disease incidence in experimental plots varied between 2 and 44.5%. Planting dates of 5 June and 25 June resulted in the highest biomass and yield components in two years. Significant increase (P=0.01) in maize yield and yield components varying from 9.3% to 32 % was observed in plots treated with seed-treatment insecticide and the magnitude of increase depended on planting dates. Disease incidence was determined based on the percentage of plants (total plants per plot) exhibiting symptoms. Also, samples of plants from each of the experimental plots were collected and tested for presence of MIMV with TAS-ELISA method and the results were supported in both years of study. The highest populations of Laodelphax striatellus and Unkanodes tanasijevici were also observed when maize seedlings at the first planting date (10 May) were at three-leaf growth stage. Almost 3% plants in some plots were showed symptoms of infection other viral diseases such as Maize rough dwarf virus (MRDV), Wheat streak mosaic virus (WSMV) and Barley yellow dwarf virus (PAV and MAV) based on symptoms and ELISA test. In 2009, seven cultivars of maize, including: ZP677, ZP505, ZP684, Single cross 704, KONSOUR, KSC500 and TWC 647, were evaluated in view of their resistance level to MIMV, in Shahrekord and Lordegan regions. The highest and the lowest infection rates with MIMV belonged to Single cross 704 (57%) and KONSOUR (3.8%), respectively.

Viral diseases with natural vector in Chahar Mahal va Bakhtiari province in most occasions cause economic damage. During 2006-2008, Rhopalosiphum padi, Schizaphis graminum, Sipha elegans, Sitobion avenae, Rhopalosiphum maidis and Metopolophium dirhodum in order of frequency, respectively, were identified as the most important vectors of barley yellowdwarfvirus and cerealyellowdwarfviruses in Shahrekord. barley yellow dwarf virus-PAV (PAV), barley yellow dwarf virus-MAV (MAV) and cereal yellow dwarf virus-RPV (RPV) serotypes, respectively, were abundant. Aphid populations increased from late September and reached to the peak in mid-October. With the onset of early fall frosts,, nymph of some species moved to crown and roots of wheat and barley but none of the species were capable of overwintering in wheat and barley. There were relationships between incidence of serotypes PAV, MAV and RPV in wheat, barley and aphid vector population due to vector-serotype specificity. Under greenhouse conditions, based on symptoms and ELISA, were shown PAV by R. padi, S. avenae, M. dirhodum and S. graminum, MAV by S. graminum, R. maidis, R. padi and M. dirhodum and RPV by R. padi and S. avenae were transmitted.