جستجوی مقالات مرتبط با کلیدواژه « fungi » در نشریات گروه « گیاهپزشکی »
تکرار جستجوی کلیدواژه «fungi» در نشریات گروه «کشاورزی»-
هدف از این تحقیق ارزیابی فعالیت ضدقارچی اسموتین در برابر چندین بیمارگر قارچی مهم گیاهی شامل میشد. به منظور انجام این مطالعه، ژن اسموتین از گیاه تنباکو) (Nicotiana tabacumدر باکتری) Escherichia coli (Rosetta DE3همسانهسازی و بیان گردید. به منظور بهینهسازی شرایط بیان پروتئین، از آزمون تاگوچی استفاده شد. آزمون وسترن بلات بیان پروتئین نوترکیب را مورد تایید قرار داد. بررسیها نشان داد پروتئین نوترکیب بیان شده عمدتا به شکل نامحلول اینکلوژن بادی در سلول انباشته میشود؛ لذا پس از محلول ساختن این توده ها با کمک مواد احیا کننده شرایط ایجاد ساختمان طبیعی تامین شد. اثر اسموتین نوترکیب بر قارچهای Rhizoctonia Alternaria brassicola وVerticillium dahleae ،Fusarium oxysporum ،Sclerotinia sclerotiorum ،Botrytis cinerea ،solani مورد بررسی قرار گرفته و فعالیت پروتئین خالص شده از طریق سه آزمون ضدقارچی متفاوت Disk Diffusion ،Radial Diffusionو Spore Germinationارزیابی و مشاهده شد که این پروتئین رشد قارچهای فوق را مهار میکند. همچنین آزمون همولیتیک خونی نشان داد که این پروتئین برای سلولهای پستانداران فاقد سمیت میباشد. یافته های فوق نشان میدهد که ژن اسموتین گیاه تنباکو دارای توانایی قابل توجهی در مهار رشد قارچ های بیماریزا گیاهی میباشد. همچنین این ژن میتواند درتولید گیاهان تراریخته مقاوم به قارچهای بیماریزا مورد استفاده قرار گیرد.
کلید واژگان: اسموتین, PRپروتئین, بیان پروکاریوتی, قارچ, پروتئین نوترکیب}The aim of this investigation was to evaluate the antifungal activity of Osmotin against several important economically improtant plant pathogenic fungi. The Osmotin gene from Nicotiana tabacum was overexpressed in Escherichia coli (Rosetta DE3). Taguchi test was applied to optimize the conditions for protein expression, and Western blot analysis confirmed expression of the recombinant protein. The expressed Osmotin was found in the form of insoluble inclusion bodies, which were then solubilized and refolded. The purified and refolded protein's activity was verified by three different antifungal activity assays. The purified recombinant Osmotin demonstrated a wide range of antifungal activity against various types of phytopathogenic fungi: Botrytis cinerea, Sclerotinia sclerotiorum, Fusarium oxysporum, Verticillium dahliae and Alternaria brassicola. Hemolysis biosafety test demonstrated that the protein is non-toxic to mammalian cells. All these findings suggest that the Osmotin gene from N. tabacum has promising potential as an antifungal agent against various phytopathogenic fungi and also to be utilized for production of antifungal agents and fungal-resistant transgenic plants.
Keywords: Osmotin, PR Protein, Prokaryotic Expression, Fungi, Recombinant Protein} -
The bulb mite, Rhizoglyphus robini Claparédè has been identified as a common pest attacking saffron corms. This mite is also a saprophytic species that is able to feed on fungi (mycelium). It has also been demonstrated that some soil-born fungi can attack and establish on saffron corms. After related fungi were isolated and identified either in saffron corms and mite bodies, the fungus Fusarium oxysporum Schlecht was the most abundant species in both samples; subsequently, it was used in the experiments. For studying the role of soil-borne fungi on life-table parameters of the mite, an even-aged cohort of eggs was obtained and transferred to experimental units to feed on saffron corm sections in two groups (fungal-infected and non-infected corms) in laboratory conditions. A total of 36 individuals were used for each treatment. The life-history data were analyzed according to the age-stage, two-sex life table model. Results showed that total pre-adult development of R. robini was significantly faster on Fusarium-infected rather than healthy corms (10.91 and 11.48 days respectively, P < 0.05). Adult pre-oviposition period (APOP) was significantly shorter when females were reared on fungal-infested than non-infested corms (1.84 and 2.88 days, respectively, P < 0.05). In addition, survivorship and fecundity of the mite on the two diets indicated higher rates and consequently, the net reproductive rate (R0) and intrinsic rate of increase (r) were significantly higher (P < 0.05 for both parameters) (202.07 and 351.13 offspring for R0 and 0.218 and 0.251 day−1 for r respectively on non-infested and infested diets). According to the results obtained, the soil-borne fungus affected demographic parameters of the bulb mite and it supports the hypothesis that the mite prefers plant tissues infected with soil-borne fungi because these are more suitable hosts.
Keywords: Astigmata, bulb mite, Crocus sativus, demography, Fungi} -
افزایش روز افزون جمعیت و مسئله جهانی امنیت غذایی، تولید محصولات کشاورزی را به استفاده از رویکردهای متعدد برای غلبه بر علف های هرز سوق داده است؛ عواملی که می توانند بهره وری محصول زراعی را تا 70 درصد کاهش دهند. علف کش های شیمیایی و روش های مکانیکی و زیستی از یک سو بر مشکل علف های هرز غلبه کرده، اما از سوی دیگر محیط زیست را تخریب کرده و اثرات مخربی بر سلامت انسان گذاشته اند. علف کش های زیستی عوامل کنترل بیولوژیکی هستند که با روش های مشابه با علف کش های شیمیایی برای کنترل علف های هرز به کار می روند. از میان مجموعه ای از علف کش های زیستی موجود، به نظر می رسد موفق ترین محصولات علف کش های قارچی با حداقل 16 محصول برای استفاده تجاری در سطح جهانی باشند. طی چند دهه گذشته، علف کش های زیستی حاصل از باکتری ها و عصاره های گیاهی (مانند آللوکمیکال ها و اسانس ها) همراه با ویروس ها، موفقیت چشمگیری در کنترل علف های هرز مختلف نشان داده اند. علی رغم این روند دلگرم کننده، همچنان نیاز به تحقیقات مداوم بر روی این ترکیبات است تا در دراز مدت نتایج مقرون به صرفه و موفقیت آمیزی حاصل شود. این بررسی اهمیت و تاثیرات علف کش های زیستی را با شرح محدودیت های آنها در تولید و کاربرد، توضیح خواهد داد.
کلید واژگان: عصاره های گیاهی, قارچ ها, باکتری ها, اسانس ها, ویروس ها}The ever increasing population and global issue for food security have led us to use multiple approaches to overcome the weed problems that can reduce the crop productivity up to 70%. Chemical herbicides and mechanical and other biological approaches have overcome weed problem on one hand but also destroy the environment and caused some human health impacts on the other hand. Bioherbicides are biological control agents applied in similar ways to chemical herbicides to control weeds. Of the array of bioherbicides currently available, the most successful products appear to be sourced from fungi (mycoherbicides), with at least 16 products being developed for commercial use globally. Over the last few decades, bioherbicides sourced from bacteria and plant extracts (such as allelochemicals and essential oils), together with viruses, have also shown marked success in controlling various weeds. Despite this encouraging trend, ongoing research is still required for these compounds to be economically viable and successful in the long term. This review will explain the importance and impacts of the bioherbicides by elaborating the constraints which this approach is facing in its production and application.
Keywords: Viruses, Plant Extracts, Essential Oils, Bacteria, Fungi} -
Endophytic fungi are a group of host-associated fungal communities that benefit their hosts. According to the conditions of their specific living environment, plant endophytic fungi produce many bioactive metabolites with different structural features. The bioactive compounds isolated from endophytic fungi, have significant effects on increasing the compatibility of both endophytic fungi and their host plants, such as the tolerance to biotic and abiotic stresses. In addition, some of these metabolites have indicated medicinal and ecological importance. In the present investigation, five fungal endophytes were isolated from the seeds of some medicinal plants. These endophytic isolates were characterized by sequencing of Internal Transcribed Spacer (ITS) regions as Acremonium sp. isolated from Echium amoenum, Epicoccum nigrum from Rosa canina, Fusarium sp. and Fusarium equiseti from Calendula officinalis and Lecanicillium aphanocladii from Physalis peruviana. To screen the phytochemical derivatives of ethyl acetate of these endophytic fungal isolates, the extracts were subjected to phytochemical analysis by gas chromatography-mass spectrometry (GC-MS). GC-MS spectrum of the compounds found in the extracts of the endophytic fungi was matched with the standard compounds present in the WILEY8 library and the National Institute of Standards and Technology (NIST14) library. The GC-MS analysis of extracts from these endophytic fungi revealed the presence of 49 phytocompounds such as 2,4-Di-tert-butylphenol, Hexadecane, Eicosane, Octadecane, Docosane, Nonadecane, Isopropyl myristate, Hexadecanoic acid, Undecane, Methyl stearate and so on. The results of the present study acknowledge that the endophytic fungi of these medicinal plants are the potential source of biologically active compounds and envisage the possible drug discovery using them. In addition, the compounds 14-Beta-H-Pregna and Cyclohexane,1,1'-(2-methyl-1,3-propanediyl) bis are reported here for the first time as fungal metabolites.
Keywords: endophytes, fungi, Medicinal plants, Secondary metabolites, GC-MS} -
Large flowered pelargonium (Pelargonium grandiflorum) is a perspective flowering crop which is distributed around the world. The area of its application is quite wide: from room floriculture to design the gardens and parks. Observation of leaf spot symptoms on this plant, which was collected from Alborz province (Karaj) motivated us to find the causal agent(s) of the disease. So, the symptomatic parts were cultured on the PDA medium after surface sterilization. Two fungal colonies were appeared on the culture medium. They were identified as Alternaria alternata and Botrytis cinerea according to the morphological characterizations. Molecular study using the gapdh for Alternaria and ITS regions and rpb2 gene for Botrytis confirmed the result of the morphological identification. In the pathogenicity tests, the same spots on inoculated plants with Alternaria and the same spots plus gray mold symptoms and fungal body on leaves, buds and stems of the inoculated plants with Botrytis were another confirmation. Based on our knowledge, this is the first report of these two fungal species on the Pelargonium grandiflorum in Iran.
Keywords: disease, fungi, phylogeny, pathogenicity, Pelargonium} -
در میان آفات زعفران، کنه Rhizoglyphus robini به عنوان یکی از مهمترین عوامل محدود کننده عملکرد زعفران در ایران قلمداد می شود .نمونه برداری از مزارع زعفران از نواحی زعفران خیز استان خراسان رضوی انجام و قارچ های مرتبط با بنه زعفران و نیز قارچ های مرتبط در داخل بدن کنه جداسازی و سپس با کشت نوک هیف خالص سازی شدند. گونه قارچی Fusarium oxysporum در نمونه های مربوط به بنه زعفران و همچنین کنه به عنوان گونه غالب شناسایی شد. سپس زیست شناسی، رفتار و توانایی نفوذ و تشکیل کلنی کنه در ارتباط با آلودگی بنه ها به این گونه قارچ خاک زاد ارزیابی شد. آلودگی به قارچ مذکور به صورت معنی داری بر طول کلیه مراحل زیستی کنه به غیر از مرحله تخم تاثیر گذار بود. بر این اساس طول دوره لاروی آفت در حالت آلودگی به قارچ 0.08 ±2.45 و بر روی بنه های سالم 0.088± 2.72 برآورد گردید. طول دوره پوره سن اول برای بنه های آلوده 0.053 ± 2.12 و سالم 0.08 ±2.47 و برای پوره سن آخر نیز به ترتیب 0.067 ± 2.15 و 0.081 ± 2.45 اندازه گیری گردید. مرحله پیش از بلوغ کنه نیز بر روی بنه های آلوده کوتاه تر از بنه های سالم بود (0.077 ± 1.36 و 0.177 ± 2.04 به ترتیب بر روی بنه های آلوده و سالم). همچنین نرخ زادآوری روزانه کنه تحت تاثیر آلودگی به قارچ خاک زاد به صورت معنی داری افزایش یافت. همچنین واکنش جلب شدن کنه ها به سمت بنه های زعفران نشان دهنده اختلاف معنی داری در رابطه با تمایل کنه ها نسبت به قطعات بنه آلوده به قارچ در مقایسه با سالم (غیرآلوده) بود. نتایج آزمایش نفوذ و توانایی کلنی سازی کنه نشان داد که روی بنه های آلوده به قارچ نفوذ آن ها سریعتر و متعاقبا سرعت رشد جمعیت و تشکیل کلنی پایدار افزایش یافت. بر اساس نتایج این مطالعه، اخسارت کنه R. robini به عنوان گونه غالب مزارع زعفران ارتباط تنگاتنگی با آلودگی بنه ها به قارچ ساپروفیت داشت. بنابراین در برنامه مدیریت تلفیقی این آفت، بایستی خسارت کنه را در ارتباط با آلودگی همزمان بنه ها به قارچ های ساپروفیت ارزیابی و سپس با توجه به مساله اولیه یا ثانویه بودن منشاء خسارت، اقدام مدیریتی متناسب برمبنای مهار جمعیت کنه و قارچ به صورت همزمان اتخاذ گردد. به عبارت دیگر، با مهار جمعیت قارچ های ساپروفیت بر روی بنه های زعفران می توان خسارت کنه را تا حد زیادی کاهش داد.کلید واژگان: زعفران, کنه زعفران, قارچ های خاکزاد, رفتار شناسی, رشد جمعیت}IntroductionSaffron is one the most expensive crops and like other agricultural products, attacked by pest such as bulb Mite Rhizoglyphus robini Claparede (Acari: Astigmata). The bulb mite is one of the most important soil pest attacking plants with bulbs, corms and also tubers. In Iran it has been reported by Rahimi and Kamali (1993) for the first time on saffron corms from Gonabad and Qaen cities. Also it has been recorded that the bulb mite feeding on soil born fungi (Diaz et al., 2000; Nesvorna et al., 2012). On the other hand, there are many saprophytic fungi into the soil of saffron fields. Subsequently it may question whether the mite is primary or secondary pest on saffron corms. Despite many literatures on biology and ecology of Rhizoglyphus mites, there is not sufficient evidence on understanding the biology, behavior and colonization of R. robini regarding its damage to saffron corms when arriving after establishment of the soil born fungi.Materials and MethodsTo investigate the impact of soil-borne fungi on the biology of the bulb mite, we obtained a cohort of even-aged eggs from the mites in our stock culture. These eggs were then transferred to individual experimental units and monitored until they reached adulthood. Daily observations were made and recorded.
To assess mite fecundity, we selected thirty young ovipositing females and divided them into two groups: one group was exposed to fungal infection while the other group was not. Each saffron corm was placed in a 50mm Petri dish lined with wet filter paper. A starved mated female was added to each dish, and every three days for a period of 21 days, the number of eggs laid per dish was counted and then removed. The number of eggs per day per female was calculated based on these counts.
To study the attraction of bulb mites to the fungus, saffron corm sections with and without fungal infection were placed in a 50mm Petri dish. Four sections, with equal distances from each other and from the center, were arranged. Female R. robini mites were introduced into the dish, and after a four-hour period, the number of mites on each section was recorded.
For evaluating the population dynamics of the mite, we used four types of saffron corms: healthy corms, corms infected by the fungus, mechanically injured corms, and corms both infected and injured. Each experimental unit consisted of three saffron corms of the same size placed in an 80mm Petri dish. Five adult mites were added to each unit. Continuous observations were made daily to track the initial penetration and colonization of the mites in each treatment. The numbers of all motile stages of mites in each experimental unit were recorded using a stereomicroscope. These observations continued until the corms were completely destroyed by the feeding mites.Results and DiscussionAfter culturing of sections of infected corms and mite body, the fungi, Penicillium spp., Aspergillus niger Vantieghem, Embelisia sp. and Fusarium oxysporum Schlecht were isolated and identified mutually in both samples. As the fungus F. oxysporum was the most abundant species, then it was used in the experiments. The fungus significantly affected the generation time (from egg stage to egg produced by adult) of the mite (Table. 1). Also mite fecundity was significantly higher on infested corms with the fungus than on non-infested ones (t = 10.79, d.f.= 27.31, P<0.001)(Figure 1). An obvious attraction of the females was observed toward fungal infected sections and significantly more mites were recorded on them than non-infected ones (W = 400, P<0.001)(Figure. 2).These findings are supported by some other studies (Czajkowska, 1995; Kasuga and Honda 2006; Ofek et al., 2013). Higher fecundity and faster development when mites were fed on the fungus on the infected corms are probably due to availability of a special nutrient source (mycelium). The ability of the bulb mite to digest fungi has been attributed to chitinase-producing symbiotic bacteria (Zindel et al., 2013). Based on the evidence provided by this study and previous ones (Okabe and Amano, 1990; Ofek et al., 2013), the mite R. robini was attracted more to fungal infected corms, it might because of metabolites and alcoholic secretions of the fungi. These findings demonstrate the suitability of saffron corms infected with soil fungi for development and population increase of the Robine mite.
The result on mite penetration and population dynamics on four types of treated corms indicated that the mite on infected corms penetrated within two weeks and thereafter population increased exponentially until the end of 5th week. In comparison on healthy corms and even injured ones the mite showed almost no increase during first three weeks and it was not able to penetrate and develop a stable colony on these corms. Also on infected and injured treatment similar population dynamics was observed as on infected ones (Figure. 3). These observations implying that the mite for penetrating into healthy corms encounters some difficulty and considerable time is needed to establish and colonized on such environment. Okabe and Amano (1991) has been found similar results and suggested that earlier penetrations of mites result in a faster population growth and colonization.ConclusionFor many years the saffron bulb mite has been considered as a primary pest and historically control strategies has relied on the use of chemical miticides (for disinfection and etc.,) and some non-chemical methods. Subsequently the role of soil born fungi has receiving limited attention in this regards. According to the results of the present study, this acarine pest relies on the soil born fungi to penetrate and establish on the saffron corms. In other words, a close relationship exists between fungal infection and damage by R. robini on saffron bulbs. It suggest that for improving management strategies in regards of this pest, we should consider the role of saprophytic fungi as a main cause which provides condition for the bulb mite colonization and occurring damage. Further researches is proposed using appropriate methods to suppress soil born fungi and subsequent the bulb mite damage on saffron.Keywords: Bulb mite, Fungi, Population Growth, Saffron} -
در این تحقیق فعالیت آنزیمی لیپاز و کیتیناز قارچ های همراه نماتد سیستی چغندرقند (Heterodera schachtii) جمع آوری شده از استان خراسان رضوی مورد مطالعه قرار گرفت. به این منظور در سال زراعی 95-94، حدود 300 جدایه قارچی از سیست، ماده و تخم و لارو نماتد سیستی چغندرقند جداسازی گردید. جدایه های مذکور پس از خالص سازی، مورد بررسی های ماکروسکوپی، میکروسکوپی و مولکولی قرار گرفتند و با استفاده از کلیدهای معتبر شناسایی شدند. از میان آن ها شش گونه شامل Simplicillium lanosoniveum، Penicillium chrysogenum، Colletotrichum gloeosporioides، Neonectria macrodidyma، Fusarium oxysporum و Alternaria chlamydospora شناسایی شدند. در بررسی نسبی فعالیت آنزیم لیپاز، قارچ C .gloeosporioides بیشترین میزان تولید این آنزیم را نشان داد و در بررسی نسبی فعالیت کیتیناز، بیشترین تولید این آنزیم مربوط به قارچ P .chrysogenum بود.
کلید واژگان: چغندر قند, نماتد سیستی, قارچ, لیپاز, کیتیناز}IntroductionSugar beet is adaptable to be cultivated in different weather conditions and regions. In 2015, the overall area for sugar beet cultivation was estimated about 105,000 hectares which 19000 of this was in Khorasan Razavi province. Sugar beet is considered as a valuable agricultural crop both for economy and employment. Nevertheless, producing this crop faces many challenges including the high number of pests. One of these pathogenic factors is the nematodes. Among plant-parasitic nematodes cyst nematodes are a large group with economic importance in different countries. These nematodes cause much damage to agricultural crops. Among the different cyst nematode genera Globodera and Heterodera have species which are important due to economic damage.
Materials and MethodsDuring the year of 2016, 22 samples of soil and roots of sugar beet in cyst nematodes contaminated field in Khorasan Razavi were gathered. Cyst nematodes were extracted by the use of a small clip and a binocular and put in petri dish with some water. White materials were also taken from the root by a delicate needle and put in sterile distilled water after washing. Separating and purifying fungi were done in 3 parts: separating fungi from cysts and materials, separating fungi from eggs and larvae nematode, and making single spore fungi and pure culture. The cysts and separated materials were washed by distilled water for several times and antisepticised for 1, 2 or 3 minutes in 10% Sodium Hypochlorite, and 10% and 20% Ethyl alcohol. Cysts and materials were washed again with sterile distilled water and sterile sifter was used. The cysts and materials in petri dish containing PCA, PDA, CMA and MEA culture mediums were separately taken and cultured by a needle under laminar. Four cysts were placed at the 4 sides of each 8cm petri dish containing the above mentioned culture mediums. 16 brown cysts from each soil sample were cultured. Two petri dishes from each sample were kept and checked consistently in two hot and cold temperatures in incubator with 20-25 and incubator with 8-10. After 7-14 days the grown fungi were taken to a new culture medium of PDA for a better development and in later stages they were purified on WA culture medium by single spore or hyphal tip methods. Purified fungi were kept in test tubes containing PCA food environment and 4 temperature and also on sand for later studies. Cyst shells were destructed by cyst crusher (homogenizer) and their eggs and mash were released. Released eggs from cysts were formed into suspension in sterile water. 0.5-1 ml of suspension of eggs and larvae were taken by sterile micropipette and diffused on petri dish containing water agar culture medium. These culture mediums were kept and checked regularly in dark in the incubator with 20-25. Grown fungi from these eggs and larvae were taken to a new culture medium and purified by single spore and hyphal tip methods. WA culture medium was used for single spurring and purifying fungi. PCR based methods morphological and molecular identification, were used to identify the fungi isolates. Mycelium fungi growth phases, fungi DNA extraction, PCR reaction and electrophoresis were done to identify molecular fungi. Lipase and chitinase assays were performed on the isolates.
Results and DiscussionFor Lipase test, each fungal isolate was cultured on peptone agar media and after 7 days isolates were examined. Around the colony of the isolates produced by the lipase enzyme formed a precipitate or a colorless aura, which is due to the formation of calcium salts from free lauric acid by the lipase enzyme, which indicates the positive activity of lipase. Among the isolates, Colletotrichum gloeosporioides had the highest sediment content, indicating the activity of lipase enzyme and the highest isolate in this test. After that, Neonectria macrodidyma and Penicillium chrysogenum showed the highest activity of lipase enzyme activity. Fusarium oxysporum showed no sediment and the lowest level of lipase enzyme activity was observed in this fungus. For chitinase test, isolates were cultured on colitic kitein medium. Around the colony and also the color of the culture medium, the chitinase-producing isolates changed the violet color, which indicates the positive activity of the chitinase enzyme in these isolates. Relative analysis of chitinase activity showed that the isolate of P. chrysogenum had the largest and fastest change in color to violet, indicating the highest production of chitinase enzyme by this fungus. The lowest chitinase production was by C. gloeosporioides, which showed the slightest and slowest changes in color compared with other isolates and the weakest isolate was introduced for the production of chitinase enzyme.
ConclusionIn this research, different fungi were isolated from sugar beet cystc. Most fungal isolates belonged to Torbat-e-Haidiriyah and Fariman, and the least isolates belonged to Khaf. The highest frequency of Fusarium isolates was found to be 37.35%. Isolation of Simplicillium lanosoniveum fungi, P. chrysogenum, C. gloeosporioides was the first reported cyst nematode in sugar beet. In the relative analysis of lipase activity, it was found that P. chrysogenum and C. gloeosporioides fungi exhibited the highest amount of lipase production, which was the highest marker in this test. Relative analysis of chitinase activity showed that P. chrysogenum had the largest and fastest color change to purple, indicating the highest production of chitinase enzyme by this fungus. The lowest chitinase production was obtained by isolate C. gloeosporioides, which showed the slightest and slowest changes in color compared with other isolates. The fungus P. chrysogenum showed the best results in both tests, this fungus is, therefore, recommended for further research with the observation of the necessary points.
Keywords: sugar beet, cyst nematode, lipase, chitinase, fungi} -
Since the beginning of the 20th</sup> century, several scientific names have been used for the causal agent of powdery mildew on evergreen spindle Euonymus japonicus</em>. The nomenclature of this powdery mildew is reviewed and using Erysiphe euonymicola</em> as current name for the species is suggested. Information on the history of occurrence, natural host range and distribution of E. japonicus</em> powdery mildew in Iran is provided. Morphological differences between E. euonymicola</em> and E. euonymi</em>, a powdery mildew on other species of Euonymus</em> in Europe is discussed.
Keywords: Nomenclature, Erysiphales, Fungi} -
Filamentous fungi Trichoderma spp. are efficient hyper-producers of industrially important enzymes. Xylanases are essential hemicellulases having vast ranges of applications in the various industrial sectors. In this study, the protoplast fusion of two T. virens and T. harzianum strains resulted in 2.5 Uml-1 xylanase activity in fusant X3 showing 4.7-fold improvement in xylanase activity compared to that of parents with 0.54 Uml-1. Moreover, to evaluate the influence of protoplast fusion on the xylanase activity, the expression patterns of the xylanase gene xyn3 was analyzed in the parental strains and the using qPCR. The results demonstrated that the relative expression of the xyn3 increased in X3 by 4.9 fold compared to that of the parents. Finally, based on the results, it could be concluded that the protoplast fusion technology is a promising approach to generate new superior fungi with high production ability of the industrially important enzymes.
Keywords: fungi, hemicellulases, Enzyme activity, qPCR} -
یکی از مشهورترین قارچهای بیمارگر حشرات، anisopliae Metarhizium می باشد که در خاک وجود داشته و از قابلیت بیمار کردن آفات گیاهی و جانوری برخوردار میباشد. شته ی سبز هلو(Myzus persicae) در کلیهی مناطق ایران وجود داشته و به درختان هلو، مرکبات، سبزیجات و گیاهان زینتی گلخانه ای خسارت می زند. در این مطالعه مرگ و میر شتهی سبز هلو توسط قارچ Metarhizium anisopliae مورد بر رسی قرار گرفت. از دو جدایه Metarhizium anisopliae به نام های A3 و M1 موجود در گروه میکروبیولوژی سازمان جهاد دانشگاهی تهران استفاده شد. تست زیست سنجی علیه شته ی سبز هلو در داخل ظروف پتری 18 سانتیمتری با غلظتهای 103× 1، 105×1 و 107×1 کنیدی در میلی لیتر در شرایط 14:10 ساعت تاریکی: روشنایی و دمای 28 درجهی سانتیگراد به مدت 9 روز انجام گرفت. کمترین مقدار LC50 برای جدایه A3 غلظت 105×5/6 کنیدی در میلیلیتر بود و بهترین LT50 نیز برای جدایه A3 برابر با 82/3 روز در غلظت 107×1 کنیدی در میلیلیتر بود. کمترین مقدار LT50 جدایهی M1 نیز در غلظت 107×1 برابر با 51/5 روز بود.کلید واژگان: بیمارگر حشرات, زیست سنجی, قارچ, متاریزیوم}Metarhizium anisopliae, is one of the most famous soil inhabitant entomopathogenic fungi, has a virulence potential on plant pests and animals. The green peach aphid, Myzus persicae, exists in all over of the Iran and causes damages to peach trees, citrus, vegetables and ornamental plants grown in greenhouses. The aim of this study is checking peach aphid mortality by Metarhizium anisopliae. Two strains of Metarhizium anisopliae, namely M1 and A3 available by Department of applied microbiology of Tehran organization of Academic Center for Education, Culture and Research (ACECR) were used in this study. Bioassay test against peach tree aphids was done in 18 cm diameter Petri dishes with three gradient suspensions consisted of 1×103, 1 ×105 and 1 ×107 conidia ml−1 and 14: 10 h of dark: light photoperiod in ambient temperature for 9 days. The least amount of LC50 determined for A3 with concentration of 6.5×105 conidia/ml and the best LT50 for A3 with concentration of 1×107 conidia ml−1 was 3.82 days. The least LT50 for M1 with concentration of 1×107 conidia ml−1 was 5.51 days.Keywords: Entomopathogen, Bioassay, Fungi, Metarhizium}
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Some fungal species were isolated from scab or scab-like symptoms on leaves of various plant hosts in Iran. Some of them isolated from apple and pear leaves were investigated in the present study. The isolates were identified based on the morphological and cultural characteristics. On the other hand, for molecular identification and phylogenetic analyses were carried out based on the sequence of ITS-rDNA region (including 5.8S rDNA). As a result, six species, namely Acremonium fusidioides, Acrostalagmus luteoalbus, Clonostachys rosea, Sarocladium kiliense, Sarocladium strictum and Endoconidioma populi were identified. Among them, Acremonium fusidioides is a new taxon for the mycobiota of Iran.Keywords: Apple, Biodiversity, fungi, molecular identification, taxonomy}
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به منظور بررسی تاثیر مایکوریزا و آزوسپیریلوم در میزان مقاومت به بیماری زنگ زرد در ارقام گندم پژوهشی در سال زراعی 1392-1391 در مزرعه تحقیقاتی دانشگاه شهید چمران اهواز اجرا شد. طرح آزمایشی به صورت فاکتوریل در قالب بلوک کامل تصادفی و در 3 تکرار بود. عوامل آزمایش شامل قارچ مایکوریزا در سه سطح (عدم کاربرد، استفاده از گونهGlomus intraradices و G. mosseae)، باکتری lipoferum Azospirillum در دو سطح (عدم تلقیح و تلقیح بذور با قارچ) و ارقام گندم در سه سطح شامل رقم چمران، ارقام دوروم دنا و بهرنگ بود. در این آزمایش شدت آلودگی، میانگین ضریب آلودگی، تیپ آلودگی و سطح زیر منحنی پیشرفت بیماری (AUDPC) زنگ مورد ارزیابی قرار گرفت. یادداشت برداری از شدت و تیپ آلودگی در مرحله برگ پرچم با مقیاس اصلاح شده کب صورت گرفت. اولین علائم ظهور زنگ زرد در محل اجرای آزمایش در نیمه بهمن ماه سال 91 مشاهده شد. نتایج تجزیه واریانس نشان داد که تلقیح بذور با آزوسپیریلوم صفات اندازهگیری شده را بین 10 تا 13 درصد کاهش داد. استفاده از مایکوریزا شدت آلودگی را 45-51 درصد، میانگین ضریب آلودگی و (AUDPC) را 74-85 درصد به ترتیب برای گونه های G. intraradices و G. mosseae نسبت به تیمار کنترل کاهش داد. رقم چمران بین 40-70 درصد از ارقام دوروم حساسیت بیشتری به بیماری نشان داد. به طور کلی کمترین شدت آلودگی (33/18) از تیمار تلقیح بذور رقم دنا با آزوسپیریلوم و استفاده از گونه G. mosseae به دست آمد.کلید واژگان: باکتری, برگ پرچم, رقم دنا, شدت آلودگی, قارچ}IntroductionWheat is one of the major agricultural crops with respect to human nutrition. It is cultivated over a wide range of environments, because of wide adaptation to diverse environmental conditions. In Iran, 6.2 million hectares are under wheat cultivation, of which 33% is irrigated and 67% is rain-fed, the irrigated wheat growing areas (2 million hectares) are located mostly in southern, central and east of Iran Production of crops is under the influence of plant genetic structure, environmental conditions and their interactions. Biotic and abiotic stresses are considered to lower production. Among the biotic stress, the fungal disease is the main factor limiting production of crop plants in hot and humid regions. Stripe rust was not a serious economic concern to the wheat industry for most of the 1990s due to the use of resistant varieties. However, by 2003 it had developed into a significant issue, particularly as new path types evolved. Even in the dry years of 2003 and 2004, stripe rust cost growers significant income. Provide country's need for wheat as a strategic product, meanwhile, production is free from chemical fungicide is a high but achievable goal. So in order to achieve fertilizer and fungicide resources that in addition to having no adverse effects on consumers and the environment, has been economically able to provide nutrition need of crop plant, is very important.Materials And MethodsWith this approach, to survey the effect of Mycorrhiza and Azospirillum in resistance to yellow rust in wheat cultivars, an experiment was conducted at the research station of the Shahid Chamran University of Ahvaz, Iran in 2012-13. The experimental design was factorial based on a randomized complete block design with three replications. The treatments include of Mycorrhiza fungi in three levels (without application of Mycorrhiza strain and using strain Glomus intraradices and Glomus mosseae), Azospirillum lipoferum bacterium in two-levels (non-inoculated seeds and inoculated seed) and wheat cultivars in three levels, Chamran (bread wheat), Dena and Behrang (durum wheat) varieties. In this experiment evaluated, to yellow rust disease, the intensity of infection, the average coefficient of infection, type of infection and area under disease progress curve (AUDPC). Infection type and disease severity were also recorded at flag leaf stage using modified Cobbs scale. First symptoms of yellow rust were observed in middle January of 2013. Analysis of variance was performed using PROC ANOVA of SAS (version 9.1.3, 2004The comparison of the means was done by Duncan test at a probability level of 5 percent.Results And DiscussionSurvey on the resistance to yellow rust in wheat cultivars treated with Mycorrhiza and Azospirillum showed that seed inoculation with Azospirillum traits reduced between 10 percent to 13 percent and the use strains of Mycorrhiza fungi intensity of infection 45-51 percent, the average coefficient of infection and AUDPC 74-85 percent respectively for G. intraradices and G. mosseae strains have been reduced compared with control and Chamran cultivar between 40-70 percent showed more Sensitivity to disease from durum varieties. Generally, the lowest of infection intensity (18.33) was obtained from inoculation of C.V Dena seeds with Azospirillum and G. mosseae strain. According to the result, we found yellow rust in all experiment field also the incidence varied between 10-70 percent. Therefore, it is concluded that, given the climatic conditions favorable to the spread of yellow rust, the incidence of yellow rust in the region that have a high degree of pathogenicity. In general the results of this test, mycorrhiza application has a significant role in enhancing wheat resistance to yellow rust. The seed inoculation with Azospirillum although did not have significant role in disease control, but increased at an acceptable level resistance to wheat rust. But the important point was the combined use of fungi and bacteria the synergistic effect of the two substances for all traits were assessed, leading to an increase of more than 20 percent in the wheat varieties resistant to rust.ConclusionGenerally associated with resistance to yellow rust in wheat cultivars inoculation with A. lipoferum and usage of G. mosseae in Dena cultivar that was durum wheat, showed the highest resistance to yellow rust, probably this has been due to the Dena cultivar which is durum wheat. It seems, use of the biofertilizers can be the perfect solution to eliminate the nutritional requirements of wheat, in addition, it has been an important effect in enhancing resistance to yellow rust.Keywords: Bacteria, Dena cultivar, Disease severity, Flag leaf, Fungi}
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The history of mycology in Iran is presented in five periods. In the first period (until 1860) there is no sign of Iranian fungi in scientific literature. In the second period (18601941) the study of Iranian fungi was started by foreign mycologists who did not visit Iran but worked on plant material collected by botanists. In the third period (19411963) the study of Iranian fungi was started by a first generation of Iranian mycologists and also fungal plant pathology was started in Iran. A second generation of Iranian mycologists used pure culture technique in the fourth period (19632000). In this period mycology was taught separately from botany and plant pathology at universities, and MSc and PhD courses were initiated at some universities. In the fifth period (from 2000), a third generation of Iranian mycologists used molecular techniques to study Iranian fungi. An Asian Mycological Congress was held in Iran in 2001; the Iranian Mycological Society was founded in 2010; an MSc course of mycology was initiated at Esfahan University; the first Iranian Mycological Congress was held at Gilan University in 2013, and the first Iranian mycological journal (Mycologia Iranica) was launched.Keywords: Iranian mycology, fungi, historical review, fungal plant pathogens}
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افزودن عوامل آنتاگونیست به محیط ریشه گیاهان ازجمله رویکردهای مهم در مهار زیستی بیمارگرهای خاکزاد است. استقرار و دوام عوامل کنترل زیستی در خاک از دغدغه های مهم در مهار زیستی است. این مطالعه به منظور تعیین اثر بقایای گیاهی جنگل بلوط بر فعالیت آنتاگونیستی Pseudomonas fluorescens و Trichoderma vierns علیه نماتد ریشه گرهی Meloidogyne javanica در گوجه فرنگی انجام گردید. این آزمایش در قالب طرح کاملا تصادفی با هشت تیمار و پنج تکرار در گلخانه گروه گیاهپزشکی دانشگاه کردستان انجام شد. در تیمارهای آزمایش از یک یا هر دو عامل آنتاگونیست در دو حالت با و بدون افزودن بقایای گیاهی استفاده گردید. براساس نتایج به -دست آمده، شاخص های رشدی گوجه فرنگی در تیمارهایی که بقایای گیاهی به خاک افزوده شده بودند، به طور چشم گیری بهبود یافت. در مورد شاخص های تکثیری نماتد هم تعداد گال در ریشه در تیمارهایی که دارای بقایای گیاهی بودند به طور معنی داری کم شد که بیشترین کاهش در تیمارهای با یک یا دو عامل آنتاگونیست مورد بررسی، صورت پذیرفت. در مقایسه با تیمارهای بدون بقایای گیاهی، میزان کاهش گال زایی در تیمار دارای T. virens حدود 61 درصد و میزان افزایش وزن خشک ریشه در تیمار دارای P. fluorescens یا T. virens به ترتیب حدود 68 درصد و 56 درصد بود.
کلید واژگان: کنترل زیستی, امنیت غذایی, قارچ ها, مدیریت نماتد, مواد آلی}Application of antagonistic agents in the rhizosphere of plants is an important approach in control of soil-borne pathogens. Establishment and persistence of biocontrol agents in the soil is a major concern in biological control. This study aimed to determine the effect of plant debris of oak forests on activity of Pseudomonas fluorescens and Trichoderma vierns against Meloidogyne javanica in tomato in green house conditions. In different treatments, both or one of the bioagents were applied to the soil inoculated with M. javanica and amended or unamended with oak plant debris. Based on the results, the growth–related factors of tomato improved in those treatments, in which plant debris were mixed with the soil. In case of nematode-related factors, the number of galls on roots decreased significantly in pots amended with plant debris. Maximum reduction in reproduction factor was observed in treatments with one or both of the biocontrol agents. In comparison to unamended treatments, the rate of reduction in root gall was 56.3% for treatments receiving T. virens and maximum increase in dry weight of root was observed in soils treated with P. fluorescens or T. virens, 68.2% and 56.1%, respectively.
Keywords: Biocontrol, Food security, Fungi, Nematode management, Organic matter} -
Asparaginase and amylase are widely used enzymes in various industries, which can be produced by endophytic fungi. In this study, the ability of producing these two enzymes in endophytic fungi isolated from six species of Thymus has been reported for the first time in the world. Among 89 isolates of the test, 34 isolates produced asparaginase which among M24 (Fusarium subglutinans) displayed the greatest enzyme activity. Thirty three isolates showed the ability to produce amylase while the greatest enzyme activity belonged to M53 (Curvularia akaii). This study can be regarded as a preliminary work and endophytic fungi of high activity are proposed as possible resources to control cancer in human and other industrial applications.Keywords: Amylase, Asparaginase, Endophyte, Fungi, Thymus}
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نماتد مرکبات، Tylenchulus semipenetrans، دارای گسترش جهانی بوده و یکی از عوامل سرخشکیدگی در باغ های مرکبات محسوب می شود. آلودگی توام نماتد و قارچ های بیمارگر، تاثیر مضاعفی بر رشد گیاه می گذارد. به منظور بررسی اثر اکتینومیست ها در کنترل نماتد و بیمارگرهای ثانویه، تعداد 30 نمونه خاک آلوده از فراریشه مرکبات شرق استان گیلان و غرب استان مازندران جمع آوری شدند. در نتیجه20 جدایه اکتینومیست با استفاده از کشت روی محیط های انتخابی جداسازی و اثر آن ها در تفریخ تخم و مرگ ومیر لاروها مورد ارزیابی قرار گرفت. در آزمایشی دیگر، تاثیر اکتینومیست ها بر قارچ های بیماری زای Fusarium oxysporum، Fusarium solani، Penicilium digitatum، Rhizoctonia solani،Pestaliopsis spp و Colletotrichum gloeosporioides بررسی شد. در آزمون اول، هشت جدایه با توان کاهش میزان تفریخ تخم در مدت هفت روز و کشتن لاروها در طول چهار روز، از قابلیت آنتاگونیستی خوبی برخوردار بودند. در آزمون دوم، شش جدایه موفق به کنترل قارچ های بیمارگر مورد مطالعه شدند. جدایه Streptomyces sp. IGM05 بیش ترین توانایی را در کنترل قارچ های بیمارگر نشان داد در حالیکه جدایه Streptomyces sp. IGM17 با کاهش تفریخ تخم به میزان 2/37 درصد و مرگ ومیر 4/52 درصدی لاروها، توانایی آنتاگونیستی بالایی در برابر نماتد بروز داد.
کلید واژگان: استرپتومایسس, آنتاگونیست, قارچ, Tylenchulus semipenetrans}Citrus nematode، Tylenchulus semipenetrans has worldwide distribution and is one of the causal agents of dieback disease in citrus orchards. The infection by the nematode in association with secondary fungal pathogens affects plant growth adversely. In order to evaluate antagonistic effects of actinomycetes in control of the nematode and secondary pathogens، 30 infested soil samples were collected from rhizosphere of citrus trees in east of Guilan and west of Mazandaran provinces، Iran. As a result، 20 strains of actinomycetes were isolated using selective culture media and their effects on egg hatching and juvenile mortality of the nematode were evaluated. In another experiment، actinomycetes efficacy on plant pathogenic fungi including Fusarium oxysporum، Fusarium solani، Penicilium digitatum، Rhizoctonia solani، Pestaliopsis spp. Colletotrichum gleosporeides were also tested. The results of the first experiment revealed that eight actinomycets isolates having good antagonistic capacity، reduced egg hatching during seven days and caused juvenile mortality in four days. In the second experiment، six isolates showed the ability of control against plant pathogenic fungi. Streptomyces sp. IGM05 strain had the maximum ability in control of the plant pathogenic fungi while Streptomyces sp. IGM17 reduced egg hatching rate up to 37. 2% and juvenile mortality rate to 52. 4% and exhibited the highest potential of antagonism.Keywords: Antagonist, Fungi, Streptomyces, Tylenchulus semipenetrans} -
قارچ Rhizoctonia oryzae-sativae عامل لکه موجی غلاف برگ یکی از بیمارگرهای برنج در استان گیلان است. با توجه به شیوع بیماری در اکثر مزارع برنج استان و عدم وجود اطلاعات کافی از زیست شناسی آن، این پژوهش با هدف بررسی برخی از جنبه های زیست شناسی این قارچ صورت گرفت. در این بررسی ضمن اندازه گیری دمای بهینه رشد این قارچ، کاه برنج آلوده شده با میسلیوم و سختینه قارچ در شرایط مختلف مزرعه مانند سطح خاک، عمق پنج سانتی متری، شرایط غرقاب و سطح خاک حاشیه مزرعه رهاسازی شد و با فواصل زمانی مشخص مورد بررسی قرار گرفت. هم چنین امکان بقای سختینه و توانایی جوانه زنی آن در دماهای مختلف (5، 0، 5-، 10-، 15-، 20-، 72- و دمای محیط) به مدت یک ماه ارزیابی شد. بر اساس نتایج به دست آمده دمای بهینه رشد برای جدایه های مورد مطالعه، 32 درجه سلسیوس تعیین شد. بر همین اساس، قارچ شرایط نامساعد زمستان را به صورت میسیلوم روی بقایای گیاهی در سطح خاک مزرعه و حاشیه آن و سختینه در خاک تا فصل رشد بعدی، سپری می کند. هم چنین نتایج به دست آمده امکان بقا و زنده ماندن سختینه ها را در دماهای زیر صفر ثابت کرد، به طوری که 4/30 درصد از سختینه هایی که در دمای 72- درجه سانتی گراد قرار داشتند، پس از گذشت یک ماه، روی محیط PDA قادر به جوانه زنی بودند.
کلید واژگان: برنج, لکه موجی غلاف, بقا, زمستان گذرانی, سختینه, سوختگی, قارچ}Rice aggregate sheath spot disease is caused by Rhizoctonia oryzae-sativae (Sawada) and occurs more or less at all paddy fields in Guilan province. In this study some aspects of biology of Rhizoctonia oryzae-sativae and optimal growth temperatures were examined. Rice straw colonized with mycelia and sclerotia of Rhizoctonia oryzae-sativae were incubated in different field conditions such as natural field soil surface, 5 cm deep under the soil, flooding condition, on soil surface at the borders of the field. The effects of variable conditions on viability of fungus were studied. Moreover, the effects of different temperatures (5, 0, -5, -10, -15, -20 and -72) on germination and viability of sclerotia were assessed during one month. Optimum growth rate was found to take place at 32 ºC. Results showed that R. oryzae-sativae overwinters as mycelia on the rice straw on the soil surface in the field, soil surface at field margins and as sclerotia in the soil. According to the results 30.4% of sclerotia were able to germinate after one month storage at minus 72 ºC.Keywords: Aggregate sheath spot, Blight, Fungi, Overwintering, Rice, Sclerotia, Viability} -
اطلاعات جدیدی در مورد سیاهک های ایران ارایه می گردد. هیبرید Ustilago hordei × U. nuda روی جو در استان یزد به عنوان عامل غالب سیاهک سخت جو گزارش می شود. گونه Urocystis tianschanica روی Critesion violaceum گزارش می گردد. گونه Tranzscheliella iranica برای دومین بار بعد از نمونه درج شده در پروتولوگ بازیابی و برای اولین بار به طور مصور تشریح می شود. هم چنین Tilletia loliolli به عنوان عامل سیاهک Loliolum subulatum در ایران معرفی می شود.
کلید واژگان: قارچ, قارچ شناسی, تنوع زیستی, بیماری های گیاهی, تاکسونومی}The following new findings about Iranian smut fungi are presented: 1-Ustilago hordei × U. nuda hybrids are reported on Hordeum vulgare from Yazd province. Our study showed that main causal agent of covered smut in the province is above hybrids. 2- Urocystis tianschanica is newly reported from Iran on Critesion violaceum. 3- Tranzscheliella iranica is also reported from Yazd province, Deh Bala. Before our report, this species was known only from the type locality. 4- Revision of herbarium specimens of infected Loliolum subulatum revealed that smut species on these specimens belongs to Tilletia lolioli not T. bromi. All above mentioned taxa are documented by microphotographs and Persian description.Keywords: Fungi, Mycology, Biodiversity, Plant Diseases, Taxonomy} -
The present study is based on oribatid mite material collected from fungi during the Russian-Vietnamese expedition in July 2012 in Dong Nai Biosphere Reserve of Southern Vietnam. An annotated checklist of oribatid mite taxa is presented. It includes 61 species and one subspecies, 44 genera and 27 families. Nine species (Allonothrus russeolus, Basilobelba retiaria, Acroppia processigera, Dolicheremaeus junichiaokii, Basiceramerus igorotus, Zetorchella reticulata, Tuberemaeus singularis, Nesopelops intermedius, Notogalumna foveolata), one subspecies (Scheloribates praeincisus interruptus), five genera (Allonothrus, Acroppia, Basiceramerus, Nesopelops, Notogalumna) are first records for Vietnam. A new oribatid mite species, Carabodes (Klapperiches) mikhaetandreorum sp. nov. (Carabodidae), is described. The new species is very similar morphologically to C. (K.) atrichosus Mahunka, 1984 and C. (K.) problematicus Mahunka, 1985, however, it clearly differs from both by the absence of the translamella and the position of the adanal setae ad1. Basiceramerus igorotus Corpuz-Raros and Gruèzo, 2011 (Otocepheidae) is redescribed, based on the Vietnamese specimens.Keywords: oribatid mites, new species, Carabodes (Klapperiches), redescription, Basiceramerus, fauna, fungi, new record, checklist, Vietnam}
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