First report of Clavibacter michiganensis subsp. sepedonicus causing bacterial ring rot of potato in

Ş. Altundağ¹, A. Karahan^1*, A.O. Kılınç¹ and M. Özakman²   

¹ Plant Protection Central Research Institute, Gayret Mahallesi, Fatih Sultan Mehmet Bulvarı No: 66, Yenimahalle 06172, Ankara, Turkey
² Gennova Pesticide Company, Bekir Saydam Cad., No: 31, Pancar, Torbalı, İzmir, Turkey

* [e-mail]

Accepted for publication 04 Dec 2008

During the 2007 seed potato monitoring programme in Turkey, 336 tuber samples from Kayseri province were tested for the presence of ring rot and brown rot diseases according to the EC Directives 93/85/EEC (Anon., 1993) and 98/57/EC (Anon., 1998). Three samples gave a positive immunofluorescence test (IF) result for the ring rot pathogen, Clavibacter michiganensis subsp. sepedonicus (Spieckermann & Kotthoff) Davis. et al.(Cms). Tuber heel end extracts were plated onto NCP-88 medium. Creamy-white, smooth, mucoid-fluidal colonies were selected and purified. External symptoms were observed on tubers of all three samples (two of cv. Soleia and one of cv. Safrane) as sunken and cracked areas (Fig. 1). When tubers were cut transversely, typical symptoms were seen through the vascular ring of tubers as a brown cheesy decay. Bacterial ooze was expressed when tubers were squeezed (Fig. 2). A positive IF result was obtained directly from the ooze. Isolates hydrolysed aesculin and produced catalase. They did not produce acid from glycerol, lactose, rhamnose and salicin. They gave negative results for oxidase activity, growth at 37°C, urease activity, starch hydrolysis, tolerance of 7 % NaCl, indole production and gelatine liquefaction.

Suspensions of pure colonies in water (c. 10⁹ cfu per ml from each of the three samples were used for real-time PCR (Schaad et al. ,1999), with Ct values of 16.53, 16.21 and 32.2. Suspensions (10⁶ cfu/ml) were injected into stems of ten Solanum melongena plants (cv. Black Beauty) at leaf stage 3. Control plants were inoculated with sterile water. Plants were incubated at 21°C and 70-80 % humidity. First symptoms were observed as dark green areas on leaves after ten days followed by wilting and necrosis (Figure 3). Cms was re-isolated and identified.

An intensive survey in 1988-1989 had shown that the potato growing areas of Turkey were free of the ring rot pathogen (Benlioğlu et al., 1991). This is the first report of Cms in Turkey. Strict control measures have been taken in contaminated and potentially contaminated fields since Cms is a regulated quarantine organism in Turkey.

 

 

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References

Anon., 1993. Council Directive 93/85/EEC on the control of potato ring rot . Official Journal of the European Communities L 259, 1-25.

Anon., 1998. Council Directive 98/57/EC on the control of Ralstonia solanacearum (Smith) Yabuuchi et al. Official Journal of the European Communities L 235, 1-39.

Benlioğlu K, Öktem Y.E, Özakman M, 1991. Bacterial diseases of potatoes in the major potato-growing areas in Turkey. Bulletin OEPP/EPPO Bulletin 21, 67-72.

Schaad N.W, Berthier-Schaad Y, Sechler A, Knorr D, 1999. Detection of Clavibacter michiganensis subsp. sepedonicus in potato tubers by Bio-PCR and an automated real-time fluorescence detection system. Plant Disease 83, 1095-1100

First report of citrus huanglongbing disease on orange in Iran

M. M. Faghihi¹, M. Salehi², A. Bagheri¹ and K. Izadpanah^3*

¹ Hormozgan Agriculture and Natural Resources Research Centre, Iran
² Fars Agriculture and Natural Resources Research Centre, Iran
³ Department of Plant Protection, College of Agriculture, Shiraz University, Shiraz, Iran 

*[e-mail] 

Huanglongbing (HLB), also known as greening, is a destructive disease of citrus that may limit production of this crop in many parts of Asia, Africa and South America. HLB is caused by a non-culturable phloem-limited bacterium of the genus ‘Candidatus Liberibacter’. Three Candidatus species of Liberibacter, namely, ‘Ca. L. asiaticus’, ‘Ca. L. africanus’ and ‘Ca. L. americanus’, have been identified (Bové, 2006). The psyllid Diaphorina citri, vector of ‘Ca. L. asiaticus’ was first detected in December 1997 in Iran in an area close to the border with Pakistan (Bové et al., 2000). Since then, high populations of D. citri have been found in citrus plantations of Hormozgan and Kerman provinces in southern Iran (Bové, 2006). Citrus trees in this region exhibit typical HLB symptoms including mottling of leaves and yellowing of shoots. In the present study leaf samples from 20 symptomatic and 20 symptomless Valencia sweet orange trees (Citrus sinensis) and over 50 psyllid samples were collected from various locations in Sistan-Baluchistan and Hormozgan provinces and total DNA was extracted using the CTAB (cetyltrimethylammonium bromide) method. DNA samples were tested for presence of ‘Ca. L. asiaticus’ by nested PCR using primer pairs F1 (5’-TGAATTCTTCGAGGTTGGTGAGC-3’)/R1(5’-GAATTCGACTTAATCCCCACCT-3’) as the first set and F2(5’ GCGTTCATGTAGAAGTTGTG-3’) / R2(5’-CCTACAGGTGGCTGACTCAT-3) as the second set. Both primer pairs were designed based on the published beta-operon of ribosomal protein encoding sequence of ‘Ca. L. asiaticus’ (Villechanoux et al. 1993). Nested PCR resulted in amplification of a 400 bp product from five out of 20 leaf samples and 26 out of 50 psyllid samples. No amplicons were obtained from symptomless sweet orange trees and psyllid samples reared on healthy sweet orange seedlings. The amplified fragment from a psyllid sample was cloned and sequenced (GenBank Accession No. FJ172759). BLAST search showed 100% identity with corresponding sequences of ‘Ca. L. asiaticus’ (M9439, AY34200 and EU078703). This is the first report on the occurrence of HLB disease in Iran. The disease appears to be widely distributed in citrus growing regions of southern Iran and may be a component of citrus decline in this area.

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References

Bové JM, 2006. Huanglongbing: A destructive, newly–emerging, century-old disease of citrus. Journal of Plant Pathology 88, 7-37.

Bové JM, Danet G L, Bananej K, Hassanzadeh N, Taghizadeh M, Salehi M, Garnier M, 2000. Witches' broom disease of lime (WBDL) in Iran. In Yokomi, RH, da Graça, JV, Lee, RF, eds. Proceedings of the 14th Conference of the International Organization of Citrus Virologists, 300-309. Riverside, CA, USA: IOCV.

Villechanoux S, Garnier M, Laigret F, Renaudin J, Bové JM, 1993. The genome of the non-cultured, bacterial-like organism associated with citrus greening disease contains the nusG-rplKAJL gene cluster and the gene for a bacteriophage type DNA polymerase. Current Microbiology 26, 161-166.

Rathayibacter iranicus isolated from symptomless wheat seeds in Turkey

E. Postnikova¹, I. Agarkova², S. Altundag³, F. Eskandari¹, A. Sechler¹, A. Karahan³ A.K. Vidaver² W. Schneider¹, M. Ozakman³ and N.W. Schaad^1*

¹ ARS-USDA, Foreign Disease-Weed Science Research Unit, Ft. Detrick, Maryland, USA
² Department of Plant Pathology, University of Nebraska, Lincoln, Nebraska, USA
³ Plant Protection Research Institute, P.O. Box 49, Ankara, Turkey

*[e-mail]

Rathayibacter iranicus (Ri), originally reported in Iran in 1961 (Sharif, 1961), has not been reported outside Iran and only one strain is known to exist. Like R. tritici (Rt), Ri causes a gumming disease of wheat in association with the nematode Anguina tritici (Paruthi et al., 1989). During 2003, a survey of wheat seed for Rathayibacter species (RS) in Turkey using samples from 799 farmers in six provinces in Central Anatolia was conducted. The samples showed neither the brown to black galls typical of Anguina nor the yellowish galls typical of Ri and Rt. To determine the presence of RS, 120 g samples were washed in 100 ml of sterile 0.85% NaCl with 0.02% Tween 20 and plated onto 523 agar (Schaad et al., 2001) modified by adding 30 mg nalidixic acid, 15 mg polymixin B sulphate and 100 mg cycloheximide per litre. After incubation at 27º C for seven days, several typical colonies of RS were cloned by streaking onto YDC agar (Schaad et al., 2001). Twenty five strains were presumptively identified as RS based on a Gram positive reaction, oxidase negative reaction and yellow growth.

Three strains, TRS2 from Konya, TRS10 from Hisarkikaya, and TRS25 from Ankara, were used for further identification and speciation. The other 22 strains were archived for later studies. The type strains of Rt, (International Collection of Phytopathogenic Bacteria [ICPB] 70004^T; FH-5; CT 102^T) and Ri (ICPB 70005^T; FH-6 ^T; CI 148^T), were included as controls. All three strains were biochemically typical of Ri and Rt by producing acid from D-mannose, inulin, galactose, and mannitol.However, the strains failed to utilize acetate, or to hydrolyze casein, failed to grow in greater than 1% sodium chloride amended NBY, or on CNS agar, which is characteristic of Ri but not Rt (Davis & Vidaver, 2001). The new strains contained the fatty acids iso-14:0 and 16:0; anteiso 15:0 and 15:1, and 17:0, and 16:0, also typical of Ri. Identification of the three strains as Ri was further supported by 16s rDNA sequence similarities to Ri and Rt of 100%and 99.3%, respectively (GenBank Accession Nos. FJ595101 - Ri, ICPB 70005 and FJ595102 – Rt, ICPB 70004). Identification asRi was confirmed by AFLP analysis (EcoRI+0 and MseI+C) showing a pattern of 90% similarity to Ri but only 46% to Rt. This is the first report of Ri outside of Iran. Cultures have been deposited in the ICPB at Ft. Detrick, MD, USA, as ICPB 70146 (FH-154; TRS2), 70154 (FH-162; TRS10), and 70169 (FH-177; TRS25).

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References

Davis M.J., Vidaver A.K., 2001. Gram Positive Bacteria, Coryneform Plant Pathogens. In: Schaad N.W., Jones J.B., Chun W., eds, Laboratory Guide for Identification of Plant Pathogenic Bacteria, 3rd Edn, St. Paul, MN, USA: APS Press, 218-234.

Paruthi I. J., Bajaj H.K., Bhatti D.S., 1989. Further observations on Anguina tritici (Nematoda) and Corynebacterium michiganense pv. tritici causing earcockle and yellow ear rot in wheat. Nematologica 35, 491-493.

Schaad N.W., Jones J.B., Chun W., eds, 2001. Laboratory Guide for Identification of Plant Pathogenic Bacteria, 3rd Edn, St. Paul, MN, USA: APS Press, 373 pp.

Scharif G., 1961. Corynebacterium iranicum sp. nov. on wheat (Triticum vulgare L.) in Iran, and a comparative study of it with C. tritici and C. rathayi. Entomologie et Phytopathologie Appliqués 19, 1-24.

First report of Pseudomonas savastanoi pv. savastanoi causing olive knot in Syria

N. Alabdalla¹, F. Valentini¹, C. Moretti^2*, S. Essa³, R. Buonaurio² and M. Abu-Ghorra⁴

¹ Istituto Agronomico Mediterraneo, Via Ceglie 9, I-70010 Valenzano (Bari), Italy
² Dipartimento di Scienze Agrarie e Ambientali, sez. Arboricoltura e Protezione delle Piante, Via Borgo XX Giugno, 74, I-06121 Perugia, Italy
³ General Commission for Scientific and Agriculture Research, Lattakia Center, Lattakia, Syria
⁴ Division of Plant Pathology and Plant Protection, Faculty of Agriculture, University of Damascus, Syria

*[e-mail]

Accepted for publication 25 Mar 2009

During field surveys carried out in 2007 in the main Syrian olive (Olea europaea) growing areas, bacterial knot symptoms were observed on olive twigs and branches, with the highest incidence (70%) in the coastal region (Lattakia and Tartous). Bacterial colonies isolated from knots resembled those of Pseudomonas savastanoi pv. savastanoi. Ten selected representative bacterial strains and the reference strains LMG 2209^T, CFBP 6012 and 6013 of P. savastanoi pv. savastanoi were subjected to identification tests. All strains were Gram negative, fluorescent on King’s medium B and had oxidative but not fermentative metabolism. They were negative for levan, oxidase, potato rot and arginine dihydrolase and positive for tobacco hypersensitivity. One-year-old olive plants (cvs. Nebali and Jlot) were inoculated by introducing bacterial suspensions (10⁸ cfu/ml) into wounds made in the bark with a sterile scalpel. All strains induced knots at the site of inoculation from 20 days onwards. Bacteria with characteristics identical to the original strains were re-isolated from inoculated plants. PCR analysis using primers specific for P. savastanoi pv. savastanoi, which amplify fragments of iaaL (Penyalver et al., 2000) and ptz (Powell & Morris, 1986) genes, generated amplicons of the expected size from all strains. Using BOX-, ERIC- and REP-PCR, we demonstrated that the isolates have a similarity of 87-98.9 % between themselves and with the reference strains. Based on morphological, biochemical, physiological and pathogenicity tests as well as molecular analyses, we can conclude that the Syrian strains belongs to P. savastanoi pv. savastanoi.

Although strains from Syria have previously been characterised with respect to their ability to produce auxin (Gardan et al., 1992), this is the first authoritative report of olive knot disease symptoms in Syria caused by P. savastanoi pv. savastanoi.

 

Figure 1: Agarose gel electrophoresis of REP-, BOX-, and ERIC-PC fingerprint patterns obtained from Pseudomonas savastanoi pv. 9, SYR 38, SYR 43, SYR 62, SYR 2, SYR 3, SYR 49, SYR 24, SYR 56, SYR 53 (lanes 1 - 10); CFBP 6012 (lane 11); CFBP 6013 (lane 12); LMG 2209T (lane 13); negative control (lane C). M = molecular weight marker DNA Ladder Mix (MBI Fermentas, Burlington ON, Canada).

Figure 2: Dendrogram derived from REP-, BOX-, and ERIC-PCR fingerprint data and obtained by cluster analysis (UPGMA) and Dice’s coefficient.

Acknowledgements

The authors would like to thank Mr. L. Bonciarelli for his excellent technical assistance.

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References

Gardan L, David C, Morel M, Glickmann E, Abu-Ghorra M, Pettit A, Dessaux Y, 1992. Evidence for a correlation between auxin production and host plant species among strains of Pseudomonas syringae subsp. savastanoi. Applied and Environmental Microbiology 58, 1780-1783.

Penyalver R, García A, Ferrer A, Bertolini E, López MM, 2000. Detection of Pseudomonas savastanoi pv. savastanoi in olive plants by enrichment and PCR. Applied and Environmental Microbiology 66, 2673-2677.

Powell GK, Morris RO, 1986. Nucleotide sequence and expression of a Pseudomonas savastanoi cytokinin biosynthetic gene: homology with Agrobacterium tumefaciens tmr and tzs loci. Nucleic Acids Research 14, 2555-2565.

First report of pathogenicity group 2 of Leptosphaeria maculans causing blackleg of oilseed rape in

A. Z. Mirabadi^1*, K. Rahnama² and A. Esmaailifar³

¹ Oilseeds Research & Development Company, Pasdaran Avenue Sari province, Iran
² Department of Plant Protections, GorganUniversity Agricultural Sciences&Natural Resources, Iran
³ Department of Plant Protections, Faculty of Agriculture and Natural Resources Islamic AzadUniversity, Arak

*[e-mail]

Accepted for publication 28 Apr 2009

Rapeseed (Brassica napus) is one of the most important oilseed crops in Iran with more than 200,000 ha planted in 2008. Phoma blackleg (Leptosphaeria biglobosa), pathogenicity group 1 (PG-1) or non-aggressive type, has been reported on rapeseed from Golestan province (Fernando et al., 2007). Recently, in some regions of Mazandaran and Golestan provinces of northern Iran,typical stem canker symptoms were observed with incidence ranging from 20 to 60%. During October and November 2008, ascospores were isolated from pseudothecia on infected rapeseed debris and cultured on V8-agar medium (Mengistu et al. 1993). Based on the description of Punithalingam & Holliday (1972), sporulating colonies were identified as Leptosphaeria maculans (Desmaz.) Ces. & de Not. (Anamorph Phoma lingam (Tode: Fr.) Desmaz.).

Eleven isolates of L. maculans were used for determining the pathogenicity group according to phenotypic interaction (PI) on rapeseed cultivars including Westar, Quinta and Glacier. Nine seven-day old seedlings of each cultivar were inoculated for each isolate and the test was repeated three times. Wounded cotyledons were each inoculated with 10µl of conidial suspensions at 2 x 10⁷ spores/ml. All plants were maintained in a growth chamber at 21° C (light) to 16° C (dark), with a 16-hour photoperiod and relative humidity of 95%. After 10 days, disease severity wasrated on a 0-9 scale (Williams, 1985) (Fig. 1).

Two isolates (Es-5 and Es-7) were classified as belonging to pathogenicity group PG2 and nine isolates as PG1. PG2 isolates showed PI reactions 0 to 2, 7 to 9 and 7 to 9 on Glacier, Quinta and Westar, respectively. In addition, cultivars Hyola401 and Okapi were highly sensitive to PG-2 isolates in the cotyledon assay. This is the first report ofthe occurrence of Leptosphaeria maculans PG-2 in Iran.

Figure 1: Phenotypic interaction (PI) of Leptosphaeria maculans isolates (Es-5 and Es-7) on five rapeseed cultivars after 10 days.

Acknowledgements

Special thanks to the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) for providing the seeds needed for this testing.

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References

Fernando WGD, Ghanbarnia K, Salati M, 2007. First report on the presence of phoma blackleg pathogenicity group 1 (Leptosphaeria biglobosa) on Brassica napus (canola/ rapeseed) in Iran. Plant Disease 91, 465.

Mengistu A, Rimmer RS, Williams PH, 1993. Protocols for in vitro sporulation, ascospore release, sexual mating, and fertility in crosses of Leptosphaeria maculans. Plant Disease 77, 538-540.

Leptosphaeria maculans. CMI descriptions of pathogenic Fungi and Bacteria. No. 331. Kew, UK: Commonwealth Mycological Institute.

Williams PH, 1985. Crucifer Genetics Cooperatives (CrGC) Resource Book. Madison, WI, USA: University of Wisconsin.

First report of a potato cyst nematode, Globodera rostochiensis, on potato, in Iran

M. Gitty¹ and Z. Tanha Maafi ²*

¹ Agricultural and Natural Resources Research Center of Hamadan, Iran
² Iranian Research Institute of Plant Protection, P.O. Box 1454, Tehran, 19395, Iran

*[e-mail]

Accepted for publication 05 May 2009

In June 2008 a few ware potato fields in Hamadan Province in the western part of Iran showed patches of about 20-200 m2of poor growth. Potato plants in these areas exhibited symptoms of severe stunting and nutrient deficiency along with yellow leaves and wilting (Fig. 1). Roots of infested plants showed white, golden mature females and brown cysts on their surface (Fig. 2). Cysts and second stage juveniles were extracted from soil and root samples.

The morphological and morphometrical characters of second stages juveniles and perineal area of cysts were examined by light microscope. The cysts showed the general characteristics of Globodera genus i.e. almost spherical body without vulval cone, circumfenestrate opening of the perineal area and subterminal anus, with the distance from anus to the vulval basin (n=25) 49.56 ± 9.68 (32-68) µm, the vulval basin diameter 15.24 ± 1.92 (10-17) µm, the Granek's ratio 3.27±0.61 (2.25-4.47), and the number of cuticular ridges between anus and vulval basin (n=16) 19±2.5 (15-24). Second stage juveniles (n=16) had stylet length 21.12±0.95 (20-23) µm with rounded knobs, tail length 52.7±2.9 (48-57) µm, and hyaline part of tail 28.12±3.53 (20-33) µm.

A molecular test was done for complementary diagnosis. DNA was extracted from several single cysts as described by Tanha Maafi et al. (2003) and amplified by species specific primers (Fullaondo et al., 1999). On the basis of the results obtained the cysts were identified as Globodera rostochiensis [Wollenweber, 1923 (Behrens, 1975)] (Wouts & Baldwin, 1998; OEPP/EPPO. 2004). The morphological diagnosis was confirmed by amplifying a single fragment of 315bp length which corresponded with Fullaondo et al., 1999. No amplification was produced with the specific primers for G. pallida. Potato cyst nematodes (PCNs) are considered quarantine pests in Iran and this is the first report of the genus Globodera and G. rostochiensis from Iran.

Figure 1: Patches of infested potato field showing poor growth

Figure 2: Mature females and cysts of Potato cyst nematode, Globodera rostochiensis on the root surface of potato plant

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References

OEPP/EPPO, 2004. Globodera rostochiensis and Globodera pallida. PM 7/40(1),Bulletin OEPP/EPPO Bulletin34, 309 –314.

Fullaondo A, Barrena E, Viribay M, Barrena I, Salazar A, Ritter, E. 1999. Identification of potato cyst nematode species Globodera rostochiensis and G. pallida by PCR using specific primer combinations. Nematology 1, 157-163.

Tanha Maafi Z, Subbotin SA, Moens M, 2003. Molecular identification of cyst-forming nematodes (Heteroderidae) from Iran and a phylogeny based on the ITS sequences of rDNA. Nematology 5, 99-111.

Wouts WM, Baldwin JG, 1998. Taxonomy and Identification. In: Sharma SB, ed. The Cyst Nematodes. Dordrecht, The Netherlands: Kluwer Academic Publishers, 83-122

خصوصيات فنوتيپي استرين هاي ايراني ‏‎Erwinia amylovora ( Burill) Winslow et al. ,‎‏ عامل باكتريايي بي

                                                 محمدرضا افيونيان

در اين بررسي تعداد پنجاه استرين جدا شده از ميزبانهاي سيب ، گلابي ، به ، گل سرخ و ازگيل از مناطق قزوين ، تهران ، كرج ، هشتگرد ، طالقان ، خوي ، سلماس و اروميه مورد بررسيهاي فنوتيپي و الكتروفورز پروتئين و پلاسميد و حساسيت نسبت به آنتي بيوتيكها قرار گرفت . استرين ها لوان و كاتالاز مثبت ، قادر به تحريك واكنش فوق حساسيت در برگهاي توتون و شمعداني و توليد تراوشات باكترياييبر روي ميوه هاي نارس گلابي بودند . واكنش گرم و اكسيداز منفي بوده و قادر به احياي نيترات و يا توليد رنگ فلورسانت نبودند. همه استرين ها هوازي اختياري ، اوره آز منفي ، قادر به تحمل نمك طعام 5% و دماي 35 درجه سانتي گراد بودند . واكنش توليد مواد احياء كننده از ساكارز در تمامي استرينها مثبت بود . توليد استوئين پس از دو روز مثبت و پس از پنج روز منفي ثبت گرديد. ژلاتين به كندي هيدروليز شده ولي هيچكدام از استرينها قادر به هيدروليز نشاسته ، كازئين ، آرژي نين ، توئين 80 و يا اسكولين نبودند . توليد اندول ، گاز از گلوكز ، فنيل آلانين دي آميناز ، لستيناز ، فسفاتاز و يا توليد رنگ صورتي در محيط ‏‎YDC‎‏ در تمامي استرينها منفي بود . تمامي استرينها از گلوكز ، ساكارز، گالاكتوز ، مانيتول ، تري هالوز ، ريبوز ، ساليسين ، آرابينوز ، سلوبيوز ، اينوزيتول ، فروكتوز ، گليسرول ، سيترات ، سوكسينات و فومارات استفاده كرده و توليد اسيد يا قليا نموده و اكثرا توانايي مصرف فرمات را داشتند ولي قادر به مصرف اينولين ، اسيد نيكوتينيك ، نيكوتين آميد ، مالونات، تارتارات ، آسكوربات ، گلوكانات ، گالاكتيورونات ، پروپيونات ، اگزالات ، دي گلوتاميك اسيد ، لاكتات ، بنزوات ، استات و يا پلي پكتات سديم نبودند . نقوش الكتروفورز پروتئين همه استرينها يكسان بود و در الكترفورز ژل آگارز نيز تمامي آنها داراي دو نوار پلاسميدي با وزن هاي مولكولي مشابه بودند . تمامي استرين ها در آزمون نشت دو طرفه در آگار در برابر سه آنتي سرم مصرفي يك باند رسوبي قوي ايجاد نمودند. واكنش غير اختصاصي مشاهده نگرديد. آنتي ژن حاصل از باكتري كشته شده با حرارت ، واكنش قوي تر نسبت به آنتي ژن تيمار نشده ( سوسپانسيون باكتري زنده ) توليد نمود . كروماتوگرام حاصل از كروماتوگرافي ليپيدهاي استرين ها روي صفحه نازك سيليكاژل شامل سه لكه عمده بود و تفاوتي بين استرين ها مشهود نبود . بر اساس نتايج حاصله ، استرين ها باكتري عامل آتشك سيب و گلابي جدا شده از مناطق مختلف ايران در خصوصيات بررسي شده همانند ( هموژن ) و غير قابل تمايز بودند.

تعيين خصوصيات و تفكيك استرين هاي ايراني باكتري Erwinia amylovora با استفاده از روش هاي بيوشيميايي و

                                                              رضا اميدوار

بيماري آتشك درختان ميوه دانه دار گسترش جهاني داشته و در سال هاي اخير نيز خسارات هنگفتي به باغ هاي ميوه دانه دار در برخي مناطق ايران وارد كرده است. از آنجا كه بدون شناخت دقيق عامل بيماري مبارزه با آن مشكل خواهد بود، لزوم بررسي و شناخت دقيق عامل بيماري و تنوع ژنتيكي آن ضروري مي باشد. با توجه به اين كه تنوع ژنتيكي استرين هاي باكتري E,amylovora، جداشده از ميزبان ها و مناطق مختلف ايران بررسي نشده است، اين تحقيق به بررسي تنوع ژنتيكي جدايه هاي ايراني باكتري اختصاص يافت. جدايه هاي باكتريايي جمع آوري شده از ميزبان ها و مناطق مختلف جغرافيايي ايران، از لحاظ ويژگي هاي فنوتيپي و الگوي پروتئيني و همچنين تنوع ژنتيكي تعدادي از استرين ها با استفاده از نشانگر RAPD مورد بررسي قرار گرفت. انجام آزمون هاي فيزيولوژيكي و بيوشيميايي و مقايسه الگوي پروتئيني، وجود سطح تشابه بالايي را در ميان استرين ها آشكار ساخت. همچنين تمامي استرين ها در آزمايشات RAPD-PCR، الگوهاي يكساني توليد كردند. بنابراين مشخص گرديد كه استرين هاي ايراني E.amylovora از نظر ژنتيكي مشابه بوده و بر اساس منطقه جغرافيايي، ميزبان و سال جداسازي قابل تفكيك نيستند.

 

درخت انجیلی

Parrotia persica (Persian Ironwood) is a deciduous tree in the family Hamamelidaceae, the sole species in the genus Parrotia but closely related to the genus Hamamelis (Witch-hazels). It is native to northern Iran, where it is endemic in the Alborz mountains

.

لکه برگی های درخت اوکالیپتوس

Eucalypt leafspots Species:

Aulographina eucalypti (Ascomycete) (anamorph Thyrinula eucalypti)

Mycosphaerella cryptica (Ascomycete) (anamorph Colletogloeum nubilosum)

Mycosphaerella nubilosa (Ascomycete)

Mycosphaerella swartii (Ascomycete) (anamorph Sonderhenia eucalyptorum, syn. Hendersonia eucalyptorum)

Phaeophleospora eucalypti (Ascomycete) (syn. Kirramyces eucalypti, Septoria pulcherrima)

Phaeothyriolum microthyrioides (Ascomycete) (syn. Microthyrium eucalypti)

Pseudocercospora eucalyptorum (Ascomycete anamorph) (syn. Cercospora eucalypti)

Trimmatostroma bifarium (Ascomycete anamorph)

Trimmatostroma excentricum (Ascomycete anamorph

Fig, 13: Leafspots caused by Aulographina eucalypti on Eucalyptus regnans



Fig. 16: Cankers on twigs of Eucalyptus delegatensis caused by Mycosphaerella cryptica)

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