Conidial state of Leveillula taurica (Ascomycota: Erysiphaceae): A new record on Peganum harmala from arid Sinai, Egypt

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1 Basic Research Journal of Agricultural Science and Review ISSN Vol. 4(11) pp November 2015 Available online http// Copyright 2015 Basic Research Journal Full Length Research Paper Conidial state of Leveillula taurica (Ascomycota: Erysiphaceae): A new record on Peganum harmala from arid Sinai, Egypt Ahmed I. S. Ahmed 1* and Ahmed M. Abdel-Azeem 2 1 Plant Pathology Unit, Plant Protection Department, Desert Research Center; El-Matarya, Cairo, Egypt. 2 Department of Botany, Faculty of Science, University of Suez Canal, Ismailia, 41522, Egypt. *Corresponding author ahmed_drc@yahoo.com; Accepted 26 November, 2015 Abstract In May 2013 to May 2015, leaves of Peganum harmala with typical symptoms of powdery mildew were collected in Saint Katherine Protectorate, South Sinai, Egypt. The pathogen was identified as the anamorphs of Leveillula taurica. Phenotypic identification of the pathogen with light and SEM is provided. This is the first report of a powdery mildew on Pegaum harmala in Egypt. Keywords: anamorph, powdery mildew, Saint Katherine protectorate, wild Syrian rue INTRODUCTION Egypt is home to 384 different species of medicinal plants found in the Mediterranean coastal region, in the deserts, in the oases of the Libyan Desert and in the Sinai Peninsula (Baka, 2014). The Sinai Peninsula is one of Egypt s most floristically diverse and phytogeographically interesting regions. Many of the plants growing the desert in Sinai and the Negev are utilized by Bedouin for pasture, medicine (for animals and themselves), food and other miscellaneous uses (Bailey and Danin, 1981). The mountainous region of southern Sinai contains a greater biodiversity than the rest of Egypt, and 4350 km 2 of the area was declared a Protectorate in 1996 (Zalat et al., 2008). The Saint Katherine Protectorate is one of Egypt s largest protected areas and includes the country s highest mountains. Its situated in the southern part of Sinai and is a part of the upper Sinai massif. It is located between 33 55' to 34 30' East and 28 30' to 28 35' North (Khafagia et al., 2012). Wild Syrian rue (Peganum harmala L. family Zygophyllaceae) is well-known in the high-elevation sites surrounding the ring dyke of Saint Katherine Protectorate, South Sinai and various parts of this plant including, its seeds, bark, and root have been used as folk medicine (Chatterjee et al., 1968; Mahmoudian et al., 2002; Guenther et al., 2005; Movafeghi et al., 2009; Aboul-Enein et al., 2012; Zhao et al., 2011). Powdery mildew disease is one of the most important obligate parasitic diseases infecting a large number of plant species and causing economic losses of the plant, both in terms of quantity or quality (Hirata, 1968; Amano, 1986; Correll et al., 1987; Carlos and Soares, 2012). Surveying of plant pathogens in Egyptian prtoctorates is overlooked and only one study has been conducted during the last decade in Saint Katherine protectorate (Abdel-Azeem and Abdel-Moneim, 2009). During our continous survey of plant pathogens conducted on wild plants in Saint Katherine protectorate, typical symptoms of powdery mildew disease were observed on nearly 7% of the Peganum harmala plants in Wadi Itlah, Al-Arbaen and El-Talaa during the period from 2013 to However such symptoms were not observed in Pegaum harmala in Saint Katherine Protectorate before. The pathogen was examined and the pathogenicity test was demonstrated by fulfilling Koch's

2 Ahmed and Abdel-Azeem Figure 1. Study area map within Saint Katherine Protectorate. Table 1. Location of sampling sites Site No. Site Name GPS Reading N E Elevation (m) 1 Abu Sayla 28º 35' 15.9" 33º 55' 05.6" Abu Sayla 28º 35' 32.6" 33º 55' 11.9" Itlah 28º 34' 34.0" 33º 55' 34.5" Tala' 28º 34' 31.4" 33º 55' 34.9" Tala' 28º 34' 31.6" 33º 55' 34.4" Itlah 28º 34' 20.0" 33º 55' 43.5" Arbaein 28º 33' 04.0" 33º 56' 54.0" Arbaein 28º 32' 55.3" 33º 57' 01.2" Arbaein 28º 32' 40.1" 33º 56' 28.0" Arbaein 28º 33' 04.8" 33º 56' 53.0" 1594 postulates. MATERIALS AND METHODS Infected plants of P. harmala were collected from different altitudes and locations and recorded by GPS (Global Positioning System) form Wadi Itlah, Al-Arbaen and El-Talaa, Saint Katherine protectorate respectively from May 2013 to May 2015 (Figure 1, Table 1). Cotton-like masses of mycelia and conidia were recorded as the disease progressed on abaxial leaf surface, stems and petioles (Figure 2). Ascoma were not observed in any of sampled plants. Representative material of each of the examined samples is deposited as typical dried samples in the Mycological Herbarium of Royal Botanical Garden, Kew, UK with an accession number is: H2014/ Samples were collected under the permission of Saint Katherine protectorate for scientific purposes. Morphological characterization Infected leaves and hand made cross sections of infected petioles of all samples were examined under 100 to 1,000 using bright field microscopy (Leitz Laborlux S, Germany). Measurements of conidia length and width were done using 1000 primary and secondary conidia that were collected from host plant described in the present investigation. Other morphological criteria of the fungal structures associated with the imperfect stages of powdery mildew fungi were observed including color of conidia, vacuoles and type of germination tube according

3 323. Basic Res. J. Agric. Sci. Rev Figure 2. Symptoms of Leveillula taurica on Peganum harmala leaves, A- Infected plant in the field, B- Herbarium of the infected plant. to relevant references (Boesewinkel, 1980; Braun, 1987; Palti, 1988; Liberato and Barreto, 2005; Cook and Braun, 2009 and Vivas, et al., 2010). For SEM specimens were kept in 100% ethanol for 2 h and then successively transferred to mixtures of amyl acetate-ethanol according to Figueras and Guarrou (1988). Observations were done using an Environmental Hitachi scanning electron microscope S Pathogenicity test Six-week-old twenty plants of P. harmala were used for Koch postulates in the garden of Mr. Ramadan Gably Wadi Al-Arbaen, Saint Katherine ( in early of March 2014 and Plants were dusted copiously with conidia (3x10 6 conidia/ml) collected from infected P. harmala until the young leaves had a white powdery appearance. Relative humidity was not controlled and fluctuated between 23 and 55%. Development of powdery mildew symptoms as evidenced by white powdery spots was observed and recorded at 2-day intervals for 3 weeks, then at weekly intervals until plants matured. The experiment was repeated twice. RESULTS AND DISCUSSION Phenotypic examination showed that mycelium internal and external, superficial mycelium on stem and leaves, amphigenous, mostly persistent, thin to dense, white, patches, or covering the inter leaves or stems occasionaly effuse or evanesecent hyphae 5 µm wide. Conidiophores emerging through stomatas, solatory or in groups (Figure 3A), occasionally rising from superficial hyphae, erect, straight, cylinderical-filiform about µm long, 4 µm wide, forming conidia singly, rarely adhering in short false chains. Primary conidia lanceolate (Figure 3B) in the upper half narrowed towards the apex, tips pointed, base rounded, subtruncate to obconically truncate, vase-like, relatively cylinder, x µm, mostly widest in the lower half, sometimes in the middle of conidium, secondary conidia cylinderical, subcylinderical or some what clavate, approximately as large as the primary conidia, usualy x µm, widest in the middle or usually in the upper half. SEM studies show that conidial surface wrinkled to form ridges (Figure 4), um thick; and a net of polyangular, oblong meshes, 3-7 x µm, papillate usually hemispherical, usualy evenly scattered, but on the secondary conidia also in groups within meshes, 0.3 x 0.07 µm. Chasmothecia completely absent. Koch s postulates were fulfilled for P. harmala healthy plants after 32 to 45 days. Symptoms and signs of powdery mildew developed on the foliage of inoculated plants. Fungal morphology on all samples was similar to that described for the imperfect stage of Leveillula taurica (Braun and Cook 2012). Leveillula taurica has been reported on P. harmala worldwide (Marios-Nektarios 2004; Khodaparast et al., 2011) but this is the first report of this powdery mildew species on P. harmala in Egypt (Abdel-Azeem, 2010; Abdel-Azeem and Salem, 2014). Finally, the spread of plant pathogens among wild plants in Saint Katherine

4 Ahmed and Abdel-Azeem Figure 3. Leveillula taurica conidial state on Peganum harmala. A- Branched conidiophore, B- Primary Conidia. Figure 4. A- Low maginfication SEM micrograph showing conidia on the upper surface of infected leaf, B. High maginification of primary conidium showing wrinkled surface. protectorate may be refered to the climate change which affected the area in the last five years. Our findings in agreement with Pautasso et al. (2012) who stated that climate change is one of the most important factors affecting the spread of plant diseases by increasing, decreasing or remain stable depending on the particular pollutant and host-pathogen interaction. CONCLUSION We conclude that Egyptian Evironmental Affairs Agency (EEAA) should make a regular survey and update the information concerning plant pathogens infect the wild plants especialy medicinal taxa in the Egyptian protectorates. REFERENCES Abdal-Azeem AM, and Abdel-Moneim TS (2009). First record of Oidiopsis taurica causing powdery mildew of Capparis spinosa in Egypt. Plant Disease 93 (5): 555. Abdel-Azeem AM (2010). The history, fungal biodiversity, conservation, and future perspectives for mycology in Egypt. IMA Fungus 1(2): Abdel-Azeem AM and Salem FM (2014). In: Fifth National Report ( Aboul-Enein AM, Abu El-Ela F, Shalaby EA, El-Shemy HA (2012). Traditional medicinal plants research in Egypt: Studies of antioxidant and anticancer activities. J. Med. Plants Res. 6(5): Amano K (1986). Host Range and Geographical Distribution of the Powdery Mildew Fungi. Japan Scientific Societies Press, Tokyo. Baka ZAM (2014). Biological control of the predominant seed-borne fungi of tomato by using plant extracts. J. Phytopathol. Pest Manag. 1(3): Boesewinkel HJ (1980). The morphology of the imperfect states of powdery mildews (Erysiphaceae). The Botanical Review 46: Braun U (1987). A monograph of the Erysiphales (powdery mildews). Nova Hedwigia. 89:

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