نماتدهاي انگل خانواده Hoplolaimidae همراه گياهان زينتي در استان گيلان

Parasitic nematodes (Family: Hoplolaimidae) associated with ornamental palnts in Guilan Province

به منظور شناسايي نماتدهاي انگل گياهان زينتي استان گيلان، طي فصول تابستان و پاييز ، تعداد 115 نمونه خاك از فراريشه ي گونه هاي مختلف گياهان زينتي گلخانه اي و فضاي سبز از نقاط مختلف استان جمع آوري شد. پس از استخراج، تثبيت و انتقال نماتدها به گليسيرين، پرپاراسيون‌هاي ميكروسكوپي دائمي تهيه گرديد. شناسايي گونه ها با استفاده از ميكروسكوپ نوري مجهز به لوله ترسيم و دوربين ديجيتال، بر اساس ويژگي هاي ريخت شناختي و ريخت سنجي و به كمك كليدهاي شناسايي معتبر انجام گرفت. در اين بررسي، هفت گونه نماتد متعلق به خانواده Hoplolaimidae شامل Helicotylenchus dihystera، H. erythrinae، H. exallus،H. microlobus، H. pseudorobustus، H. sharafati وScutellonema brachyurus شناسايي شد. گونه هاي H. microlobus و H. sharafati براي اولين بار از ايران گزارش مي شوند. گونه H. microlobus با فقدان ناحيه مشبك روي دم، ادغام خطوط داخلي شيارهاي جانبي به اندازه ي طول دو حلقه ي كوتيكولي در انتهاي دم و فاسميدي كه به‌سختي ديده مي‌شود، از گونه هاي نزديك متمايز مي گردد. ويژگيهاي قابل تفكيك H. sharafati از گونههاي مشابه، كمتر بودن تعداد حلقههاي سر، گوشه‌دار بودن گره هاي استايلت و شكل متفاوت دم (سطح پشتي انتهاي دم، تخت و در انتها داراي زائده‌ي كوتاه به طول يك حلقه‌ي كوتيكولي) به‌همراه انتهاي خاص شيارهاي جانبي (عدم ادغام شيار‌ها و گرد شدن آن‌ها در انتهاي دم) است. همچنين به دليل موجود نبودن شرح كاملي از H. erythrinae در ايران، اين گونه نيز توصيف شده است.

Background and Objectives Ornamental plants are grown for decorative purposes in gardens and landscape design projects, as houseplants, for cut flowers and specimen display. The cultivation of these, called floriculture, forms a major branch of horticulture. Nematodes are a diverse group of wormlike animals found in a number of habitats. Plant-parasitic nematodes are recognized as one of the greatest threats to crops throughout the world. Nematodes alone or in combination with other soil microorganisms have been found to attack almost every part of the plant including roots, stems, leaves, fruits and seeds. Hoplolaimidae is a family of plant parasitic nematodes. The common name, spiral nematode, is most often applied to nematodes in the genus Helicotylenchus, but it is also sometimes applied to other genera in the family Hoplolaimidae. These are called spiral nematodes because their bodies tend to curl into a spiral when the nematodes are relaxed or dead. The spiral nematodes have been reported in the worlds associated with various cultivated horticultural, agronomic, ornamental, and turfgrass plants. Materials and Methodes In order to identify the ornamental plants parasitic nematodes in Guilan province, 115 soil samples from rhizosphere of various species of ornamental plants in greenhouse and landscaping were collected from different parts, during the summer and fall in 2011-12. After extraction, fixation and transferring nematodes to anhydrous glycerol, the nematodes were mounted on permanent microscopic slides and nematode species were identified by using light microscope, equipped with drawing tube and digital camera, based on morphological and morphometric characters using valid identification keys. Results In this research, 7 nematode species belonging to Hoplolaimidae family including Helicotylenchus dihystera, H. erythrinae، H. exallus, H. Microlobus, H. Pseudorobustus, H. sharafati and Scutellonema brachyurus were indentified. Two species, H. pseudorobustus and H. sharafati were reported for the first time from Iran. Discussion H. microlobus is distinguished from close speciecs by lack of areolation on the tail, fusing of inner incisures of the lateral fields distally for about two annules and unclear phasmid. Distinguishable charatcters of H. Sharafati from close species are as below: less labial annules, angular spear knobs and differently shaped tail with characteristic endings of lateral fields. There is no measurement and description of H. erythrinae available in Iran so the description of this species is also illustrated.