Karakterizacija Eutypa lata, prouzrokovača odumiranja čokota vinove loze u Srbiji i osetljivost sorti

Abstract

U peroiodu od 2004. do 2012. godine, na teritoriji Srbije, uočeni su simptomi odumiranja čokota vinove loze. Simptomi se najpre ispoljavaju u vidu sitnih, hlorotičnih i nekrotičnih pega po obodu listova, deformacijom listova, pojavom skraćenih lastara, često sa tzv. cik-cak porastom internodija. Vremenom dolazi do delimičnog ili potpunog sušenja čokota vinove loze. Primenom standardnih fitopatoloških metoda iz simptomatičnih biljaka vinove loze dobijeno je 47 izolata Eutypa sp. iz 14 lokaliteta. Izolati potiču iz sledećih sorti vinove loze: Kaberne sovinjon, Rkaciteli, Prokupac, Rizling rani, Burgundac crni, Italijanski rizling, Sovinjon, Šardone, Frankovka i Kardinal. Patogenost izolata proverena je veštačkom inokulacijom zdravih reznica vinove loze sorte Kaberne sovinjon. Svi proučavani izolati prouzrokuju nekrozu tkiva oko mesta inokulacije, hlorozu i deformaciju listova kao i pojavu sitnih, nekrotičnih pega po obodu liski koji vremenom opadaju. Inokulisane reznice zaostaju u porastu dobijajući žbunast izgled sa cik-cak porastom internodija. Identifikacija proučavanih izolata Eutypa sp. izvršena je na osnovu morfoloških osobina i prisustvo piknida u kulturi. Piknidi su loptastog ili nepravilnog oblika, tamnosmeđe do crne boje, veličine 0,5-1 mm. Iz piknida se izlučuje konidijalna masa krem do bledo narandžaste boje. Konidije su jednoćelijske, neseptirane, hijalinske, izdužene i umereno krive sa spljoštenom osnovom, dimenzija 36,10 μm × 1,71 μm. Različite hranljive podloge i tipovi svetlosti imaju veliki uticaj na sporulaciju proučavanih izolata Eutypa sp. Najintenzivnija sporulacija svih proučavanih i kontrolnih izolata odvijala se na PDA podlozi, zatim na MA, GWA i WA, dok na podlogama YA i TA ni nakon 3 meseca ne dolazi do sporulacije. Izlaganje kultura režimu od 24 h UV svetlosti se pokazalo kao najpogodnije za razvoj konidija, potom 12 h UV i 12 h tame, dok je najnepovoljniji režim svetlosti za razvoj konidija je 12 h svetla i 12 h tame. Pročavane kulture ne formiraju teleomorfni stadijum...

During the period from 2004 to 2012, symptoms of grapevine dieback were observed in Serbia. Symptoms initially appear as small, chlorotic and necrotic spots along the rim of the leaves, deformation of leafs and the appearance of shortened shoots, often with the so-called zig-zag internodes. Over time, partial or complete dying of the vines develops. Standard phytopathological methods were used and 47 isolates were obtained from symptomatic grapevine plants from 14 localities. The isolates originate from the following cultivars: Cabernet Sauvignon, Rkaciteli, Prokupac, Riesling early, Pinot noir, Italian Riesling, Sauvignon, Chardonnay, Franconien noir and Cardinal. Pathogenicity of isolates was tested by artificial inoculation of healthy grapevine cuttings cv. Cabernet Sauvignon. All studied isolates cause tissue necrosis around the site of inoculation, chlorosis and deformation of the leaves, along with the appearance of tiny, necrotic spots on the periphery of the leaf that falls of over time. Inoculated cuttings are stunted, dwarf-like with zig-zag internodes. Identification of the studied isolates was performed on the basis of morphological properties and the presence of pycnidia in the culture. Pycnidia are spherical or irregular shape, ranging from dark brown to black, measuring 0,5-1 mm. Pycnidia exude conidial mass pale brown to pale orange color. Conidia are single celled, non-septate, hyaline, elongated and curved with flat basis, measuring 36,10 μm × 1,71 μm. Different artificial mediums and types of light have major influence on sporulation of tested isolates Eutypa sp. Most intense sporulation of all studied and control isolates was on PDA medium, followed by MA, GWA and WA, while on YA and TA mediums no sporulation occurred after 3 months. Exposure of cultures to 24h UV light proved to be the most suitable for the development of conidia, followed by 12h UV and 12h darkness, while the most unfavorable regime of light for the development of conidia was 12h light and 12h darkness. Tested cultures of Eutypa sp. did not form a teleomorphic stage...