New host and country records of the Dothistroma needle blight pathogens from Europe and Asia
Dothistroma needle blight (DNB) is a serious disease of pines (Pinus spp.), with a worldwide distribution. It is caused by the ascomycete fungi Dothistroma septosporum (teleomorph: Mycosphaerella pini) and Dothistroma pini (teleomorph unknown). Recently, DNB was found on Pinus peuce in Austria, Pinus pallasiana in Ukraine and the European part of south-western Russia, as well as on Pinus radiata and Pinus wallichiana in Bhutan. Based on DNA sequence comparisons of the internal transcribed spacer and β-tubulin gene regions, isolates from Austria and Bhutan were identified as D. septosporum, while isolates from Ukraine and south-western Russia were identified as D. pini. Additional isolates studied from Pinus mugo in Hungary confirmed the presence of D. septosporum in this country. The record of D. septosporum on exotic P. peuce in Austria represents a new host report of this needle blight pathogen in Europe. Likewise, DNB and the associated pathogen, D. septosporum are reported from Bhutan, eastern Himalayas, for the first time. In addition, D. pini was found in two European countries and on a new host, P. pallasiana. These European records represent the only reports of D. pini from outside the north-central USA. Morphological examination of selected specimens from different hosts and countries showed that D. septosporum and D. pini overlap in the length of their conidia, while the width is slightly wider in D. pini than in D. septosporum. The differences in conidial width are so small, however, that identification of the two Dothistroma species solely based on morphology is virtually impossible. The new host and country records provided here are consistent with the continuing trend of reports of the DNB pathogens from new hosts and new geographical areas during the last two decades, particularly in the northern hemisphere.
Document Type: Research Article
Affiliations: 1: Institute of Forest Entomology, Forest Pathology and Forest Protection (IFFF), Department of Forest and Soil Sciences (DFS), University of Natural Resources and Applied Life Sciences, Vienna (BOKU), Vienna, Austria 2: Department of Mycology and Plant Resistance, V.N. Karasin National University of Kharkiv, Kharkiv, Ukraine 3: Renewable Natural Resources Research Centre (RNR-RC), Jakar, East Central Region, Council for RNR Research of Bhutan, Ministry of Agriculture, Royal Government of Bhutan, Bumthang, Bhutan 4: Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa 5: Department of Biology and Pedology, South Federal University, Rostov-na-Donu, Russia
Publication date: June 1, 2008