Differences in Occurrence and Co-occurrence of Sirococcus conigenus and Diplodia pinea on Blighted Red Pine Shoots

Blighted red pine shoots, either having symptoms nly on the most recent year’s growth or having symptoms present both on most recent and pre vious year’s growth, were examined for pycnidia of Sirococcus conigenus , Diplodia pinea, or both. On shoots having symptoms only on the most recent year’s growth, S. conigenus was detected more frequently than D. pinea. On shoots having symptoms on both the most recent and the previous year’s growth, however, D. pinea was detected more frequently than S. conigenus on the most recent year’s growth. In addition, on those shoots having symptoms on both t he most recent and the previous year’s growth, D. pinea was detected almost eight times more frequently on the previous year’s growth than the most recent year’s growth. Whether only one pathogen was detected or the two pathogens were detected co-occurring on a singl e year’s growth also varied with shoot condition and shoot year of growth, but the two fun gi co-occurred on shoots of each condition. Pinus resinosa / Sirococcus strobilinus / Sphaeropsis sapinea Kivonat – Eltérések a Sirococcus conigenus és a Diplodia pinea előfordulása és együttes előfordulása között Pinus resinosa pusztuló hajtásain. Vagy csak a folyó évi, vagy a folyó és el őző évi növedékeken is tünetet visel ő, pusztuló Pinus resinosa hajtásokon vizsgáltunk a Sirococcus conigenus és/vagy Diplodia pinea piknídiumok jelenlétét. A csak folyó évi tünetes hajtásokon a S. conigenus gyakoribb volt, mint a D. pinea. A folyó, és el őző évi növedéken is tünetes hajtásokon viszont a legújabb növedéken a D. pinea gyakoribb volt, mint a S. conigenus . Ráadásul a legújabb és az el őző évi növedéken is tüneteket hordozó hajtások esetében az el őző évi növedéken a D. pinea csaknem nyolcszor gyakoribbnak bizonyult, mint a folyó évi növedéken. Csak az egyik, vagy mindkét kórokozó együttes el őfordulása az egyes növedékeken a hajtás állapotától és a növedék évét ől függően változott, de a két gomba minden állapotú hajtáson együttesen fordult el ő. Pinus resinosa / Sirococcus strobilinus / Sphaeropsis sapinea * Corresponding author: grs@plantpath.wisc.edu; 1630 Linden Drive, Madison, WI 53706, USA Stanosz, G. – Smith, D.R. Acta Silv. Lign. Hung. Spec. Edition, 2007 116

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