Alternaria leaf spot on Paeonia peregrina and Paeonia tenuifolia in Serbia

Tatjana Marković,Željana Prijić,Sara Mikić,Nina Vučković,Jingqi Xue

doi:10.61652/leksir2343e176m

Abstract

&lt;p&gt;&lt;em&gt;Paeonia peregrina&lt;/em&gt; Mill. and &lt;em&gt;Paeonia tenuifolia&lt;/em&gt; L. are endangered species of herbaceous plants with high ornamental and medicinal values. There are a few natural habitats in Serbia where these plants spontaneously grow: Krivi Vir, Skrobnica, Golina, Pirot, Deliblato Sands, and Sokobanja, in the municipality of Knjaževac. In July 2021, the symptom of leaf spots was observed on &lt;em&gt;P. peregrina&lt;/em&gt;, while spots on leaves, stems, and lower branches on &lt;em&gt;P. tenuifolia&lt;/em&gt; in the localities of Pirot and Deliblato Sands. Disease incidence was estimated to 32% in Pirot and 25-35% in Deliblato Sands. Therefore, the aim of the study was to identify the causal agent of leaf spot on &lt;em&gt;P. peregrina&lt;/em&gt; and &lt;em&gt;P. tenuifolia&lt;/em&gt; in Serbia by molecular identification and characterization, and morphological characterization. For molecular identification and characterization, nuclear ribosomal internal transcribed spacer (ITS) region, partial translation elongation factor 1-alpha (&lt;em&gt;EF-1&amp;alpha;&lt;/em&gt;), beta-tubulin (&lt;em&gt;TUB2&lt;/em&gt;) and histone 3 (&lt;em&gt;H3&lt;/em&gt;) genes were amplified using primer pairs ITS1/ITS4, EF1-728F/EF1-986R, T1/Bt2b, and H3-1a/H3-1b, respectively. Morphological characterization of the representative isolates was done on potato dextrose agar (PDA) and potato carrot agar (PCA) media at 22 &lt;sup&gt;◦&lt;/sup&gt;C under an 8 h light:16 h dark regime. Based on the molecular and morphological characteristics of the obtained isolates, &lt;em&gt;Alternaria alternata &lt;/em&gt;was identified as the causal agent of leaf spot on &lt;em&gt;P. peregrina&lt;/em&gt; and &lt;em&gt;P. tenuifolia&lt;/em&gt;. In Serbia, to the best of our knowledge, this is the first report of &lt;em&gt;A. alternata &lt;/em&gt;causing a leaf spot of &lt;em&gt;P. tenuifolia&lt;/em&gt;.&lt;/p&gt;

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