First Report of Leaf Spot Caused by Phyllosticta capitalensis on Illicium difengpi in China

• DOI: 10.1094/pdis-01-22-0164-pdn
• Publication Date: 2022-07-08T13:16:07Z
• Authors: Aiming Jiang; Jiangan Hou; Guihe Jiang; Chunli Fan; Jiguang Wei; Liyun Ren; Jifeng Wei
• Keywords: 0301 basic medicine; 03 medical and health sciences

Illicium difengpi B. N. Chang et al., a shrub with aromatic odor in the genus, is extensively used as medicinal plant China. In June of 2020, leaf spot on I. incidence about sixty percent was observed field located Guilin (25°4'40"N; 110°18'21"E), Guangxi Province, Initial symptoms were round spots gray centers, surrounded by yellow halos. The gradually spread and merged. Six samples symptomatic leaves collected from six diseased plants, they surface disinfested before isolation. Potato dextrose agar (PDA) to culture pathogens. Successively, pure cultures obtained transferring hyphal tips new PDA plates. A total 10 isolates affected leaves. Two single-spore (GX-1 GX-2) confirmed be identical based morphological characteristics. representative isolate GX-2 selected for further study molecular colony 4 cm diameter plate 5 days, dark green granular surface, irregular white edge. Conidia hyaline, unicellular, oval, narrow at end single apical appendage, 8.2 13.8 × 3.7 7.2 µm (n = 50). Spermatia bacilliform swollen ends, 3.8 8.9 1.3 1.9 Morphological characteristics consistent description Phyllosticta capitalensis (Wikee al. 2013). internal transcribed spacer (ITS) region, translation elongation factor 1-α (tef1-α), glyceraldehyde-3-phosphate dehydrogenase (GPDH) actin (ACT) amplified using primers ITS1/ITS4, EF-728F/EF-986R, Gpd1-LM/Gpd2-LM ACT-512F/ACT-783R, respectively Sequences deposited GenBank accession numbers OL505439 ITS, OL539429 ACT, OL539430 tef1-α OL539431 GPDH. BLAST analysis showed that these sequences 99 100% similar corresponding ITS (MT649668), ACT (MN958710), (MN958711) GPDH (KU716077) P. capitalensis. Also, phylogenetic tree genes tef1-α, maximum likelihood method clustered together pathogenicity tests carried out healthy 3 year-old greenhouse 80% relative humidity 25 °C. Four sterilized wounded needle inoculated 20 μL spore suspension (1 106 spores/ml). Another four sterile water control. All plants incubated chamber 98% ± 1°C. After 12 disease leaves, whereas control remained healthy. successfully reisolated only identified characters. caused various host around world 2013), including tea China (Cheng 2019) oil palm Malaysia (Nasehi 2020), but it has not been reported difengpi. Thus, this first report causing This will provide an important reference disease. epidemiology should investigated research.