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1.
Plant Dis ; 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37555726

RESUMO

More than 30% of fruits of Chinese Quince (Chaenomeles speciosa) and peach (Prunus persica) showed circular, water-soaked and brown spots in July 2022 in Kunming, Yunnan, China. The center of these spots was covered by a large number of earthy brown and oblate sporogeneous mycelium containing conidiophore and conidia, which were one-celled, limoniform, hyaline (13.73 to 22.77 x 8.17 to 12.84 µm, n=50). By September 2022, almost 100% of fruits showed symptoms. Later, most of them fell or a few stiff, black and mummified fruits were left on the trees. Fungal isolates were isolated by single-spore technique on Potato Dextrose agar (PDA) from the diseased fruits, and incubated at room temperature (20-28 °C) in darkness for 14 days. The colony was gray, smooth at margins, 7.6-8.0 cm in diameter. To fullfill Koch's postulates, mycelial plugs of one representative isolate YHD611 from Chinese Quince and another YHD610 from peach were used to inoculate three wounded and three non-wounded surface-disinfected fruits of both hosts at room temperature (19-27 °C), respectively. Three wounded and three non-wounded fruits inoculated with sterile PDA plugs served as the control. The wounded peaches appeared water-soaked and had brown lesions after three days of inoculation, then completely decayed after nine days, while non-wounded fruits showed symptoms after five days. The wounded fruits of Chinese Quince developed similar symptoms after eight days of inoculation, and completely decayed after 13 days, while non-wounded fruits showed obvious symptoms after 15 days. In a subsequent study, isolate YHD611 was inoculated to peach while isolate YHD610 was inoculated to Chinese Quince to understand host specificity of the isolates. The results showed that when peaches were infected with YHD611, symptoms were observed on wounded fruits after three days while on non-wounded fruits after five days. When Chinese Quince was infected with YHD610, symptoms were observed on wounded fruits after 14 days while on non-wounded fruits after 21 days. Fungal isolates from symptomatic fruits were identical to the original isolates. There were no symptoms on the control fruits of both hosts. Molecular identification was confirmed based on the sequences of internal transcribed spacer (ITS, primers ITS1 and ITS4) and ß-tubulin (TUB2, primers Bt2a and Bt2b) genes (Niu et al. 2016). BLASTn analysis of the ITS (OQ15519and OQ155196) and TUB2 (OQ185202 and OQ185201) of YHD611 and YHD610 revealed a 100% sequence identity, respectively, to Monilia yunnanensis AH7-2 (KT735924.1 for ITS, KT736008.1 for TUB2). In the phylogenetic analyses based on ITS and TUB2 sequence data, the isolates YHD611 and YHD610 belonged to the M. yunnanensis clade. Based on morphological and molecular identification, both isolates were identified as M. yunnanensis, which was reported as the pathogen causing brown rot of plum, peach, apple and pear in Yunnan, China (Hu et al. 2011; Yin et al. 2015). To our knowledge, this is the first report of M. yunnanensis causing brown rot on the fruits of Chinese Quince in Yunnan, China. This study also reports that M. yunnanensis from Chinese Quince can infect peach, and the pathogen from peach can infect Chinese Quince. These findings suggest that M. yunnanensis can transfer from one host to another and causing serious economic losses in multiple fruit crops in Yunnan, China. References: Hu, M. J., et al. 2011. PLoS One. 6:e24990. Niu, C. W., et al. 2016. Mycosystema, 35(10):1. Yin, L. F., et al. 2015. Plant Dis. 99:1775.

2.
Biodivers Data J ; 10: e80034, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36761562

RESUMO

Background: Ganoderma is a white-rot fungus with a cosmopolitan distribution and includes several economically important species. This genus has been extensively researched due to its beneficial medicinal properties and chemical constituents with potential nutritional and therapeutic values. Traditionally, species of Ganoderma were identified solely based on morphology; however, recent molecular studies revealed that many morphology-based species are conspecific. Furthermore, some type species are in poor condition, which hinders us from re-examining their taxonomic characteristics and obtaining their molecular data. Therefore, new species and fresh collections with multigene sequences are needed to fill the loopholes and to understand the biological classification system of Ganoderma. New information: In a survey of Ganoderma in Guizhou Province, southwest China, we found a new species growing on soil and, herein, it was identified by both morphology and phylogenetic evidence. Hence, we propose a new species, Ganodermaovisporum sp. nov. This species is characterised by an annual, stipitate, laccate basidiome, with a red-brown to brownish-black pileus surface and pale white pores, duplex context, clavate pileipellis terminal cells, trimitic hyphal system, ellipsoid basidiospores with dark brown eusporium bearing coarse echinulae and an obtuse turgid appendix. Phylogenetic analyses confirmed that the novel species sisters to G.sandunense with high bootstrap support. Furthermore, the RPB2 sequence of G.sandunense is supplied for the first time. Notably, we re-examined the type specimen of G.sandunense and provide a more precise description of the duplex context, pileipellis terminal cells and basidia. All species collected are described and illustrated with coloured photographs. Moreover, we present an updated phylogeny for Ganoderma, based on nLSU, ITS, RPB2 and TEF1-α DNA sequence data and species relationships and classification are discussed.

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