Khanobporn Tangtrakulwanich

Members of Stachybotryaceae are distributed worldwide, with certain species playing a significant role as bio-degraders and some causing diseases in plants, humans, and animals. Other species within this family can be found in soil and have been reported as saprobes in various plants. In this study (2021–2022), fungal taxa resembling Stachybotryaceae, isolated from dead leaves of Agave sisalana and a dead stem of Wurfbainia villosa in Guangdong Province, China, are identified based on morphological characteristics and molecular data. Multi-locus phylogeny based on calmodulin (cmdA), internal transcribed spacer (ITS), the large subunit nuclear rDNA (LSU), RNA polymerase II second largest subunit (rpb2), the partial translation elongation factor 1-α (tef1-α), and β-tubulin (tub2) revealed that nine strains were grouped within Stachybotryaceae. Nigrosynnema guangdongensegen. et sp. nov., typical of Stachybotryaceae but having unusual olivaceous brown to black synnemata that are narrower towards the apex and produce phialidic, aseptate, slimy conidia in black and glistening heads, is introduced. Additionally, Brevistachys wurfbainiae and Sirastachys guangdongensis are introduced as new species. Stachybotrys microsporus is a new host record for Agave sisalana. The present study provides comprehensive descriptions, illustrations, and molecular data analyses of the newly discovered taxa and newly recorded species as a taxonomic and phylogenetic contribution to Stachybotryaceae. Furthermore, a new combination, Nigrosynnema natarajanensis, is proposed for the previously described Virgatospora natarajanensis.

Stem blight is a significant disease affecting blueberries worldwide, caused by various pathogens. This study investigated stem blight disease in Ji’an, Jilin Province, China. Fungi isolated from diseased stems were identified as Colletotrichum temperatum, Curvularia austriaca, and Diaporthe unshiuensis based on morphological characters and multi-locus phylogenetic analyses using the internal transcribed spacer (ITS) region, glyceraldehyde 3-phosphate dehydrogenase (gapdh), chitin synthase (chs), actin (act), β-tubulin (tub2), the translation elongation factor 1-alpha (tef1-α), calmodulin (cal), and histone 3 (his3) regions. Pathogenicity test was conducted on detached green blueberry shoots, all shoots inoculated by mycelium plugs presented necrotic lesions with dark brown margins, while the control (PDA plugs) group did not show any symptoms. Koch’s postulates were confirmed by re-isolating the inoculated pathogen from the disease symptoms. The study provides three new host–pathogen records of fungi associated with blueberry stem blight.

Blueberry has been a burgeoning fruit in China in recent years, but its perishable nature places a constant strain on industrial development. To determine the pathogens infecting blueberry fruits, diseased samples were collected from Guizhou and Fujian Provinces. Isolates from the samples were identified by morphological characterization and phylogenetic analyses. Pathogenicity assays were conducted on fresh blueberry fruits using spore suspensions. Sixteen isolates were identified as seven species, namely, Botryosphaeria dothidea, Botrytis cinerea, Cladosporium guizhouense, Colletotrichum fioriniae, Diaporthe anacardii, Fusarium annulatum, and Neopestalotiopsis surinamensis, and their pathogenicity on blueberry fruits were confirmed following Koch’s postulates. The current study reported Cladosporium guizhouense, Fusarium annulatum, and Neopestalotiopsis surinamensis for the first time on blueberry. The study (1) demonstrated that fruit rot disease results from a mixed infection of multiple pathogens; and (2) expanded the understanding of causal agents of blueberry fruit rot during the growth stage, highlighting their potential as latent pathogens that contribute to post-harvest losses. Relevant results provide a reference for the etiological research and disease management in blueberry fruit diseases.

Ophiocordyceps is the largest genus in Ophiocordycipitaceae and has a broad distribution with high diversity in subtropical and tropical regions. In this study, two new species, pathogenic on lepidopteran larvae are introduced, based on morphological observation and molecular phylogeny. Ophiocordyceps fenggangensissp. nov. is characterised by having fibrous, stalked stroma with a sterile tip, immersed perithecia, cylindrical asci and filiform ascospores disarticulating into secondary spores. Ophiocordyceps liangiisp. nov. has the characteristics of fibrous, brown, stipitate, filiform stroma, superficial perithecia, cylindrical asci and cylindrical-filiform, non-disarticulating ascospores. A new combination Ophiocordyceps musicaudata (syn. Cordyceps musicaudata) is established employing molecular analysis and morphological characteristics. Ophiocordyceps musicaudata is characterised by wiry, stipitate, solitary, paired to multiple stromata, yellowish, branched fertile part, brown stipe, immersed perithecia, cylindrical asci and cylindrical-filiform, non-disarticulating ascospores.

Apiospora, an ascomycetous genus in Apiosporaceae, comprises saprobes, endophytes, and pathogens of humans and plants. They have a cosmopolitan distribution with a wide range of hosts reported from Asia. In the present study, we collected and isolated Apiospora species from Wurfbainia villosa and grasses in Guangdong and Yunnan provinces in China. Multi-locus phylogeny based on the internal transcribed spacer, the large subunit nuclear rDNA, the partial translation elongation factor 1-α, and β-tubulin was performed to clarify the phylogenetic affinities of the Apiospora species. Based on the distinctive morphological characteristics and molecular evidence, Ap. endophytica, Ap. guangdongensis, Ap. wurfbainiae, and Ap. yunnanensis are proposed. Descriptions, illustrations, and notes for the newly discovered species are provided and compared with closely related Apiospora species. An updated phylogeny of Apiospora is presented, along with a discussion on the phylogenetic affinities of ambiguous taxa.

Brown planthopper (BPH) is the most problematic insect in rice cultivation, as it decreases crop yields. In this study, 143 upland rice varieties were genotyped for five essential Bph resistance genes: bph2, Bph3, Bph14, Bph15, and Bph17. The gene frequencies of the five Bph resistance genes varied from 33.57% to 61.54%. The 139 varieties contained one to five Bph resistance genes. Polymorphism information content values ranged from 0.4460 to 0.4984 with an average of 0.4744. Cluster analysis supported the subpopulations identified by STRUCTURE. An analysis of molecular variance analysis identified 7% variance among and 92% variance within subpopulations, indicating a significant gene exchange between the two subpopulations. The evaluation of BPH resistance using the SEM system by IRRI showed that 2 varieties were resistant to BPH, 29 varieties were moderately resistant, and 112 varieties were susceptible. The Bph3, Bph14, and Bph15 genes and BPH resistance showed significant correlation. These findings provide important information regarding BPH-resistant varieties for future use in rice breeding programs.

A species of entomopathogenic fungi was found on ants in Guizhou Province, China. It is described as Cordyceps poluscapitis (Cordycipitaceae), a novel species with both a sexual and an asexual morph. Cordyceps species are characterized by producing brightly coloured, fleshy stromata and long, filiform ascospores. Cordyceps poluscapitis is unique in that it is parasitic on ants and produces multiple-septate conidia. Multi-gene phylogeny based on combined sequence data of 6-loci genes (ITS, SSU, LSU, TEF, RPB1 and RPB2) confirmed that it is a new species in Cordyceps.