Leaf spot disease on Juglans regia caused by Ragnhildiana diffusa in China.

Juglans regia L. is commercially important for its edible nuts, which is a major species of walnut trees in Sichuan Province (Luo et al. 2020). In September 2021, brown leaf spot symptoms were observed on roughly 75% of 60 J. regia trees surveyed in an orchard of Chongzhou city (30°40'6''N, 103°40'18''E). Initially, the lesions measuring 2-10 mm were reddish to brown with a yellowish halo, then increased in size and coalesced to cover the whole leaf, eventually resulting in severe defoliation. Six symptomatic leaves from different trees were collected, and a single fungal isolate was obtained from each of the sampled leaves using single-spore isolation (Chomnunti et al. 2014). The isolates were incubated on potato dextrose agar (PDA) with a 12h photoperiod at 25 ℃, and deposited at the Culture Collection of Sichuan Agricultural University. Colonies were identical with black center and reddish-brown periphery, and the diameter reached 2 cm after 7 days. On the host, conidiophores were mostly reduced to conidiogenous cells, with prominent and thickened conidiogenous loci. Conidia were light green to light brown, and curved with a thickened and darked hilum at the base, 0-17 septate, tapering toward the distal end, and measuring 20-120 × 3-5 µm ((x ) ̅= 56 × 4, n = 30). Morphological characteristics fit the description of Ragnhildiana diffusa (Heald & F.A. Wolf) Videira & Crous (Synonym: Sirosporium diffusum (Heald & F. A. Wolf) Deighton) (Poletto et al. 2017). The internal transcribed spacer (ITS) region, the large subunit of the nrDNA (LSU), and RNA polymerase II second largest subunit (rpb2) were amplified by polymerase chain reaction and sequenced with primers ITS5/ITS4 (White et al. 1990), LR0R/LR5 (Vilgalys & Hester 1990), fRPB2-5F/Rpb2-R3 (Liu et al. 1999, Videira et al. 2017), respectively. The nucleotide blast of the two isolates (SICAUCC 22-0077, SICAUCC 22-0078) showed 99.7% and 99.5% (ITS, 472/473 bp, 471/473 bp), 100% (LSU, 725/725 bp, 725/725 bp), 99.8% (rpb2, 866/867 bp, 866/867 bp) identities with the ex-type strain of Ragnhildiana diffusa (CBS 106.14). The phylogenetic tree combined with ITS, LSU, and rpb2 genes and morphological characteristics confirmed the identification as R. diffusa. These sequences of the three gene regions of two isolates were deposited in GenBank with accession numbers ON409525 and ON409526 (ITS), ON409559 and ON409560 (LSU), ON417473 and ON417474 (rpb2), respectively. The isolate SICAUCC 22-0077 was used for pathogenicity test to fulfill Koch's postulates. Three leaves of each walnut seedlings (2-year-old seedlings) were inoculated by placing a mycelium plug onto fresh wounds on the upper leaf surface punctured via a fine needle (0.7 mm in diameter), and three replicate seedlings were inoculated. For the control, a sterile PDA plug was placed on the same number of replicate leaves on the plants. The inoculated and control plants were placed in a growth chamber at 25°C with relative humidity >80% and a 12-h photoperiod. Irregular light to dark brown spots developed on inoculated leaves after twenty days, and no symptoms were observed on controls. The re-isolation and examination of the fungus showed it to be morphologically and phylogenetically identical to the originally isolated pathogen. R. diffusa has been described on J. regia in Mexico (Farr & Rossman 2022). To our knowledge, this is the first report of R. diffusa causing brown leaf spot on J. regia in China. The identification of the pathogen will provide a basis for disease management in walnut planting areas.

Insight into the Systematics of Novel Entomopathogenic Fungi Associated with Armored Scale Insect, Kuwanaspis howardi (Hemiptera: Diaspididae) in China.

This study led to the discovery of three entomopathogenic fungi associated with Kuwanaspis howardi, a scale insect on Phyllostachys heteroclada (fishscale bamboo) and Pleioblastus amarus (bitter bamboo) in China. Two of these species belong to Podonectria: P. kuwanaspidis X.L. Xu & C.L. Yang sp. nov. and P. novae-zelandiae Dingley. The new species P. kuwanaspidis has wider and thicker setae, longer and wider asci, longer ascospores, and more septa as compared with similar Podonectria species. The morphs of extant species P. novae-zelandiae is confirmed based on sexual and asexual morphologies. Maximum likelihood and Bayesian inference analyses of ITS, LSU, SSU, tef1-α, and rpb2 sequence data provide further evidence for the validity of the two species and their placement in Podonectriaceae (Pleosporales). The second new species, Microcera kuwanaspidis X.L. Xu & C.L. Yang sp. nov., is established based on DNA sequence data from ITS, LSU, SSU, tef1-α, rpb1, rpb2, acl1, act, cmdA, and his3 gene regions, and it is characterized by morphological differences in septum numbers and single conidial mass.

The complete chloroplast genome of Chimonobambusa hejiangensis.

Chimonobambusa hejiangensis is of the unique edible bamboo specie of high quality in China. We studied the complete chloroplast(cp) genome of C. purpurea in this study. The cp genome of C. hejiangensis (GenBank accession: MW186792) was 138,911 bp in length, including a large single-copy (LSC) region of 82,498 bp, a small single-copy (SSC) region of 12,743 bp and a pair of inverted repeated (IR) regions of 21,835 bp. The genome contained 133 genes, including 86 protein-coding genes, 39 tRNA genes, and 8 rRNA genes. Based on 39 cp genomes, we used the phylogenetic analysis to build phylogenetic tree, indicating that C. hejiangensis is closely related to C. tumidissinoda. Also, the phylogenetic relationship of lineages might be (Hsuehochloa + (((Shibataea clade + Arundinaria clade) + Indocalamus wilsonii) + ((Bergbambos + Indocalamus) + (((African alpine bamboos + Gaoligongshania) + (Chimonocalamus + Kuruna))+(Thamnocalamus + Phyllostachys clade))))). It could be devoted to phylogenetic analysis of Arundinarieae.

The complete chloroplast genome of Chimonobambusa purpurea (Bambusatae).

Chimonobambusa purpurea is one of the important bamboo species in southwest of China. We studied the complete chloroplast (cp) genome of C. purpurea in this study. The cp genome of C. purpurea (GenBank accession: MW030500) was 139,574 bp in length, including a large single-copy (LSC) region of 83,171 bp, a small single-copy (SSC) region of 12,811 bp, and a pair of inverted repeated (IR) regions of 21,796 bp. And the genome contained 133 genes, including 86 protein-coding genes, 39 tRNA genes, and 8 rRNA genes. Based on 30 cp genomes, we used the phylogenetic analysis to build phylogenetic tree, indicating that C. purpurea is closely related to C. tumidissinoda.

Morpho-molecular diversity of Linocarpaceae (Chaetosphaeriales): Claviformispora gen. nov. from decaying branches of Phyllostachys heteroclada.

In this paper, Claviformispora gen. nov. in Linocarpaceae is introduced from Phyllostachys heteroclada in Sichuan Province, China. The new genus is characterised by its distinct morphological characters, such as ostiole with periphyses, asci with a thick doughnut-shaped, J- apical ring and clavate ascospore without septum-like band and appendage. Maximum Likelihood and Bayesian Inference phylogenetic analyses, based on DNA sequence data from ITS, LSU, SSU and TEF-1α regions, provide further evidence that the fungus is a distinct genus within this family. The new genus is compared with similar genera, such as Linocarpon and Neolinocarpon. Descriptions, illustrations and notes are provided for the new taxon.

The complete mitochondrial genome of the fig weevil, Aclees cribratus (Coleoptera: Curculionidae).

Aclees cribratus Gyllenhyl (Coleoptera: Curculionidae) is an important pest of fig. In this study, the complete mitogenome of A. cribratus was determined, which was 17,329 bp in length and contained 37 genes, including 13 protein-coding genes (PCGs), 2 rRNA, 22 tRNA genes, and 2 control regions. The phylogenetic analysis based on mitogenomes showed that A. cribratus is the sister group of Molytinae.