Lijuan Yang

Paramyrothecium foliicola is a species of ascomycete in the family Stachybotryaceae. In recent years, it has been reported as a threat to crop production in different countries. Because of its wide host range and high virulence, this pathogen may present as a major global concern in the near future. Despite its importance, there is no sufficient genomic information for P. foliicola. Our work introduces the initial PacBio-Illumina hybrid draft genome for TJWQPF1, the P. foliicola strain, together with the related annotations. This genome was assembled into 18 contigs, with the largest contig size of 8,042,417 bp. Genome annotation identified 13,330 protein-coding genes. The draft genome data will aid in understanding the pathogenic mechanism of P. foliicola, which is a valuable resource to explore the genetic diversity, pathogenicity, and evolution of this important pathogen. [ ] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Strawberry (Fragaria × ananassa Duch.) is a widely cultivated economic crop in China. In April 2022, an unusual wilt disease was observed on strawberry plants (6 months’ old) in Chenzui town, Wuqin...

Cercospora apii is an important seedborne pathogenic fungus causing severe Cercospora leaf spot of celery worldwide. Here, we first present a complete genome assembly of C. apii strain QCYBC from c...

Shine muscat is a Vitis vinifera hybrid (Akitsu-21 × Hakunan), that has emerged as a popular table grape cultivar in China. In recent years, shine muscat has been widely cultivated with 66,667 ha b...

Geranium (Pelargonium hortorum) is a widely cultivated ornamental plant in the world. In August 2021, geranium plants exhibited stem and root rot symptoms in a garden in Tianjin, China (117°20’E, 3...

Tomato (Solanum lycopersicum) is a staple vegetable across the world. In October 2019, leaf spots were observed on tomato (cv. Tianmi) in a greenhouse in JiZhou District Tianjin, China(117°10 ′E; 39°55 ′N). Symptoms initially appeared as small brown spots, which gradually expanded and turned into circular, oval or irregular spots (some spots with distinct concentric zones). In severe cases, some spots coalesced and eventually covered the whole leaf. Disease incidence ranged between 12 and 18%. Twenty symptomatic leaves from five plants were collected and cut into small pieces, surface disinfested in 2% NaClO for 60 s, rinsed three times in sterile water, and subsequently plated on potato dextrose agar (PDA). Plates were incubated at 25°C in the dark for 7 days. A total of 102 isolates were obtained and 92 isolates had the same morphology. Colonies were initially white with abundant aerial mycelia and formed sporodochia with conidial masses in olivaceous green concentric rings. All isolates formed single-celled, hyaline, and rod-shaped conidia were 4.91 to 7.43 (avg. 6.53±0.72) × 1.41 to 2.45 （avg. 2.11±0.30）μm with rounded ends (n=50). Conidiophores were highly branched. These characteristics resembled a Paramyrothecium-like fungus (Lombard et al. 2016). The genomic DNA of three representative single-spored isolates TJJXPF1-3 were extracted and the internal transcribed spacer (ITS) region, β-tubulin (tub2), large subunit ribosomal RNA (LSU), calmodulin (cmdA) and translation elongation factor 1-alpha (tef1) genes were amplified and sequenced using the primer pairs ITS4/ITS5 (White et al. 1990), Bt2a/Bt2b (Glass and Donaldson 1995), LR0R/LR5 (Rehner and Samuels 1995; Vilgalys and Hester 1990), CAL-228F/CAL2Rd (Carbone and Kohn 1999; Groenewald et al. 2013) and EF1-728F/EF2 (O’Donnell et al. 1998), respectively. All sequences were deposited in GenBank (ITS: MW463444, OM368178, OM368179; tub2: MW269542，OM714930，OM714931; LSU: OM349050, OM397398, OM390582; cmdA: MW280443, OM350474, OM350476; tef1: MW560083, OM350475, OM350477). BLASTN analysis showed 99.3-100% similarity with reference isolate QB1 of P. foliicola (MK335967, MT415353, MT415362, MT415356 and MT415359). Multilocus phylogenetic analysis showed that TJJXPF1-3 best grouped with the P. foliicola clade, which was identified by morphological characteristics and phylogenetic analysis. To fulfill Koch’s postulates, pathogenicity tests were conducted by spray-inoculation with a conidial suspension of isolate TJJXPF1 prepared with distilled water (1×105 conidia/mL) on five 45-day old tomato plants. Three healthy plants were sprayed with sterile water as control. All treatments were incubated in an artificial climate chamber (25°C, 80% RH, 12h light/12h dark ). After two weeks, leaf spots were observed on all inoculated plants, which were similar to those in the greenhouse of JiZhou District, while control plants remained asymptomatic. Additionally, the pathogens were reisolated from symptomatic leaves and three representative isolates TJJXPF4-6 were identified as P. foliicola. The pathogenicity tests were repeated thrice. To our knowledge, this is the first report of leaf spot caused by P. foliicola on tomato in China. This disease could be a serious threat to tomato production in the future. Our findings will help to differentiate this disease from other leaf spot-like diseases and develop disease control strategies.

Coriander or cilantro (Coriandrum sativum L.) is extensively used as a fresh herb in China. During the summer of 2019 in Tianjin, China, coriander plants showed a previously unknown wilt in commercial fields. In severely infected fields, approximately 85% of the plants at vegetative stages were stunted, chlorotic, wilted or dead. Vascular tissues of the main stem and root were discolored. Soil samples were collected from five fields with a history of severe wilt disease in Tianjin since the fall of 2019. Seeds of coriander cultivar “ansemi” were sown in soil from the five fields, and cultured in a greenhouse at 22°C/20°C (12 h /12 h, light/dark) and 75% relative humidity. After 50 days’ cultivation, infected seedlings exibited similar symptoms to those of plants in the field. Twenty symptomic seedlings from each of the collected field soil samples were harvested and washed for 3 min under running water. Then the vascular tissue fragments (3 mm2) of stem and root at the boundary of the symptomatic area were excised, and placed on improved Komada’s medium, which is selective for Fusarium sp. (Komada 1975). After incubation at 25°C for 5 days in the dark, 70% of the isolates generated white to pale pink aerial hyphae on PDA (Fig. S1). Microconidia were single-celled, hyaline, non-septate and ovoid, and measured 5.6 to 14.1 μm long and 2.1 to 3.8 μm wide (n = 40). Macroconidia were three to five-septate, slightly curved at apex, and ranged from 11.2 to 38.6 μm long × 3.2 to 4.5 μm wide (n = 40). Based on morphological characteristics, these fungi were preliminarily identified as F. oxysporum (Leslie and Summerell 2006). For molecular identification, the ITS gene, TEF1-α gene and mtSSU gene of cultures from two representative single spored isolates XC02 and XC03 were amplified and sequenced (White et al. 1990; Carbone and Kohn 1999; Li et al. 1994). The sequences were submitted to GenBank (MT579855 and OK326765 for ITS; MT597425 and OK256882 for TEF1-α; MT587799 and OK330480 for mtSSU). BLASTn analysises indicated that the nucleotide sequences of the three loci of the two isolates were 99.8% to 100% homologous to sequences of F. oxysporum in the NCBI database and Fusarium MLST database. A multilocus phylogenetic tree was drawn via UPGMA analysis of the combined ITS, TEF1-α and mtSSU partial sequence data from Fusarium MLST database (Fig. S2). Pathogenicity of each isolate was tested on ten 15-day-old healthy coriander seedlings in each treatment according to the method of Yang et al. (2020). The first wilt symptoms developed 3 days after inoculation, and 7 to 10 days after inoculation 90% to 100% of the plants were dead. Control plants remained healthy. To fulfill the Koch's postulates, F. oxysporum were reisolated from the diseased tissues and verified based on morphology and sequencing as described above. The experiments were repeated twice with similar results. F. oxysporum has been reported to cause coriander wilt disease in India, Argentina, California (Koike and Gordon 2005), and Italy (Gilardi et al. 2019). To our knowledge, this is the first report of F. oxysporum causing coriander wilt disease in north China. Compared with F. equiseti in the previous report (Yang et al. 2020), F. oxysporum isolates possessed higher separation frequence and stronger pathogenicity to coriander seedlings. Thus attentions should be taken on F. oxysporum causing coriander wilt diseases when developing effective management strategies in north China.

Jasminum sambac (Linnaeus) Aiton belonging to Oleaceae family, has been cultivated in China over 1500 years. It is an important tea crop in South China, and popular ornamental plant in North China....

Coriander (Coriandrum sativum L.) is one of the most important vegetables used as a seasoning in China. During the summer of 2019 and 2020, two-month-old coriander plants with stem and root rot wer...