The Whole Genome Sequence of Fusarium redolens Strain YP04, a Pathogen that Causes Root Rot of American Ginseng

Identification and Fungicide Sensitivity of Fusarium spp. Associated with Root Rot of Scutellaria baicalensis in Shanxi Province, China

Fusarium root rot is usually classified as an extremely destructive soilborne disease. From 2020 to 2021, Fusarium root rot was observed in production areas and seriously affected the yield and quality of Scutellaria baicalensis in Shanxi Province, China. Based on morphological characteristics and combined analysis of the internal transcribed spacer region of ribosomal DNA and translation elongation factor 1-alpha sequences, 68 Fusarium isolates obtained in this work were identified as F. oxysporum (52.94%), F. acuminatum (20.59%), F. solani (16.17%), F. proliferatum (5.88%), F. incarnatum (2.94%), and F. brachygibbosum (1.47%). In the pathogenicity tests, all Fusarium isolates could infect S. baicalensis roots, presenting different pathogenic ability. Among these isolates, F. oxysporum was found to have the highest virulence on S. baicalensis roots, followed by F. acuminatum, F. solani, F. proliferatum, F. brachygibbosum, and F. incarnatum. According to fungicide sensitivity tests, Fusarium isolates were more sensitive to fludioxonil and difenoconazole, followed by carbendazim, thiophanate-methyl, and hymexazol. In brief, this is the first report of Fusarium species (F. oxysporum, F. acuminatum, F. solani, F. proliferatum, F. incarnatum, and F. brachygibbosum) as causal agents of root rot of S. baicalensis in Shanxi Province, China. The fungicide sensitivity results will be helpful for formulating management strategies of S. baicalensis root rot.

Mining Tamarix ramosissima roots for endophytic growth promoting fungi to improve wheat root growth

Endophytic fungi are commonly found in the root endosphere and can enhance plant growth through various mechanisms. The aim of this study was to isolate cultivable endophytic fungi associated with the roots of Tamarix ramosissima and to evaluate their plant growth promoting properties. About 35 isolated fungal endophytes belonging to the Ascomycota from four different genera were isolated from the endosphere of T. ramosissima: Alternaria, Aspergillus, Fusarium and Talaromyces. These fungal endophytes showed different abilities to solubilize phosphate and produce indole-3-acetic acid (IAA). The fungal isolates of T. allahabadensis (T3) and A. niger (T4) showed different efficiency in solubilizing phosphate. Almost all fungal isolates were able to produce IAA, and the highest value (0.699 μg/ml) was found in the isolate of F. solani (T11). Inoculation of wheat seeds with endophytic fungi significantly increased the initial growth of wheat roots. The results showed that inoculation with the endophytic fungus A. fumigatus T15 significantly increased root length by 75%. The extensive root system of T. ramosissima may be due to symbiosis with IAA-producing endophytic fungi, which enhance root development and water uptake in dry conditions. These fungi can also boost soil phosphorus levels, promoting plant growth.

Draft Genome Sequence of a New Fusarium Isolate Belonging to Fusarium tricinctum Species Complex Collected From Hazelnut in Central Italy

In summer 2019, during a survey on the health status of a hazelnut orchard located in the Tuscia area (the province of Viterbo, Latium, Italy), nuts showing symptoms, such as brown-grayish spots at the bottom of the nuts progressing upward to the apex, and necrotic patches on the bracts and, sometimes, on the petioles, were found and collected for further studies. This syndrome is associated with the nut gray necrosis (NGN), whose main causal agent is Fusarium lateritium. Aiming to increase knowledge about this fungal pathogen, the whole-genome sequencing of a strain isolated from symptomatic hazelnut was performed using long Nanopore reads technology in combination with the higher precision of the Illumina reads, generating a high-quality genome assembly. The following phylogenetic and comparative genomics analysis suggested that this isolate is caused by the F. tricinctum species complex rather than F. lateritium one, as initially hypothesized. Thus, this study demonstrates that different Fusarium species can infect Corylus avellana producing the same symptomatology. In addition, it sheds light onto the genetic features of the pathogen in subject, clarifying facets about its biology, epidemiology, infection mechanisms, and host spectrum, with the future objective to develop specific and efficient control strategies.