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Abstract Epidemic of Cashew Fusarium wilt disease (CFWD) has been a continuous focal challenge in the cashew farming, in Tanzania. Limited to edaphic conditions as a major factor in its epidemic, the current study aimed to assess the habitat-disease relationship. Purposive surveys involving assessment of disease prevalence and habitat compositions were conducted across four landscapes of southeastern zone from 2019 to 2023. Findings revealed a widespread of CFWD across diversified landscapes possessing varying habitat characteristics, mainly cultivated land with mature cashew, brownish sand loamy soils, grassland or shrub vegetation, seasonal river streamlines and natural water wells. The highest disease incidence and severity were noted at Nachingwea/Masasi plain (99.28:88.34%) followed by Liwale inland plain (98.64:89.3%), Coastal zone (72.72:59.83%) and Tunduru dissected plain (62.13:54.54%). The habitat characteristics were strongly similar within the landscape (0.86-Jaccard index) except between villages of the coastal zone (0.71-Jaccard index). Across landscapes, Nachingwea/Masasi plains and the Coastal zone were strongly similar to Tunduru dissected plain (0.63—1.0-Jaccard index), but strongly dissimilar with the Liwale inland plain (0.67—0.70- Jaccard distance). Furthermore, the presence of greater than 0.5 suitability indices across landscapes were revealed, with Liwale inland plain having strongest suitability index of 0.743 followed by Coastal zone (0.681), Tunduru dissected plain (0.617) and Nachingwea/Masasi plain. Significantly, the habitats had an increase of 0.1 suitability index, and positively correlated with disease prevalence by triggering disease incidence of 13.9% and severity of 31.4%. The study for the first time revealed the presence of an association between disease prevalence and landscape habitat characteristics of southeastern, Tanzania; paving the way to inclusive thinking of habitat as one of the drivers in the prevalence of fusarium wilt disease of cashews. Further research on the genetic coevolution of Fusarium oxysporum across landscapes to strengthen disease risk management in the cashew industry is recommended.

Abstract Background Mushroom cultivation in Burundi provides an excellent way to diversify agricultural production although domestication of mushroom species is at an infancy stage. The country is endowed with indigenous forests that harbour a wide diversity of mushrooms with potential for domestication. This study was undertaken to explore opportunities for domestication of saprophytic wild edible mushrooms from the Kibira National Park (KNP) in Burundi. Methods Samples of Lentinus squarrosulus Mont. and Neonothopanus hygrophanus (Mont.) De Kesel & Degreef were collected from the field, and tissue cultured on Potato Dextrose Agar (PDA) medium. Spawn production and development was performed on sorghum grains and lignocellulosic substrates respectively and the parameters of mycelial growth and mushroom yield were determined. Results The germplasm of L. squarrosulus and N. hygrophanus was successfully isolated with an average tissue culture incubation time of 6.4 ± 0.54 days and 7.6 ± 0.54 days for L. squarrosulus and N. hygrophanus, respectively. Spawn production incubation time on sorghum grains was 12.6 ± 0.89 days and 14.8 ± 0.83 days for L. squarrosulus and N. hygrophanus, respectively. For full colonization of lignocellulosic substrates, spawn production time ranged between 19 ± 1 and 21 ± 1 days for L. squarrosulus and between 17 ± 1.22 and 18 ± 1.22 days for N. hygrophanus. Both species successfully produced fruiting bodies and mushrooms yielded at a rate of 18.24 ± 9.76 to 22.85 ± 9.16% for L. squarrosulus and 12.66 ± 8.95 to 15.3 ± 8.94% for N. hygrophanus which is here reported for the first time to be successfully domesticated. For both species, the cottonseed hulls substrate comparatively showed the best yield followed by the combination of maize cobs/soybean straws (MC + SBS) (50:50), the combination of rice straws/soybean straws (RS + SBS) (50:50) and the maize cobs substrate respectively, while the rice straw showed the least. The combinations of MC + SBS (50:50) and RS + SBS (50:50) showed a yield close to that of cottonseed hulls. Conclusions For the first-time, this study presents successful domestication of N. hygrophanus and L. squarrosulus from KNP. It is concluded that the substrates combinations used in the study give good yields, and therefore recommended for use as cost-effective and efficient alternative substrates.

Abstract Background Edible fungi including wild mushrooms have been largely neglected and underutilized in Africa. Not only is the number of edible species unknown, but the critical role they play in human food and nutrition and the ecosystem services they provide have remained poorly understood and undervalued. Methods We reviewed the literature with the objective of providing a synthesis of knowledge on (1) the diversity of wild edible fungi of Africa with emphasis on mushrooms; (2) the ecosystem services provided by wild edible fungi; (3) anthropogenic threats to their diversity and utilization; and (4) opportunities for their conservation and cultivation. Results We identified a total of 480 species of wild edible mushrooms in 126 genera belonging to 60 fungal families across Africa. A total of, 249 species were mycorrhizal, 28 species were termitophilic and 203 species were saprophytic or parasitic. Wild edible mushrooms provide food that is high in digestible proteins, antioxidants and fibre but low in fats. They are also sources of income for rural populations. Almost all species play a role in nutrient recycling and hence the productivity of forests and agroecosystems. However, deforestation and land degradation are threatening the mushroom diversity in some regions of Africa. Conclusion The African continent is endowed with a tremendous diversity of neglected and underutilized edible wild mushrooms providing nutritious food for humans and playing a key role in the structure and functioning of native forests and woodlands. Deforestation and the loss of habitat are the greatest threats to edible wild species in Africa. The loss of indigenous knowledge can also potentially limit dietary choices and market opportunities. Therefore, we recommend national forestry research and development programs and international frameworks such as Reducing Emissions from Deforestation and Degradation (REDD +) to invest in the conservation, cultivation and valorisation of wild edible mushrooms to achieve sustainable forest management and the welfare of local communities.

Calicioids form a research field that has encompassed ascomycetous fungi with stalked ascomata similar to those of the lichen genus Calicium. Early generic circumscriptions of calicioid lichens and fungi were mainly based on morphological and secondary chemistry information. After the introduction of molecular data, taxonomy in the group has been reconsidered. Here, based on a broad geographical sampling, Coniocybe Ach. was revised using molecular and morphological features. Three loci (ITS, LSU and rpb1) were compared to infer its phylogenetic position, and a total of 52 new sequences (14 ITS, 24 LSU and 14 rpb1) were produced. Apart from its type C. furfuracea, Coniocybe was revised and emended to also include C. brachypoda and C. confusa. In addition, a new species, Coniocybe eufuracea, was described, and a key to the species of Coniocybe was provided.

Cashew (Anacardium occidentale L.) is an important cash crop in Tanzania as a source of income to cashew growers and provides foreign exchange for the country. Despite its significance, the crop is threatened by fast spreading disease known as cashew Fusarium wilt caused by Fusarium oxysporum. Field assessment and laboratory tests were conducted to determine incidences of the disease, severity, ecological factors that influence them and explored the pathogen host specificity in six cashew growing districts. The results revealed significant (P

Several Usnea species in subgenus Eumitria (Parmeliaceae, lichenized Ascomycota) have been described from East Africa in the past decades. These have been based on morphology and chemistry data while molecular studies remain very limited. In this paper we are for the first time publishing phylogenetic analyses along with morphological and chemical data for Eumitria. ‬A total of 62 new sequences of Eumitria (26 ITS, 20 nuLSU, 6 MCM7, 10 RPB1) were generated in this study. nuLSU, MCM7 and RPB1 sequences are here for the first time reported for U. baileyi. A phylogeny of subgenus Eumitria from Tanzania based on Bayesian and maximum likelihood analyses of a concatenated four-loci data set is presented, confirming the monophyly of Eumitria. Further, secondary chemistry and variation in characters, such as the pigmentation of the central axis and branch shape were investigated.

Endophytic fungi are useful in a variety of biological processes and may find value in pharmaceutical settings. However, there hasn't been much research done on the bioactive compounds produced by mangrove fungal endophytes from the East African coast. Our previous research revealed a significant number of mangrove endophytic fungi in Dar es Salaam, Tanzania. This study explores the antimicrobial and cytotoxic properties of these endophytic fungi. Crude extracts of 34 mangrove endophytic fungal isolates were screened, with thirteen showing antimicrobial activity against tested microorganisms. MIC and cytotoxicity tests revealed varying bioactivity. Aspergillus fumigatus (HMD45) was particularly potent against tested organisms (MIC = <0.195 to 0.391 mg/ml) and (LC50 = 36.001). GC-MS evaluation of HMD45 extracts indicated the existence of compounds including dodecanoic acid, n-heptadecanol-1, and n-hexadecanoic acid, which may contribute to its bioactivity. These findings offer insight into the bioactivity of mangrove endophytic fungi and trigger interest for further research.

The application of biocontrol biopesticides based on plant growth-promoting rhizobacteria (PGPR), particularly members of the genus Bacillus, is considered a promising perspective to make agricultural practices sustainable and ecologically safe. Recent advances in genome sequencing by third-generation sequencing technologies, e.g., Pacific Biosciences' Single Molecule Real-Time (PacBio SMRT) platform, have allowed researchers to gain deeper insights into the molecular and genetic mechanisms of PGPR activities, and to compare whole genome sequences and global patterns of epigenetic modifications. In the current work, this approach was used to sequence and compare four Bacillus strains that exhibited various PGPR activities including the strain UCMB5140, which is used in the commercial biopesticide Phytosubtil. Whole genome comparison and phylogenomic inference assigned the strain UCMB5140 to the species Bacillus velezensis. Strong biocontrol activities of this strain were confirmed in several bioassays. Several factors that affect the evolution of active PGPR B. velezensis strains were identified: (1) horizontal acquisition of novel non-ribosomal peptide synthetases (NRPS) and adhesion genes; (2) rearrangements of functional modules of NRPS genes leading to strain specific combinations of their encoded products; (3) gain and loss of methyltransferases that can cause global alterations in DNA methylation patterns, which eventually may affect gene expression and regulate transcription. Notably, we identified a horizontally transferred NRPS operon encoding an uncharacterized polypeptide antibiotic in B. velezensis UCMB5140. Other horizontally acquired genes comprised a possible adhesin and a methyltransferase, which may explain the strain-specific methylation pattern of the chromosomal DNA of UCMB5140. KEY POINTS: • Whole genome sequence of the active PGPR Bacillus velezensis UCMB5140. • Identification of genetic determinants responsible for PGPR activities. • Role of methyltransferases and epigenetic mechanisms in evolution of bacteria.

Bacillus velezensis strains are applied as ecologically safe biopesticides, plant growth promoting rhizobacteria (PGPR), and in veterinary probiotics. They are abundant in various environments including soil, plants, marine habitats, the intestinal micro-flora, etc. The mechanisms underlying this adaptive plasticity and bioactivity are not well understood, nor is it clear why several strains outperform other same species isolates by their bioactivities. The main objective of this work was to demonstrate versatility of bioactivities and lifestyle strategies of the selected B. velezensis strains suitable to serve as model organisms in future studies. Here, we performed a comparative study of newly sequenced genomes of four B. velezensis isolates with distinct phenotypes and isolation origin, which were assessed by RNA sequencing under the effect of root exudate stimuli and profiled by epigenetic modifications of chromosomal DNA. Among the selected strains, UCMB5044 is an oligotrophic PGPR strain adapted to nutrient poor desert soils. UCMB5113 and At1 are endophytes that colonize plants and require nutrient rich media. In contrast, the probiotic strain, UCMB5007, is a copiotroph, which shows no propensity to colonize plants. PacBio and Illumina sequencing approaches were used to generate complete genome assemblies, tracing epigenetic modifications, and determine gene expression profiles. All sequence data was deposited at NCBI. The strains, UCMB5113 and At1, show 99% sequence identity and similar phenotypes despite being isolated from geographically distant regions. UCMB5007 and UCMB5044 represent another group of organisms with almost identical genomes but dissimilar phenotypes and plant colonization propensity. The two plant associated strains, UCMB5044 and UCMB5113, share 398 genes putatively associated with root colonization, which are activated by exposure to maize root exudates. In contrast, UCMB5007 did not respond to root exudate stimuli. It was hypothesized that alterations in the global methylation pattern and some other epigenetic modifications enable adaptation of strains to different habitats and therefore may be of importance in terms of the biotechnological applicability of these bacteria. Contrary, the ability to grow on root exudates as a sole source of nutrients or a strong antagonism against phytopathogens showed by the strains in vitro cannot be considered as good predictors of PGPR activities., (Copyright © 2019 Reva, Swanevelder, Mwita, David Mwakilili, Muzondiwa, Joubert, Chan, Lutz, Ahrens, Avdeeva, Kharkhota, Tibuhwa, Lyantagaye, Vater, Borriss and Meijer.)