Continuous replanting could degrade soil health in short-rotation plantation forestry

PURPOSE OF REVIEW : Continuous replanting of land with the same or similar plant species can result in the accumulation of harmful soil microbes, which can lead to crop failure. In this review, we explore the influence of constant replanting on the health of short-rotation forestry soil, focusing on the accumulation of deleterious microbes and the decline of beneficial microbes. We also suggest possible practical solutions to address this problem and consider future research that could be conducted to better understand and reduce the build-up of deleterious soil microbes in short-rotation forestry soil. RECENT FINDINGS : Compelling evidence that continuous replanting of the same tree species in short-rotation plantation forestry might contribute to the build-up of deleterious soil microbes is still lacking. However, our assessment of existing soil microbiome data from global short-rotation plantation environments suggests a high risk of an accumulation of harmful microbes and a loss of beneficial microbes in plots that were continually replanted with the same tree species. Based on this evidence, and that from agriculture, we propose further research to acquire a better understanding of the build-up of harmful soil microbes in short-rotation plantation forestry, and suggest crop rotation and intercropping strategies to avoid this malady in the future. SUMMARY : The accumulation of microbes detrimental to plantation trees and the decline of microbes beneficial to these trees are realistic risks when plantations are continually replanted with the same tree species. Extensive research is necessary to evaluate the impact of short continuous planting rotations on the biodiversity of soil microbes in plantations and to develop strategies that would alleviate the build-up of detrimental microbes.Open access funding provided by University of Pretoria. This work was financially supported by the University of Pretoria and the Tree Protection Cooperative Programme (TPCP), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, South Africa.https://link.springer.com/journal/40725hj2023BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyPlant Production and Soil ScienceZoology and Entomolog

Molecular data confirm the mitosporic state of Hyphodermella rosae (Phanerochaetaceae) as the pathogen of rosaceous fruits in northern Iran

Hyphodermella is a genus of corticioid white rot fungi from the Phanerochaetaceae. Molecular data (partial SSU, LSU and complete ITS nrDNA) confirm the mitosporic state of Hyphodermella rosae as the causal agent of dry fruit rot of plum (Prunus domestica) and peach (Prunus persica) from Mazandaran, Iran. The asexual state of H. rosae is characterized by the presence of unicellular, spherical mitospores, which are terminal or intercalary in position. Both basidia and mitospores were observed in the matured cultures of H. rosae, although we did not observe any basidiospores. The phylogeny of Phanerochaetaceae confirms Hyphodermella as a monophyletic lineage within the family and sister group to Phanerochaete with considerable bootstrap support. Both the isolates of mitosporic H. rosae nest within a clade, which includes its sexual counterpart. Hence, we conclude that the lifecycle of H. rosae includes at least two reproductive states, i.e. sexual and asexual. Mitosporic H. rosae is capable of infecting plants and produce similar disease symptoms as its sexual state.http://www.sydowia.at/syd62-1/syd62-1.htm2016-12-30am2016Forestry and Agricultural Biotechnology Institute (FABI

Community composition and distribution of Phytophthora species across adjacent native and non-native forests of South Africa

The diversity of Phytophthora species associated with various ecological niches is poorly understood. In this study, the community composition and distribution of Phytophthora species associated with non-native plantation trees, Eucalyptus grandis and Acacia mearnsii, was compared with adjacent natural forests in South Africa using soil baiting and metabarcoding approaches. Through soil baiting, 85 Phytophthora isolates were recovered representing five taxa: P. alticola, P. cinnamomi, P. frigida, P. multivora and P. pseudocryptogea. Metabarcoding revealed molecular operational taxonomic units corresponding to 32 Phytophthora taxa. Among these, 14 were new reports from South Africa, including seven undescribed taxa. The community composition of Phytophthora species clustered according to vegetation type. Most species in plantations were present in the natural forest sites, but few species were exclusively associated with the non-native plantations. Overall, the results revealed a substantial diversity of Phytophthora species that includes both described and novel phylotypes previously unknown from South Africa.The University of Pretoria, the members of the Tree Protection Co-operative Programme and the Department of Science and Technology - National Research Foundation Centre of Excellence in Tree Health Biotechnology.http://www.journals.elsevier.com/fungal-ecology2019-12-01hj2018BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyPlant Production and Soil Scienc

Susceptibility of Eucalyptus grandis and Acacia mearnsii seedlings to five Phytophthora species common in South African plantations

Eucalyptus grandis and its hybrids, as well as Acacia mearnsii, are important non‐native trees commonly propagated for forestry purposes in South Africa. In this study, we conducted pathogenicity trials to assess the relative importance of five commonly isolated Phytophthora spp. (Phytophthora alticola, P. cinnamomi, P. frigida, P. multivora and P. nicotianae) from the plantation environment on E. grandis and A. mearnsii seedlings. Overall E. grandis was more susceptible to the tested Phytophthora spp. than A. mearnsii. Phytophthora cinnamomi was the only pathogen that had a significant negative effect on both the host tree species, leading to a reduction in root and shoot weight as well as to death in the case of E. grandis. Phytophthora alticola and P. nicotianae exclusively affected E. grandis and A. mearnsii, respectively. This study updated the current knowledge on the pathogenicity of Phytophthora spp. on two important non‐native commercially propagated tree species from South Africa.The University of Pretoria, members of the Tree Protection Co-operative Programme (TPCP), and the DST-NRF Centre of Excellence in Tree Health Biotechnology (CTHB), South Africa.http://wileyonlinelibrary.com/journal/efp2020-12-01hj2019BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyPlant Production and Soil Scienc

Phytophthora species associated with roots of native and non-native trees in natural and managed forests

Roots act as a biological filter that exclusively allows only a portion of the soil-associated microbial diversity to infect the plant. This microbial diversity includes organisms both beneficial and detrimental to plants. Phytophthora species are among the most important groups of detrimental microbes that cause various soil-borne plant diseases. We used a metabarcoding approach with Phytophthora-specific primers to compare the diversity and richness of Phytophthora species associated with roots of native and non-native trees, using different types of soil inocula collected from native and managed forests. Specifically, we analysed (1) roots of two non-native tree species (Eucalyptus grandis and Acacia mearnsii) and native trees, (2) roots of two non-native tree species from an in vivo plant baiting trial, (3) roots collected from the field versus those from the baiting trial, and (4) roots and soil samples collected from the field. The origin of the soil and the interaction between root and soil significantly influenced Phytophthora species richness. Moreover, species richness and community composition were significantly different between the field root samples and field soil samples with a higher number of Phytophthora species in the soil than in the roots. The results also revealed a substantial and previously undetected diversity of Phytophthora species from South Africa.The University of Pretoria, the Tree Protection Co-operative Programme (TPCP) and the Department of Science andTechnology–National Research Foundation (DST-NRF) Centre ofExcellence in Tree Health Biotechnology (CTHB).http://link.springer.com/journal/2482021-08-02hj2021BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyPlant Production and Soil Scienc

Two novel Phytophthora species from the southern tip of Africa

The microbial diversity associated with natural vegetation in the Greater Cape Floristic Region of South Africa is largely unexplored. As part of the Cape Citizen Science programme and independent research, surveys were conducted between 2015 and 2019 to catalogue the diversity of Phytophthora species associated with many plant species endemic to this region. Using soil and water baiting techniques, six isolates of the provisionally described Phytophthora taxon emzansi were recovered, together with three isolates of an undescribed Phytophthora species. In this study, we used both molecular and morphological data to describe these Phytophthora species. Isolates of P. emzansi sp. nov. and P. afrocarpa sp. nov. formed monophyletic lineages within Phytophthora Clades 2 and 10, respectively. Phytophthora emzansi sp. nov. and P. capensis are sister species residing in the P. citricola species complex, and both are homothallic. Phytophthora afrocarpa sp. nov. is a sister species to P. gallica, and both these taxa are sexually sterile. The present study augments our knowledge of the unique Phytophthora species associated with the native vegetation of southern Africa.Crowd-funding initiative of Joseph M. Hulbert, the University of Pretoria, members of the Tree Protection Cooperative Programme (TPCP), DSI/NRF Centre of Excellence in Plant Health Biotechnology (CPHB) South Africa and the Department of Forestry, Fisheries and the Environment (DFFE), South Africa.http://link.springer.com/journal/11557hj2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyPlant Production and Soil Scienc

Ophiostomatoid species associated with pine trees (Pinus spp.) infested by Cryphalus piceae from eastern China, including five new species

Cryphalus piceae attacks various economically important conifers. Similar to other bark beetles, Cr. piceae plays a role as a vector for an assortment of fungi and nematodes. Previously, several ophiostomatoid fungi were isolated from Cr. piceae in Poland and Japan. In the present study, we explored the diversity of ophiostomatoid fungi associated with Cr. piceae infesting pines in the Shandong Province of China. We isolated ophiostomatoid fungi from both galleries and beetles collected from our study sites. These fungal isolates were identified using both molecular and morphological data. In this study, we recovered 175 isolates of ophiostomatoid fungi representing seven species. Ophiostoma ips was the most frequently isolated species. Molecular and morphological data indicated that five ophiostomatoid fungal species recovered were previously undescribed. Thus, we proposed these five novel species as Ceratocystiopsis yantaiensis, C. weihaiensis, Graphilbum translucens, Gr. niveum, and Sporothrix villosa. These new ophiostomatoid fungi add to the increasing number of fungi known from China, and this evidence suggests that numerous novel taxa are awaiting discovery in other forests of China.Shandong Normal University.https://mycokeys.pensoft.netam2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Phylogenetic and morphological analyses of Coniochaeta isolates recovered from Inner Mongolia and Yunnan revealed three new endolichenic fungal species

Lichens are the result of a symbiotic interaction between fungi (mycobionts) and algae (phycobionts). Aside from mycobionts, lichen thalli can also contain non-lichenised fungal species, such as lichenicolous and endolichenic fungi. For this study, three surveys were conducted in China’s Yunnan Province and Inner Mongolia Autonomous Region between 2017 and 2020. Several samples of four lichen species were collected during these surveys: Candelaria fibrosa, Flavoparmelia caperata, Flavopunctelia flaventior and Ramalina sinensis. Six isolates of Coniochaeta were recovered from these four lichen species. The phylogenetic and morphological analyses revealed that two of these isolates were previously identified species, Coniochaeta velutinosa and C. acaciae. Those remaining were from potentially unknown species. We used molecular and morphological data to describe these previously-unknown species as Coniochaeta fibrosae sp. nov., C. mongoliae sp. nov. and C. sinensis sp. nov. The findings of this study significantly improve our understanding of the variety and habitat preferences of Coniochaeta in China and globally.The National Natural Science Foundation of China.https://mycokeys.pensoft.netam2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Fungal diversity associated with the mycorrhizosphere soil of Brachycorythis conica subsp. transvaalensis, a critically endangered and endemic terrestrial orchid from South Africa

DATA ACCESSIBILITY : The high-throughput sequencing data generated in this study is available at the NCBI Sequence Read Archive (https://submit.ncbi.nlm.nih.gov/ subs/sra/) under the accession number PRJNA693177.The Albertina Sisulu orchid, Brachycorythis conica subsp. transvaalensis is a critically endangered terrestrial orchid with a single population remaining in the Gauteng Province of South Africa. For the conservation of this endemic orchid, several strategies are being implemented such as protection of habitat, identifying pollinators and in vitro propagation. For symbiotic germination, it is essential to identify the mycorrhizal associates of this orchid using non-destructive sampling. In this study, high-throughput sequencing was used to catalogue and compare the diversity of fungi associated with the mycorrhizosphere of this orchid and non-mycorrhizosphere soils collected from the same coordinates. Bioinformatics and statistical analyses of the data showed that, despite the substantial overlap in the community composition of fungi associated with these two soil types, several exclusive fungal species were identified from the mycorrhizosphere of the orchid. These included an assortment of potential orchid mycorrhizal species from the orders Agaricales, Cantharellales and Sebacinales. This study provides the first insight into the soil fungal diversity associated with the mycorrhizosphere of this critically endangered orchid. In the future, data from this study can be used for optimising conservation measures and isolation of suitable mycorrhizal species required for in vitro symbiotic germination of this orchid.The NRF Foundational Biodiversity Information Programme, the International Partnergroup Program of the Max Planck Society and the NRF SARChI Chair in Fungal Genomics.http://www.elsevier.com/locate/sajbhj2023BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyZoology and Entomolog