scholarly journals A fungus-eat-fungus world: Digitopodium, with particular reference to mycoparasites of the coffee leaf rust, Hemileia vastatrix

IMA Fungus ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Adans A. Colmán ◽  
Harry C. Evans ◽  
Sara S. Salcedo-Sarmiento ◽  
Uwe Braun ◽  
Kifle Belachew-Bekele ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Democratic Republic Of Congo ◽  
Sequence Data ◽  
Molecular Study ◽  
Classical Biological Control ◽  
Coffea Canephora ◽  
Molecular Data ◽  
Phylogenetic Position ◽  
Hemileia Vastatrix ◽  
Coffee Leaf Rust

AbstractDigitopodium hemileiae was described originally in 1930 as Cladosporium hemileiae; growing as a mycoparasite of the coffee leaf rust (CLR), Hemileia vastatrix, in a sample of diseased leaves of Coffea canephora collected in the Democratic Republic of Congo. No cultures from this material exist. More recently, the type material was re-examined and, based on morphological features, considered to be incorrectly placed in Cladosporium. The new genus Digitopodium was erected to accommodate this species. Interest in fungal antagonists of H. vastarix, as potential biocontrol agents of CLR, led to comprehensive surveys for mycoparasites, both in the African centre of origin of the rust, as well as in its South American exotic range. Among the rust specimens from Ethiopia, one was found to be colonized by a fungus congeneric with, and similar to, D. hemileiae. Pure cultures obtained from the Ethiopian material enabled a molecular study and for its phylogenetic position to be elucidated, based on DNA sequence data from the ITS and LSU regions. Molecular data showed that two members of the recently erected genus Hyalocladosporiella (Herpotrichiellaceae: Chaetothyriales) are congeneric with Digitopodium from Ethiopia and morphologically similar to both D. hemileiae and the two Ethiopian isolates. These isolates were found to be morphologically and genetically identical to H. tectonae, described previously from Brazil. Thus, species of Hyalocladosporiella are re-allocated to Digitopodium here; including D. tectonae, and a novel species, D. canescens, recently found in Brazil growing as a mycoparasite of Puccinia thaliae. The potential use of D. hemileiae and D. tectonae for classical biological control of CLR is discussed.

scholarly journals New species and records of Trichoderma isolated as mycoparasites and endophytes from cultivated and wild coffee in Africa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
María del Carmen H. Rodríguez ◽  
Harry C. Evans ◽  
Lucas M. de Abreu ◽  
Davi M. de Macedo ◽  
Miraine K. Ndacnou ◽  
...  
Keyword(s):  
New Species ◽  
Cloud Forest ◽  
Elongation Factor ◽  
Classical Biological Control ◽  
Hemileia Vastatrix ◽  
Translation Elongation ◽  
Coffee Leaf Rust ◽  
Novel Taxa ◽  
Coffee Plants ◽  
Wild Coffee

AbstractA survey for species of the genus Trichoderma occurring as endophytes of Coffea, and as mycoparasites of coffee rusts (Hemileia), was undertaken in Africa; concentrating on Cameroon and Ethiopia. Ninety-four isolates of Trichoderma were obtained during this study: 76 as endophytes of healthy leaves, stems and berries and, 18 directly from colonized rust pustules. A phylogenetic analysis of all isolates used a combination of three genes: translation elongation factor-1α (tef1), rpb2 and cal for selected isolates. GCPSR criteria were used for the recognition of species; supported by morphological and cultural characters. The results reveal a previously unrecorded diversity of Trichoderma species endophytic in both wild and cultivated Coffea, and mycoparasitic on Hemileia rusts. Sixteen species were delimited, including four novel taxa which are described herein: T. botryosum, T. caeruloviride, T. lentissimum and T. pseudopyramidale. Two of these new species, T. botryosum and T. pseudopyramidale, constituted over 60% of the total isolations, predominantly from wild C. arabica in Ethiopian cloud forest. In sharp contrast, not a single isolate of Trichoderma was obtained using the same isolation protocol during a survey of coffee in four Brazilian states, suggesting the existence of a ‘Trichoderma void’ in the endophyte mycobiota of coffee outside of Africa. The potential use of these African Trichoderma isolates in classical biological control, either as endophytic bodyguards—to protect coffee plants from Hemileia vastatrix, the fungus causing coffee leaf rust (CLR)—or to reduce its impact through mycoparasitism, is discussed, with reference to the on-going CLR crisis in Central America.

scholarly journals Structural and functional analysis of genes with potential involvement in resistance to coffee leaf rust: a functional marker based approach

2019 ◽  
Author(s):  
Geleta Dugassa Barka ◽  
Eveline Teixeira Caixeta ◽  
Sávio Siqueira Ferreira ◽  
Laércio Zambolim
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Function Analysis ◽  
Bac Library ◽  
Leaf Rust Resistance ◽  
Molecular Data ◽  
Coffee Leaf Rust ◽  
Rust Resistance Genes

AbstractPhysiology-based differentiation of SH genes and Hemileia vastatrix races is the principal method employed for the characterization of coffee leaf rust resistance. Based on the gene-for-gene theory, nine major rust resistance genes (SH1-9) have been proposed. However, these genes have not been characterized at the molecular level. Consequently, the lack of molecular data regarding rust resistance genes or candidates is a major bottleneck in coffee breeding. To address this issue, we screened a BAC library with resistance gene analogs (RGAs), identified RGAs, characterized and explored for any SH related candidate genes. Herein, we report the identification and characterization of a gene (gene 11), which shares conserved sequences with other SH genes and displays a characteristic polymorphic allele conferring different resistance phenotypes. Furthermore, comparative analysis of the two RGAs belonging to CC-NBS-LRR revealed more intense diversifying selection in tomato and grape genomes than in coffee. For the first time, the present study has unveiled novel insights into the molecular nature of the SH genes, thereby opening new avenues for coffee rust resistance molecular breeding. The characterized candidate RGA is of particular importance for further biological function analysis in coffee.

scholarly journals Stability of Arabica coffee genotype (Coffea arabica L.) against leaf rust (Hemileia vastatrix)

2021 ◽  
Vol 748 (1) ◽  
pp. 012002
Author(s):  
Sabam Malau ◽  
Albiner Siagian ◽  
Maria Rumondang Sihotang
Keyword(s):  
Leaf Rust ◽  
Block Design ◽  
Research Result ◽  
Dry Season ◽  
Environment Interaction ◽  
Rust Disease ◽  
Hemileia Vastatrix ◽  
Arabica Coffee ◽  
Coffee Leaf Rust ◽  
Rust Severity

Abstract Coffee is now experiencing a serious threat from fungus Hemileia vastatrix which caused epidemic of rust disease in America, Africa, and Asia. As solution, the use of resistant cultivars is the best way. However, interaction between genotype and environment can change the rank of genotypes that shows instability of these genotypes against leaf rust. Purpose of this research was to study stability of genotypes of Arabica coffee against coffee leaf rust. A field experiment was arranged as factorial randomized complete block design with 2 factors (genotypes and climate zones) with three replication. The observed parameters were branch rust incidence, leaf rust incidence, and leaf rust severity. This research result showed significant genotype x environment interaction in all variables. Length of dry season is the most important factor affecting coffee leaf rust because it had the highest correlation coefficient with leaf rust severity (r = 0.662**). Less length of dry season should be the first criteria for selection of coffee farms. The most desired genotype was G7 which performed low leaf rust severity (7.71%) and had a stable resistance indicated by the same leaf rust severity in all environments and 6 SMg. Due to the significant interaction between genotypes and the environment, the genotype to be planted in a region must be tested in that region first.

scholarly journals Phylogenetic position and taxonomy of Cycloseris explanulata and C. wellsi (Scleractinia: Fungiidae): lost mushroom corals find their way home

2012 ◽  
Vol 81 (3) ◽  
pp. 125-146 ◽  
Author(s):  
Francesca Benzoni ◽  
Roberto Arrigoni ◽  
Fabrizio Stefani ◽  
Bastian T. Reijnen ◽  
Simone Montano ◽  
...  
Keyword(s):  
Molecular Study ◽  
Molecular Data ◽  
Phylogenetic Position ◽  
Distribution Data ◽  
Data Sets ◽  
Free Living ◽  
New Findings ◽  
The Family ◽  
Ecological Implications ◽  
History Of

The scleractinian species Psammocora explanulata and Coscinaraea wellsi were originally classified in the family Siderastreidae, but in a recent morpho-molecular study it appeared that they are more closely related to each other and to the Fungiidae than to any siderastreid taxon. A subsequent morpho-molecular study of the Fungiidae provided new insights regarding the phylogenetic relationships within that family. In the present study existing molecular data sets of both families were analyzed jointly with those of new specimens and sequences of P. explanulata and C. wellsi. The results indicate that both species actually belong to the Cycloseris clade within the family Fungiidae. A reappraisal of their morphologic characters based on museum specimens and recently collected material substantiate the molecular results. Consequently, they are renamed Cycloseris explanulata and C. wellsi. They are polystomatous and encrusting like C. mokai, another species recently added to the genus, whereas all Cycloseris species were initially thought to be monostomatous and free-living. In the light of the new findings, the taxonomy and distribution data of C. explanulata and C. wellsi have been updated and revised. Finally, the ecological implications of the evolutionary history of the three encrusting polystomatous Cycloseris species and their free-living monostomatous congeners are discussed.

Non-host resistance responses of Arabidopsis thaliana to the coffee leaf rust fungus (Hemileia vastatrix)

Botany ◽  
2010 ◽  
Vol 88 (7) ◽  
pp. 621-629 ◽  
Author(s):  
Helena Gil Azinheira ◽  
Maria do Céu Silva ◽  
Pedro Talhinhas ◽  
Clara Medeira ◽  
Isabel Maia ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Leaf Rust ◽  
Rust Fungus ◽  
Hemileia Vastatrix ◽  
Callose Deposition ◽  
Mesophyll Cells ◽  
Model Plant ◽  
Heterologous System ◽  
Coffee Leaf Rust ◽  
Model Plant Arabidopsis Thaliana

Leaf rust, caused by Hemileia vastatrix Berk & Broome, is the most destructive fungal disease of coffee. In the absence of a suitable gene validation system in coffee, the objective of this study was to investigate whether the model plant Arabidopsis thaliana (L.) Heynh. may be used as a heterologous system for the molecular dissection of coffee responses to leaf rust. Histological examination of A. thaliana (Col-0) leaves inoculated with H. vastatrix (race II) showed that by 24 h after inoculation (hai), H. vastatrix uredospores differentiated appressoria and penetrated the stomata, but failed to form haustoria. Arabidopsis thaliana cellular resistance responses included hypersensitive-like response (HR) of stomata guard cells together with accumulation of phenolic compounds and callose deposition in walls of epidermal and mesophyll cells. Results indicate that H. vastatrix infection triggered the induction of a set of defence-related genes peaking at 18 and 42 hai. The non-host HR triggered by H. vastatrix in the model plant A. thaliana makes it usable to infer the function of coffee genes involved in pre-haustorial rust resistance.

Phylogenetic position of Arabis arenicola and generic limits of Aphragmus and Eutrema (Brassicaceae) based on sequences of nuclear ribosomal DNA

2006 ◽  
Vol 84 (2) ◽  
pp. 269-281 ◽  
Author(s):  
Suzanne I. Warwick ◽  
Ihsan A. Al-Shehbaz ◽  
Connie A. Sauder
Keyword(s):  
Internal Transcribed Spacer ◽  
Sequence Data ◽  
Its Region ◽  
Molecular Data ◽  
The Other ◽  
Nuclear Ribosomal Dna ◽  
Phylogenetic Position ◽  
New Combinations ◽  
Arabidopsis Lyrata ◽  
Relationship Of

Sequence data from the nuclear ribosomal internal transcribed spacer (ITS) region of 45 taxa were used to determine the phylogenetic relationship of Arabis arenicola to Arabis , Arabidopsis , Braya , and Eutrema , and that of Eutrema to the purportedly related genera Aphragmus , Lignariella , Neomartinella , Platycraspedum , Taphrospermum , and Thellungiella . Arabis arenicola was originally described as Eutrema in 1830, transferred to Arabis in 1898, and has remained in Arabis to the present, even though it is morphologically more similar to Arabidopsis, Braya, and Eutrema. Sequence data were obtained from representative taxa of Arabis, Arabidopsis, and related Boechera and Catolobus, Braya and Neotorularia, and Eutrema, Aphragmus, Lignariella, Neomartinella, Platycraspedum, Taphrospermum, and Thellungiella. The five Arabis arenicola accessions examined had ITS sequences that were identical to each other and to four Arabidopsis lyrata accessions. In both maximum parsimony and maximum likelihood analyses, Arabis arenicola fell within the Arabidopsis clade and was closely aligned with Arabidopsis lyrata. Two of six purportedly related genera were not closely related to Eutrema. Both analyses placed Lignariella within a separate well-supported clade with Aphragmus, while the other four genera, Neomartinella, Platycraspedum, Taphrospermum, and Thellungiella, fell within a well-supported clade with Eutrema. Morphology and molecular data strongly suggest transferring Arabis arenicola to Arabidopsis, expanding Aphragmus to include Lignariella, and expanding Eutrema to include Neomartinella, Platycraspedum, Taphrospermum, and Thellungiella. New combinations in Arabidopsis and Aphragmus are proposed.

Evaluation of Different Botanicals for the Control of Coffee Leaf Rust (Hemileia vastatrix Berkeley and Broome)

2017 ◽  
Vol 14 (6) ◽  
pp. 1-8
Author(s):  
R Mudyiwa ◽  
N Mwatsiya ◽  
B Manenji ◽  
P Chidoko ◽  
C Mahoya
Keyword(s):  
Leaf Rust ◽  
Hemileia Vastatrix ◽  
Coffee Leaf Rust

Sensitization to the fungus Hemileia vastatrix (coffee leaf rust)

Allergy ◽  
2001 ◽  
Vol 56 (7) ◽  
pp. 684-687 ◽  
Author(s):  
M. A. Croce Portocarrero ◽  
E. Rosa da Costa Manso ◽  
W. Gambale ◽  
L. Takayama ◽  
C. E. Oliveira Andrade ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Hemileia Vastatrix ◽  
Coffee Leaf Rust

scholarly journals Cytological and molecular description of Hamiltosporidium tvaerminnensis gen. et sp. nov., a microsporidian parasite of Daphnia magna, and establishment of Hamiltosporidium magnivora comb. nov.

Parasitology ◽  
2010 ◽  
Vol 138 (4) ◽  
pp. 447-462 ◽  
Author(s):  
KAREN LUISA HAAG ◽  
J. I. RONNY LARSSON ◽  
DOMINIK REFARDT ◽  
DIETER EBERT
Keyword(s):  
Daphnia Magna ◽  
Sequence Data ◽  
Polar Filament ◽  
Molecular Data ◽  
Phylogenetic Position ◽  
Microsporidian Parasite ◽  
Isolated Nuclei ◽  
Host Interactions ◽  
Ultrastructural Characteristics ◽  
Molecular Description

SUMMARYWe describe the new microsporidium Hamiltosporidium tvaerminnensis gen. et sp. nov. with an emphasis on its ultrastructural characteristics and phylogenetic position as inferred from the sequence data of SSU rDNA, alpha- and beta-tubulin. This parasite was previously identified as Octosporea bayeri Jírovec, 1936 and has become a model system to study the ecology, epidemiology, evolution and genomics of microsporidia - host interactions. Here, we present evidence that shows its differences from O. bayeri. Hamiltosporidium tvaerminnensis exclusively infects the adipose tissue, the ovaries and the hypodermis of Daphnia magna and is found only in host populations located in coastal rock pool populations in Finland and Sweden. Merogonial stages of H. tvaerminnensis have isolated nuclei; merozoites are formed by binary fission or by the cleaving of a plasmodium with a small number of nuclei. A sporogonial plasmodium with isolated nuclei yields 8 sporoblasts. Elongated spores are generated by the most finger-like plasmodia. The mature spores are polymorphic in shape and size. Most spores are pyriform (4·9–5·6×2·2–2·3 μm) and have their polar filament arranged in 12–13 coils. A second, elongated spore type (6·8–12·0×1·6–2·1 μm) is rod-shaped with blunt ends and measures 6·8–12·0×1·6–2·1 μm. The envelope of the sporophorous vesicle is thin and fragile, formed at the beginning of the sporogony. Cytological and molecular comparisons with Flabelliforma magnivora, a parasite infecting the same tissues in the same host species, reveal that these two species are very closely related, yet distinct. Moreover, both cytological and molecular data indicate that these species are quite distant from F. montana, the type species of the genus Flabelliforma. We therefore propose that F. magnivora also be placed in Hamiltosporidium gen. nov.

Sign in / Sign up

Export Citation Format

Share Document