Coffee Disease Research Articles

Organization and molecular evolution of a disease-resistance gene cluster in coffee trees

BackgroundMost disease-resistance (R) genes in plants encode NBS-LRR proteins and belong to one of the largest and most variable gene families among plant genomes. However, the specific evolutionary routes of NBS-LRR encoding genes remain elusive. Recently in coffee tree (Coffea arabica), a region spanning the SH3 locus that confers resistance to coffee leaf rust, one of the most serious coffee diseases, was identified and characterized. Using comparative sequence analysis, the purpose of the present study was to gain insight into the genomic organization and evolution of the SH3 locus.ResultsSequence analysis of the SH3 region in three coffee genomes, Ea and Ca subgenomes from the allotetraploid C. arabica and Cc genome from the diploid C. canephora, revealed the presence of 5, 3 and 4 R genes in Ea, Ca, and Cc genomes, respectively. All these R-gene sequences appeared to be members of a CC-NBS-LRR (CNL) gene family that was only found at the SH3 locus in C. arabica. Furthermore, while homologs were found in several dicot species, comparative genomic analysis failed to find any CNL R-gene in the orthologous regions of other eudicot species. The orthology relationship among the SH3-CNL copies in the three analyzed genomes was determined and the duplication/deletion events that shaped the SH3 locus were traced back. Gene conversion events were detected between paralogs in all three genomes and also between the two sub-genomes of C. arabica. Significant positive selection was detected in the solvent-exposed residues of the SH3-CNL copies.ConclusionThe ancestral SH3-CNL copy was inserted in the SH3 locus after the divergence between Solanales and Rubiales lineages. Moreover, the origin of most of the SH3-CNL copies predates the divergence between Coffea species. The SH3-CNL family appeared to evolve following the birth-and-death model, since duplications and deletions were inferred in the evolution of the SH3 locus. Gene conversion between paralog members, inter-subgenome sequence exchanges and positive selection appear to be the major forces acting on the evolution of SH3-CNL in coffee trees.

Diseases in tropical and plantation crops as affected by climate changes: current knowledge and perspectives

Tropical and plantation crops include important crops for food security and alternative energy resources. Even so, there are few studies on the impact of climate change on diseases of these crops. Findings from previous studies concerning some climate‐change effects on diseases of coffee, sugarcane, eucalyptus, cassava, citrus, banana, pineapple, cashew, coconut and papaya have been summarized to provide a context. By reviewing available methods to evaluate the impact of climate change on diseases of tropical and plantation crops, we present trends for some diseases and their management strategies, identify critical gaps in knowledge, and suggest experimental and analytical approaches to advance knowledge. As the projected climate conditions will probably vary greatly in the future from continent to continent and from developed to developing countries, studies must be conducted under tropical regions considering their specific environmental conditions. Multifactor studies under realistic field situations, such as free air CO2 enrichment with increasing CO2 and O3 concentrations incorporating spectral reflectance measures in situ for realistic assessment of plant growth, are a way forward. Effects of a changing climate on chemical and biological controls are discussed in the context of changing global outlook on environmental demands for the future.

Infection Process of Cercospora coffeicola on Coffee Leaf

Brown eye spot, caused by Cercospora coffeicola, is an important disease of coffee. Both adaxial and abaxial leaf surfaces were inoculated with a conidial suspension of C. coffeicola. Samples were collected from 4 to 168 h after inoculation and then again at 35 days. Germinated conidia showed positive tropism to stomata where attempted penetrations occurred. Appressoria were not observed. After penetration, C. coffeicola colonized the lacunous parenchyma both inter and intracellularly. Sporulation occurred through or around the stomata. Results from this study provide new insights into the infection process of C. coffeicola on coffee leaf.

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

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.

Identification of Colletotrichum species associated with anthracnose disease of coffee in Vietnam

Twenty-three isolates of Colletotrichum gloeosporioides, five isolates of C. acutatum, two isolates of C. capsici and six isolates of C. boninense associated with anthracnose disease on coffee (Coffea spp.) in Vietnam were identified based on morphology and DNA analysis. Phylogenetic analysis of DNA sequences from the internal transcribed spacer region of nuclear rDNA and a portion of mitochondrial small subunit rRNA were concordant and allowed good separation of the taxa. We found several Colletotrichum isolates of unknown species and their taxonomic position remains unresolved. The majority of Vietnamese isolates belonged to C. gloeosporioides and they grouped together with the coffee berry disease (CBD) fungus, C. kahawae. However, C. kahawae could be distinguished from the Vietnamese C. gloeosporioides isolates based on ammonium tartrate utilization, growth rate and pathogenicity. C. gloeosporioides isolates were more pathogenic on detached green berries than isolates of the other species, i.e. C. acutatum, C capsici and C. boninense. Some of the C. gloeosporioides isolates produced slightly sunken lesions on green berries resembling CBD symptoms but it did not destroy the bean. We did not find any evidence of the presence of C. kahawae in Vietnam.

Partial resistance to leaf rust (Hemileia vastatrix) in coffee (Coffea arabica L.): genetic analysis and molecular characterization of putative candidate genes

One of the major production limiting diseases in coffee is the orange leaf rust caused by the fungus Hemileia vastatrix (Berkeley and Broome). Little is known about the inheritance and genetic determinism of partial resistance in coffee (C. arabica L.) to H. vastatrix. This information would be useful to breed durable resistant cultivars efficiently. In this report, a genetic analysis of partial resistance to leaf rust in Coffea arabica was performed using nine segregating progenies from a cross between the susceptible variety Caturra and the resistant introgressed line DI200. Evolution of partial resistance was evaluated under field conditions by measuring rust incidence (RI) and defoliation (DEF) in two separate regions of productive branches per tree and during four successive years (2003-2006). Genetic components of rust resistance were estimated using the Means and Variance Generation Method, under an additive-dominant model. The most important genetic effect was the additive one, while resistance heritability estimates ranged from 73 to 53% for broad and narrow sense heritabilities, respectively. Genetic estimates for the number of segregating genes showed that at least five independent genes or genetic regions are implicated in the partial resistance to rust. We further analyzed the presence of resistance (RGC) and defense (DGC) gene candidates in the resistant and susceptible parents by using a degenerated-primer PCR approach. A total of 40 different genomic coffee sequences were isolated exhibiting strong similarity to known RGC or DGC homologous. Phylogenetic analysis clustered these sequences into nine families. One family exhibited the TIR protein element, representing the first TIR class proteins identified in coffee. While genetic analysis suggest a predictable success in the processes to improve the selection of resistant lines for future varieties with durable resistance, the molecular characterization of candidate genes represent a primary approach towards the identification of mechanisms involved in partial resistance to coffee leaf rust.

BIOLOGICAL CONTROL OF COFFEE LEAF RUST PATHOGEN, HEMILEIA VASTATRIX BERKELEY AND BROOME USING BACILLUS SUBTILIS AND PSEUDOMONAS FLUORESCENS

ABSTRACT Bacterial antagonists isolated from coffee rhizosphere soils were evaluated at different concentrations alone and in combination against Hemileia vastatrix, the causal organism of leaf rust disease of coffee under in vitro and in vivo conditions. Under in vitro conditions, the rhizobacterium, Bacillus subtilis inhibited the growth of urediospores to an extent of 68.20% at a test dosage of 1 x 109 cfu ml-1 followed by Pseudomonas fluorescens to an extent of 64.50% at the same test dose. Combination of P. fluorescens and B. subtilis at 1 x 108 cfu ml-1 inhibited the growth of urediospores of the CLR pathogen to an extent of 61.46%. The natural inhibition of germination in the check treatment was 37.79%. Among fungicides used for comparison, the percent inhibition over control was maximum in Bayleton (89.03%) followed by Bordeaux mixture (80.64%). Under in vivo conditions, during the period of season-I, maximum reduction in disease index was recorded in treatment with Bayleton (71.84%) followed by Bordeaux mixture (53.37%). Among the bioagents, B. subtilis recorded maximum disease reduction (42.98%) at a test dosage of 1 x 109 cfu ml-1 followed by P. fluorescens (33.65 %) at the same test dose. P. fluorescens and B. subtilis in combination at 1 x 108 cfu ml-1 reduced the disease incidence to an extent of 26.45%. The season-II (post-monsoon period) has recorded less disease reduction compared to season-I (pre-monsoon period).

Mating Test and <i>In Vitro</i> Production of Perithecia by the Coffee Wilt Pathogen , <i>Gibberella xylarioides</i> (<i>Fusarium xylarioides</i>)

Gibberella xylarioides Heim & Saccas, the teleomorphic state of Fusarium xylarioides Steyaert, is a fungal pathogen causing a vascular wilt disease of coffee known as tracheomycosis. Coffee wilt disease has been one of the endemic diseases of Arabica coffee (Coffea arabica) with increasing outbreaks and prevalence in Ethiopia. In the present study, in vitro production of fertile perithecia was assessed by crossing eight randomly selected monoconidial isolates of G. xylarioides (F. xylarioides) collected from C. arabica, including few strains from C. canephora and C. excelsa. Five media types and two temperature levels were compared for inducing the sexual structures in the fungus. In vivo development of perithecia on coffee trees in the field and on inoculated young seedlings in the greenhouse was also examined. More than 30% of the crosses formed perithecia in vitro including those pairings of isolates recovered from the different Coffea spp. Isolate Gx1 (BBA 71975) showed high intra- and inter-fertility with most of the strains indicating that this isolate was most probably ‘female fertile' mating type. This interfertility was successfully achieved only on carrot agar and V-8 juice medium at 20oC and 12-hr photoperiod 10 – 12 wks after plating. The fungus often produced abundant perithecia containing enormous ascospores in the barks of dead coffee trees in the field and in the artificially infected young seedlings. The in vitro and in vivo perithecial developments were most likely favoured by cool and moist (wet) conditions. Abundant production of ascospores in the field is an integral part of survival and dispersal mechanisms along with genetic exchange system. The in vitro formation of fertile perithecia enables to study inheritance of traits such as pathogenicity (virulence) and gene flow and genetic diversity in populations of G. xylarioides. Keywords : Coffee wilt disease; Coffea arabica; Ethiopia; Gibberella xylarioides; Mating test; Perithecia Ethiopian Journal of Biological Sciences Vol. 6 (1) 2007: pp. 63-75

Biological control of coffee rust by antagonistic bacteria under field conditions in Brazil

Rust ( Hemileia vastatrix) is the most important coffee disease in Brazil. Organic coffee production has increased in the country and a research program aimed to develop alternatives to chemicals for disease control was required. Seven bacterial isolates, isolated from organic coffee plantings and selected in greenhouse tests, were evaluated under commercial organic crop conditions in 2005 (Experiment 1) and 2005/2006 (Experiment 2), in Machado, MG, Brazil. Ten treatments consisting of the seven bacterial isolates, copper hydroxide, calcium silicate and water were applied as three or four monthly sprays in Experiment 1 or 2, respectively. Rust severity and incidence were evaluated monthly. In Experiment 1, the sprays started in January when rust incidence was 23.8%, and none of the treatments reduced rust progress significantly. In Experiment 2, the sprays began in November 2005, when rust incidence was approximately 7.5%. There were significant differences ( P < 0.0001) between treatments regarding maximum incidence and severity (as assessed in June, 2006), the rate of increase of the incidence between November 2005 and June 2006 and for the areas under disease progress curves for both rust incidence and severity. Lower values for these treatments were obtained in the plots treated with copper hydroxide or Bacillus sp. isolate B157, and intermediate values with the Pseudomonas sp. isolate P286. In a third experiment conducted in 2007 in Ervália, MG, isolates B157 and P286 were also evaluated; isolate B157 reduced rust intensity as effectively as copper hydroxide. Isolate B157 is considered a potential biocontrol agent for coffee rust for organic crop systems in Brazil.

Common pests and diseases of coffee.

Common pests and diseases of coffee.

The Potential Use of a Silicon Source as a Component of an Ecological Management of Coffee Plants

AbstractCoffee is one of the most important agricultural export commodities in the world and it represents the main export from some developing countries. Therefore, the development of new methods of coffee management that improves production without causing any damage to the environment is an attractive alternative for producers. Much effort has been invested towards understanding the mode of action of compounds that can induce resistance against several pathogens without injuring the environment. Many researches have considered silicon efficient in avoiding plant pathogen penetration and development. Our aim was to verify the effect of potassium silicate and calcium/magnesium silicate in the development of coffee seedlings (Coffea arabica cv. Mundo Novo) as well as to evaluate the incidence of coffee leaf rust development under greenhouse conditions. The experiment was a completely randomized design with 12 treatments with 10 plants per treatment. The treatments were 0, 0.25, 1.25, 2.5, 4 and 5 μm of Si for each source of silicon incorporated into the soil. The seedlings were inoculated with a urediniospores suspension of Hemileia vastatrix (2 mg/ml) at the seventh month after planting (six pair of leaves). Evaluations were performed by counting the number of lesions per leaf. The statistical analysis showed that the number of lesions reduced by up to 66% at the highest silicon dose when compared to the number of lesions in control plants. Infected plants were found to have a linear decrease of lesions with the increase of silicate concentration. The lowest number of lesions per leaf area was observed in plants that received 5 μm of Si from potassium silicate. This result indicates the use of silicon as an alternative for an ecological management system for coffee disease protection.

Development of sequence characterized DNA markers linked to leaf rust (Hemileia vastatrix) resistance in coffee (Coffea arabica L.)

Coffee leaf rust due to Hemileia vastatrix is one of the most serious diseases in Arabica coffee (Coffea arabica). A resistance gene (SH3) has been transferred from C. liberica into C. arabica. The present work aimed at developing sequence-characterized genetic markers for leaf rust resistance. Linkage between markers and leaf rust resistance was tested by analysing two segregating populations, one F2 population of 101 individuals and one backcross (BC2) population of 43 individuals, derived from a cross between a susceptible and a SH3-introgressed resistant genotype. A total of ten sequence-characterized genetic markers closely associated with the SH3 leaf rust resistance gene were generated. These included simple sequence repeats (SSR) markers, sequence-characterised amplified regions (SCAR) markers resulting from the conversion of amplified fragment length polymorphism (AFLP) markers previously identified and SCAR markers derived from end-sequences of bacterial artificial chromosome (BAC) clones. Those BAC clones were identified by screening of C. arabica genomic BAC library using a cloned AFLP-marker as probe. The markers we developed are easy and inexpensive to run, requiring one PCR step followed by gel separation. While three markers were linked in repulsion with the SH3 gene, seven markers were clustered in coupling around the SH3 gene. Notably, two markers appeared to co-segregate perfectly with the SH3 gene in the two plant populations analyzed. These markers are suitable for marker-assisted selection for leaf rust resistance and to facilitate pyramiding of the SH3 gene with other leaf rust resistance genes.

Diseases of Tropical Perennial Crops: Challenging Problems in Diverse Environments.

The world’s oldest ecosystems are found in the tropics. They are diverse, highly evolved, but barely understood. Diseases that impact crops in these regions can be significant contraints to production, especially when they occur in lowland environments with high rainfall and uniform, warm temperatures; respites from disease pressure there are often infrequent. Difficulties in managing diseases in the humid tropics are multiplied when the affected crops are perennial. The favorable conditions for disease development and the presence of susceptible host tissue over long periods make diseases of tropical perennial crops serious management challenges. This topic is introduced with a few concepts on the occurrence and development of these pathosystems. Peculiar aspects and scenarios that influence the types of and extent to which different diseases develop are summarized. Measures that are useful on annual or short-term crops may be ineffective against these diseases. They are scientifically interesting problems. New vectors, as for mango malformation, or pathogens, as for bunchy top of papaya, are associated with some of the diseases. And some of the diseases are caused by two or more distinct taxa; for example, citrus greening, mango malformation, Panama disease, and tracheomycosis of coffee. Some of the most important diseases are host-specific and are caused by either coevolved or new-encounter pathogens. Resistance, the most effective tool with which many of these diseases are managed, is usually available in coevolved pathosystems but may be uncommon in new-encounter situations. Inadequate host resistance can be a significant barrier in the management of both coevolved and new encounter diseases. General tactics are described that are useful against diseases of tropical perennials. The successful management of plant disease utilizes several principles and practices, regardless of the host and environment in which it is grown. These include the avoidance, exclusion, and eradication of the causal agents. Host protection is of great importance, as is the identification and incorporation of resistance in the host plant. All of these approaches are discussed with tropical perennial examples.

Fusarium-Induced Diseases of Tropical, Perennial Crops

ABSTRACT The world's oldest ecosystems are found in the tropics. They are diverse, highly evolved, but barely understood. This and subsequent papers describe diseases of tropical, perennial plants that are caused by Fusarium spp. Many of these are economically significant, difficult to manage, and of scientific interest. Some represent coevolved patho-systems (e.g., Panama disease, tracheomycosis of coffee, fusariosis of pineapple, and Fusarium wilt of oil palm), whereas others may be new-encounter diseases or are caused by generalist pathogens (cushion gall of cacao). New vector relationships are evident in other pathosystems (e.g., mango malformation), and two or more pathogens have been shown to cause some of the diseases (Panama disease and tracheomycosis of coffee). More work on these pathosystems is warranted as they could reveal much about the evolution of plant pathogens and the important diseases they cause.

PERKECAMBAHAN UREDOSPORA HEMILEIA VASTATRIX PADA EKSTRAK RIMPANG JAHE DAN KUNYIT SERTA DAUN CENGKEH DAN SIRIH

Germination of Hemileia vastatrix uredospores on crude water extracts of zinger and turmeric rhizome and clove and Piper betle leaves. Coffee leaf rust caused by H. vastatrix especially on Arabica coffee is one of most important diseases in coffee and conventional control methods of leaf coffee rust is still unsatisfactory. The objective of this study was to determine the effect of crude water extract on the germination of H. vastatrix uredospores. The study was conducted from January to September 2004 in the Laboratory of Plant Pathology at Unila. In each test, treatments were arranged in a randomized complete block design with four replications. Crude water extract was prepared by homogenizing 100 g of material in 100 ml sterilized distilled water. After being passed through four layers of sterilized cheesecloth, the mixture was defined as the aliquot (100% extract) and dilutions were made with sterile distilled water to obtain concentrations of 2.5 to 10%. Each of four materials (zinger, turmeric, clove, and Piper betle) was tested separately in five aliquot concentration levels. One ml of each extract was mixed with 0.25 ml of uredospora suspension (4 x 105 per ml), and 0.2 ml of the mixture was incubated. The variable was germinated uredospora (%) that was determined under a mikroscope. The results show that significant reduction in spore germination occurred by turmeric, clove, and P. betle extracts at &gt; 2.5% and by zinger extract at &gt; 5%. Some uredospora exposed to plant extract germinated abnormally: germ tubes shorten, swollen, or malform.

CPEST: An expert system for the management of pests and diseases in the Jamaican coffee industry

Abstract Over the last few years, environmental concerns have led to the emergence of the integrated management of pest and pesticides (IMPP) as a new way to deal with pests and pesticides in agriculture. Although the environmental and economic benefits of IMPP are beyond doubt, its use has been somewhat limited. One reason is the sheer amount of knowledge required of such things as climate, topography, soil type of the farm, agronomic practices, crop phenology, biology and damage potential of the pests and options available for suppressing their population below the economic injury levels. Unfortunately, such knowledge typically resides within a few experts and is not easily available to farmers. In order to make this knowledge more widely available, we developed CPEST, an expert system for managing pest and diseases of coffee in a developing country. The paper describes the architecture and development of CPEST, gives examples of the interface that a farmer would use to enter information and provides an evaluation of the quality of the advice that CPEST provides.

Coffee and disease: an overview with main emphasis on blood lipids and homocysteine

The issue of whether coffee is detrimental or beneficial to health has been studied in a large number of observational and clinical studies. Some observational studies have shown an association between coffee and coronary heart disease (CHD), while others have not. Both clinical trials and observational studies have shown that coffee consumption affects some CHD risk factors, e.g. plasma total homocysteine and serum total cholesterol. Studies on the association between coffee consumption and health have shown protective effects against type 2 diabetes, Parkinson’s disease and Alzheimer’s disease, whereas the protective effect against certain forms of cancer and possible hazards with regard to reproductive health are still debated. This review reports on the association between coffee intake and homocysteine and blood lipids in light of the results of studies by this group. A review of published papers on the relevant issues found that protective effects of cof fee have been reported for type 2 diabetes, Parkinson’s disease and Alzheimer’s disease. These results are based on observational studies. More studies with adequate control of confounding variables are needed to confirm these findings. There are at present no relevant biological explanations for any protective effect. Studies by this group have confirmed that even filtered coffee has a total cholesterol-increasing effect. Whether this is due to changes in filter-paper quality or other unknown mechanisms is not clear. The homocysteine-raising effect of coffee is mainly seen among subjects with the methylenetetrahydrofolate reductase (MTHFR) 677TT polymorphism, demonstrating a nutrition_/gene effect modification. In conclusion, the effects of coffee on blood lipids and plasma homocysteine are firmly based, but the studies reflect a certain heterogeneity, in part explained by genetic susceptibility. The coffee_/health issue is still pending; there are certain firmly establ i shed biological effects of coffee intake, but the impact on future health is virtually unknown. Keywords: blood lipids; coffee; coronary heart disease; homocysteine; reproductive hazards

Gibberella xylarioides (anamorph: Fusarium xylarioides), a causative agent of coffee wilt disease in Africa, is a previously unrecognized member of the G. fujikuroi species complex

Tracheomycosis or coffee wilt has emerged as a major disease of robusta coffee in Uganda in the past 10 years. Coffee wilt historically has been associated with Fusarium xylarioides Steyaert (teleomorph Gibberella xylarioides Heim and Sacc.), a species that has been classified as a member of Fusarium section Lateritium. We investigated the molecular phylogenetics of fusarial coffee wilt isolates by generating partial DNA sequences from two protein coding regions, translation elongation factor 1-α and beta-tubulin, in 36 isolates previously identified as F. xylarioides and related fusaria from coffee and other woody hosts, as well as from 12 isolates associated with a current coffee wilt outbreak in Uganda. These isolates fell into two morphologically and phylogenetically distinct groups. The first group was found to represent previously unidentified members of the Gibberella fujikuroi species complex (GFC), a clade that replaces the artificial Fusarium section Liseola. This group of isolates fit the original description of F. xylarioides, thus connecting it to the GFC. The second group, which was diverse in its morphology and DNA sequences, comprised four distinct lineages related to Fusarium lateritium. Our finding of unrelated species associated with coffee wilt disease has important implications regarding its epidemiology, etiology and control.

Crop protection strategies for major diseases of cocoa, coffee and cashew in Nigeria

A great percentage of people in the developing countries are engaged in agriculture, but the yields of their produce are low due to diseases that plague their crops. In Nigeria, crop protection measures that are cheap, simple, cost-effective and sustainable are desirable to combat Phytophthora pod rot (black pod) and cocoa swollen shoot virus diseases of cocoa, coffee leaf rust and coffee berry diseases, inflorescence blight disease of cashew in order to make farming profitable and sustainable. Disease control strategies include the use of resistant cultivars, chemicals, biological, botanicals, cultural, physical controls and application of biotechnology, each of which is discussed in this paper.

Gibberella xylarioides (anamorph: Fusarium xylarioides), a causative agent of coffee wilt disease in Africa, is a previously unrecognized member of the G. fujikuroi species complex

Tracheomycosis or coffee wilt has emerged as a major disease of robusta coffee in Uganda in the past 10 years. Coffee wilt historically has been associated with Fusarium xylarioides Steyaert (teleomorph Gibberella xylarioides Heim and Sacc.), a species that has been classified as a member of Fusarium section Lateritium. We investigated the molecular phylogenetics of fusarial coffee wilt isolates by generating partial DNA sequences from two protein coding regions, translation elongation factor 1-alpha and beta-tubulin, in 36 isolates previously identified as F. xylarioides and related fusaria from coffee and other woody hosts, as well as from 12 isolates associated with a current coffee wilt outbreak in Uganda. These isolates fell into two morphologically and phylogenetically distinct groups. The first group was found to represent previously unidentified members of the Gibberella fujikuroi species complex (GFC), a clade that replaces the artificial Fusarium section Liseola. This group of isolates fit the original description of F. xylarioides, thus connecting it to the GFC. The second group, which was diverse in its morphology and DNA sequences, comprised four distinct lineages related to Fusarium lateritium. Our finding of unrelated species associated with coffee wilt disease has important implications regarding its epidemiology, etiology and control.