Phytophthora megakarya (Pmeg) and Phytophthora palmivora (Ppal) are closely related species causing cacao black pod rot. Although Ppal is a cosmopolitan pathogen, cacao is the only known host of economic importance for Pmeg. Pmeg is more virulent on cacao than Ppal. Many members of the RxLR, necrosis-inducing phytophthora protein, and pectinase genes families were specifically induced in planta.Abstract Black pod rot, caused by Phytophthora megakarya, is the main cause of cocoa harvest losses in Cameroon. Field experiments were carried out over two successive years in two smallholders' plots of cocoa trees, in order to assess the impact of.Title / Subtitle: Phytophthora megakarya and P. palmivora on Theobroma cacao: Aspects of virulence and the effects of temperature on growth and resistance to fungicides Subject description: This thesis investigates the dynamics of black pod disease of cocoa caused by Phytophthora megakarya and P. palmivora species in Ghana.Phytophthora megakarya is predominant in the Volta region of Ghana and it remains to be seen whether it can displace P. palmivora from cacao plantations of Ghana as it has in Nigeria and Cameroon.In African cacao-producing countries, control of cacao black pod disease caused by Phytophthora megakarya is a priority. Introducing biological control ...Objective: The in vitro and in vivo effects of seed extracts of Thevetia peruviana (Apocynaceae) on the growth and the germination of spores of Phytophthora megakarya causal agent of black pod of cocoa was evaluated. Methodology and results: Five extracts obtained by soxhlet apparatus (extracts of hexane, ethyl acetate, acetone, methanol and aqueous extract) were used.Phytophthora megakarya plugs from 3-days preculture was placed at the centre of V8 agar plate. The antimicrobial activities were done according to the method describe by Vinale et al. (2006). The crude organic extract was diluted in Dimethyl Sulfoxide (DMSO) at the concentration ranging from 25 to 100μg/ml/l/ and 10μl of each concentration ...Incidence of cocoa black pod disease (Phytophthora palmivora) in relation to time of crop maturity in the Eastern Region of Ghana. J Hort Sci 46: 185-193. Google Scholar Nyassé, S., 1997. Étude de la diversité de Phytophthora megakarya et caractérisation de la résistance du cacaoyer (Theobroma cacao L.) à ce pathogène. Thèse, Inst ...Nana et al. (2015) estimated the MIC of clove EO on Phytophthora megakarya at 250 μL/L on solid medium. For P. parasitica, the highest anti-oomycete activity was highlighted for clove EO with ...Download scientific diagram | Mycoparasitism of Phytophthora megakarya NKOM-00 by fungal isolates from publication: Isolation and identification of mycoparasitic isolates of Trichoderma asperellum ...In Ghana, Phytophthora palmivora and P. megakarya are the main causes of black pod disease of cocoa (Dakwa, 1988;Luterbacher and Akrofi, 1993; Opoku et al, 1999). Research has shown that the ...Phytophthora megakarya is an Oomycete which has a negative impact on Cameroon cocoa production. An assessment of the level of virulence of different isolates of P. megakarya in mono or coinfection ...In Cameroon, Phytophthora megakarya is the causal agent of black pod rot of cacao (Theobroma cacao L). Primary inoculum of P. megakarya is located in the soil. With the onset of the rainy season ...Phytophthora megakarya is the most destructive fungal pathogen on cocoa production in Ghana . The disease has been in Ghana for many years but on other alternative hosts [ 16 ]. It was originally identified in Nigeria in 1979 [ 17 ], reported in Togo in 1982 [ 18 ], and was subsequently reported in Ghana in 1985 [ 16 ].Molecular and morphological identification of Phytophthora species based on the types and other well-authenticated specimens. IDphy was developed to facilitate accurate and efficient identification of Phytophthora to species, using type specimens from the original descriptions for reference wherever possible.IDphy emphasizes species of high …Effect of Thevetia peruviana seeds extract on in vitro growth of four strains of Phytophthora megakarya Author(s) Ambang, Z; Dooh, JPN; Essono, G; Bekolo, N; Chewachong, G; Asseng, CC Year. 2010 Is Peer Reviewed? 1 Journal. Plant Omics ISSN: 1836-0661 Publisher. SOUTHERN CROSS PUBL ...Research on resistance to black pod caused by Phytophthora megakarya has been carried out in Cameroon for 40 years. It has yielded a significant database which is currently being exploited for the modelling of disease resistance levels of the major clones selected as candidate parents for the creation of new resistant and consequently more productive cocoa varieties. The negative control using sterile distilled water showed no inhibitory effect on Phytophthora megakarya while 41.00 mm zone of clearance was observed in the positive control test using Metalaxyl ...Phytophthora megakarya (Pmeg) and Phytophthora palmivora (Ppal) cause black pod rot of Theobroma cacao L. (cacao). Of these two clade 4 species, Pmeg is more virulent and is displacing Ppal in many cacao production areas in Africa. Symptoms and species specific sporangia production were compared when the two species were co-inoculated onto pod pieces in staggered 24 h time intervals. Pmeg ...Phytophthora megakarya (Pmeg) and Phytophthora palmivora (Ppal) are closely related species causing cacao black pod rot. Although Ppal is a cosmopolitan pathogen, cacao is the only known host of economic importance for Pmeg. Pmeg is more virulent on cacao than Ppal. Many members of the RxLR, necrosis-inducing phytophthora protein, and pectinase genes families were specifically induced in planta.Background: Phytophthora megakarya is an invasive pathogen endemic to Central and West Africa. This species causes the most devastating form of black pod disease. Despite the deleterious impacts ...There was a significant genetic correlation between pod rot rate in the field and leaf test data, so using this resistance test could shorten cocoa tree selection cycles. Cocoa pod rot, caused by different Phytophthora species, is rife in all production zones. Phytophthora spp. control is therefore a major challenge for world cocoa cultivation, and selection of resistant material is a priority ...Objective: The in vitro and in vivo effects of seed extracts of Thevetia peruviana (Apocynaceae) on the growth and the germination of spores of Phytophthora megakarya causal agent of black pod of cocoa was evaluated. Methodology and results: Five extracts obtained by soxhlet apparatus (extracts of hexane, ethyl acetate, acetone, methanol and aqueous extract) were used.The aim of this study was to evaluate the ability of oyster shell powder soil amendment to enhance cocoa seedling growth and induce resistance against Phytophthora megakarya in nurseries. The results showed that heat-treated oyster shells powder at 1% (w/w) soil amendment significantly increased plant height, leaf number, leaf area, dry shoot and root weight more than chemical fungicide and ...DOI: 10.1016/J.CROPRO.2003.09.010 Corpus ID: 71098484; Impact of removing diseased pods on cocoa black pod caused by Phytophthora megakarya and on cocoa pr @article{NdoumbNkeng2004ImpactOR, title={Impact of removing diseased pods on cocoa black pod caused by Phytophthora megakarya and on cocoa pr}, author={M. Ndoumb{\`e}-Nkeng and Christian Cilas and E. Nyemb and Salomon Nyass{\'e} and Daniel ...Phytophthora megakarya thrives in very humid climates. Although soil texture plays a central role in the epidemiology of some Phytophthora species (Corcobado et al., 2013), there is a dearth of infor-ABSTRACT Pathogens of the Straminipile genus Phytophthora cause significant disease losses to global cocoa production. P. megakarya causes significant pod rot and losses due to canker in West Africa, whereas P. capsici and P. citrophthora cause pod rots in Central and South America. The global and highly damaging P. palmivora …The effects of some selected arbuscular mycorrhizal (AM) fungi, Gigaspora margarita and Glomus mossae on the growth and the role of soluble amino acids of two contrasting cocoa cultivars (ICS84 tolerant and SNK10 sensitive) against black pod disease caused by Phytophthora megakarya were investigated. Root colonization by AM fungi …Technical Factsheet Basic 17 November 2021 Phytophthora megakarya (black pod of cocoa) Publication: PlantwisePlus Knowledge Bank …PDF | On Aug 14, 2015, Wakam Louise Nana and others published Antimicrobial Activity of Syzygium aromaticum and Zanthoxylum xanthoxyloides Essential Oils Against Phytophthora megakarya.htm | Find ...PDF | On Jan 1, 2019, Tene Tayo Paul Martial and others published Enhancement of Theobroma cacao Seedling Growth and Tolerance to Phytophthora megakarya by Heat-Treated Oyster Shell Powder | Find ...[Show full abstract] genotypes and their offsprings with Phytophthora megakarya was performed in the nursery for two seasons (dry and rainy). Percentage success for crosses made using hand ...Phytophthora pod rot disease commonly known as the Black pod disease caused by Phytophthora palmivora and P. megakarya is the most destructive cocoa disease worldwide accounting for over 30% pod yield loss through pod rot and 10% tree death .The oomycete genus Phytophthora includes devastating plant pathogens that are found in almost all ecosystems. We sequenced the genomes of two quarantined Phytophthora species–P. fragariae and P. rubi.Comparing these Phytophthora species and related genera allowed reconstruction of the phylogenetic relationships within the …Phytophthora megakarya —one of the cocoa black pod disease species, is invasive and probably responsible for the greatest cocoa crop loss in Africa Phytophthora multivora …Physiological studies were made of six isolates of Phytophthora from cocoa, three of the A2 mating type of P. palmivora (71, 78, and 29) and three of the A1 mating type of the recently described P. megakarya (9A, 75, and 10B). Many of these studies revealed a clear differentiation between the two species. In all experiments the growth rate of the isolates of P. palmivora was higher than that ...Phytophthora megakarya Brasier & Griffin, is one of the Oomycete pathogens reported on Theobroma cacao,and it is the most virulent of the Phytophthora species that causes black pod disease. Phytophthora megakarya was first reported as the causal agent of black pod disease in 1979 after the reclassification of Phytophthora species recovered from ...1. Introduction. Diseases caused by species of oomycetes of the genus Phytophthora are responsible for substantial losses in the worldwide production of cocoa (Theobroma cacao L.) [].Among the most prevalent species, P. palmivora (E. J. Butler) affects cocoa plantations globally, while P. megakarya (Brasier and Griffin), which occurs only in Africa, affects the production of this cultivar.Black pod disease (BPD) is the major cocoa pathology constraint caused by an Oomycete, Phytophthora megakarya prevailing in African cocoa producing countries. The development of T. cacao planting material tolerant to BPD lies on cross-pollination ofBlack pod rot of cocoa caused by Phytophthora megakarya causes significant losses in Cameroon. Studying the spatial and temporal disease dynamics of P. megakarya provides useful information on the mechanisms of dispersal and the physiological and biological factors that are important for its spread and ultimately its management.lorsqu'elles infectent les cabosses. Phytophthora megakarya est la plus agressive et peut provoquer entre 60 % et 100 % des pertes de récoltes (Luterbacher et al., 1993, Berry and Cilas, 1994), Opoku et al., 2000), quand les conditions favorisent le développement de la maladie. En revanche, P . palmivora est moins agressif et peut entrainer desBlack pod rot, caused by Phytophthora megakarya, is the main cause of cocoa losses in Cameroon.A few studies have focused on describing black pod epidemics in cocoa yet numerous questions remain. Here, an epidemiological model describing the temporal evolution of cocoa black pod, taking into account the development stages of pods, is developed and studied.EFFET DES TRAITEMENTS DU SOL SUR LE DEVELOPPEMENT DE L'EPIDEMIE DE LA POURRITURE BRUNE (Phytophthora megakarya) DU CACAOYER AU CAMEROUN . × Close Log In. Log in with Facebook Log in with Google. or. Email. Password. Remember me on this computer. or reset password. Enter the email address you signed up with and we'll email you a reset link. ...Objective: The in vitro and in vivo effects of seed extracts of Thevetia peruviana (Apocynaceae) on the growth and the germination of spores of Phytophthora megakarya causal agent of black pod of cocoa was evaluated. Methodology and results: Five extracts obtained by soxhlet apparatus (extracts of hexane, ethyl acetate, acetone, methanol and aqueous extract) were used.Phytophthora pod rot disease causes almost 30% loss in world cocoa production. ... Phytophthora megakarya · Theobroma cacao · Previous article View issue table of ...taken from infected pods on P. megakarya [18]. The objective of this work was to improve the tolerance of a hybrid family of Theobroma cacao against the attack of Phytophthora megakarya through the assessment of the phenolic compounds content of the hybrid genotypes of the hybrid family F79SA of T. cacao after leaf infection withPhytophthora megakarya, on the other hand, occurs only in Africa, but represents a major threat to cacao production, the countries of West Africa being the largest producers of cacao in the world ...Control of Phytophthora megakarya, the causal agent of cocoa black pod in Cameroon is commonly obtained by fungicide spraying of either copper compounds or a mixture of metalaxyl-M with copper compounds. Research on biocontrol of P. megakarya has identified an isolate of Trichoderma asperellum, PR11 as a promising biocontrol agent (BCA) of P ...Phytophthora megakarya and P. palmivora are oomycete pathogens that cause black pod rot of cacao (Theobroma cacao), the most economically important …Phytophthora megakarya and Phytophthora palmivora, closely related causal agents of cacao black pod rot, underwent increases in genome sizes and gene numbers by different mechanisms. Genome Biol Evol. 9(3): 536 – 557. doi: 10.1093/gbe/evx021 , [Web of Science ®], [Google Scholar] Anderson RG, Deb D, Fedkenheuer K, McDowell JM. 2015.Feb 15, 2016 · A phylogenetic tree generated for 119 Phytophthora isolates, based on the 60S ribosomal protein L10 gene and rDNA sequence, verified the PCR-based identification assay and showed high interspecific variation among the species causing black pod. Phytophthora megakarya isolates were uniformly virulent in an assay using susceptible cacao pod husks Feb 23, 2016 · Phytophthora megakarya (Brasier and Griffin 1979 ), one of several species of Phytophthora causing black pod rot (BPR) of cacao ( Theobroma cacao ), is a diploid heterothallic oomycete (Nyasse et al. 1999 ). Phytophthora megakarya ( Pmeg ) and P. palmivora ( Ppal ) are oomycete pathogens that cause black pod rot of cacao ( Theobroma cacao ), the most economically important disease on cacao globally. While Ppal is a cosmopolitan pathogen, Pmeg , which is more aggressive on cacao than Ppal , has been reported only in West and Central Africa where it has been spreading and devastating cacao farms ...The arrival and subsequent dispersal of Phytophthora megakarya within young cacao plantations, previously free of black pod and containing cacao germplasm that is evaluated for its resistance to P ...Phytophthora megakarya is a devastating oomycete pathogen that causes black pod disease in cacao. Phytophthora species produce a protein that has a similar sequence to the necrosis and ethylene inducing protein (Nep1) of Fusarium oxysporum.Multiple copies of NEP1 orthologs (PmegNEP) have been identified in P. megakarya and four other Phytophthora species (P. citrophthora, P. capsici, P ...Phytophthora spp. in Clade 4: portion of the seven-loci ML phylogeny featuring the type cultures of 212 described species (by T. Bourret).Notice the position of P. megakarya selected specimen CBS 238.83 = S&T BL 73.Premise of the study: Phytophthora megakarya is the agent of black pod disease of cacao and is the main pathogen of this crop in Africa. Population genetic studies are required to investigate how ...2018年10月12日 ... (2008). Bioassay of five trichoderma strains against Phytophthora megakarya (Cacao pod-rot) in Nigeria. Scientific Research and Essays, 3(9), ...those of unknown sources constituted 19.0%. Phytophthora megakarya was frequently isolated from all the three sources of canker infections, indicating P. megakarya readily causes stem canker on cocoa.Phytophthora megakarya was more aggressive than P. palmivora on attached SCA-6 pods, causing expanding necrotic lesions with or without wounding. Phytophthora megakarya is predominant in the Volta region of Ghana and it remains to be seen whether it can displace P. palmivora from cacao plantations of Ghana as it has in Nigeria and Cameroon.Aug 26, 2021 · Phytophthora megakarya is the most destructive fungal pathogen on cocoa production in Ghana . The disease has been in Ghana for many years but on other alternative hosts [ 16 ]. It was originally identified in Nigeria in 1979 [ 17 ], reported in Togo in 1982 [ 18 ], and was subsequently reported in Ghana in 1985 [ 16 ]. A phylogenetic tree generated for 119 Phytophthora isolates, based on the 60S ribosomal protein L10 gene and rDNA sequence, verified the PCR-based identification assay and showed high interspecific variation among the species causing black pod. Phytophthora megakarya isolates were uniformly virulent in an assay using susceptible cacao pod husksMany Phytophthora species have a soil borne phase in their natural life cycles even though disease expression often occurs on aerial plant parts. In Cameroon, black pod rot of cacao (Theobroma cacao L.), is caused by P. megakarya. Primary inoculum ofPhytophthora megakarya and Phytophthora palmivora, closely related causal agents of cacao black pod rot, underwent increases in genome sizes and gene numbers by different mechanisms. Genome Biol Evol. 9(3): 536 – 557. doi: 10.1093/gbe/evx021 , [Web of Science ®], [Google Scholar] Anderson RG, Deb D, Fedkenheuer K, McDowell JM. 2015.Phytophthora megakarya (Pmeg) and P. palmivora (Ppal) are oomycete pathogens that cause black pod rot of cacao (Theobroma cacao), the most economically important disease on cacao globally. While Ppal is a cosmopolitan pathogen, Pmeg, which is moreNov 17, 2021 · (From Brasier and Griffin, 1979).P. megakarya is a member of Group II of Phytophthora, as defined by Stamps et al. (1990).It produces caducous papillate sporangia, is heterothallic and antheridia are amphigynous.Sporangia are limoniform, obpyriform or ellipsoid with rounded bases, varying from 20-60 x 13-41 µm, with a length-breadth ratio of 1.2-1.6, and are formed in a sympodium. In-vitro study of Chromolaena odorata extracts was determined against isolated Phytophthora megakarya for the purpose of investigating the antifungal activity of ethanolic, cold-water and warm-water extracts of the medicinal plant againstPhytophthora palmivora (Butler) is an hemibiotrophic oomycete capable of infecting over 200 plant species including one of the most economically important crops, …In West and Central Africa, Phytophthora palmivora and P.megakarya are the main causal agents of black pod disease. P.megakarya is the most aggressive pathogen on cocoa. Originally restricted to Central Africa it had by the end of the 1980’s moved into Ghana. Crop losses due to P.palmivora, prior to the appearance of P.megakaryaPhytophthora megakarya thrives in very humid climates. Although soil texture plays a central role in the epidemiology of some Phytophthora species (Corcobado et al., 2013), there is a dearth of infor-mation on the effect of edaphic factors on the per-sistence of P. megakarya. A sharp contrast exists between weather conditions required for zoosporeThe black pod disease caused by Phytophthora megakarya is responsible for 80% of the cocoa production loss in Cameroon. To assess the resistance of cocoa plants against this pathogen, necrotic lesions, phenolic content and qualitative alteration of phenolics were conducted in ICS84 and ICS95 clones (two Trinitario introduced from Trinidad) and ...Feb 1, 2000 · A severe black pod disease of cocoa in Ghana caused by Phytophthora megakarya was first reported in 1985, even though there is evidence that the fungus might have existed earlier. Until then, only ... Molecular and morphological identification of Phytophthora species based on the types and other well-authenticated specimens. IDphy was developed to facilitate accurate and efficient identification of Phytophthora to species, using type specimens from the original descriptions for reference wherever possible.IDphy emphasizes species of high economic impact and species of regulatory concern for ...Dec 11, 2015 · Phytophthora megakarya was more aggressive than P. palmivora on attached SCA-6 pods, causing expanding necrotic lesions with or without wounding. Phytophthora megakarya is predominant in the Volta region of Ghana and it remains to be seen whether it can displace P. palmivora from cacao plantations of Ghana as it has in Nigeria and Cameroon. Phytophthora megakarya and P. palmivora are oomycete pathogens that cause black pod rot of cacao (Theobroma cacao), the most economically important …Seven Phytophthora species have been reported causing black pod disease on cacao, so far, with Phytophthora megakarya, Phytophthora palmivora, Phytophthora capsici, and Phytophthora citrophthora being considered the most important species (Ali et al., 2016; Marelli et al., 2019).Phytophthora megakarya is an oomycete plant pathogen that causes black pod disease in cocoa trees in west and central Africa. This pathogen can cause ...Phytophthora megakarya is a plant pathogen that causes black pod disease in cocoa trees in West and Central Africa. This pathogen can cause detrimental loss of yield in the economically important cocoa industry. It can damage any part of the tree, causing a wide range in the reduction of yield. A miCropProtection21(2002)629-634 Shadetreesarealternativehostsofthecocoapathogen Phytophthora megakarya I.Y.Opoku*,A.Y.Akrofi,A.A.Appiah Cocoa Research Institute of ...Phytophthora megakarya, on the other hand, occurs only in Africa, but represents a major threat to cacao production, the countries of West Africa being the largest producers of cacao in the world ...Phytophthora megakarya (Pmeg) and Phytophthora palmivora (Ppal) cause black pod rot of Theobroma cacao L. (cacao). Of these two clade 4 species, Pmeg is more virulent and is displacing Ppal in ...Phytophthora megakarya and Phytophthora palmivora, Closely Related Causal Agents of Cacao Black Pod Rot, Underwent Increases in Genome Sizes and Gene Numbers by DifferentMechanisms. / Ali, Shahin S.; Shao, Jonathan; Lary, David J. et al. In: Genome biology and evolution, Vol. 9, No. 3, 2017. Figure 1: The life cycle of Phytophthora megakarya highlighting the main spores type and describing in, Pathogens of the Straminipile genus Phytophthora cause significant disease losses to global cocoa production. P. megak, Incidence of cocoa black pod disease (Phytophthora palmivora) in rel, The only economically important host of Phytophthora megakarya Brasier & Griff, Apr 1, 2018 · Phytophthora megakarya and Phytophthora palmivora cause black pod rot of cacao. P. megakarya occurs , Phytophthora megakarya is restricted to Cameroon, Nigeria,, INTRODUCTION Phytophthora megakarya, causing cacao black pod disea, Phytophthora root rot, caused by several species of Phytoph, The only economically important host of Phytophthora megakarya B, The arrival and subsequent dispersal of Phytophthora megakarya with, Dec 11, 2015 · Phytophthora megakarya was more aggressive than P. pal, Black pod disease caused by P. Palmivora and P. megakarya is an, Phytophthora megakarya (Pmeg) and Phytophthora pal, The only economically important host of Phytophthora megakarya Brasie, those of unknown sources constituted 19.0%. Phytopht, Phytophthora megakarya is a devastating oomycete pathoge, Phytophthora megakarya obtained from a 7-day-old potato dextros, Phytophthora megakarya has spread westwards from Camer.