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Aims: The objective of this work is to evaluate the effect of (aqueous (EAq) and methanolic (ME)) extracts of Thevetia peruviana on the in vitro development of Rigidoporus lignosus. Study Design: A synthetic fungicide (Onazol 100), two extracts at differents concentrations: C1 = 3.5 mg / ml; C2 = 7 mg / ml; C3 = 15 mg / ml; C4 = 30 mg / ml; C5 = 50 mg / ml and C6 = 100 mg / ml for EAq; C1 = 3.5 ml/ml; C2 = 7 ml/ml; C3 = 15 ml/ml; C4 = 30 ml/ml; C5 = 50 ml/ml for ME and a negative control (T = 0 mg / ml) were used. Place and Duration of Study: The study was conducted in pathology laboratory at University of Yaounde I and IRAD of Nkolbisson in 2018. Methodology: Daily measurements of the pathogen's development was used to evaluate the average growth (D) of the mycelium. The inhibition percentages of the different doses of EAq, ME and ONAZOL 100 were calculated after 4 to 5 days of growth of the fungus. Results: The major result obtained compared to the rate of rot showed that the treatments EAq, ME (C6) and ONAZOL 100 were closed. The disease rates at different concentrations of C1 to C6 were 13.91 to 100% for ME, 9.34 to 100% for EAq, and 100% for ONAZOL 100. Conclusion: The two extracts are promising, and on small and medium scale, could be an effective and cheap formulation for the control of Rigidoporus lignosus.

One of the main obstacles in rubber cultivation is the white root fungus (JAP) attack which caused by Rigidophorus ligonosus. This pathogen infects rubber plants from the nursery until the mature plants. Efforts to control the disease have been carried out by chemical, technical culture and use of biological agencies. This research was conducted at the STIP-AP Medan in January 2017 to June 2017, this study used a non-factorial Randomized Block Design (RBD) with four replications and four treatments. Using Trichoderma koningii with somes doses were 20 grams, 30 grams, and 40 grams/seedling. The results of this study indicate that the biofungicide application of Trichoderma koningii 30 g/seedling produces the greatest inhibition of the rubber plants seedling nursery against the growth of pathogens Rigidoporus lignosus.

Cultivation of nutmeg (Myristica fragrans) is running into several problems, one of these is caused by white root fungus (Rigidoporus lignosus) which causes losses to nutmeg farmers. This fungus is known to be controlled by biological control using microorganisms such as Penicillium sp. This research was conducted to determine the efficacy of application time of Penicillium sp. crude extract against white root fungus (Rigidoporus lignosus) in nutmeg plants. The design used in this study was a non-factorial completely randomized design with the main factor being the application time of Penicilllium sp. crude extract with 4 treatments. Each treatment on 7 replicates. Control without suspension application Penicillium sp. (PK0), Application of Penicillium sp. 7 days before inoculation of Rigidoporus lignosus (PK1), Application of suspension of Penicillium sp. concurrently with Rigidoporus lignosus (PK2) inoculation, Application of suspension of Penicillium sp. 7 days after Rigidoporus lignosus (PK3) inoculation. Total are 28 experimental units. In this case, the test plants used are 11 months old nutmeg. The research parameters consisted of the incubation period, disease incidence and attack intensity. The results showed that the treatment at one-time application of the suspension of Penicillium sp. Significantly affect the intensity of attacks and the incidence of infectious disease pathogens Rigidoporus lignosus. Application time for Penicillium sp. 7 days before the suspension of Rigidoporus lignosus is the best offer in the attack of Rigidoporus lignosus disease.

The study was conducted to evaluate in vitro and in vivo control of fungal antagonists on Rigidoporus lignosus (klotzsch) Imaz in Hevea brasiliensis (Willd. ex A. Juss.) Muell. Arg. in the rain forest zone of Nigeria. In vitro assessments of biological agents were carried out in dixenic cultures in Petri plates. In vivo tests were carried out in the nursery using Hypocrea virens and Hypocrea jecorina. Significant differences were observed with the dual inoculations of fungal antagonists and R. lignosus inoculated the same day, and the antagonists inoculated 24 h before inoculation of R. lignosus. Hypocrea jecorina was most effective in the control of R. lignosus with percentage inhibition of 86.83 %. Hypocrea virens, H. jecorina, Trichoderma spirale, Trichoderma sp., Trichoderma sp. Pers, and Hypocrea lixii were effective on R. lignosus. Fungal antagonists inoculated 24 h before inoculation of R. lignosus exhibited higher inhibitory efficacies than antagonists and R. lignosus inoculated the same day. In the in vivo evaluation of fungi antagonists on R. lignosus, seedlings in H. jecorina treatment at 60 d and H. virens treatment at 150 d after inoculations respectively had the highest plant heaths (highest length of stem and length of tap rot, lowest plant death, and least foliar symptom) compared to the control. Mortality rate was higher at 60 d after inoculation and decline from the third months onward. Significant differences were observed between the control and R. lignosus treatment in all the parameters evaluated.

Evaluation of mycoparasitic Trichoderma isolate mixtures to control white root disease on rubber seedlings. Eight isolates of mycoparasitic Trichoderma, as single cultures or in isolate mixtures were tested for their biocontrol efficacy against rubber seedlings inoculated with one of three strains of Rigidoporus lignosus. Biocontrol efficacy of isolates was varied, but not significantly affected by strains of R. lignosus. Mixtures of four isolates were significantly (P < 0.05) reduced the disease severity and percentage of root necrotic as compared to mixtures of two isolates as well as single isolates. The highest disease suppression (65% relative to control) and reduction of inocula on rubber wood sticks (91% relative to control) was achieved in four isolate mixtures of Trichoderma virens (T1+T4+ T9+ T11).

The potential of fluorescent bacteria as biological control agents for white root disease caused by Rigidoporus lignosus has been investigated. Isolation of bacteria from the soil using S1 media produced two fluorescent bacteria isolates. Using the Microbact 12A+12B method, both bacteria were identified as Pseudomonas fluorescens and P. aeruginosa. These two species of bacteria were then used as antibiosis activity test against R. lignosus. Four series antibiosis activity tests were done, that were antibiosis test of media culture bacteria growth to R. lignosus colony, antibiosis test of dry fluorescent pigment extract to R. lignosus, influence of Fe3+ to antibiosis activity of bacteria test, and affinity of media supernatant to Fe3+. The results were: antibiosis activity of King’s B (KB) media was more effective than media 523 in the inhibition of R. lignosus colony growth. There was no significant different antibiosis activity of dry fluorescent pigment extract from media KB and media 523 in the inhibition of R. lignosus colony growth. The level of Fe3+ in the media might influence antibiosis activity of fluorescent pigment. Affinity test of KB supernatant from fluorescent bacteria culture with Fe3+ showed an absorption peak of 410 nm on spectrophotometer, and none for the fungi. These results indicate that P. fluorescens and P. aeruginosa produce cathecol-type siderophore with high affinity against Fe3+ compared with hydroxamate-type siderophore which is generally produced by fungus.

White Root Fungus Disease (JAP) is the biggest threat in rubber. The attack can result in a significant reduction in number, especially in plants lasting 0-3 years. The pathogen that causes white fungus is Rigidoporus lignosus. In JAP endemic areas, decreased tree density 40-50%. In rubber seedlings, symptoms of JAP attack with yellowing color leaves, then dry and fall. This study was conducted at STIP-AP Medan from January 2017 to June 2017. The aim of the study was to determine the effectiveness of several doses of hexaconazole. This study uses a non-factorial Randomized Block Design (RBD) with four replications. Hexaconazole fungicides are active with treatment of A0, A1, A2, A3 and A4 (0, 5, 10, 15 and 20 ml / l air). The results of this study indicate that A2 application of hexaconazole-active fungicides (10 ml / l air) has been effective in controlling JAP disease in rubber seedlings.

The corelations between White Rot (Rigidoporus lignosus L.) incidence and soil characters of rubber ecosystem in Penumangan Baru, Lampung. A study was conducted to evaluate the corelation between soil characters and white rot incidence. The study was done in Penumangan Lampung from June 2007 to July 2008. Seven sites were observed on the incidence of white rot of indicator plants (cassava). Physical, chemical, and biological soil characters were correlated and regressed with white rot incidence. The results showed that there were correlation between white rot incidence and soil characters such as pH KCl, number of fungal genus (fungal diversity), Ca+, total cation, CEC, and saturation base. Ion Ca+, total cation, saturation base correlated positively with white rot incidence, on the contrary, fungal diversity, cation exchange capacity, and pH KCl correlated negatively with white rot incidence. Thus, efforts to increase fungal diversity, cation exchange capacity, and pH (in acidic soil) could be used as basic strategies to develope intergrated control of white rot disease.

Monitoring of phenolic compounds in the food industry and for environmental and medical applications has become more relevant in recent years. Conventional methods for detection and quantification of these compounds, such as spectrophotometry and chromatography, are time consuming and expensive. However, laccase biosensors represent a fast method for on-line and in situ monitoring of these compounds. We discuss the main transduction principles. We divide the electrochemical principle into amperometric, voltammetric, potentiometric and conductometric sensors. We divide optical transducers into fluorescence and absorption. The amperometric transducer method is the most widely studied and used for laccase biosensors. Optical biosensors present higher sensitivity than the other biosensors. Laccase production is dominated by a few fungus genera: Trametes, Aspergillus, and Ganoderma. We present an overview of laccase biosensors used for the determination of phenolic compounds in industrial applications. © 2015 The Authors.

A study was conducted to determine the spatial distribution of somatic incompatibility groups (SIGs) in Rigidoporus lignosus populations responsible for white root disease in a south Sumatera rubber plantation. Most isolates colonizing the stumps were somatically compatible with isolates from either a nearby stump or a living rubber tree, which suggested evidence of stump-to-tree or stump-to-stump clonal growth of the fungus. SIGs of R. lignosus occupied an area territorially in which the minimum size estimate for the largest genotype was 25 m in length.

Early detection of root diseases is a great problem in perennial crops, especially in rubber tree. Planters are continually confronted with the balance of efficiency/cost of the detection. Therefore, a trial was set up to compare three sampling densities and four exposure techniques for detection of white root rot in rubber plantings. A complete census of all trees is the only efficient method of detection in a control program. When reducing the sampling density, a lot of infected trees are not detected and they remain an inoculum source for the spread of the disease. Mulching for one month followed by root exposure is the best technique to reveal the presence of the fungus. The sampling density is of greater significance than the infection exposure method.

Les trois principaux parasites des racines d'Hevea brasiliensis en Afrique sont Rigidoporus lignosus, Phellinus noxius et Armillaria sp.. Seul Rigidoporus lignosus, qui est responsable de la pourriture blanche des racines est présent dans les zones hévéicoles et reste la cause principale de mortalité des arbres en Afrique. De nouveaux fongicides ont été testés afin d'améliorer la lutte contre la pourriture blanche des racines causée par Rigidoporus lignosus. Certains composés à base de triazole se sont révélés être très efficaces in vitro et sur des expérimentations à petite échelle avec des seedlings ou des stumps placés en sols infestés artificiellement. Deux applications tous les 6 mois de fongicide sous forme liquide (Alto, Sandoz) et des applications de triadimenol sous forme granulaire (Bayfidan, Bayer) à raison de 0,5 g a.i. par arbre ont donné de bons résultats au champ. Leur utilisation est recommandée dans la pratique. (traduction du résumé d'auteur)

On rubber plantations Hevea brasiliensis is attacked mainly by Rigidoporus lignosus and Phellinus noxius, two Basidiomycete causing white rots (they degrade lignin) of tree roots. Some infected trees were shown to survive to the fungal aggression, both in field and greenhouse conditions, pointing out that rubber trees are able to develop successful reactions. Therefore host reactions were extensively investigated both at cellular and molecular levels.

Three phenol oxidases, of which two are excreted byRigidoporus lignosus and one byPhellinus noxius, have been isolated and purified from culture filtrates. Based on their substrate specificities and spectral characteristics, these enzymes arep-diphenol : oxygen oxidoreductases (laccases; EC 1.10.3.2). A number of their physicochemical properties have been determined. The fact that the two parasites excrete laccases indicates that they belong to the group of lignin degrading (white rot) fungi. Laccase L1 fromR. lignosus was purified to homogeneity.

Une enquête épidémiologique a été menée pendant 6 ans dans une jeune plantation d'hévéa (#Hevea brasiliensis$ Willd. ex A. Juss) afin d'étudier et de prévoir le développement des champignons agents de pourridié, #Rigidoporus lignosus$ (Klotzsch) Imazeki et #Phellinus noxius$ (Corner) G. Cunn. Pendant cette période, la contamination et la mortalité de ces arbres ont été systématiquement prises en compte tous les 6 mois. Durant la première année, on a assisté à une explosion de la maladie se traduisant par l'accroissement des foyers initiaux et par l'apparition de nouveaux. A compter de la sixième année après la plantation, on a observé un net fléchissement des activités parasitaires possiblement lié à l'augmentation des capacités réactionnelles des arbres avec l'âge ainsi qu'à la rupture des liens trophiques entre l'inoculum et les racines des arbres en état de décomposition. Le type de maladie pouvant caractériser ces pourridiés est discuté, essentiellement, sur la base des cinétiques d'apparition des foyers parasitaires. (Résumé d'auteur)

The acitivty and spatial distribution of eight enzymes in adult tap root tissues colonized by R. lignosus and P. noxius are investigated. Their physiological significance in the pathogenic process is discussed.

Some reactions differentiated by rubber trees to root rot diseases are described at molecular, cellular and histological levels.

In spite of numerous aeroplane flights and different interpretations of the infrared colour photographs obtained, the remote sensing of root rotting fungi of rubber tree has failed in practice in the Ivory Coast. The reasons for this failure and conclusions on the efficiency of this method are discussed.

New method of direct control of Rigidoporus lignosus, causing agent of white root rot of Hevea. A new method of direct control of Hevea whith root disease caused by Rigidoporus lignosts (Kl.) Imaz is being used in many countries in Africa; after detection and marking diseased trees and trees in direct contact, the treatment consists of pouring 21 of 0.5% calixin cmulsion into the cuvette 2 times every 6 months. This method which has been used in field trials for 3 years, seems to give encouraging results. and has confirmed the efficiency of Calisin for direct control of the white root disease.

Pathogenicity and physiological characteristics were studied for the two populations of isolates. Exidence of variations has been demonstratcd for each fungus but no correlations could be established between the in vivo and in vitro parameters.

Pathogenicity of isolates of the root rotting fungi Rigidoporus lignosws and Phellinus noxius was tested on rubber seedlings (Hevea brasiliensis) by artificial inoculation under controlled conditions. Variation in virulence within the isolates tested was demonstrated and discussed.

Root rot disease of teak (Tectona grandis Linn. f.) is widely distributed in Nigeria where it is present in about 70% of teak plantations. The disease is caused by Rigidoporus lignosus (Klotzsch) Imazeki, sporocarps of which have been found in about 64% of the infected plantations. Disease incidence is more serious in shallow lateritic soils and sites with impeded drainage. The disease can be controlled using 2% Tillex chemical spray on infected trees. It can also be largely reduced in proposed plantations by careful site selection and pre-treatment of stumps left behind after land clearing.

The fungal agents of root rots in West Africa. Characteristics of the main root rot fungi infecting forests and plantations in West Africa are described. The biological cycle of the parasites, type of decay, detection and control methods are reviewed and discussed.

A description is provided for Rigidoporus lignosus . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Hevea and over 40 other tropical genera icluding cacao, coconut, coffee, tea and bamboo. DISEASE: White root rot. Common on rubber where it destroys the tap root so that diseased trees are easily blown over. The foliage turns yellow and this is accompanied by die-back in Asia, but these symptoms are absent in West Africa (45, 1166). Also parasitic on other perennial crops. GEOGRAPHICAL DISTRIBUTION: Africa (Cameroon, Congo, Ethiopia, Fernando Po I., 'French Equatorial Africa', Ghana, Ivory Coast, Kenya, Mauritius, Nigeria, Sierra Leone, Uganda), Asia (Brunei, Burma, Ceylon, India, Indo- China, Indonesia, Japan, Malaysia, Philippines, Thailand); Australasia & Oceania (New Guinea, New Hebrides); North America (Mexico); Central America & West Indies (Costa Rica, Dominica); South America (Argentina, Brazil, Guyana). (CMI Map 176, ed. 2, 1966). TRANSMISSION: Rigidoporus lignosus is a rhizomorphic root-infecting fungus with an ectotrophic growth habit. The rhizomorph requires a food base, generally the tree stump on which it originated, until it encounters other dead wood or living or moribund tree roots which it can invade. Epiphytic growth of rhizomorphs may extend 5-15 feet ahead of actual penetration of live rubber roots (Napper, 1938) and descend the full length of the tap root to a depth of 181 feet (45, 1161d). Air-borne spores may also infect tree stumps immediately after felling (45, 201) and thus provide foci for the spread of rhizomorphs, as was earlier postulated by Petch (1921). This source of infection, however, is regarded as less important than root-infection (46, 1089).