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Black bean aphid (Aphis fabae scop.), belongs to order Hemiptera and family Aphididae, is one of the important pests of the Fabaceae family. Beauveria bassiana is an important biocontrol agent to replace chemical insecticides. Therefore, in this research, two different varieties of broad bean with three different concentrations of B. bassiana were investigated on adults of fabae aphids under field conditions. After 3, 5, 7, and 14 days, the effect of the B. bassiana on the population of aphids was measured. The local variety was found to be more sensitive to the aphids compare with the Spain variety. In the high concentration (108 spores/ml), 80% mortality was obtained with B. bassiana in day 3 with local variety; then mortality increased after 5, 7, and 14 days of measuring the population of the adults. Mortality declined with the decrease in concentrations. The Spain variety was found to be resistance because fewer aphids were recorded compared to the local variety. In the highest concentration and day 14, mortality was 100%. The achieved results showed that B. bassiana can be used as a potential biocontrol agent for the management of black bean aphid in the fields.

Fusarium wilt of tomato plants caused by Fusarium oxysporum Schlecht. emend. Snyder & Hansen and Fusarium solani (Mart.) Sacc. are serious problem limiting tomato production worldwide. Biological control has emerged as one of the most promising alternatives to chemical fungicides. The biological control capability of a T. harzianum isolate against F. solani and F. oxysporum has been investigated. It inhibited colony growth of two Fusarium species by more than 80 % in dual culture tests. Results of greenhouse experiments revealed that disease severity in the tomato plants co-inoculated with T. harzianum was significantly lower than plants only infected with the Fusarium pathogens. Tomato plants inoculated with the antagonistic T. harzianum isolate, showed enhanced peroxidase and polyphenol oxidase activities in greenhouse experiments and increased resistance to F. solani and F. oxysporum. The T. harzianum isolate indirectly affected the Fusarium pathogens by enhancing plant defence.

The prevalence of Anthracnose disease, which is caused by a number of Colletotrichum spp., takes its toll on the tomato (Lycopersicon esculentum Mill.) and poses a significant economic constraint on its production. Successful efforts towards controlling this organism remain a deficient task. Rhus coriaria fruit extracts were subjected to screening, in vitro and in vivo, for antifungal activities. Under light and Scanning Electron Microscopy (SEM), the crude extract’s effect on the morphological structures of hyphae underwent an observation and study. Experimental results surfaced proofs that acetone, aqueous, methanol, and ethanol extracts have fungicidal properties on C. acutatum (GenBank accession No. KT215296) growth, which multiplied when extract concentrations were higher. Observations from scanning electron microscope showed that active extracts led to hyphal degradation where the hyphae were retarded. Tomato plants and fruits, which were treated with aqueous extracts, have been observed to have a significantly lower disease incidence, index, and severity. The anthracnose incidence in fruits that were coated with aqueous extract exhibited a maximum reduction with severity scores consistently at (0%). Aqueous extract in the glass house test significantly reduced the total area ‎under the disease progress curve (AUDPC) and disease severity in the studied disease. The shoot height, root length, dry shoot height, dry root length, chlorophyll content and leaf surface area significantly improved and increased with these treatments. The results indicate that R. coriaria extract can be judged as a cost effective and eco-friendly replacement to chemical fungicides in the management of tomato anthracnose disease.

The Streptomyces strain UPMRS4 was selected as a potential biocontrol agent for rice blast disease based on its strong antagonistic activity against Pyricularia oryzae strain UPMPo in vitro . It was further identified as a novel Streptomyces sp. through 16S ribosomal DNA sequence analysis. Biochemical characterization indicated that UPMRS4 was positive for ammonia, urea and siderophore production, as well as amylase, protease and lipase enzymatic tests. Treatment with UPMRS4 was able to reduce 67.9% of disease severity compared with other treatments and able to increase shoot height (15.13%), shoot dry weight (45.75%), leaf surface area (44.6%), root length (48.93), root dry weight (63.25%), number of tillers (42.26%), yield (36.96%), panicle length (15.4%) and the number of spikelet/panicles (29.39%) compared to the control plants at three months after inoculation. The transcript level of chitinase ( Cht-1 ), glucanase ( Gns1 ), pathogenesis-related gene ( OsPR1a ) and salicylic acid-responsive gene ( Oswrky45 ) were up-regulated during early rice-UPMRS4 interactions. These results suggest that UPMRS4 is a very promising antagonist candidate against P. oryzae which could be developed for sustainable rice blast disease management. To our best knowledge, this is the first study related to the effects of an actinomycete on rice blast disease and plant growth in Malaysia.

The aim of this work to identify chemical components of Garcinia mangostana leaves and test the antibacterial effect on Pseudomonas syringe pv. tomato and Xanthomonas oryzae pv. oryzae using bioautographic procedure. Phytochemical screening of methanolic extract showed that the leaf extract of G. mangostana rich in alkaloids, Flavonoids, Saponins, Tannins, Phenol, Terpenoids, Anthraquinone and Cardiac glycosides. A simple bioautographic procedure, involving spraying suspensions of the bacteria on thin layer chromatography (TLC) plates developed in solvents of varying polarities was used to detect the number of antibacterial compounds present in the extract. This activity was indicated by white spots against a red background on the TLC plates after spraying with 5% TTC aqueous solution. P. syringae and X. oryzae were inhibited by the most compounds separated on the TLC plates from the extract.

Aspergillus spp. has been widely found as useful microorganism in biotechnology. They have a high ability in the production of secondary metabolites. Therefore, isolates of Aspergillus were isolated from healthy rice field located in Selangor State/Malaysia. The obtained strain (UPMZ01) was conducted against Pyricularia oryzea by applying dual culture and culture filtrate technique. The antagonism of strain UPMZ01 in the dual culture was 81.326% inhibition percentage against P. oryzae given the optimum inhibitory percentage 100% at all concentration of secondary metabolites aged 14 days. The isolate (UPMZ01) was identified as Aspergillus niger with accession number (KY698415). The environment factors such as pH and temperature influencing on production of secondary metabolites. The results were shown that pH at level 5.0 and temperature between 21℃ to 29℃ is the optimum condition for A. niger to produce efficient antifungal metabolites which given 100% PIGR against blast pathogen. The secondary metabolites compounds were identified by Gas Chromatography-Mass Spectrometry (GC-MS). Fifteen compounds were recognized as major compounds which may have the possibility of possessing antifungal characteristics. Most of identified compounds are Oleic Acid, n-Hexadecanoic acid, Hexose, Glycerol, Stearic acid, Tetradecanoic acid, Dodecanoic acid and 5-Hydrxoymethylfurfural.

Endophytic fungi are potential antimicrobial agents that play an important role in improving plant growth. Endophytic fungi from healthy tomato plants have been evaluated for their potential antibacterial activity against Xanthomonas vesicatoria causing bacteria spot disease of tomato Thirty-eight different endophytic fungal isolates were isolated, and their extracts were screened for antibacterial activity using the well diffusion method. Three isolates showed strong antibacterial activity, which were molecularly identified as Diaporthe phaseolorum (USt1), Aspergillus fumigatus (USt2) and Aspergillus versicolor (USt3), respectively. Comparison of the components of the extracts between three isolates was made using a gas chromatography-mass spectrometry. Thirty eight compounds were found in A. fumigatus, thirty six compounds in D. phaseolorum and fourty two compounds were found in A. versicolor. The most prevalent compounds were acetol, hexanoic acid and acetic acid in all three fungi. Hexanoic acid (39.52%), acetic acid (8.95%) and acetol (8.10%), were found in A. fumigatus. However, the D. phaseolorum extract contained mainly hexanoic acid (42.35%) and acetic acid (11.89%) and acetol (9.52%), while A. versicolor contained hexanoic acid (34.44%), acetic acid (13.44%) and acetol (10.61%). Our results suggest that the three active endophytic fungi isolates provide a basis for the identification of new bioactive compounds, and for the effective biocontrol of bacterial spot of tomato.

A Streptomyces isolate having antifungal activity against Pyricularia oryzae, the causal agent of rice blast disease, was isolated from soil collected in rice fields of Tanjung Karang Selangor, peninsula Malaysia.The aim of the study was to determine the antifungal activity of Streptomyces sp. isolate UPMRS4 extracts against P. oryzae and to identify bioactive antifungal compounds produced by UPMRS4. Various solvents were used for extraction of antifungal compounds and well diffusion method was used to determine the antifungal activity of the extracts. The ethyl acetate extract demonstrated the highest activity against mycelial growth of P. oryzae, with an effective inhibitory concentration (EIC) of 1.562 μg/ml significantly higher compared to that of chloroform, diethyl ether, methanol, acetone, ethanol and water. Based on GC-MS and LC-MS/MSanalyses,compounds with antifungal activity were detected such as (Pyrrolo[1,2-a] pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl); Pyrrolo[1,2-a] pyrazine-1,4-dione, hexahydro-3-(phenylmethyl); ergotamine; amicomacin; fungichromin; rapamycin and N-Acetyl-D, L-phenylalanine. These compounds had good general antifungal activity and might have potential future agricultural applications.

This study was conducted in order to determine the fungi and bacteria associated with tomato plants at Cameron Highlands Malaysia. The fungi which have been isolated and detected from tomato plants were: Fusarium oxysporum, F. solani, F. acuminatum, Rhizoctonia solani, Colletotrichum boninense, C. acutatum and Phoma destructiva. The bacteria which have been isolated and detected from tomato plants were: Ralstonia solanacearum, Xanthomonas vesicatoria, X. gardneri and Pseudomonas syringae. While the most pathogenic fungi were C. boninense, P. destructive and F. oxysporum with the disease incidence (89.6%, 86.6%, 85.6%) respectively, the most pathogenic bacteria were X. vesicatoria and R. solanacearum with the disease incidence (96.6% and 87.6%) respectively.

The potential of Garcinia mangostana as a biological control agent against plant pathogenic bacteria which decrease the quality and volume of crop production worldwide was assessed. Mangosteen leaves were extracted by maceration using chloroform, n-hexane, and methanol. For the in vitro antibacterial activity, two dissimilar species of plant pathogenic bacteria: Pseudomonas syringe pv. tomato and Xanthomonas oryzae pv. oryzae were acquired. Four different concentrations, 12.5, 25, 50, and 100 mg/ml were obtained through the cup-plate agar diffusion technique. Streptomycin sulphate at 30 μg/ml concentration was set as the positive control, whereas every respective solvent used in the leaf extraction was set as the negative control. The results have shown that, only methanol extract demonstrated antibacterial activity when tested on the plant pathogenic bacteria. The highest diameter of inhibition zones was observed in X. oryzae pv. oryzae, at all range of concentrations, followed by P. syringae pv. tomato. The least methanol extract concentration utilised in determination of minimum inhibitory concentration (MIC) assay was at 1.562 mg/ml, inhibiting X. oryzae pv. oryzae, followed by P. syringe pv. tomato at a concentration 3.125 mg/ml. Antibacterial impacts of the most effectual extract of mangosteen crude were supported by the existence of chemical components identified by GC-MS. Cycloartenol, Caryophyllene, Docosane, Phenol, 4,4-Methylenebis (2,6-di-tert-butylphenol) and Chromium were noted as key compounds in the mangosteen leaf extract, which were perhaps causing the antibacterial activity.

Plant pathogenic bacteria are recognized to be harmful microbes able to decrease the quantity and quality of crop production in the world. Punica granatum peel was screened for its potential use as biological control agent for plant pathogenic bacteria. P. granatum peel was successfully extract using n-hexane, methanol and ethyl acetate by maceration. The highest yield obtained by ethyl acetate showed that ethyl acetate extracted more compounds that readily soluble to methanol and n-hexane. For in-vitro antibacterial activity, three different species of plant pathogenic bacteria were used namely Erwinia carotovorum subsp. Carotovorum, Ralstonia solanacearum, and Xanthomonas gardneri. For all crude extracts, four different concentrations 25, 50, 100 and 200 mg/ml were used in cup-plate agar diffusion method. Streptomycin sulfate at concentration 30 μg/ml was used as positive control while each respective solvent used for peel extraction was used as negative control. The results obtained from in vitro studies showed only ethyl acetate extract possessed antibacterial activity tested on the plant pathogenic bacteria. Methanol and n-hexane did not show any antibacterial activity against plant pathogenic bacteria selected where no inhibition zones were recorded. R. solanacearum recorded the highest diameter of inhibition zones for all range of concentrations introduced followed by E. carotovorum subsp. Carotovorum and X. gardneri. For the minimum inhbitory concentration (MIC) and minimum bactericidal concentration (MBC), only the ethyl acetate extract was subjected to the assay as only ethyl acetate extract exhibited antibacterial activity. The minimum concentration of ethyl acetate extract that was able to inhibit plant pathogenic bacteria was recorded at a concentration of 3.12 mg/ml which inhibited R. solancearum and E. carotovorum subsp. Carotovorum, followed by X. gardneri at concentration 6.25 mg/ml. For the minimum bactericidal concentration (MBC), the results showed that at the concentration of 12.5 mg/ml, the extract was still capable of killing the pathogenic bacteria, R. solanacearum, and P. caratovora sub.sp. caratovora while for the bacteria X. gardneri, the concentration that was able to kill the bacteria was 25 mg/ml. The qualitative estimation of phytochemical constituents within P. granatum L. ethyl acetate peel extracts had revealed the presence of tannins, flavonoids, phenols alkaloid, Saponins, and terpenoids. This study has demonstrated that Ethyl Acetate peel extracts of P. granatum has significant antibacterial activity against pathogenic plant bacterial, and it could be of high agricultural value.

Rhizosphere microorganisms play an important role in the soil ecosystem. Thirty three different isolates of Streptomyces isolated from healthy tomato rhizosphere soil. Antifungal activities against Colletotrichum acutatum)Accession no. KT215296) were checked by streak method. Isolate TS9 displayed better outcomes against C. acutatum as compared to other isolates. High Performance Liquid Chromatography was used for antifungal compounds from isolate TS9 by comparing with other six isolates that did not showed antifungal activity. The active compound was between (50–60) retention times other peaks did not chosen because the peaks were available in the other isolates which they did not show any effect on the C. acutatum. 10 fractions, named as F1 to F10, came from the preparative HPLC separation of the selected crude extract. One fraction showed highest inhibition to C. acutatum and it was at the retention time (56.232). The selected peak was compared with the 8 standards and was identified as (quercetin) when completely matched with the standard. The present study reports the purification of potential antifungal compound from Streptomyces zaomyceticus isolated from the tomato rhizosphere can be used as a promising fungicide in the near future.

During June 2011 to March 2012, Moko disease symptoms were observed in banana cv. Nipah in two Malaysian states. The primer pairs ISRso19F/ISRso19R were used for defined identification of Ralstonia solanacearum race 2 strain. PCR amplification of all isolates produced a 1900 amplicon and exhibited 93% phylogenetic similarity with reference strain (AF450275). Based on symptoms, biochemical tests, pathogenicity assay, molecular and phylogenetic studies, we concluded that the isolated bacterium was R. solanacearum race 2 biovar 1.

An experiment was performed to study the antibacterial activity of methanol, acetone, alcohol and aqueous extracts from the fruit of R. coriaria by disk diffusion assay in terms of minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC) and killing-time curve. The detection of the components was also fulfilled using Gas Chromatography–Mass Spectrometry (GC-MS) and also tested for their antibacterial activity. The tested bacteria were Pseudomonas syringae (Accession No. KJ858057), a tomato bacterial speck causal agent, and Ralstonia solanacearum (Accession No. KJ881159) causing tomato bacterial wilt. Furthermore, the inhibition criteria were made by different extracts of the sampled bacteria which were measured and compared with standard antibiotic (chloramphenicol). Aqueous extract displayed better outcomes against P. syringae and R. solanacearum as compared to chloramphenicol. According to the GC-MS test results, the aqueous extract was composed of 39 different phytocompounds, together with eight elements in the high peak region, namely Furfural, 1-Cyclopetene, 2,5 Furandione, Phloroglucinol, Succinic acid, Malic acid, P-Tolylacetic acid and Coumalic acid. Among these, it was discovered that 2,5 Furandione was the most important antibacterial element that is present in sumac. The results from the current study indicate that different extracts of R. coriaria contain a variety of antibacterial compounds which can potentially be used to produce an extensive range of herbal mixtures with anti-bacterial properties for controlling diseases in crops belonging to the Solanaceae family.

In May 2013, tomato plants cultivated in the Cameron Highlands, Pahang, Malaysia, had extensive fruit, stem and leaf spots. In severe cases, disease incidence reached 70% in glasshouses. Leaf lesions were initially small (1-2 mm), black on either surface enlarging to 1-2 cm in diameter, irregular to round in shape and slightly sunken and zonate. Stem lesions were longer, but were similar in appearance. Fruit lesions were sunken black spots of variable size at sites of wounds, insect punctures or stem scar cracks. The causal pathogen was identified as Phoma destructiva based on morphological, genetic (ITS and PCR) and pathogenicity analyses. This is thought to be the first report of Phoma blight caused by P. destructiva on tomato in Malaysia.