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S. R. Venkateswara Murthy , Ashok Kumar , A. Chandrasekaran , S. Nakkeeran

Abstract

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P. Suneeta ¹, K. Eraivan Arutkani Aiyanathan ¹, S. Nakkeeran ¹, V. Chandrasekhar ²

Affiliations
1 Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore - 641003, Tamil Nadu, IN
2 Department of Plant Pathology, Agricultural College, Naira-532185, Acharya N. G. Ranga Agricultural University, Andhra Pradesh, IN

Abstract

Objectives: To study the antifungal activity of Bacillus spp. against Fusarium oxysporum f. sp. gerberae (FOG) and studies of interaction between Bacillus subtilis (PSB5) and commercially active fungicides against FOG. Methods: Extraction of crude antibiotics (PSB5, BSD5, BmTNAU1) was done by continuous precipitation and acidification to pH 2.0 using solvent ethyl acetate and further subjected to GC/MS analysis (PSB5). Bioassay of these extract against the pathogen (FOG) was done by Agar Diffusion method. The control employed was ethyl acetate alone in the media. Further the compatibility test was done by Poisoned food technique. Findings: The crude antibiotic extracts (PSB5, BSD5, BmTNAU1) were highly effective against the FOG probably due to the presence of antimicrobial compounds in strain PSB5 detected through GC/MS. Moreover, the test of compatibility of PSB5 with fungicides revealed the growth promotion of the bacteria at lower dosages of fungicides alone. The most effective fungicide, tebuconazole 250 EC(Score) against FOG showed compatibility at moderate dosage (250 ppm) with the highly efficient strain of bacteria, PSB5. Application: In our present study, we tried to emphasize on the efficacy of antifungal activity of Bacillus spp. and compatibility interactions of antagonistic bacteria and fungicides which could be utilized for further field experiments against FOG.

Keywords

Antimicrobial Compounds, Bacillus, Fungicides, Fusarium, Gerbera.

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S. Nakkeeran ¹

Affiliations
1 Department of Mechanical Engineering, Bharath University, Chennai – 600073, Tamil Nadu, IN

Abstract

In this paper, the performance and the emission testings are carried out on a single cylinder diesel engine. The experiment involves the blending of diesel with methanol, ethanol and biodiesel by some definite proportion by volume, in order to obtain the maximum blending at which the engine performs its best and also the emission of harmful gases get reduced. Biodiesel is obtained by trans-esterification of castor oil. Here the blending is done with 5%, 10% and 15% of methanol, ethanol and with 20% and 40% of biodiesel with that of diesel. By blending, improved efficiency of the diesel engine and consequently reduced emission of harmful gases can be obtained than diesel. Also the blended fuel has many other advantages. This blended fuel can be used in an automobile at lower cost than that of diesel and also with improved efficiency and reduced emission of gases.

Keywords

Trans Esterification, Blending, Biodiesel

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M. Suganyadevi ¹, P. Renuka Devi ¹, S. Nakkeeran ¹

Affiliations
1 Department of Plant Pathology, Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore (T.N.), IN

Abstract

Bacterial blight of Anthurium incited by Xanthomonas axonopodis pv. dieffenbachiae (XAD) is one of the most serious and devastating disease causes severe losses to cut flower production. In vitro screening of antagonistic B. mojavensis strain KA3 inhibited the growth of X. axonopodis pv. dieffenbachiae over an area of 3730 mm². It was followed by B. subtilis isolate BSD4, which inhibited the pathogenic bacteria to an extent of 3430 mm². In vitro screening with bactericides and fungicides against X. axonopodis pv. dieffenbachiae reflected that streptomycin sulphate was most effective in inhibiting the bacterial blight pathogen at 2000 ppm which confers an area of inhibition of 1810 mm², which was significantly superior over all other treatments and succeeded by 1000 ppm of streptomycin sulphate, which recorded 1254 mm² area of inhibition against XAD. Screening with gentamycin, indicated that the mean maximum area of inhibition of the bacterial pathogen XAD was 1054 mm² at 2000 ppm against XAD under in vitro. However, comparison of the efficacy between streptomycin sulphate and gentamycin, indicated that, streptomycin sulphate was highly effective rather than gentamycin. Similarly, fungicides such as copper oxychloride, alliete, isotianil and bromopol (2-bromo 2-nitro propane 1, 3-diol) which had antibacterial activity were tested against XAD under in vitro.

Keywords

In vitro, Anthurium, Bactericides and Fungicides.

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R. Priyanka ¹, S. Nakkeeran ¹, I. Arumuka Pravin ¹, A. S. Krishna Moorthy ¹, U. Sivakumar ²

Affiliations
1 Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore – 641003, Tamil Nadu, IN
2 Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore 641003, Tamil Nadu, IN

Abstract

Biological control with bioagents is a cost effective alternate method for the management of crop diseases. The antagonistic bacterial strains were explored for the management of leaf blight of marigold which is caused by Alternaria alternata. The present study clearly proved that the mycelial growth of A. alternata was inhibited up to 83% by Bacillus subtilis subsp. spizizenii (MM19) in vitro. GC/MS analysis of partially purified extracts of B. subtilis subsp. spizizenii (MM19) revealed the presence of antifungal Phthalic acid esters which might be responsible for the inhibition of the pathogen. Foliar application of B. subtilis subsp. spizizenii (MM19) under field conditions suppressed leaf blight by 77%. This study highlighted the potential of B. subtilis subsp. spizizenii (MM19) for the management of Alternaria leaf blight.

Keywords

Alternaria, Bacillus subtilis Subsp. spizizenii, GCMS, PCR.

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S. Vinodkumar ¹, S. Nakkeeran ¹

Affiliations
1 Department of Plant Pathology, Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore 641 003, IN

Abstract

Fairy ring spot incited by Cladosporium echinulatum is an unexplored yet disastrous disease of carnation. Bacillus amyloliquefaciens (VB7) with 10 diverse antimicrobial peptide genes, effectively reduced fairy ring spot intensity to 6.44 (per cent disease index, PDI) and increased flower yield (196.61 Nos/m²) compared to control (PDI - 60.33; flower yield - 140.70 Nos/m²). Plants treated with tebuconazole (250 EC, emulsifiable concentrate) and alternated with mancozeb (75% WP, wettable powder) were much effective and reduced disease intensity up to 3.46 PDI. However, flower yield was comparatively lesser to the treatment of B. amyloliquefaciens (VB7). Results revealed that B. amyloliquefaciens out-performed fungicides in growth promotion.

Keywords

Antimicrobial Peptide, Bacillus amyloliquefaciens (VB7), Cladosporium echinulatum, Fairy Ring Spot.

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P. R. Nithya ¹, S. Manimegalai ¹, S. Nakkeeran ², S. Mohankumar ³, S. Jayarajan Nelson ¹

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore – 641003, Tamil Nadu, IN
2 Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore – 641003, Tamil Nadu, IN
3 Centre for Plant Molecular Biology and Biotechnology, Tamil Nadu Agricultural University, Coimbatore – 641003, Tamil Nadu, IN

Abstract

Entomopathogenic fungi are known to produce a multitude of low molecular weight secondary metabolites involved in different biological processes including fungal development, intercellular communication and interaction with other organisms in complex niches. In the present investigation, heterogeneity in metabolome profile of three isolates of Beauveria bassiana viz., MH590235 (TM), MK918495 (BR) and KX263275 (BbI8) were analyzed through GC-MS. Distinct differences in metabolite profile of the isolates were observed. A total of 63 metabolites were detected from all the isolates combined. Metabolites, 5-Oxotetrahydrofuran-2-carboxylic acid and undecane were found to be specific to BR isolate. Macrocyclic gamma lactones were detected in culture filtrates of BR and BbI8, oleic acid and hexadecanoic acid in TM and BR. An insecticidal compound, levoglucos an was detected in all the fungal isolates. Among the isolates, TM revealed higher variability in the metabolite production through PCA analysis. The metabolome of TM isolate contained compounds having several biological functions, viz., insecticidal and antimicrobial activity, lipid and fatty acid metabolisms and virulence enhancing factors.

Keywords

Beauveria bassiana, Biological Functions, GC-MS, Metabolome Heterogeneity, PCA Analysis.

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S. B. AKSHAYA ¹, A. S. KRISHNAMOORTHY ², S. NAKKEERAN ², U. SIVAKUMAR ³, G. THIRIBHUVANAMALA ²

Affiliations
1 College of Agricultural Sciences – SRM Institute of Science and Technology, Baburayanpettai – 603203, Chengalpattu, Tamil Nadu, IN
2 Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore – 641003, Tamil Nadu, IN
3 Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore –641003, Tamil Nadu, IN

Abstract

Plant diseases especially wilt disease caused by Fusarium spp. pose a major threat to the cultivation of vegetables. In the present study, experiments were undertaken to explore the potential antifungal metabolites produced by macro basidiomycetes viz., Lentinus edodes, Ganoderma lucidum and Schizophyllum commune against Fusarium oxysporum and F. solani causing wilt disease of cucumber and capsicum. Among these, the ethyl acetate fraction of Cell-Free Culture Filtrate (CFC) of L. edodes exhibited maximum per cent inhibition of the mycelial growth of F. oxysporum and F. solani (61.11 and 57.77 %, respectively) at a concentration of 2000 ppm. Characterization of antifungal metabolites of Cell Free Condensate (CFC) of ethyl acetate fraction of L. edodes observed as prominent bands in Thin Layer Chromatography (TLC) indicated with an RF value of 0.25 and 0.69. Further GC-MS characterization of TLC-eluted compounds from L. edodes indicated the presence of 14 different compounds including 2H-pyran-2-one 6-pentyl-, possessing antifungal activity. The Fourier-transform Infrared Spectroscopy  (FTIR) spectrum revealed the functional groups such as alcohol (O-H), amides (C-O), aliphatic polyes (CH₂), triazenes (N=N), silicon compounds (Si-O-Si), amines (C-N) and phosphorus (P=S). The comparison of metabolite distribution patterns by Principal Component Analysis (PCA) obtained from L. edodes (PC 1) showed a positive correlation between the compounds. This study infers that L. edodes possess antifungal activity against F. oxysporum and F. solani that can be explored for formulation and application of these antifungal compounds in plant protection.

Keywords

Antifungal activity, Cell-Free Condensate (CFC), FTIR, macro basidiomycetes, mycelial inhibition.

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