Antimicrobial nature of specific compounds of Ampelomyces quisqualis identified from gas chromatography-mass spectrometry (GCMS) analysis and their mycoparasite nature against powdery mildew of grapes

Grapevine powdery mildew is the world's most important plant disease, and Ampelomyces frequently fight them. While it does not usually cause plant death, its major infections can result in significant production losses and severely impact wine quality. Fungicides are frequently used to control the disease, which can have long-term adverse effects on the ecosystem. As a result, alternative and environmentally friendly disease management approaches must be developed. The study aimed to reduce costly and toxic fungicide use by using Ampelomyces, a natural biofungicide, against various powdery mildew fungi. GC-MS analysis was also used to determine the antagonistic potential and efficacy of volatile organic chemicals produced by several Ampelomyces spp. against Erysiphe necator, which causes powdery mildew of grapes. The molecular characterization of A. quisqualis isolates based on using rDNA ITS region was also carried out and sequenced. GC-MS analysis identified various antimicrobial compounds, such as squalene (4.643%), octadecanoic acid (3.862%), tetradecanoic acid (3.600%), and 9,12-octadecadienoic acid (Z,Z) (1.451%). The least abundant compounds were 2-Hexadecanol, 1-Tricosanol, and 2-propenyl ester, with percentages of 0.485, 0.519, and 0.560, respectively. These bioactive compounds revealed by GC-MS analysis in crude extracts of A. quisqualis had a stronger antifungal and antibacterial activity against E. necator. As a result, using A. quisqualis to control the powdery mildew of grapes significantly reduced pathogen growth and disease incidence

Evaluation of Trichoderma spp. and Fungicides in the Management of Collar Rot of Gerbera Incited by Sclerotium rolfsii

An extensive study was undertaken to manage the most vigorous, polyphagous pathogen Sclerotium rolfsii causing collar rot disease in Gerbera by utilizing nine commercial fungicides and eight novel Trichoderma spp. Under in vitro conditions, there was 61.11 per cent reduction of pathogen (S. rolfsii) by T. harzianum NVTH2 and T. viride TV1 over control and was followed by T. citrinoviride NVTC1, T. citrinoviride NVTC2 and T. asperellum NVTA1 with per cent inhibition of 55.55, 54.44 and 53.33 respectively. On the other hand, commercial fungicides, tebuconazole 50%+ trifloxystrobin 25%, tebuconazole 250 EC, propioconazole 25% EC, fenamidone 10%+ mancozeb 50%WG and propineb 70WP reduced the growth of S. rolfsii to an extent of 100 per cent inhibition in all the tested concentrations. Combination of most effective Trichoderma spp. and fungicides had resulted in the best treatment T2 against the collar rot pathogen of Gerbera under protected cultivation

Biodiversity and Molecular Characterization of Trichoderma spp. and Exploring its Synergistic Action for the Management of Cucumber Damping Off Incited by Pythium aphanidermatum

Bioversity of fungal antagonist, Trichoderma from different locations of Nilgiri district of Tamil Nadu, India, were characterized through molecular methods. Thirty four isolates were tentatively identified as Trichoderma and confirmed upto species level through molecular tools. PCR amplification of the 18s-28s rRNA gene region revealed that all thirty four isolates produced amplicon size of 600bp and were further confirmed through sequencing. The sequences of various Trichoderma spp. were compared with both NCBI and TrichOKEY database to validate their molecular identity. Among 34 isolates, 31 isolates were identified as T. asperellum (KT462693, KU361372, KX533978 to KX533999, KX523262 to KX523264, KX555650, KX147092 to KX147094, KX5334000), 2 isolates as T. harzianum (KX533989, KX533990) and 1 isolate as T. virens (KU666466) through NCBI data base. However, all the T. asperellum isolates identified through NCBI database were identified as T. koningiopsis using TricHOKEY data base. Identity of T. harzianum isolates (TRI 35 and TRI 36) and T. virens isolate (TRI 37) were same in both NCBI and TricHOKEY database. Antagonistic assay with diverse species of Trichoderma revealed that T. virens (TRI 37) was effective in inhibiting the radial growth of Pythium aphanidermatum (87.78%) followed by T. harzianum (TRI 35), (TRI 36) and T. asperellum (TRI 9) in vitro. The effective isolates T. virens (TRI 37), T. harzianum (TRI 35, TRI 36) and T. asperellum (TRI 9) were compatible with each other. Biopriming of cucumber seeds with talc based formulation of the consortia comprising of T. virens isolate ( TRI 37), T. harzianum isolates (TRI 35 and TRI 36) and T. asperellum TRI 9 @ 108 cfu/g and soil application suppressed damping off to an extent of 76.82% over untreated control

Promissory Action of Trichoderma spp. and Fungicides in the Management of Fusarium Wilt of Gerbera

Novel Trichoderma harzianum isolate NVTH2, effective against Fusarium oxysporum f. sp. gerberae (FOG) causing wilt in Gerbera showed growth tolerance against azoxystrobin 23 % SC, kresoxim methyl 44.3% SC and carbendazim 50% WP at all the tested concentrations (50ppm, 100 ppm, 250 ppm, 500 ppm, 1000 ppm, 1500 ppm and 2000 ppm) followed by fosetyl Al 50% WP, difenoconazole 25% EC and tebuconazole 250 EC (effective against FOG) moderately tolerant at lower concentrations. The fungicides like propioconazole 25% EC, propineb 70 WP and tebuconazole 50%+ trifloxystrobin 25% WG (effective against FOG) completely resisted the growth of NVTH2. Finally, a field experiment was designed by utilizing 3 most efficient Trichoderma spp. and 4 fungicides in combination treatments. As a result, root dipping+ soil drenching with NVTH2 @5ml/lit followed by soil drenching of tebuconazole @1ml/lit at fortnight interval alternately resulted in highest yield, growth promotion and percent inhibition of wilt incidence

Growth Promoting Trait of Yeasts Isolated from Tomato in Relation to IAA Production

Yeasts are the useful microorganism widely present in nature and are the common inhabitants of soil, vegetation, and other environments. Through this study, thirty yeast isolates were isolated from phylloplane, fructoplane and as endophyte from leaves and fruits of tomato plant. The most effective one in promoting plant growth and IAA production was recorded in the isolate PY 15 (11.35±0.495 µg/mL) and it was followed by PY14 (10.38±0.452 µg/mL) and least recorded in the FY1 (0.53±0.03 µg/mL) isolate. Among the various isolates tested in vitro for the promotion of growth, the highest root and shoot length of 7.56±0.007 cm and 31.79±0.802 cm was recorded in the effective isolate PY15. The effective isolate (PY15) was identified as Meyerozyma guilliermondii (QR485249) based on morphological and molecular characterization. This study result concluded with statement that yeast strains found to promote plant growth by IAA production and could be considered for the development of biological products to enhance plant growth and to replace/reduce the use of synthetic fertilizers in the market