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This study was carried out to identify antimicrobial phytoconstituents present in n-butanol soluble part of methanolic flower extract of Cassia fistula L. The flowers were dipped in methanol for two weeks, filtered and the solvent was evaporated on a rotary evaporator. The n-butanol fraction was separated in a separating funnel and analyzed by GCMS. There were 18 phytoconstituents in this fraction. The most abundant compound was 1H-indene, octahydro-, ciswith 35.13% peak area followed by cyclohexene, 1-butyl- (21.88%) and cyclohexane, butyl- (12.87%). Other compounds included 9-heptadecanol (3.70%), behenic alcohol (1.63%), decane, 3-methyl- (2.90%), cyclohexane, 1- methyl-3-(1-methylethenyl)-, cis- (1.25%), 3-hexanol, 5-methyl- (1.67%), acetaldehyde isopentyl propyl acetal (1.69%), undecane (2.12%), 1,3-dioxane, 2-ethyl-5-methyl- (1.13%), acetaldehyde butyl pentyl acetal (3.04%), acetaldehyde dipentyl acetal (3.24%), cycloheptasiloxane, tetradecamethyl- (1.11%), Cyclooctasiloxane, hexadecamethyl- (1.77%), cyclononasiloxane, octadecamethyl- (1.48%), n-hexadecanoic acid (2.01%), and tetracosamethyl-cyclododecasiloxane (1.46%). A thorough literature survey showed that n-hexadecanoic acid; cyclohexane, butyl-; cyclooctasiloxane, hexadecamethyl-; cyclononasiloxane, octadecamethyl- and behenic alcohol in n-butanol fraction possess antifungal, antibacterial and/or antiviral properties. [ABSTRACT FROM AUTHOR]

The present study was carried out to find out mycochemical profile of culture filtrates of Alternaria japonica through GC-MS analysis. The fungus was incubated for 21 days using malt extract broth as growth medium. Culture filtrate was filtered and concentrated by evaporating water at 45 °C. Filtrates were partitioned using n-hexane followed by chloroform. Both the organic solvent fractions were analyzed through GC-MS. In n-hexane and chloroform fractions, 14 and 10 compounds were identified, respectively. Major compounds in n-hexane fraction were o-xylene (36.9%); ethyl benzene (19.3%), hexane, 2-4-dimethyl- (16.8%), 1-2 dimethylbenzene (7.56%), cyclohexane, 1-ethyl-1-methyl (3.36%), heptane, 2,5-dimethyl- (3.36%) and octane, 4-methyl- (2.52%). Likewise, predominant compounds in chloroform fraction were octane-4 methyl (24.62%), carbonic dihydrazine (16.41%), octane, 2,4,6-trimethyl (12.56%), hydrazine, (1,1-dimethylethyl) (8.75%), 16-hexadecanoyl hydrazide (7.66%) and stearic acid hydrazide (7.08%). Literature surveyed showed that many compounds identified in both the fractions possess antimicrobial, pharmacological, antioxidant, antidepressant, anticancer and anti-inflammatory properties. [ABSTRACT FROM AUTHOR]

Fungicidal potential of three different concentrations (3.15, 6.30 and12.5 mg mL-1) of ethyl acetate sub-fraction of shoot and root of Cenchrus pennisetiformis (Hochst. & Steud) Wipff was evaluated against Fusarium oxysporum f. sp. lycopersici under Cr(III) and Cr(VI) toxicity. Ethyl acetate sub-fraction of methanolic root extract exhibited greater antifungal activity than that of shoot extract either alone or combined with the metal ions. Different concentrations of Cr(VI) were found to be more inhibitory to F. oxysporum f. sp. lycopersici than that of Cr(III). Various concentrations (3.15-12.5 mg mL-1) of ethyl acetate sub-fraction of methanolic root and shoot extracts significantly decreased fungal biomass by 20-70% and 10-50%, respectively over negative control (without Cr ions or plant extracts). Fungal biomass was significantly declined by 60-90% and 40-60% due to different concentrations (100, 200 and 300 ppm) of Cr(VI) and Cr(III), respectively, over negative control. There was up to 100% and 80% reduction in the fungal biomass due to combined effect of ethyl acetate sub-fraction of root and shoot extract, respectively, with various concentrations of Cr(III) or Cr(VI). It was concluded that ethyl acetate sub-fractions of both methanolic shoot and root extracts exhibited significant antifungal potential against F. oxysporum f. sp. lycopersici in the presence as well as in the absence of Cr ions. [ABSTRACT FROM AUTHOR]

Sclerotium rolfsii Sacc. is a devastating soil-borne fungal pathogen that causes collar rot disease in chili (Capsicum annuum L.) and causes pronounced yield losses. In the present study, S. rolfsii inoculated soil was amended with 1, 2, 3 and 4% (w/w) dry leaves of Eucalyptus camaldulensis and their effect was studied on disease incidence, mortality, growth and physiology of the host plant. In positive control, there was 73% disease incidence that was further enhanced to 93% in 1% soil amendment treatment. However, further increase in dose of soil amendment (2% and 3%) decreased disease incidence to 66% and 53%, respectively. A similar effect of soil amendment was observed on plant mortality. A 3% dose of E. camaldulensis leaf biomass alleviated biotic stress of S. rolfsii and increased leaf dry biomass of chili by 67% as compared to positive control. Chlorophyll content and polyphenol oxidase activity were significantly lower in E. camaldulensis amended treatments over positive control. Protein content was gradually increased by increasing leaf amendment dose while reverse was recorded in case of peroxidase activity. The present study concludes that soil amendment with 3% leaf dry biomass of E. camaldulensis can alleviate biotic stress of S. rolfsii on growth of chili to some extent. [ABSTRACT FROM AUTHOR]

The present study was carried out to explore the causal organism of dieback of Eucalyptus citriodora Hook in different areas of Punjab, Pakistan. Diseased samples of E. citriodora suffering from dieback were collected during January to March 2010. Purple to reddish spots were observed on leaf of this tree. Pathogen was isolated on malt extract agar medium. Isolated fungus was identified as Alternaria alternata (Fr.) Keissl. The isolated fungus was inoculated on E. citriodora leaves. The same fungus was re-isolated from the artificially inoculated diseased leaves that confirms A. alternata as causal agent of dieback in E. citriodora in Pakistan. [ABSTRACT FROM AUTHOR]

A pot experiment was conducted to evaluate the effect of Sclerotium rolfsii inoculation and soil amendment with leaves of Azadirachta indica A. Juss. on southern blight disease, growth and physiology of chili (Capsicum annuum L.). The highest disease incidence (60%) and plant mortality (46%) were recorded in positive control where S. rolfsii was inoculated without soil amendment. Application of lower doses (1% and 2%) generally enhanced disease incidence. However, in 3% soil amendment, minimum disease incidence (27%) and plant mortality (27%) were recorded. S. rolfsii significantly reduced root and shoot growth as well as leaf chlorophyll and protein content. None of the soil amendment treatments significantly improved crop growth over positive control treatment. However, 3% soil amendment significantly enhanced chlorophyll content over positive control. In contrast, all the soil amendment treatments significantly declined leaf protein contents as compared to negative and positive control treatments. Application of different doses of A. indica significantly enhanced polyphenol oxidase (PPO) and peroxidase (PO) activities as compared to both the control treatments. This study concludes that soil amendment with 3% dry leaves of A. indica significantly decreased disease incidence and plant mortality in chili caused by S. rolfsii, possibly by enhancing production of defence related enzymes viz. PPO and PO. [ABSTRACT FROM AUTHOR]

Collar rot caused by a fungus Sclerotium rolfsii, is a serious soil-borne disease of chickpea (Cicer arietinum L.). Present study was carried out to manage this disease by commercial fungicides under in vitro and in vivo conditions. In vitro bioassays were carried out using four fungicides namely Tegula (tebuconazole), Thiophanate Methyl, Ridomil Gold (metalaxyl + mancozeb) and Mancozeb at 50, 100, ..., 250 ppm concentrations. All the concentrations of these fungicides significantly decreased radial growth of S. rolfsii over control. In vivo bioassays were carried out in plastic pots of 15-cm diameter and 20 cm deep with 1 kg soil in each pot. Treatments included a negative control, a positive control (with pathogen only), and two chemical fungicides viz. Thiophanate methyl and Mancozeb. There was 95% and 50% reduction in plant mortality due to Thiophanate methyl and Mancozeb over positive control, respectively, after 30 days of sowing. [ABSTRACT FROM AUTHOR]

Tolerance of plant pathogens to heavy metal stress is an important area of research that has been rarely explored in Pakistan. The current research work was carried out to investigate the impact of Cr(III) on growth of Sclerotium rolfsii Sacc., the cause of collar rot of chilli (Capsicum annuum L.). Laboratory bioassays were conducted in using solid as well as liquid malt extract growth medium amended with 14 different concentrations (0, 5, 10, 20, 30, ...,100, 150, 200, 300, 400, 500 ppm) of Cr(III). Growth medium flasks with different concentrations of Cr(III) were inoculated with the pathogen and incubated for 7 days at 25±2 °C. Results showed that radial growth of S. rolfsii on solid medium and its biomass on liquid medium were significantly decreased with the increase in concentrations of Cr(III) up to 100 ppm, while fungus was unable to grow at concentrations above 100 ppm. There was a linear relationship (R2 = 0.9242) between Cr(III) concentrations and fungal biomass on liquid medium, and a non-linear relationship (R2 = 0.9264) between Cr(III) concentrations and fungal radial growth on solid growth medium. [ABSTRACT FROM AUTHOR]

Ascochyta rabiei (Pass.) Lab. causes blight that is a major constraint in chickpea (Cicer arietinum L.) production worldwide including Pakistan. Disease is generally controlled by repeated applications of foliar fungicides that cause environmental pollution and also responsible for health hazards. The present study was carried out to investigate the antifungal potential of different organic solvent fractions of methanolic fruit extract of Melia azedarach L. against A. rabiei (Pass.) Lab. Methanolic fruit extract of this tree was partitioned with n-hexane, chloroform, ethyl acetate and nbutanol. After evaporation of solvents in a rotary evaporator, different concentrations of the crud organic fraction were prepared and evaluated against the target fungal pathogen. All the concentrations of organic solvent fractions significantly reduced the fungal biomass over corresponding control treatments. There was 43-87%, 75-94%, 69- 95%, 38-89% and 63-94% reduction in fungal biomass due to different concentrations of n-hexane, chloroform, ethyl acetate, n-butanol and aqueous fraction of methanolic fruit extract of M. azedarach, respectively. The present study concludes that all these fractions of methanolic fruit extract of M. azedarach possess substantial antifungal potential against A. rabiei. These fractions and their purified compounds may be used as alternatives to synthetic fungicides for the management of A. rabiei. [ABSTRACT FROM AUTHOR]

A field study was undertaken to investigate the effect of weeds, soil amendments and Biopower (a commercial biofertilizer) on vesicular arbuscular mycorrhizal (VAM) colonization in rice (Oryza sativa L.) var. Basmati Super. i)- Field soil was amended with recommended doses of NPK fertilizers, ii)- half N and recommended doses of P and K fertilizers, and iii)- farmyard manure. Four common rice weeds namely Cyperus rotundus L., Echinochloa colonum (L.) Link, Paspalum paspaloides (Michx.) Scribn. and Marsilea minuta L. were planted as 1:1 weed rice plant ratios in all the three soil amendments. All the treatments were with or without Biopower application. Mycorrhizal colonization was studied after 50, 80 and 110 days of rice transplantation corresponding to various growth stages viz. vegetative, flowering/panicle and maturity, respectively. The highest mycorrhizal colonization in rice was recorded at panicle stage i.e. 80 days after transplantation. Mycorrhizal colonization in rice varied with weed species, soil amendment and growth stage of rice. Generally, weeds stimulated mycelial, arbuscular and vesicular colonization in rice roots. The highest stimulatory effect on mycorrhizal colonization was due to mixed weeds in all the three soil amendments at various growth stages of the crop. Biopower application significantly enhanced mycorrhizal colonization in weed free treatment or rice plants co-cultivated with P. paspaloides and M. minuta in one or the other soil amendment. [ABSTRACT FROM AUTHOR]

In vitro bioassays were carried out to evaluate antagonistic behavior of seven species of Trichoderma namely T. pseudokoningii, T. harzianum, T. reesei, T. koningii, T. hanatus, T. viridi and T. aureoviridi, against two highly problematic soil-borne plant pathogenic fungi viz. Fusarium oxysporum f. sp. lycopersici (Sacc.) Snyder & Hansn and Macrophomina phaseolina (Tassi) Goid. All the Trichoderma species exhibited pronounced antagonistic behavior against the target fungal pathogens in dual cultures resulting in 45-65% and 59-74% reduction in radial growth of M. phaseolina and F. oxysporum f. sp. lycopersici, respectively. T. harzianum was found to be the most effective biocontrol agent against both the fungal pathogens followed by T. aureoviridi and T. hanatus. [ABSTRACT FROM AUTHOR]

Present study was undertaken to investigate the antifungal potential of methanolic fruit extract of Datura metel L. (Syn. Datura alba Nees.) and its various solvent fractions against Sclerotium rolfsii Sacc., the cause of devastating collar rot disease of bell pepper (Capsicum annuum L.). In an in vitro study, conducted in 250-mL conical flasks, different concentrations of methanolic fruit extract (0.5, 1.0, 1.5,..., 4.0%) significantly reduced the fungal biomass by 69-94%. Methanolic fruit extract was successively partitioned among n-hexane, chloroform, ethyl acetate and n-butanol in order of increasing polarity. Different concentrations (3.125, 6.25, 12.50, 25, 50, 100, 200 mg mL-1) of these fractions were used against the test pathogen. Pronounced variability in antifungal activity was recorded with respect to extracting solvent and the extract concentration. Chloroform fraction exhibited the highest antifungal activity resulting in 36-50% reduction due to different concentrations. Ethyl acetate was found comparatively less inhibitory where only 8-35% reduction in fungal biomass was observed due to different concentrations of the extract. n-hexane, n-butanol and aqueous fractions generally stimulated the fungal growth to variable extents. The present study concludes that S. rolfsii can be controlled by natural antifungal compounds in chloroform fraction of methanolic fruit extract of D. metel. [ABSTRACT FROM AUTHOR]