Fusarium oxysporum f. sp. lycopersici causal agent of vascular wilt disease of tomato: Biology to diversity– A review

Tomato (Lycopersicon esculentum) is one of the widely grown vegetables worldwide. Fusarium oxysporum f. sp. lycopersici (FOL) is the significant contributory pathogen of tomato vascular wilt. The initial symptoms of the disease appear in the lower leaves gradually, trail by wilting of the plants. It has been reported that FOL penetrates the tomato plant, colonizing and leaving the vascular tissue dark brown, and this discoloration extends to the apex, leading to the plants wilting, collapsing and dying. Therefore, it has been widely accepted that wilting caused by this fungus is the result of a combination of various physiological activities, including the accumulation of fungal mycelia in and around xylem, mycotoxin production, inactivation of host defense, and the production of tyloses; however, wilting symptoms are variable. Therefore, the selection of molecular markers may be a more effective means of screening tomato races. Several studies on the detection of FOL have been carried out and have suggested the potency of the technique for diagnosing FOL. This review focuses on biology and variability of FOL, understanding and presenting a holistic picture of the vascular wilt disease of tomato in relation to disease model, biology, virulence. We conclude that genomic and proteomic approachesare greater tools for identification of informative candidates involved in pathogenicity, which can be considered as one of the approaches in managing the disease

Efficacy of botanicals on soybean seed-borne Fusarium equiseti.

Soybean is one of the most important oilseed crops cultivated in India. A large number of fungi have been reported to be associated with soybean seeds and few of them are pathogenic. These pathogenic fungi are known to cause seed and seedling diseases at early plant growth stages and many other diseases. The objective of this work was to study the efficacy of the solvent extract of botanicals on seed-borne Fusarium equiseti isolated form soybean seed variety (JS-335). F. equiseti are associated with soybean seed-borne diseases such as seed rot, root rot, wilting, blight pod, collar rot and sudden death syndrome. Out of the eight botanicals screened few of the botanicals showed promising activity, among them Emblica officinalis fruit extract showed the most effective activity against F. equiseti. These natural products may be alternatives to chemicals fungicides and provide an easy method to store soybean seed for long period

Effects of high energy electrons on physical and tensile properties of non-mulberry silk fibers

Tassar silk fiber (Antheraea mylitta) was irradiated with the available maximum dose range upto 100 kGy using 8 MeV electron beam at room temperature. Irradiation effect in these fibers is quantified in terms of the changes in microstructural parameters studied using wide-angle X-ray scattering data (WAXS). The crystal imperfection parameters such as crystallite size (<N>), lattice strain (g in %), and surface weighted crystallite size (D s in à ) have been determined by line profile analysis (LPA) using Fourier method of Warren. For this purpose, exponential, lognormal, and Reinhold functions for column length distribution have been used for the determination of these parameters. These parameters were compared with tensile properties of the fibers. The increasing trend of crystallite size values (<N> as well as D s in à ) and tenacity (gf/den) with increasing dosage of radiation clearly indicates the cross linking polymer network in fiber. Comparison of SEM photographs also confirms the X-ray results

The correlation among morphology, oxygen vacancies and properties of ZnO nanoflowers

Despite numerous reports have investigated the effect of morphology on the properties of nanomaterials, its role in tuning nanomaterials properties is still not clear to date. This work introduces a unique attempt to explore the correlation among morphology, surface defects (oxygen vacancies), and properties of nanomaterials. To achieve this task, three different morphologies of ZnO nanoflowers were prepared via hydrothermal method by varying the concentration of diethylamine. It was observed that a change in ZnO nanoflowers morphology results in changes in their optical, photocatalytic, and antibacterial properties. Photoluminescence and X-ray photoelectron spectroscopy analyses reveal the presence of oxygen vacancies (VO) in ZnO nanoflowers with a concentration varies with respect to morphology. VO concentration plays a key role in tuning ZnO band gap and the concentration of reactive oxygen species and thereby tuning optical, photocatalytic, and antibacterial properties of ZnO nanoflowers. Our results suggest that VO concentration, morphology, and properties of ZnO nanoflowers are correlated

Plant growth promoting rhizobacteria- Bacillus amyloliquefaciens improves plant growth and induces resistance in chilli against anthracnose disease

The present study was aimed to screen plant growth promoting rhizobacteria (PGPR) for their effect on induction of resistance in chilli (Capsicum annum L.) against anthracnose disease. A total of 59 PGPR were evaluated for their antagonistic activity against Colletotrichum truncatum and only fourteen PGPR were able to inhibit the mycelial growth of the pathogen. The pathogenicity and root colonization of the selected PGPR showed that out of fourteen isolates only eight isolates of Achromobacter, Bacillus, Burkholderia, Enterobacter, Ochrobactrum and Providencia genera were able to be both non-pathogenic and possessed the ability to colonize the host plant. Among the PGPR isolates, seed treatment with Bacillus amyloliquefaciens resulted in maximum enhancement of seed germination (84.75), seedling vigor (1423.8) along with an increase in vegetative growth parameters. Significant disease protection of 71 against anthracnose disease was observed in plants pretreated with B. amyloliquefaciens followed by B. cepacia and P. rettgeri, under greenhouse conditions. The induced resistance obtained upon PGPR treatment was in line with higher activity of defense enzymes phenylalanine ammonia lyase (PAL), peroxidase (POX), polyphenol oxidase (PPO) and β-1,3-glucanase. It was observed that, almost one to two-fold increase in enzyme activities was observed in PGPR treated challenge inoculated seedlings compared to control inoculated seedlings. The results evidenced that the PGPR- B. amyloliquefaciens possesses immense potential to increase the plant growth apart from suppressing anthracnose disease in chilli

Antibacterial and antimitotic potential of bio-fabricated zinc oxide nanoparticles of Cochlospermum religiosum (L.)

Zinc oxide nanoparticles synthesized through eco-friendly approach has gained importance among researchers due to its broad applications. In the present work, hexagonal wurtzite shape nanoparticles (below 100 nm size) were obtained using aqueous leaf extract of Cochlospermum religiosum which was confirmed through X-Ray diffraction (XRD) analysis. The synthesized ZnO-NPs showed an absorption peak at 305 nm which is one of the characteristic features of ZnO-NPs.The bio-fabricated ZnO-NPs were of high purity with an average size of ∼76 nm analyzed through Dynamic Light Scattering (DLS) analysis supporting the findings of XRD. The SEM images confirmed the same with agglomeration of smaller nanoparticles. The composition of aqueous leaf extract and ZnO-NPs was explored with Fourier Transform Infrared Spectroscopy (FT-IR). The plant extract as well as bio-fabricated ZnO-NPs offered significant inhibition against Gram-positive (B. subtilis and Staph. aureus) and Gram-negative (P. aeruginosa and E. coli) bacteria. The minimum inhibitory concentration (MIC) of bio-fabricated ZnO-NPs and plant extract was found between 4.8 and 625 μg/ml against test pathogens, which was authenticated with live and dead cell analysis. Apart from antibacterial potentiality, antimitotic activity was also observed with a mitotic index of 75.42 (ID50 0.40 μg mL−1) and 61.41 (ID50 0.58 μg mL−1) in ZnO-NPs and plant extract, respectively. The results affirm that plant extract and its mediated ZnO-NPs possess biological properties

Bioactive and Biocompatible Nature of Green Synthesized Zinc Oxide Nanoparticles from Simarouba glauca DC.: An Endemic Plant to Western Ghats, India

Zinc-oxide nanoparticles (ZnO-NPs) synthesized from plant extracts are considered to possess superior biological activities compared to chemically synthesized nanoparticles and are of immediate interest to pharmaceutical and agriculture industries. The current study reports the green synthesis of ZnO-NPs from the aqueous leaf extract of Simarouba glauca for the first time. The physico-chemical characterization revealed hexagonal shaped nanoparticles with a size of similar to 17 to 37 nm calculated by Scherrer's formula with a purity of 98.51%. The FT-IR results confirmed that functional groups present in the plant extract had coagulated well to form a metal oxide during the synthesis process. The antioxidant potential of green synthesized ZnO-NPs evaluated by different methods revealed significant (p <= 0.05) radical scavenging activity (5% to 59%) with IC50 value falling between 400 and 500 mu g mL(-1) among the test methods. The green synthesized nanoparticles also inhibited the mitotic cell division up to 17.46% with increase in concentration. Further, the haemolytic assay by spectroscopic analysis affirmed the biocompatible nature of the nanoparticles which was also evidenced through SEM studies. The present findings indicate that the green synthesized ZnO-NPs from S. glauca possess antioxidant and antimitotic properties apart from possessing biocompatible nature to RBCs thereby warranting in vivo studies. Graphi

Rational construction of plasmonic Z-scheme Ag-ZnO-CeO2 heterostructures for highly enhanced solar photocatalytic H-2 evolution

Rational design of photocatalyst with wide solar-spectrum absorption, negligible electron-hole recombination, and maximized redox potential is an essential prerequisite for achieving commercial-scale photocatalytic H-2 production. This contribution combines surface plasmon resonance and Z-scheme charge transport in a single photocatalyst (Ag ZnO CeO2 hetemstructure) aiming to improve its performance for photocatalytic H-2 production. The Ag-ZnO-CeO2 heterostructure is fabricated via sunlight-driven combustion and deposition approaches. The successful construction is confirmed by several characterization techniques. The Z-scheme configuration is verified by in situ irradiated XPS and ESR analyses. Ag plays dual rules as an electron mediator to facilitate the Z-scheme charge transport and plasmonic material to maximize the light absorption in the visible region. The designed photocatalyst exhibits significantly enhanced photocatalytic activity for H-2 production (18345 mu mol h(-1) g(-1)) under simulated sunlight irradiation. This work offers the opportunity of constructing efficient Z-scheme photocatalyst from wide bandgap semiconductors with full-visible light response, suppressed electronhole recombination, and optimized redox potential