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Abstract Anthracnose disease, caused by the Colletotrichum gloeosporioides species, affects vegetables, fruits, pulses, and cereals, leading to significant economic losses worldwide. Although many synthetic fungicides are used to control this pathogen, eco-friendly biological alternatives are gaining popularity. This study focuses on isolating and purifying chitinase ( Af Chi)from a marine bacterium and testing its antifungal efficacy against C. gloeosporioides spore germination by targeting the chitin in the fungal cell wall. The chitinase was purified from a marine bacterium A. faecalis from the Arabian Sea and had a molecular mass of 45 kDa and a specific activity of 84.6 U/mg. Af Chi worked best at 50 °C and pH 7.0 in Tris HCl buffer. Na+ ion was the highest cofactor, highlighting the halophilic nature of this chitinase. K+, Ca2+, Cu2+, Mg2+, Mn2+, and EDTA also increased activity, while Fe3+, Zn2+, Co2+, and Pb2+ decreased it. The Km and Vmax values were 1.87 µg/mL and 17.45 U/mL, respectively. Purified Af Chi at 10 mg/mL completely inhibited spore germination within 8 h and reduced the size of the spores.

In the present study copper nanoparticles (CuNPs) were prepared using Syzygium aromaticum (clove) bud extract through simple and eco-friendly green route. The synthesized nanoparticles were subjected to structural, morphological, optical and antimicrobial studies. The high crystalline nature of CuNPs with a face centered cubic phase is evident from the X-ray diffraction (XRD) pattern. Morphological studies were used to study the shape and size of the synthesized nanoparticles. Energy dispersive spectroscopy (EDS) attests the high intense metallic peak of copper (Cu) and low intense peaks of carbon (C), oxygen (O), chlorine (Cl) and phosphorus (P) elements due to the capping action of biomolecules of bud extract in CuNPs formation. The zeta (ζ) potential of the CuNPs attests the stability of the nanoparticles. Ultraviolet-visible (UV–vis) absorption spectrum shows the characteristic absorption peak of CuNPs. Fourier transform infrared spectroscopy (FTIR) analysis shows the presence of different functional groups at various positions. The antimicrobial activity was investigated against the selected pathogens using bio-CuNPs. The positive test results of zone of inhibitions of 8 mm and 6 mm were attained against Bacillus spp. and Penicillium spp., respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • The rice stem borer's use of trap plant, Eleocharis dulcis is examined. • The trap plants had 20 times more egg clutches of stem borer than on rice plants. • Egg functional traits and hatch rate are high in eggs on trap plants. • Egg parasitism was low for eggs deposited on rice plant. • No eggs hatched on the trap plants survived. The rice white stem borer, Scirpophaga innotata Walker (Family: Crambidae) is a major lepidopteran pest of rice from seedling to ear setting stage. Due to their hidden life style, no satisfactory means of control other than systemic pesticide application, habitat management, and egg parasitism have been prescribed yet. It is observed that S. innotata use a plant, the Chinese water chestnut (Eleocharis dulcis (Burm. F.)) (Family: Cyperaceae) for oviposition. We investigated why and how S. innotata is benefited by using E. dulcis for oviposition to prescribe it as a trap plant for managing the pest. We surveyed moths and egg clutches, and studied functional traits of eggs, egg hatching, and egg parasitism in eggs deposited on rice and the chestnut for three years in Kaipad rice fields of peninsular India. We observed 20 times more egg clutches on the chestnut than on rice. The egg density in clutches and hatching rate were high in eggs deposited on the chestnut. Egg parasitism was meager and restricted only to the eggs deposited on rice. However, no larvae hatched on the chestnut in the lab survived. The results suggest that E. dulcis could be a dead-end trap plant for biological control of S. innotata. We do not rule out the probability of the moth using E. dulcis for oviposition, escaping from egg parasitoids, and most importantly for rapid spread of neonates to rice. We recommend using E. dulcis as a trap plant to trap the eggs and removing them to manage this pest in rice fields. [ABSTRACT FROM AUTHOR]