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Fungal diseases have always been a major problem for cantaloupe crops; however, synthetic fungicides are hazardous to humans and the environment. Consequently, a feasible alternative to fungicides without side effects could be by using bio agents and naturally occurring plants with antibacterial potential. This study has achieved a novel procedure for managing wilt and root rot diseases by potentially using Trichoderma sp. culture filtrates in consortium with plant extract of Calotropis procera, Rhizoctonia solani, Fusarium oxysporum, and Pythium ultimum, which were isolated from infected cantaloupe roots with identified root rot symptoms. The antagonistic activity of four Trichoderma isolates and analysis of antibiotics and filtrate enzymes of the most active Trichoderma isolate were determined as well as phytochemical analysis of C. procera plant extract using HPLC-UV. The obtained results showed that all Trichoderma isolates considerably lowered the radial growth of P. ultimum, R. solani, and F. oxysporum in varying degrees. The scanning electron micrographs illustrate the mycoparasitic nature of Trichoderma sp. on F. oxysporum. The phytochemical analysis of C. procera indicated that phenolic contents were the major compounds found in extracts, such as vanillin (46.79%), chlorogenic acid (30.24%), gallic acid (8.06%), and daidzein (3.45%) but including only a low amount of the flavonoid compounds rutin, naringenin, and hesperetin. The Pot experiment's findings showed that cantaloupe was best protected against wilting and root rot diseases when it was treated with both Trichoderma sp. culture filtrates (10%) and C. procera extract of (15 mg/mL), both alone and in combination. This study demonstrates that the application of bio agent Trichoderma spp. filtrate with C. procera phenol extract appears useful for controlling wilting and root rot disease in cantaloupe. This innovative approach could be used as an alternative to chemical fungicide for the control of wilting and rot root diseases.

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RESUMEN

Complex diseases caused by Meloidogyne incognita and Fusarium fungus in cucumber is the most destructive disease under polyhouses. The experiment was conducted in the polyhouse of the Department of Horticulture, CCS HAU, Hisar, Haryana, India during summer season (2015-16) to evaluate the potential of bacterial and fungal biocontrol agents against Meloidogyne incognita and Fusarium oxysporum f. sp. cucumerinum in cucumber. Bioagents - Trichoderma viride (Tv), Pseudomonas fluorescence (Pf), Purpureocillium lilacinum (Pl) were taken 10 and 20 g kg-1 seed and bioagents liquid formulation, 10- and 15-ml kg-1 seed, were mixed with the potted soil. Chemical as well as untreated check were also maintained. All the treatments significantly improved the plant growth parameter, viz., shoot length (SL), root length (RL), fresh shoot weight (FSW), fresh root weight (FRW), dry shoot weight (DSW) and dry root weight (DRW) as compared to untreated check. However, significant reduction in nematode population and maximum improvement in plant growth parameter was recorded with carbofuran followed by higher dose of bioagents liquid formulation. Among the bioagents, bioagents liquid formulation was most effective in suppressing root knot nematode galling (43 / root system) and final population in soil (131 J2s / 200 cc soil) and fungus wilt incidence (25 %) at 30th day of after germination and significantly improved the plant growth parameters - shoot length (147.3 cm), fresh shoot weight (55.6 g), dry shoot weight (22.51 g) and dry root weight (4.50 g) from other bioagents. Bioagents liquid formulation was effective in suppression of root-knot nematode and fungus complex disease than the powder formulations of bioagents. More studies should be needed in future to evaluate the efficacy of bioagents as seed treatments and soil applications under field conditions.

RESUMEN

Biological toxins are a heterogeneous group produced by living organisms. One dictionary defines them as "Chemicals produced by living organisms that have toxic properties for another organism". Toxins are very attractive to terrorists for use in acts of bioterrorism. The first reason is that many biological toxins can be obtained very easily. Simple bacterial culturing systems and extraction equipment dedicated to plant toxins are cheap and easily available, and can even be constructed at home. Many toxins affect the nervous systems of mammals by interfering with the transmission of nerve impulses, which gives them their high potential in bioterrorist attacks. Others are responsible for blockage of main cellular metabolism, causing cellular death. Moreover, most toxins act very quickly and are lethal in low doses (LD50 < 25 mg/kg), which are very often lower than chemical warfare agents. For these reasons we decided to prepare this review paper which main aim is to present the high potential of biological toxins as factors of bioterrorism describing the general characteristics, mechanisms of action and treatment of most potent biological toxins. In this paper we focused on six most danger toxins: botulinum toxin, staphylococcal enterotoxins, Clostridium perfringens toxins, ricin, abrin and T-2 toxin. We hope that this paper will help in understanding the problem of availability and potential of biological toxins.

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