Molecular identification and integrated management of the Fusarium f. sp. Cucumerinu the causal agent of Fusarium wilt disease of Cucumis sativus L. in Iraq

Abstract

KEYWORDS Fusarium oxysporum f. sp. cucumerinum Chaetomium cupreum Trichoderma viride Bacillus pumilus Salicylic acid Cucumber PCR ABSTRACTThis study was aimed to isolate and identify the phytopathogenic fungus Fusarium oxysporum f. sp. cucumerinum (Foc) the causal agent of the Fusarium vascular wilt disease of cucumber in the middle and south of Iraq. The results of study indicated the presence of the pathogen with percentage of appearance 71.43% with frequency 46.43%. Molecular identification carried out using polymerase chain reaction technique indicated the presence 18 isolates of Foc pathogenic group I and 6 isolate of Foc pathogenic group II. Among these, the isolate Foc-b3 was most virulent under in vitro pathogenicity test on the cucumber seed and it exhibited 0% seed germination compared with control. An attempt of integrated management of F. oxysporum f. sp. cucumerinum under in vitro conditions was also carried out in present study and a significant inhibition were reported on the application of various bioagents such as Chaetomium cupreum (Cc), Trichoderma viride (Tv) and Bacillus pumilus (Bp) on the potato dextrose agar (PDA). Further, under greenhouse conditions, combined application (tetrainoculums) of Cc+Tv+Bp+ Salicylic acid (Sa) was significantly reduced the percentage of the disease incidence and severity up to 0% as compared with the control where it was reported 97.50%, 75.72% respectively. Effect of this combination was also reported on the dry weight of the plants and significant improvement (0.975 gm/plant) was reported as compared to control (0.098 gm/plant).

Evaluation of Bio-Control Agents against Fusarium Wilt of Cucumber

“…Mycoparasitic mechanisms such as coiling, penetration, overgrowing, lysis, and antibiosis by antagonistic fungi like Trichoderma harzianum, T. viride appears to be effective in management of soil borne pathogens. Results agree with finding of workers which tested the efficacy of Trichoderma against Fusarium wilt (Hussein, 2016;John et al, 2010;Akrami, 2015). Bacterial bio-control agents are promising as they possess many traits like production of bioactive metabolites like antibiotics, siderophores, volatiles and other attributes like colonization ability and better adaptation to environmental stresses.…”

Identification and control the causal agent of root rot disease of cucumber in Iraq

“…MgCl2 amended to 1.75 mM and 1.5 µl of the primers (TS-Fu-f and ITS-Fu-r) and 3 µl DNA of each sample individually/concentration of 50 ng/µl and 14 µl sterile distilled water, mixed by vortex, and the control prepared by adding 1.5 µl of the primer strands and 17 µl sterile distilled water to the interactions mixture. Eppendorf tubes loaded in to the polymer thermal (ThermoCycler) produced by Biocompare, USA, and program seated according to the method of Hussein (2016) with some modifications, the program included Initial denaturation heating at a temperature of 94 C ̊ for two minutes to separate the double strand of the DNA to single strand, and 30 cycle included; Denaturation at 95 C ̊ for one minute to copy the DNA strand which will be a template for the subsequent reactions, and Annealing at a 58 C ̊ for one minute to linked the primer with DNA template, and Extension cycle at 72 C ̊ for two minutes to elongate the primer which linked with the DNA template, and then final Extension cycle at a 72 C ̊ for 7 minutes.…”