LAUSR

AIM Simultaneous management of FOL, RKN causing wilt complex in tomato by chaetoglobosin producing Chaetomium globosum. METHODS AND RESULTS Random survey was carried out to isolate Fusarium and Chaetomium. Twelve Fusarium isolates were characterized and FOL4 (virulent) was molecularly identified. Wilt complex by FOL, RKN was assessed individually and in combination under greenhouse. RKN (1000 juveniles ml-1) inoculation followed by FOL4 (5 × 105 spores ml-1) accounted for 90% incidence. The chaetoglobosin-producing Chaetomium was isolated, characterized morphologically and molecularly. Among 55 isolates, nine showed more than 50% inhibition against FOL and crude culture filtrate showed significant reduction in RKN egg hatching (15.66%) and juvenile mortality (100%). Chaetomium Cg 40 was confirmed as C. globosum using SCAR (OK032373). Among 40 volatile compounds, hexadecanoic acid and 1,2-epoxy-5,9-cyclododecadiene exhibited antifungal and nematicidal properties in GC-MS. High-performance liquid chromatography revealed chaetoglobosin A (0.767 µg µl-1), and the presence of bioactive molecules chaetoglobosin (528.25 m/z), chaetomin (710 m/z), chaetocin (692.8 m/z), chaetoviridin (432.85 m/z) and chaetomugilin (390 m/z) was confirmed by LC/MS/MS. Cg 40 and Cg 6 were able to synthesize the pks1a,b gene responsible for chaetoglobosin, sporulation, and melanin biosynthesis was confirmed by PCR. The application of aqueous formulation as seed treatment, seedling dip and soil application recorded lowest wilt incidence (11.11%) and gall index (1) with the maximum growth parameter (plant height 51.9 cm), fruit yield (287.5 g) and lycopene content (11.46 mg/100 g). CONCLUSIONS Cg 40 and Cg 6 containing polyketides, secondary metabolites, antibiotics, chaetoglobosin and plant growth-promoting ability showed antifungal and nematicidal properties against FOL-RKN wilt complex in tomato in vitro and pot culture experiments.