Growth inhibition of Fusarium verticillioides [Sacc.] Nirenberg by isolates of Trichoderma pseudokoningii strains from maize plant parts and its rhizosphere

Ability of five strains of Trichoderma pseudokoningii (antagonists) to suppress radial growth of Fusarium verticillioides (Sacc.) Nirenberg (=Fusarium moniliforme Sheldon) was examined i n vi tro. These were T. pseudokoningii strain1 (IMI 380933), strain2 (IMI 380937), strain3 (IMI 3809 39), strain4 (IMI 380940) and strain5 (IMI 380941). Each strain was paired with pathogen by inoculating at opposite ends of 9 cm petri plates using three pairing methods. Gradings were assigned to varied growth inhibition of pathogen by antagonists and analysed using GLM procedure (SAS). Growth suppressionof F. verticillioides by all strains of T. pseudokoningii was significantly different (R2 =0.98, p=0.05) from control in all pairing methods. It differed significantly (p>0.0003) among the strains in all pairing methods. Growth suppression also differed significantly among (p>0.0001) and within (p>0.018) pairing methods. Growth suppression was best when antagonists were inoculated before pathogen. Suppression mechanisms include mycoparasitism and competition for space and nutrients. T. pseudokoningii strains 3 and 4 had the best (p=0.05) growth suppressionof F. verticillioides and could be used as biocontrol agents for endophytic F. verticillioides in maize plant. This experiment was conducted in the search for resident microorganisms that might be capable of checking F. verticillioides withinmaize plant by competitive exclusion in subsequent experiments.

W warunkach in vitro zbadano aktywność pięciu szczepów Trichoderma pseudokoningii w hamowaniu wzrostu fitopatogennego szczepu Fusarium verticillioides – sprawcy fuzaryjnego uwiądu kukurydzy. Każdy szczep antagonisty wysiewano w szalkach Petriego z grzybem chorobotwórczym i analizowano ich wzrost zgodnie z metodyką GLM(SAS). Najsilniejsze hamowanie wzrostu F. verticillioides stwierdzono, gdy antagonista był inokulowany jako pierwszy. Szczep nr 3 T. pseudokoningii wykazał najsilniejsze działanie i może być przydatny w biologicznej ochronie kukurydzy przed fuzaryjnym uwiądem.