Effect of seed biopriming with Trichoderma harzianum strain INAT11 on Fusarium ear rot and Gibberella ear rot diseases

Fusarium ear rot (FER) and Gibberella ear rot (GER) are common fungal diseases of maize responsible for yield losses and reduced kernel quality due to contamination by mycotoxins. Since no chemical treatments are available to control Fusarium disease in maize, biological control could represent a promising sustainable strategy. A commercial strain of Trichoderma harzianum (INAT11) was evaluated for its ability to antagonize Fusarium verticillioides and Fusarium graminearum and to reduce disease symptoms in plants through induction of a systemic resistance response in maize. Infection trials on maize plants under controlled greenhouse conditions showed that INAT11 applied to seeds is capable of reducing both F. verticillioides and F. graminearum disease incidence (37.1% and 30.7%, respectively) and severity (32.6% and 43.4%, respectively). Field trials performed under natural infection conditions showed a reduction in deoxynivalenol contamination in kernels, while no effect on fumonisin contamination was observed. The expression patterns of some defence-related genes belonging to both the ISR (LOX10, AOS, HPL and OPR8) and SAR pathways (PAL and PR1) indicated the upregulation of some ISR and SAR markers. These upregulations occurred at different levels likely related to the lifestyle of these two fungal pathogens.