Influence of Endosperm Starch Composition on Maize Response to Fusarium temperatum Scaufl. & Munaut

Abstract

Fusarium temperatum Scaufl. & Munaut is a newly described taxon belonging to the Fusarium fujikuroi species complex (FFSC) and a frequent causative factor of maize ear rot. The aim of the present study was to determine the responses to the disease in maize populations differing in endosperm features that were classified to flint, dent, and a group of plants with intermediate kernel characteristics. In inoculation studies, substantial variation of host response to the fungus was found among the tested maize types. The dent-type kernels contained significantly less amylose (28.27%) and exhibited significantly higher rates of infection (IFER = 2.10) and contamination by beauvericin (7.40 mg kg−1) than plants of the flint maize subpopulation. The study documents a significant positive correlation between the Fusarium ear rot intensity (IFER) and ergosterol content (the R value ranged from 0.396 in 2015 to 0.735 in 2018) and between IFER and the presence of beauvericin (the R value ranged from 0.364 in 2015 to 0.785 in 2017). The negative correlation between (IFER) and amylose content (ranging from R = −0.303 to R= −0.180) stresses the role of the endosperm starch composition in the kernel resistance to Fusarium ear rot. The conducted study indicated that the risk of kernel infection and contamination with fungal metabolites (beauvericin and ergosterol) was associated with the maize type kernels.