The richness of Fusarium species in maize tassels and their relationship with Fusarium stalk rot

ARATA A.F; MARTÍNEZ M.; CASTAÑARES E.; GALIZIO R.I.; FERNANDEZ M.D; DINOLFO M.I

EUROPEAN JOURNAL OF PLANT PATHOLOGY

SPRINGER

Lugar: Berlin; Año: 2023

0929-1873

Presence of toxigenic fungi of the genus Fusarium can cause negative effects on grainyield and the quality of maize (Zea mays L.). This study aimed to analyze the diversity ofFusarium spp. on tassel during the silking stage as a possible source of inoculum andtheir potential relationship with Fusarium stalk rot. Field experiments were carried outduring two growing seasons in Azul, Argentina, which included 12 commercial hybridsof maize. The diversity of Fusarium species isolated from tassels was analyzed byvisualizing morphological characteristics and confirming them using moleculartechniques. Subsequently, an experiment was carried out under greenhouse conditions toevaluate the pathogenicity of the Fusarium species isolated from the tassels on stalk of two maize hybrids (H1 and H2). Fusarium verticillioides (74%) was the most frequentFusarium species isolated from maize tassels, followed by species of F. incarnatum41 equiseti species complex (17%). Other species, such as F. proliferatum (4%), F.subglutinans (3%), F. graminearum (1%), and F. sporotrichioides (1%), were found inless quantity. As regards stalk pathogenicity, all Fusarium isolates used as inoculumdeveloped stalk rot symptoms in both hybrids, with H2 the most affected (1.08 ± 0.90cm2 vs. 0.52 ± 0.57 cm2. Our work demonstrated that the presence of the most frequentspecies of Fusarium isolated from maize ear on tassels would be a possible source of 7 inoculum for maize-stalk rot infection. Moreover, the capacity of the selected isolates toproduce stalk rot symptoms was studied. This information could be useful to predictwhich mycotoxins will be found in maize grains, inferring potential risks for the consumer and food safety.