Evaluation of Maize Hybrids for Resistance to Ear Rot Caused by Dominant <i>Fusarium</i> Species in Northeast China

Abstract

Ear rot caused by the Fusarium species has led to a decline in maize yield and kernel quality worldwide. The changes in the population structure of pathogens and the widespread planting of susceptible maize varieties have exacerbated the occurrence and harm of ear rot in China. Therefore, it is very important to establish the species composition of Fusarium and evaluate the resistance of the main cultivated hybrids. In this study, 366 single conidial isolates of Fusarium spp. were obtained from three provinces of Northeast China. F. verticillioides, F. subglutinans, F. proliferatum, F. oxysporum, and F. graminearum species complex (FGSC) were identified, with F. verticillioides being the most prevalent with a frequency of 44.0%. Based on the TEF-1α gene sequences analysis, the FGSC populations consisted of two independent species: F. boothii and F. graminearum, which account for 23.8% and 5.7% of the total isolates, respectively. Additionally, the resistance to ear rot by 97 maize hybrids commonly planted in Northeast China was evaluated by inoculation with F. verticillioides during 2021 and 2022. The results showed that the disease parameters of different hybrids varied significantly (p F. verticillioides in Northeast China, and many hybrids are resistant to the disease. This study will guide growers to scientifically deploy resistant commercial hybrids to control ear rot.

Keywords

• maize
• ear rot
• population structure
• resistance
• <i>Fusarium verticillioides</i>