Factors associated with variation in symptomatology induced by maize yellow mosaic virus (MaYMV) in maize crop

• Grant number: 25/09230-6
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: September 01, 2025
• End date: December 31, 2025
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Joao Roberto Spotti Lopes
• Grantee: Leonardo Coletti Spada
• Supervisor: Feng Qu
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Institution abroad: Ohio State University, Wooster, United States
• Associated to the scholarship: 24/07685-3 - Factors associated with variation in symptomatology induced by maize yellow mosaic virus (MaYMV) in maize crop, BP.IC

Abstract

The maize crop (Zea mays L.) is one of the most important worldwide, with Brazil and the United States standing out as major producers. In Brazil, this scenario is made possible by the practice of growing two or more corn crops in the same area or region throughout the year. However, this practice, combined with the presence of volunteer corn plants during the off-season, contributes to the phenomenon known as the "green bridge." This phenomenon favors the persistence of pests and pathogens in the field, particularly insect vectors. Among these, the corn aphid, Rhopalosiphum maidis (Hemiptera: Aphididae), has gained increasing relevance, as it transmits the maize yellow mosaic virus (MaYMV, family Solemoviridae, genus Polerovirus). First identified in China in 2016 and detected in South America and Africa in subsequent years, this virus has a wide distribution and high potential for impact on corn production worldwide. In Brazil, the reported symptoms include mild mosaic or asymptomatic infection, and in cases of mixed infections with sugarcane mosaic virus (family Potyviridae, genus Potyvirus), more severe mosaic with necrotic lesions. However, these reports differ from other studies conducted in China (in the provinces of Yunnan and Guizhou) and Africa, where MaYMV has been associated with yellow mosaic symptoms and reddening of the leaves, a phenomenon also observed in the Henan province of China. The present project aims to investigate the factors responsible for these symptomatic differences, through an experiment that complement ongoing studies in Brazil. The effects of MaYMV isolates from Piracicaba (SP) and Morogoro (Tanzania) with different symptomologies will be evaluated, as well as different maize genotypes. As a result, it will be possible to advance the knowledge about the virus and its impacts, complementing the studies conducted in Brazil. (AU)