Etiological characterization of small-spored Alternaria and epidemiology of potato brown spot in Brazil

• Ano de defesa: 2023
• Autor(a) principal: Nascimento, Cosma Raissa Bezerra do
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa; Fitopatologia
• Palavras-chave em Português: Solanum tuberosum; Batatas - Doenças e pragas - Identificação; Fungos fitopatogênicos; Epidemiologia; Fitopatologia
• Link de acesso: https://locus.ufv.br//handle/123456789/31903; https://doi.org/10.47328/ufvbbt.2023.587

This dissertation investigates potato brown spot, a disease that can significantly impact potato quality and yield in various parts of the world. The study focuses on small- spored Alternaria species recovered from potato leaf lesions collected in the major Brazilian potato-producing states. The isolates were characterized using morphological and molecular approaches and tested for pathogenicity. More than one small-spored Alternaria species can cause brown spot in potato, including A. arborescens and a new Alternaria sp., that was identified for the first time as a causal agent of the disease. Furthermore, the study examines the effects of temperature on the basic epidemiological/ecological variables associated with small-spored Alternaria species. The results demonstrate that temperature affects mycelial growth, sporulation, and germination of small-spored Alternaria isolates from the main potato- producing regions. The highest values for most phenotypic traits evaluated were in the range of 25 and 30 °C, and growth patterns varied among small-spored species. The severity of brown spot may vary according to the distribution of the small-spored Alternaria species, which highlights the importance of understanding the ecological characteristics of the pathogen for disease management. Overall, this dissertation provides valuable insights into the factors influencing the occurrence and severity of potato brown spot and identifies potential strategies for its control. Keywords: Solanum components. tuberosum. Identification. Pathogenicity. Epidemiological