Desenvolvimento de diagnósticos moleculares para os agentes etiológicos das podridões de raízes de mandioca na Região do Oeste do Pará

Abstract

Root rots are diseases caused by a complex of fungi and oomycetes, which in cassava have a continuous and significant impact on production and consequently cause socioeconomic damage to producing countries. For disease control, the correct diagnosis of the pathogen is essential. Thus, the objective of this work was to develop a molecular tool to differentiate the causal agents of cassava root rots through the ITS-RFLP of the main causal agents known in Brazil (, Neoscytalidium dimidiatum, Phytophthora melonis, Phytopythium sp., complexes Fusarium solani and Lasiodiplodia theobromae) digested by selected enzymes in silico (EcoRI, BmgBI, HaeIII, SmaI and XhoI). It was possible to verify the differentiation of the phytopathogens in two groups (ascomycetes and oomycetes), only by the polymorphism of the fragment size of the ITS region. Furthermore, it was possible to differentiate dry rot from black rot (Neoscytalidium dimidiatum, complexes Fusarium solani, e Lasiodiplodia theobromae) using the enzymes HaeIII, SmaI and EcoRI, as well as, within the oomycetes, to differentiate the species (P. melonis, Phytopythium sp.) through the enzymes BmgBI and XhoI. Therefore, the ITSRFLP can be a new molecular tool for the rapid and efficient diagnosis of the causal agents of cassava root rot in the main producing regions.