AN OVERVIEW OF SUGARCANE BROWN RUST IN CUBA

MARÍA LA O1, MARIA FRANCISCA PERERA, ROMINA PRISCILA BERTANI2, RICARDO ACEVEDO1, MARTA EUGENIA ARIAS3,4, MARIO ALBERTO CASAS1, JUANA PÉREZ1, YAQUELÍN PUCHADES1, EIDA RODRÍGUEZ1, ISABEL ALFONSO1, ATILIO PEDRO CASTAGNARO2,*.

SCIENTIA AGRICOLA

UNIV SAO PAOLO

Lugar: Piracicaba; Año: 2018

0103-9016

ABSTRACT: Multiple pathogens affect sugarcane, among them Puccinia melanocephala, causal agent ofbrown rust. This disease was first reported in Cuba in 1979 when caused asevere attack on the main sugarcane variety B4362. The aims ofthe present work were to give an overview of the sugarcane brown rust in Cubaand show the current disease situation in the country. A retrospective analysisregarding sugarcane cultivar composition resistant to brown rust in Cuba wascarried out. In addition 154 genotypes, including the most used progenitors inthe breeding program and commercial varieties were evaluated under naturalinfection conditions. The identity of P.melanocephalawas verified by PCR and sequencing the ITS1 region. After P.melanocephala introduction to Cuba,susceptible variety B4362 was replaced by Ja60-5 that remained resistant until1998. Since 2002, avarietal policy supported by a governmental resolution establishing that anycultivar cannot occupy more than 20% of the production area for each production company, local area and province, was applied. Out of the genotypes evaluated, 49 showedresistance to the disease and 35 intermediate behavior, while 39 were susceptibleand 31, highly susceptible. P.melanocephala was detected by PCR in all symptomatic samples and its identifyconfirmed by sequencing the ITS1 region. Theadopted measurement together with permanent phytosanitary monitoring andcommercial release of resistant or intermediate cultivars had allowed avoidingnew epidemics. Inoculum pressure was reduced, even over susceptible and highlysusceptible varieties because by resolution they cannot occupy more than 10% ofthe planted area.