Morphological and molecular characterization of Puccinia kuehnii, the causal agent of sugarcane orange rust, in Cub

PERERA, MARÍA FRANCISCA; BERTANI, ROMINA PRISCILA; ARIAS, MARTA EUGENIA; HECHAVARRÍA, MARÍA DE LA LUZ LA O; NAVARRO, MARÍA DE LOS ÁNGELES ZARDÓN; DEBES, MARIO ALBERTO; LUQUE, ANA CATALINA; CUENYA, MARÍA INÉS; CASTAGNARO, ATILIO PEDRO; ROJAS, RICARDO ACEVEDO

Scientia Agricola

Plant Pathology

Año: 2020 vol. 77

Sugarcane orange rust caused by Puccinia kuehnii has recently become an important disease in sugarcane crops and its spread is causing great concern to growers. In thisstudy, we analyzed spores from symptomatic orange rust sugarcane leaves collected in multiplelocations in Cuba in a 4-year-period in order to characterize morphological traits of P. kuehnii,establish an adequate molecular technique to characterize it, and determine its infection courtin sugarcane. Orange rust caused by P. kuehnii was confirmed by polymerase chain reaction(PCR) and morphological characterization. AFLP markers detected high diversity in P. kuenhniisamples. Sequencing of rDNA regions, as expected, did not reveal differences and SSR markersdesigned for P. melanocephala could not be transferred to P. kuehnii. In addition to stomata,entry through prickles was also detected as a new infection court in sugarcane. Although thepresence of pustules on the adaxial leaf surface was frequently detected, no clear correlationbetween this presence and density of stomata and/or prickles was found.