Location: National Peanut Research LaboratoryTitle: DIVERSITY OF PUCCINIA KUEHNII AND P. MELANOCEPHALA CAUSING RUST DISEASES ON BRAZILIAN SUGARCANE
|Urashima, Alfredo - Centro De Investigacion|
|Mistura, Tatiane - Centro De Investigacion|
|Sakuno, Carolyne - Centro De Investigacion|
|Piotto, Fernando - Centro De Investigacion|
|Rodrigo, Gazaffi - Centro De Investigacion|
|Arias De Ares, Renee|
Submitted to: Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 6/15/2015
Publication Date: 9/18/2015
Citation: Urashima, A.S., Mistura, T.F., Sakuno, C.I., Piotto, F., Rodrigo, G., Arias De Ares, R.S. 2015. DIVERSITY OF PUCCINIA KUEHNII AND P. MELANOCEPHALA CAUSING RUST DISEASES ON BRAZILIAN SUGARCANE. CINCAE: Centro de Investigacion de la Cana de Azucar del Ecuador - XI Pathilogy and IX Entomology Workshops.
Interpretive Summary: Two economically important pathogens of sugar cane are the orange rust ( Puccinia kuehnii) and brown rust (Puccinia melanocephala). In order to develop resistant varieties it is important to understand the genetic diversity of these pathogens. Here we determine significant genetic differences between P.k. and P.m., and we also identified two genotypes within P.k.
Technical Abstract: Sugarcane industry in Brazil suffers yield loss due to brown rust (Puccinia melanocephala) since 1986 and orange rust (P. kuehnii) as recent as 2009. The main control measure for both diseases has been cultivar resistance. Nevertheless, recent onsets of orange rust on previously resistant cultivars demonstrated lack of basic knowledge on pathogen genetic diversity. Therefore, the present work aimed to examine genetic diversity of isolates causing brown and orange rust on Brazilian sugarcane cultivars. Total DNA from 25 isolates of P. melanocephala and 30 of P. kuehnii were genotyped using 10 SRR primers and genetic diversity visualized through cluster analysis with UPGMA in the SAHN program of the NTSYS-pc package. Phenotypic data were evaluated by examining virulence pattern of six isolates of P. kuehnii towards eight cultivars. Evaluation was done 21 days through sporulation ability and digital image of damaged area by Assess 2.0. Data of the present work showed genetic diversity of 80% between isolates of P. kuehnii and P. melanocephala as well as genetic clones among isolates of both pathogens. Phenotypic data demonstrate existence of two different physiological races among six isolates of P. kuehnii, based on sporulation. Moreover, analyses of sugarcane resistance based solely on digital image could not differentiate cultivars with same lesion area but different sporulation capacity.