Characterization of Alternaria isolates and reaction of potato genotypes to early blight

Ciência Rural

Pereira, Francielly de Cássia¹  Alvarenga, Thayssa Vilela Miguel¹  Pinto, César Augusto Brasil Pereira¹  Ribeiro, Silvia Regina Rodrigues de Paula¹  Souza, Elaine Aparecida de¹ 

[1] Universidade Federal de Lavras, Lavras, Brazil

关键词:  Alternaria grandis;    Alternaria solani;    mycelial compatibility;    aggressiveness;    genetic resistance;   

DOI  :  10.1590/0103-8478cr20151447

学科分类：农业科学（综合）

来源: Universidade Federal de Santa Maria * Centro de Ciencias Rurais

【 摘 要 】

:Early blight is one of the most important fungal diseases of potato. The objective of this study was to evaluate the in vitro reaction of potato genotypes to the severity of early blight and compare the species Alternaria solaniandAlternaria grandis, etiologic agents of disease, through the evaluation of physiological characteristics. Twenty-two genotypes of the Potato Breeding Program at UFLA, two cultivars, Aracy and Bintje, patterns of resistance and susceptibility, respectively were evaluated. For inoculation, three isolates of A. grandisand two isolates of A. solaniwere used. Plantlets obtained in vitro were inoculated with a 5mm diameter mycelial disk of isolates Alternariaspp. of. These were incubated in severity and classified according to the rating scale. Isolates ofAlternariaspp. were evaluated for mycelial growth index (MGI) and for formation of mycelial compatibility groups (MCG). The methodology for evaluating the in vitro reaction of genotypes to severity of early blight was efficient for both isolates. The isolates of A. solaniand A. grandiswere similar in their aggressiveness. The isolates ofA. grandisMGI's had higher, and therefore mycelium grew faster when compared to those isolated from A. solani. The occurrence of mycelial compatibility among isolates ofA. solaniand A. grandisindicated the possible occurrence of parasexual cycle.

【 授权许可】

Unknown