Avaliação de resistência de genótipos de mamoeiro Asperisporium caricae

Abstract

The objectives of the study objectives were to evaluate the injured area of leaves with A. caricae, to select genotypes with resistance / tolerance to black speck of papaya producing a diagrammatic scale for assessing the severity of the disease and to study the variability of two strains of A. caricae based on severity of disease in young plants of genotypes of papaya. The size of the lesions was determined in three commercial cultivars and 19 accessions of BAG-Papaya. In assessments of severity of injuries, from images taken with a digital camera (Kodak C813) with 8.2 million pixels per image, at a distance of 30 cm, measurements were performed using the computer program Assess ®. There were significant differences between the accessions from the Papaya Germplasm Bank and the commercial cultivars, the assessment of the injured area in leaves of papaya is a useful tool in the identification of individuals resistant black spot to the papaya and is potential for the management the resistance of papaya to this pathogen. The second study was carried out in the greenhouse using plants of genotypes‘Sunrise Solo’ genotypes: CMF 003, CMF 78, CMF 231, CMF 232, CMF 234, CMF 95 and Tainung nº1 which were inoculated with A. caricae from leaves from plants in the Papaya Germplasm Bank (Embrapa isolate) and from the Palmares Farm (Palmares isolate). After the evaluations found that there is variability among isolates and that all genotypes were susceptible to A. caricae, and the CMF 095 genotype was the higher average values during the evaluation of injuries among evaluated.