Reação de genótipos experimentais de melancia ao crestamento gomoso do caule

Abstract

Reaction of experimental watermelon genotypes to gummy stem blightThe gummy stem blight, caused by the fungus Didymella bryoniae is one of the major diseases that occur in watermelon, causing seedling damping off and canker formation on the stems and stalks, reducing the yield and quality of fruits. Although sources of genetic resistance to this disease are available, in Brazil there are very few studies on this subject and the results so far obtained are not satisfactory for adoption in the field. The objective of this research was to select D. bryoniae isolates and evaluate the reaction of experimental genotypes of watermelon to gummy stem blight under greenhouse and field conditions. Under greenhouse conditions a variation was observed, regarding resistance level among genotypes. Some genotypes that were resistant in the greenhouse also behaved as resistant in the field. The genotypes

Reaction of melon genotypes to Didymella bryoniae (Fuckel) Rehm

“…Assay 3 was conducted to confirm resistance of genotypes that had lower scores for disease symptoms compared to previous assays between January and March 2014, using the methodology of resistance assessment in trays proposed by Santos et al (2013 Two seeds of each genotype were seeded per well in the 128-cell trays. Subsequently, plants were thinned, leaving only one seedling in each cell.…”

“…However, it was possible to distinguish different levels of resistance. Santos et al (2013) studied watermelon and reported that none of the evaluated genotypes was immune to the pathogen, but the resistance levels were different.…”

“…Some authors have reported the influence of environmental conditions and differences in the aggressiveness of isolates (Santos et al, 2009b;2013).…”

“…The latter is the causal agent of the main fungal diseases in melon (Ito et al, 2009;Silva et al, 2012) and watermelon (Santos et al, 2013) crops cultured in both open and protected environments.…”