Reação de genótipos experimentais de melancia ao crestamento gomoso do caule

Abstract

The 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 WMX-001E-PL#13-01, WMX-001E-PL#04-01 and WMX-001E-PL#02-02 which were resistant in the greenhouse were also resistant under field conditions.