A new method for early detection of Ceratocystis spp. on various hosts. In: Agrotrópica v. 27 p. 209-214, 2015.

Abstract

Ceratocystis wilt is a lethal disease to several hosts. This study tested the isolation of Ceratocystis spp. from the leaf blade of cacao and other hosts showing yellowing and the isolates pathogenicity to their hosts. Leaves with yellowished and/or darkened areas were disinfested and placed between slices of unripe cacao pods, like a sandwich, in a BOD chamber (25o C), for four days. Ascospores were transferred to Petri dishes containing PDA and their colonies were preserved. The presence of C. cacaofunesta in the leaf blade of cacao tree; C. paradoxa in coconut palm; and C. fimbriata in eucalyptus, rubber, soursop, custard-apple trees and coffee plants were confirmed. To test the isolates pathogenicity, culture discs or droplets of inoculum suspensions (3 × 104 i.u./mL) were applied in two points on leaves of each host, with and without wound, and evaluated in four to seven days. Chlorosis, lesions, mycelia and perithecia development were observed in the midrib and on blades of inoculated leaves. Therefore, an early method of detection of Ceratocystis spp. as well as another method to evaluate pathogenicity to various hosts using whole leaves of these hosts were described in this paper.