Presence of Fusarium spp. complex in diseased trees of Gmelina arborea Roxb (melina) in Ecuador.

Resumen

The area planted with Gmelina arborea (melina) in Ecuador has
increased in the last decade, currently this forest species is affected
by the disease "vascular wilt and stem rot", which is killing thousands
of trees in the country. Ceratocystis fimbriata is listed as the causative
agent of the disease, However, the complex symptoms and the
frequent isolation of Fusarium spp. from diseased trees, make us
suspect that this phytopathogen is involved in the pathogenesis of
melina. Koch's Postulates were applied at the greenhouse level, and
for the effect, 5 treatments based on the inoculation of 17 G. arborea
plants of 4-month-old per treatment were plated. T1 = Fusarium sp.1,
T2 = Fusarium sp.2, T3 = Fusarium sp.3, T4 = Fusarium sp.4, and T5 =
agar-agar (control). A complete randomized design (CRD) was used
and the plants were evaluated 155 days after inoculation. The
treatments Fusarium sp.1 and Fusarium sp.2 caused the largest
apparent volumes of necrosis (2.31 cm3 and 2.43 cm3), and generated
mild symptoms of disease, however they did not die, so these results
cannot be considered conclusive yet. It is necessary to continue
investigating the role of Fusarium spp. in the pathogenesis of melina.