Variabilidade em dez populações de Hemileia vastatrix em relação à germinação e ao comprimento do tubo germinativo em quatro temperaturas

Abstract

RESUMONeste trabalho, objetivou-se verificar o efeito da temperatura na germinação e no comprimento do tubo germinativo em diferentes populações de H. vastatrix (PHVs), sob quatro temperaturas. Realizou-se um bioensaio com dez PHVs, com suspensão de urediniósporos a 0,5mg/mL em solução aquosa (0,05%) de tween 80. Duas gotas de cada suspensão foram depositadas em lâminas de microscópio recobertas com camada de poliestireno e colocadas em gerbox contendo papel de filtro umedecido para constituir câmara úmida. Os gerboxes foram mantidos fechados, no escuro, a 15o C e 30ºC, por 24 horas. O ensaio foi conduzido em fatorial 10 x 4, sendo dez isolados, quatro temperaturas e duas repetições. Avaliaram-se a germinação e o comprimento do tubo germinativo. Houve variabilidade entre as PHVs quanto à temperatura ótima para germinação e alongamento do tubo germinativo.Termos para indexação: Ferrugem, Coffea arabica, populações. ABSTRACTThe objective of this work was to verify the effect of temperature in germination and germ tube length in different populations of H. vastatrix (PHVs) temperatures. A bioassay was performed with ten PHVs, using an urediniospore suspension of at 0.5mg/mL in aqueous solution (0.05%) of tween 80. Two drops of each suspension was deposited on a microscope coverslip, covered with a polystyrene layer and incubated in gerbox containing a watered filter paper to work as a wet chamber. The gerbox was kept closed, in the dark, at 15, 20, 25 and 30ºC for 24 hours. The assay was carried out in a factorial design 10 x 4, with ten isolates, four temperatures and two replicates represented by two drops of the suspension. Germination percentage and germ tube length were assessed. There was variability among PHVs for the optimum temperature for germination and elongation of the germ tube.

Urediniospore size variation and morphological novelties of Hemileia vastatrix on Coffea spp. in Mexico

“…For example, environmental conditions can regulate H. vastatrix pathogenesis by inducing lesions with higher amounts of sporulation under temperatures of 27°C (day) and 22°C (night), as well as high light intensity and low levels of nitrogen fertilization (Toniutti et al, 2017). Salustiano et al (2008) recorded pronounced variation in urediniospore germination and germ tube elongation among 10 H. vastatrix populations tested across a range of temperatures. In Brazil, teliospores of H. vastatrix showed variations in both the size and shape of their basidiospores (Fernandes et al, 2009).…”