HIGHLIGHTS:
Temperatures influenced the mycelial growth and sporulation.
The highest mycelial growth was at 25 and 30 ºC.
Colletotrichum gossypii and Colletotrichum gossypii var. gloeosporioides expressed symptoms in the BRS Cedro cotton cultivar.
ABSTRACT
Considering the importance of identifying Colletotrichum species associated with cotton plants, this study aimed to characterize the morphological and pathogenic isolates of C. gossypii var. cephalosporioides and C. gossypii under different temperatures. Five isolates of C. gossypii var. cephalosporioides and C. gossypii were incubated at 20, 25 and 30 °C. The cultural characteristics data were analyzed through ANOVA and the means compared by the Tukey test. There were differences between the isolates of the two species concerning mycelial growth and sporulation at different temperatures. Temperatures between 20 to 30 °C increased the length of conidia but did not influence the width, whereas between 25 and 30 °C, there was the highest mycelial growth. Colletotrichum gossypii expressed anthracnose symptoms, and ramulosis symptoms were observed only in plants inoculated with C. gossypii var. cephalosporioides.
Key words:
Gossypium spp.; anthracnose; ramulosis