出版社：Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul
摘要：Bipolaris sorokiniana is a phytopathogen of great importance on the wheat
culture regions, causing diseases such as spot blotch, common root rot and back
point of bthe grain. This fungus is widely distributed over the country and is
responsible for a great loss on the production and commercialization of the
grain. It has a high physiological and morphological variability what makes the
development of control measures a difficult task. The aim of this work was to
verify the influence of different culture media over this variability. For that,
21 isolates of B. sorokiniana were selected and from them polysporic and
monosporic cultures were obtained. The morphological aspects such: coloration,
edge, superficial texture aerial mycelium and color, and shape of the sectors;
and the growth rate of the isolates were analyzed in four different media:
potato dextrose agar (PDA), Sabouraud maltose, Sabouraud galactose and Sabouraud
glucose. The monosporic cultures did not present significant difference in the
growth rate among the different media. However, a small morphologic variation,
as well as on the repetitions of the isolates in the same medium was obtained.
By the other hand, polysporic cultures showed an high morphologic variability
among the four media and also the morphologic variability was evident even in
the repetitions of one isolate, in the same medium. Comparing monosporic and
polysporic cultures, considering the growth rate, a significant difference
(p< 0.05) was found in Sabouraud maltose and Sabouraud galactose media, for
the polysporic cultures. However, no significant difference was observed in the
monosporic cultures.
关键词：Bipolaris sorokiniana , physiological variability, morphology,
monoconidial and polyconidial culture
