MYCELIAL GROWTH OF PRE-GERMINATED SPORES OF THE ENDOMYCORRHIZAL FUNGUS GIGASPORA-GIGANTEA IN LIQUID-MEDIUM SUPPLEMENTED WITH NITROGENOUS ORGANIC-COMPOUNDS
Mh. Defreitas et Jo. Siqueira, MYCELIAL GROWTH OF PRE-GERMINATED SPORES OF THE ENDOMYCORRHIZAL FUNGUS GIGASPORA-GIGANTEA IN LIQUID-MEDIUM SUPPLEMENTED WITH NITROGENOUS ORGANIC-COMPOUNDS, Pesquisa agropecuaria brasileira, 29(5), 1994, pp. 751-756
The effects of 14 nitrogenous compounds on mycelial growth of G. gigan
tea spores were evaluated in a liquid medium. Spores were pre-germinat
ed in water-agar and transferred to glass tubes with nutrient liquid m
edium containing one of the following compounds: glycine, histidine, l
eucine, lysine, phenylalanine, asparagine, arginine, cysteine, methion
ine, cystine, proline, aspartic acid, glutamic acid and peptone. Each
compound was added individually to the nutrient basic medium at three
different concentrations. Tubes with spores were incubated at 25-28-de
grees-C for 15 days when mycelial growth was evaluated by grid interse
ction method. The amino acids histidine, cysteine and leucine and pept
one stimulated fungal growth, while phenylalanine and methionine showe
d significant growth inhibition. Growth enhancements were linear for h
istidine, and square-root model for leucine, cystine and peptone. Meth
ionine showed linear inhibition, while phenylalanine exhibited quadrat
ic response. All the other compounds tested showed no significant effe
ct on mycelial growth.