Canadian Forest Service Publications

Effects of amendments, soil moisture contents, and temperatures on germination of pythium sporangia under the influence of soil mycostasis. 1967. Agnihotri, V.P.; Vaartaja, O. Phytopathology 57:1116-1120.

Year: 1967

Issued by: Great Lakes Forestry Centre

Catalog ID: 33105

Language: English

Availability: PDF (request by e-mail)

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fructose, maltose, and particularly sucrose induced high germination of sporangia of Pytllium lI/timllm in soil. Polysaccharides induced some germination, but organic acids did not. Of 20 nitrogen compounds tested, high germination occurred with glutamic acid, yeast extract, and asparagine. No germination occurred in soils amended with sodium nitrate, sodium nitrite, ammonium nitrate, and urea. Germination of sporangia increased when unfavorable carbon and nitrogen sources were combined with glucose. Mixtures of sugars and of amino acids were very effective in stimulating germination. High germination also occurred when parts of different plants were incorporated into soil. With different soil types, percentage germination of sporangia increased in the following order: cultivated soil, forest soil, garden soil, uncultivated soil, nursery soil. Soil amended with glucose induced uniformly high germination at all moisture contents studied (67-85%), although without glucose, germination was reduced at 67% moisture content. When sporangia were germinated in soils amended with glucose within a wide temperature range (10-35 C), the highest germination occurred from 15 to 25 C. In nonamended soil and in many amended soils, lysis occurred in 16-hr-old germ tubes, whereas ungerminated sporangia remained viable. Lysis was prevented by those carbon compounds that were most stimulatory in inducing high sporangial germination, by most amino acids, and by various plant parts. In a cultivated soil, lysis occurred despite glucose amendments.