Snow Mold Fungi in Russia

2013 ◽  
pp. 293-303 ◽  
Author(s):  
Oleg B. Tkachenko
Keyword(s):  
Snow Mold

Polygalacturonase isolated from the culture of the psychrophilic fungus Sclerotinia borealis

1997 ◽  
Vol 43 (5) ◽  
pp. 417-424 ◽  
Author(s):  
Toshihide Takasawa ◽  
Keiko Sagisaka ◽  
Koichi Yagi ◽  
Kyoko Uchiyama ◽  
Atsushi Aoki ◽  
...  
Keyword(s):  
Culture Medium ◽  
Enzyme Reaction ◽  
Wheat Seedling ◽  
Maximum Activity ◽  
Reducing Sugar ◽  
Pectic Acid ◽  
Snow Mold ◽  
Viscosity Change ◽  
Optimum Ph ◽  
Psychrophilic Fungus

A polygalacturonase was isolated from the culture medium of Sclerotinia borealis, a psychrophilic fungus that grows on lawn and wheat seedling under the snow in winter and induces the snow mold disease. Pectic acid was a better substrate of this enzyme than pectin when the activity was determined by measuring the reducing sugar produced. However, when the activity was measured by viscosity change, the viscosity of pectin decreased more rapidly than that of pectic acid. The results of viscosity change apparently indicate that the polygalacturonase catalyzes pectin hydrolysis as an endo-type enzyme. Highly methyl-esterified pectin was a poor substrate, as determined by measurements of reducing sugar production and viscosity change. It is suggested from the results that the methoxy group of pectin affects the polygalacturonase reaction. A reaction mechanism was proposed for the polygalacturonase reaction. Molecular mass of this enzyme was 40 kDa and its isoelectric point was pH 7.5. Optimum pH of the enzyme reaction was 4.5 and its optimum temperature was 40–50 °C. Thirty percent of the maximum activity was observed at 5 °C, but it was only slightly active above 60 °C. The activity was preserved for more than 2 years at 5 °C and pH 4.5, but it was lost when kept at room temperature overnight or heated at 50 °C for 30 min. The amino acid sequence of the N-terminal region of the psychrophilic polygalacturonase of Sclerotinia borealis is compared with those of polygalacturonases of mesophilic fungi. The function of this enzyme against the target plants is discussed with reference to the reaction of polygalacturonases of mesophilic fungi.Key words: polygalacturonase, pectin-hydrolyzing enzyme, psychrophilic fungi, snow mold disease, Sclerotinia borealis.

Susceptibility of endophyte-infected grasses to winter pathogens (snow molds)

2006 ◽  
Vol 84 (7) ◽  
pp. 1043-1051 ◽  
Author(s):  
Piippa R. Wäli ◽  
Marjo Helander ◽  
Oiva Nissinen ◽  
Kari Saikkonen
Keyword(s):  
Field Experiment ◽  
Plant Protection ◽  
Inhibition Zone ◽  
Snow Mold ◽  
Dual Cultures ◽  
Endophyte Infection ◽  
Neotyphodium Endophyte ◽  
Status Interaction

Neotyphodium endophytes are suggested to be mutualistic symbionts of grasses and regarded as potential biological plant protection agents. We examined the effects of the Neotyphodium endophyte of meadow ryegrass on snow molds in vitro with dual cultures of endophyte and Typhula ishikariensis , and on grass–snow mold interactions in vivo in a greenhouse and in a field experiment. In dual cultures, the endophytes formed an inhibition zone and retarded the growth of T. ishikariensis. In the field experiment, however, the endophyte-infected (E+) meadow ryegrasses were more susceptible to T. ishikariensis than the endophyte-free (E–) grasses. Endophyte infection increased the winter damage of grasses both in greenhouse and in field conditions. After winter, the growth of E+ grasses exceeded the growth of E– plants in the field experiment, indicating the marked tolerance of E+ grasses against winter damage. We detected differences in growth and pathogenesis between the different T. ishikariensis strains and found meadow ryegrass cultivar–endophyte status interaction in the growth of meadow ryegrasses, which highlight the effects of the genetic background of the participants on endophyte–grass–snow mold interactions.

Snow Mold

2016 ◽  
Author(s):  
Naoyuki Matsumoto ◽  
Tom Hsiang
Keyword(s):  
Snow Mold

scholarly journals Note on a snow mold and a fungus-like microbe from Kuujjuarapik-Whapmagoostui, Quebec, subarctic Canada

Polar Science ◽  
2020 ◽  
pp. 100559
Author(s):  
Tamotsu Hoshino ◽  
Takuya Nakagawa ◽  
Yuka Yajima ◽  
Masaki Uchida ◽  
Motoaki Tojo
Keyword(s):  
Snow Mold

scholarly journals Pink snow mold in winter cereal crops in Belarus and in the South of Russia

2020 ◽  
Vol 21 ◽  
pp. 00006
Author(s):  
Alexander Zhukovskiy ◽  
Natalia Krupenko ◽  
Yana Yakhnik ◽  
Olga Tarancheva ◽  
Galina Volkova
Keyword(s):  
Weather Conditions ◽  
Cereal Crops ◽  
Disease Development ◽  
The South ◽  
Snow Mold ◽  
Winter Cereal ◽  
Krasnodar Krai ◽  
Spring Period ◽  
Southern Russia ◽  
The Republic

The article presents an analysis of the distribution and development of pink snow mold (pathogen Microdochium nivale (Fr.) Samuels & I.C. Hallett) on winter cereal crops in the Republic of Belarus and in the South of Russia. Pink snow mold is currently one of the most harmful diseases of winter cereal crops, as it can cause damage not only to various parts of the plants, but also lead to their complete death. The intensity of the disease development mainly depends on weather conditions in the autumn-spring period, namely, on the duration of snow cover, its height and the rate of melting in spring. We determined the dependence of the disease development progress on agroclimatic conditions. There is a description of weather conditions in combination with a gradation of the disease development level in the Republic of Belarus and in Krasnodar Krai (southern Russia) during the epiphytotic and depressive years of the pink snow mold development. The article provides a retrospective analysis of the crops infected with pink snow mold and the treated cereal crops in southern Russia in 2011 -2019.

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