Ecological niche of Fusarium poae (Peck.) Wollenw. in Western Siberia
I. G. Vorob’eva1, E. Yu. TOROPOVA2
1Central Siberian Botanical Garden SB RAS, Novosibirsk, Russia
2Novosibirsk State Agrarian University, Novosibirsk, Russia
Keywords: ecological niche, host plant, variety, root rot, competition, interspecific relationships
Abstract
Micromycete F. poae (Peck.) Wollenw. is a dominant member of pathogenic mycocenosis of host plant organs in Western Siberia. The main ecological niche of the first order, where the T and R tactics of the phytopathogen are implemented, are the underground organs of host plants, and the additional ones are generative organs. Implementation of tactics B is carried out in econiches of the second order - soil (main) and seeds (additional). The degree of implementation of the F. poae ecological niche in underground plant organs depends on a number of factors, among which the main role is played by the resistance of the host plant, hydrothermal conditions of vegetation, suppressive soil activity, and interspecific relationships with other phytopathogens. Under certain conditions, F. poae loses its dominance and, by the end of the growing season, can be completely displaced from the underground organs of plants by its competitors Bipolaris sorokiniana Sacc. Shoem. and F. oxysporum Schltdl. The overlap of ecological niches in terms of the frequency of joint occurrence in F.poae was maximum (up to 100 %) with F. oxysporum , which indicates a sharp competitive relationship. Minimal overlap (5-10 %) was found with F. sporotrichioides Sherb. and with F. sambucinum Fuckel. The strength of the influence of the year on the suppressiveness of the rhizosphere soil to F. poae in the phases of plant development varies from 29.2 % to 90.9 % and is statistical significant at the 1 % significance level. The coefficients of correlation between the induction of varieties of soil suppression to F. poae and its representation in pathogenic complexes by vegetation phases were R = -0.546 ± 0.216 … -0.765 ± 0.152 ( p < 0.05). relationship with F. oxysporum , F. solani Koord. and B. sorokiniana , and neutral ones with signs of competition with F. equiseti (Corda) Sacc. and F. sambucinum . The implementation of an additional ecological niche of the first order F. poae in the generative organs of plants was determined by the conditions of the year and the structure of the generative organs.
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