Abstract Detail

Mycology

Barrios, Alejandra [1], Velez, Patricia [2].

Concentration of organic carbon and nitrogen as a key element in modelling fungal interactions in cloud forests.

Cloud forests are endangered ecosystems characterized by the presence of fog during most of the year and high precipitation levels. In this system, soil represents a major reservoir of nutrients, contained in both inorganic and organic forms; where mycobiota plays a key role in decomposing the organic fractions of the organic matter (e.g. cellulose, lignin, hemicelluloses, chitin and lipids). For a number of ecosystems, it has been widely acknowledged that the joint effect of biotic interactions and environmental variables, including temperature, moisture, oxygen, nitrogen content, the quality and quantity of available carbon substrates, play a key role influencing decomposition rates. Within the soil several functional microfungal guilds interact, performing essential activities for ecosystem functioning. However, the effect of nutrient conditions in the interactions of microfungal species from assorted functional guilds remains poorly understood, particularly for taxa inhabiting cloud forests. Herein, we evaluated microfungal interactions under contrasting carbon and nitrogen concentrations. Fungal isolates: Clonostachys rosea (phytopathogenic), Diaporthe novem (saprotrophic), Tolypocladium geodes (entomopathogenic) and Trichoderma koningii (mycoparasite), were tested in paired in vitro bioassays, and interaction indexes were calculated. As expected, we observed a reduction in biomass production under carbon and nitrogen depleted conditions. Also, we identified three different types of interspecific interactions (antagonism, cooperation and neutralism). We conclude that nutrients influence fungal interspecific interactions between isolates from different functional guilds. Particularly phytopathogenic fungi predominated in poor conditions in carbon, while mycoparasitic fungi were the most antagonistic under rich carbon and nitrogen conditions, and under poor nitrogen concentrations.
KEY WORDS: microbial interactions, forest dynamics, nutrients

1 - Instituto de Biología, UNAM, Botánica, Cto.Zona Deportiva S/N, C.U., Coyoacán, Ciudad de México, CDMX, 04510, México
2 - Departamento de Botánica, Instituto de Biología, UNAM

Keywords:
microbial interactions
forest dynamics
nutrients
Mycology.

Presentation Type: Poster
Session: MYP2, Mycology Posters II
Location: Virtual/Virtual
Date: Tuesday, July 20th, 2021
Time: 5:00 PM(EDT)
Number: MYP2011
Abstract ID:487
Candidate for Awards:None