Seasonality and mycorrhizal colonization in three species of epiphytic orchids in southeast Mexico
Cita: Vincenzo Bertolini, Jesús Cruz-Blasi, Anne Damon, Javier Valle Mora. 2014. Seasonality and mycorrhizal colonization in three species of epiphytic orchids in southeast Mexico. Acta Botanica Brasilica. 28 (4). DOI:10.1590/0102-33062014abb3436.
En: Acta Botanica Brasilica. Vol. 28, no. 4(2014)ISSN: 0102-3306
Fecha de realización: 2014/05/31
Tipo: Artículo con arbitraje
Resumen: "Orchids establish symbiosis with
mycorrhizal fungi, forming the characteristic pelotons within the cells of
the root cortex. Under natural conditions, terrestrial and epiphytic orchids have different levels of dependence upon
the fungal symbiont, although various authors have mentioned that once orchid plants reach maturity the interaction
becomes weaker and intermittent. Recent evidence shows that in some epiphytic orchid species mycorrhization is
constant and systematic. In three species of wild orchids from southeast Mexico, we show that mycorrhization is
systematically present in roots of different ages, in the wet and dry seasons. We demonstrate that the volume of the
root that is colonized depends upon the quantity of rainfall and the diameter of the root, and that rainfall also deter-
mines the presence of fresh, undigested pelotons. In very thin roots, mycorrhizal colonization occupies a considerable
proportion of the cortex, whereas in thicker roots the proportion of the volume of the root cortex colonized is lower."