Abstract

MUNOZ-MARQUEZ, Ezequiel et al. Identification and Natural Colonization of Mycorrhizal Arbuscular Fungi in Pecan Orchards. Terra Latinoam [online]. 2009, vol.27, n.4, pp.355-361. ISSN 2395-8030.

The objective of the present study was to determine the degree of natural mycorrhizal colonization, as well as to identify, to the genus level, native arbuscular mycorrhizal fungi associated with roots of bearing pecans [Carya illinoinensis (Wangenh.) C. Koch]. Three pecan orchards, El Maguey, La Esmeralda and La Fama, from the area Delicias-Rosales in Chihuahua, Mexico, were evaluated. We collected segments of mycorrhizal roots located within the tree drip line in order to evaluate the percentage of natural colonization and identify the fungi. The El Maguey orchard had the highest degree of arbuscular mycorrhization compared with that of the La Fama and La Esmeralda orchards, with a fluctuation of 13 to 32% through the different months of the year. Crop conditions at the orchard El Maguey, including a well aerated and humid soil, use of natural cover of grasses and drip irrigation, and incorporation of soil amendments, favored mycorrhization. Most sampled roots were located at a soil depth of 5 to 35 cm in the orchards studied. Vesicles, spores and mycelium typical of arbuscular mycorrhizal were found in roots from the pecan orchards studied. The genera of arbuscular mycorrhizal fungi found in association with pecan roots in these orchards were Glomus and Gigaspora; in addition, a species of arbuscular mycorrhizal fungi, Glomus sinuosum, was identified; this is the first study to report mycorrhyzal arbuscular fungi associated with pecan roots in the Delicias and Rosales region in the state of Chihuahua.

Keywords : Carya illinoensis; mycorrhizal arbuscular; pecan three.