Resumen

PEREZ-CORRAL, Daniel Alonso et al. Isolation of actinomycetes associated to apple trees rhizosphere antagonistic to Fusarium equiseti. Rev. Mex. Cienc. Agríc [online]. 2015, vol.6, n.7, pp.1629-1638. ISSN 2007-0934.

Apple trees Malus domestica Borkh are susceptible to attacks from a wide variety of pathogens, among which are the fungi that cause root diseases, which are controlled with synthetic fungicides. However, due to its indiscriminate application, its effectiveness and use has declined.An alternative to reverse this problem is biological control, through the integration of antagonistic microorganisms, so the aim of the study was to isolate native actinomycetes from apple orchards soils in the state of Chihuahua, Mexico, with antagonistic activity to Fusarium equiseti. The study was conducted at the Centro de Investigación enAlimentación y Desarrollo, A. C. (CIAD), Unit Cuauhtemoc, Chihuahua during 2013-2014. For this purpose, soil samples near the rhizosphere from apple trees in orchards from four producing municipalities in the state of Chihuahua were collected. For isolation of actinomycetes, serial dilutions of the soil samples in sterile peptone water were made and then poured on a plate by the diffusion method, on ten semi-selective mediums, were made. Actinomycetes colonies were isolated and purified, and then be confronted in vitro against phytopathogenic fungus F. equiseti. 710 isolates were obtained, from which 222 had antagonistic activity to the phytopathogenic fungus at day 5 after confrontation and 69 retained antagonisms to day 10 post-confrontation. The high abundance of isolates and the proportion that showed antagonism to F. equiseti, shows the potential and the opportunity to evaluate them in vitro and in vivo against a wide variety of plant pathogenic fungi and bacteria from apple and other crops of agricultural interest.

Palabras llave : Malus domestica; Streptomyces spp.; antagonism; phytopathogenic fungi; rhizosphere.