Resumo

MARES-PONCE DE LEON, Yericka et al. Morphological and molecular identification of Mortierella species associated to rhizosphere of apple trees with symptoms of root diseases. Rev. mex. fitopatol [online]. 2018, vol.36, n.1, pp.184-195. ISSN 2007-8080.  https://doi.org/10.18781/r.mex.fit.1710-2.

Mortierella species were isolated on Potato Dextrose Agar and V8-agar as well as mature pear fruits and azalea leaves as substrate baits. Four hundred and nineteen Mortierella isolates were obtained from soil samples in Chihuahua, Mexico which were classified into 21 groups, according to their morphological characters. Mortierella was isolated more frequently when pear fruits were used, obtaining 143 isolates (34.1%), followed by the V8-agar-antibiotics medium with 133 isolates (31.7%), and azalea leaves with 95 isolates (22.7%). An isolate from each of the 21 groups was identified molecularly, 12 corresponded to Mortierella alpina, one to M. gamsii, one to M. capitata, and six to Mortierella sp., and one belonged to the Mortierelliales order. In addition, the putative pathogenicity of the 21 Mortierella isolates identified was tested in G30 apple rootstocks under greenhouse conditions and none was pathogenic. These species have not been reported previously in Mexico. The study showed that there are Mortierella species in the rhizosphere of apple trees in Chihuahua Mexico. These fungal isolates might produce polyunsaturated fatty acids and exert effects of elicitation in horticultural plants and fruit trees improving their resistance to multiple pathogens.

Palavras-chave : Mortierellales; diversity; substrate baits; isolation medium; pathogenicity.