Abstract

LEYVA MIR, Santos Gerardo et al. Histopathology of Pinus patula Schiede ex Schltdl. et Cham. And Pinus pseudostrobus Lindl. roots infected by Phytophthora cinnamomi Rands, 1922. Rev. mex. de cienc. forestales [online]. 2016, vol.7, n.38, pp.67-77. ISSN 2007-1132.

Phytophthora cinnamomi is one of the most devastating plant pathogens worldwide, since it causes root rot and death of many plant species. The aim of this study was to determine the histological damage induced by this organism in roots of Pinus patula and P. pseudostrobus. Both Pinus species were inoculated by immersion of roots in a suspension of mycelial fragments. Roots of control trees were immersed in sterile distilled water. Root samples were taken every four days after inoculation for 20 days. Microscopic symptoms occurred more rapidly in P. pseudostrobus, although the two species exhibited fragile and necrotic roots. Also, the histological changes at the root of both species were presented with an increase in polyphenol content, degradation of cell walls and necrosis of the periderm. In the case of P. patula, plants showed wilting of the canopy, followed by a yellowing of needles and finally with the death of the tree. For P. pseudostrobus symptoms were similar, but in this case the decay of needles was gradual and subsequently wilt thereof was observed until the total death of the tree.

Keywords : Anatomic changes; oomycete; pathogenicity; Phytophthora cinnamomi Rands; 1922; Pinus patula Schiede ex Schltdl. Et Cham.; Pinus pseudostrobus Lindl.