CONSERVATION AND UTILIZATION OF POTATO GENETIC RESOURCES
Location: Vegetable Crops Research Unit
Title: Enzimatic Activation Against (Phytophthora Infestans Mont., de Bary) in Solanum Species
Submitted to: American Journal of Potato Research
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2010
Publication Date: February 1, 2011
Citation: Lozoya, H., Cruz, A.J., Leon, M.T., Bamberg, J.B. 2011. Enzimatic Activation Against (Phytophthora Infestans Mont., de Bary) in Solanum Species [abstract]. American Journal of Potato Research. 88:53.
It is assumed that resistance of wild Solanum species to Phytophthora infestans is multigenic on the basis of the exposure of such species to a wide range of pathogenic races of the oomycete. In order to quantify some enzymatic reactions in the host plants to the attack of the pathogen, three resistant and one cultivated, susceptible, Solanum species, were exposed to natural infection by P. infestans in the Toluca valley, México in the summer of 2006. The disease was not observed in the wild species (Solanum microdontum Bitt., S. demissum Buk., and S. pinnatisectum Dun.). In the first one, significant correlations were obtained (P=a< 0.05) between total phenols (FEN) and phenylalanine-ammoniumlyase (PAL) (r=0.93); peroxidase (POX) and superoxyde dismutase (SOD) (r=0.97); and PAL/POX (r=0.79). In S. demissum the correlations with statistical significance were between FEN/PAL (r=0.94) and POX/SOD (r=0.88). In S. pinnatisectum significance was found between FEN/PAL (r=0.81), POX/SOD (r=0.89), and FEN/POX (r=0.95). For S. tuberosum L., susceptible, the disease did not allow the plant to complete its cycle and its enzymatic activity decreased in absolute terms, lower than that of the wild, resistant ones. However, there were significant correlations between FEN/PAL (r=0.97), POX/SOD (r=0.93), and FEN/POX (r=0.93) for S. tuberosum. Enzymatic activity and total phenols increased in the resistant species along the growth cycle, not so in the susceptible. The polygenic defense mechanisms of the wild species included in this study against the oomycete is confirmed.