The reaction to the fungus Phytophthom infestans in the foliage of wild species and cultivated Chilean varieties and seedlings of potatoes was studied in the Plant Pathology Laboratory of the Potato Experiment Station, Bogotá, Colombia.
In the study of the wild species, the fungus Phytophthora infestans, was isolated and cultivated according to the technic of Dickison and Keay.
The plants were inoculated with sporangia suspensions obtained in laboratory cultures. All the wild species reacted as very susceptible, this reaction being more severe in the species Solanum palustre.
The cultivated varieties and seedlings were tested against natural infection in the fielddue to the raceor race-complex of Phytophthora infestans present in the Sabana de Bogotá and the Páramo de Usme. All of the varieties reacted as susceptible.
An investigation on reaction to late blight that was carried on at Castelar, Argentina is mentioned. It included (besides other materia), 134 Chilean cultivated potatoes from the Centinela collection and from Chiloé, 34 Centinela seedlings, Cunca, C 57-28, Mantequilla 181, Mantequilla 182, and Corahila larga. All of these Chilean potatoes reacted as susceptibie to the late blight in poth the leaves and the stems.
A report is given on new breeding material from Colombia which was planted in the Centinela Potato Experiment Station and which is expeeted to combine resistance to late blight with other important agronomic characteristics.
This material includes six ipterspecificcrosses between S. demissum x S. andigenum var. tuquerreña, one seedling from a backcross of S.tuberosum x S. demissum and 8 family lines of S. demissum x S. tuberosum. |
ChileanJAR
