General

The following methodology will be applied in different analyzes and evaluations planned in this project.  

Resistance to pests and diseases in potato

Phytophthora infestans:

Laboratory tests: the modified method used Vleeshouwers et al. (1999) which uses separate and mature leaves grown in greenhouses.

Field Test: The resistance to P. infestans be determined in the field under natural infection or artificial such infection as described by Forbes and Trillos (1993). The evaluation of the disease is estimated obtain the AUDPC (Fry, 1987).    

Agronomic field trials and evaluations: Field trials will be conducted using an enhanced design Petersen (Petersen, 1985) for statistical analysis. The methodology described in Anonymous (2001) shall apply. Agronomic evaluations consider the strength of growth, vegetation cover, plant height, date and intensity of flowering and flower color. In collecting yield components (average weight and number of tubers), shape, color and uniformity of tuber depth of eyes, color of meat and commercial aspect will be evaluated. The cycle, maturation and adaptation long day will also be determined. monitor incidence of diseases and pests will be conducted throughout the growing cycle.  

Abiotic stress resistance Field trials will be conducted in places with adverse weather conditions (see Table 3). Comparing the performance of different inputs, including the reference material will assess adaptation to abiotic stresses. In addition trials shall be conducted in greenhouse to evaluate the level of tolerance to cold and drought.

Cold resistance will be evaluated following the methodology of Chen et al. (1999) and Binder & Fiedler (1996), by measuring chlorophyll fluorescence.

Adaptation to drought is measured as described by Torneaux et al. (2003), measuring the water potential of leaves with a pressure chamber Scholander.  

Post harvest behavior: The methodology is described in section agronomic trials. Analyses include evaluation of dormancy, the number of outbreaks and incidence of damage to crops (pests and diseases), which will be estimated every two weeks for three months in each of the samples stored in the dark and at room temperature. After this period the loss of performance will be evaluated. Besides induction of reducing sugars measured.