EVALUATION OF PARENTAL VALUE OF POTATO CLONES FOR LATE BLIGHT RESISTANCE

Abstract

One of the most important diseases that limit potato (Solanum tuberosum L.) production is late blight caused by Phytophthora infestans. One of the main decisions to develop resistant cultivars is about which parental materials to use. To study three methods to evaluate the parental value of potato clones in 1988 an evaluation of 59 families formed by open pollination of 59 clones was made üsing three methods, from each of 20 (10 resistant and 10 susceptible) of these clones three families were formed, by open pollination (OP), by pollination with a mixture of polleo from the 20 clones (MP), and by selfing (A). The 60 families were evaluated in a field experiment in 1989. Main results of this study indicate: (1) method A is not appropriate to assess the parental value due to the masking effects of the resulting inbreeding depression; (2) MP was the only one that yielded all families from the 10 resistant clones that were resistant too, and (3) a significant genotype by environment interaction.