TY - JOUR

T1 - Identification of stable resistance to Phytophthora infestans in potato genotypes evaluated in field experiments in Peru

AU - Wulff, Ednar Gadelha

AU - Pérez, W.

AU - Nelson, R.J.

AU - Bonierbale, M.

AU - Landeo, J.A.

AU - Forbes, G.A.

PY - 2007

Y1 - 2007

N2 - Abstract: In this study, genotype by environment (G x E) interactions and phenotypic stability of resistance to Phytophthora infestans, the cause of late blight, were analysed in Peru lot 13 potato genotypes, using additive main effects and multiplicative interaction (AMMI) analysis and Huehn's non-parametric test. The potato genotypes were tested in seven experiments over two years in the vicinity of Comas, Peru, an area used by the International potato Center to screen for resistance to late blight. Results of the two analyses generally correlated and indicated that quantitative resistance to P. infestans was stable under field conditions for all the genotypes tested. The first two principal components (PCA1 and PCA2) of the AMMI analysis explained 54%. of the G x E interaction sum of squares. A biplot of the two principal components demonstrated a strong year effect in the G x E interaction. By plotting yearly means of the relative area under the disease progress curve (rAUDPC), genotypes could be assigned to one of three resistance categories, resistant, moderately resistant or Susceptible, but the need for a more readily applicable and truly quantitative scale for resistance was noted. Based on these studies, standards can be selected for use in screening in the area where they were tested. After further testing in other locations, a standard set drawn from these genotypes Could be identified and a quantitative scale developed for evaluation of resistance under short day conditions.

AB - Abstract: In this study, genotype by environment (G x E) interactions and phenotypic stability of resistance to Phytophthora infestans, the cause of late blight, were analysed in Peru lot 13 potato genotypes, using additive main effects and multiplicative interaction (AMMI) analysis and Huehn's non-parametric test. The potato genotypes were tested in seven experiments over two years in the vicinity of Comas, Peru, an area used by the International potato Center to screen for resistance to late blight. Results of the two analyses generally correlated and indicated that quantitative resistance to P. infestans was stable under field conditions for all the genotypes tested. The first two principal components (PCA1 and PCA2) of the AMMI analysis explained 54%. of the G x E interaction sum of squares. A biplot of the two principal components demonstrated a strong year effect in the G x E interaction. By plotting yearly means of the relative area under the disease progress curve (rAUDPC), genotypes could be assigned to one of three resistance categories, resistant, moderately resistant or Susceptible, but the need for a more readily applicable and truly quantitative scale for resistance was noted. Based on these studies, standards can be selected for use in screening in the area where they were tested. After further testing in other locations, a standard set drawn from these genotypes Could be identified and a quantitative scale developed for evaluation of resistance under short day conditions.

KW - Former LIFE faculty

KW - LATE BLIGHT

KW - ENVIRONMENT INTERACTION

KW - POPULATIONS

KW - CULTIVARS

KW - STABILITY

KW - YIELD

KW - AGGRESSIVENESS

KW - DISPLACEMENT;

KW - TRIALS

KW - MONT

U2 - 10.1017/S0014479707004991

DO - 10.1017/S0014479707004991

M3 - Journal article

VL - 43

SP - 353

EP - 363

JO - Experimental Agriculture

JF - Experimental Agriculture

SN - 0014-4797

ER -