Abstract

PARGA TORRES, Víctor Manuel et al. Evaluation, Selection and Characterization of Potato Genotypes Tolerant to Purple Top Syndrome. Rev. mex. fitopatol [online]. 2011, vol.29, n.1, pp.15-24. ISSN 2007-8080.

Potato commercial yield reduction due to purple top syndrome in northeastern Mexico can reach up to 90% and sometimes losses can be total due to internal staining of the tubercles. A total of 214 genotypes were established during 2006 in Arteaga, Coah., Mexico, in order to evaluate and characterize their tolerance to the syndrome, and select those that had tolerance revealed as no vectors control were performed. The evaluated parameters were: height, foliage coverage, days to onset symptoms, days to plant death, onset of symptoms to death of the plant, total production of tubercles per plant, number of tubercles with internal staining per plant and sprouting of the plant, which were analyzed by multivariate statistical methods. The first three main components explained 76.8% of the total variance, separating first the producing genotypes from those non-producing; and second, the later with a higher coverage and lower thread outbreak from those with opposite characteristics. A total of three groups were identified by the cluster analysis: the first with 114 genotypes that did not produce tubercles, which had the symptoms revealed earlier and died. The second group, with 53 genotypes of greater tolerance, which had the highest average yield of tubercles per plant. The third with 47 genotypes, which had late manifestation of onset symptoms, had a wider range to wilt and a low production. The presence of bacteria, viruses and phytoplasm was detected in the tuber. The genotypes Gigant, Alpha, Norteña, Bayonera, Nieder, Atlantic and the clones 91-29-10, 98-14-01, 94-02-01 and 96-01-01 were selected based on their production or the absence of internal staining, even if the vectors were not controlled.

Keywords : Solanum tuberosum; purple top; production; agronomical characteristics.