LEAF SYMPTOMS, BIOMASS AND TUBER QUALITY OF POTATO GENOTYPES INOCULATED WITH Candidatus Liberibacter solanacearum

Abstract

Potato varieties (Solanum tuberosum L.) produced in Mexico are sensitive to Candidatus Liberibacter solanacearum (CaLso), which produces the disease known as ‘Zebra chip’; thus, it is necessary to know the response of experimental genotypes to the bacterium. The aim of this study was to evaluate the effect of the infection of the LsoA + LsoB CaLso haplotypes on foliage, dry biomass and tuber quality of potato cv Fianna, an accession of Solanum demissum and experimental clones T90-1-63 and T05-13-21 of Solanum spp. Internal browning of tuber pulp was determined by tuber image analysis. Fianna plants showed the highest severity of leaf damage, while the experimental clones presented 17 % less leaf damage than Fianna and 8 % more leaf damage than S. demissum. The latter was the genotype with the highest dry leaf biomass and produced tubers of a small size; the infected plants of S. demissum produced a higher number of tubers and higher tuber fresh weight than non-inoculated plants; however, they had the lowest proportion of healthy tuber surface. Clone T90-1-63 showed the highest percentages of healthy tuber surface (> 79 %) and the lowest internal browning intensity of the tuber pulp.