ANALYSIS OF RESISTANCE TO Candidatus Liberibacter solanacearum IN TOMATO GENOTYPES

Abstract

Candidatus Liberibacter solanacearum (CLs) is a bacterium associated with the psyllid yellows disease in tomato (PY), that causes great damage to tomato (Solanum lycopersicum L.) production in México. The use of resistant genotypes is the most sustainable alternative for disease management in plants; however, there are currently no reports of commercial tomato cultivars resistant to CLs. Therefore, the objective of this study was to evaluate the response to infection with CLs in cultivars Rio Grande®, Moctezuma®, Marmande, DRK2180®, La Roca®, Bonny Best® and the advanced line UAS 2016. The evaluation was carried out in Culiacan, Sinaloa, Mexico, in
greenhouse conditions through a randomized complete block design with four replications. Inoculation of CLs was carried out by means of its vector and the expression of the disease in the plant was recorded for seven weeks. Genetic variability of the genotypes was analyzed by using of 15 microsatellites (SSR). Results indicated that the damage by PY in UAS 2016 and Marmande was significantly lower than in Rio Grande® and Moctezuma® while DRK2180®, La Roca® and Bonny Best® showed significant difference in relation to the last cultivar. The total genetic diversity presented a value of 0.58 and a G_ST of 0.30, indicating that the genotypes presented similar genetic variability.