Agronomic potential of biofortified crisphead lettuce (Lactuca sativa) and its reaction to Root-knot nematodes

Lettuce is the most-consumed leafy vegetable in Brazil due to its ease of preparation, nutritional quality, and affordability. Despite these benefits, there are few cultivars of crisphead lettuce ('Lactuca sativa') that possess agronomic potential, high carotenoid content and resistance to nematodes. Therefore, we evaluated the agronomic potential of crisphead lettuce genotypes that are resistant to the root-knot nematode. The experiment was conducted at the Vegetable Experiment Station of the Federal University of Uberlandia (UFU), Monte Carmelo Campus. The trial was set up in a randomized block design with 49 treatments (43 genotypes obtained from crosses between Uberlandia 10000 and Belissima and six commercial cultivars) and three replications. After preparing the beds and before transplanting the seedlings, 11 simple samples were taken from each of the three experimental blocks to confirm the presence of nematodes within the experimental area. The following variables were determined 48 days after transplanting: chlorophyll content, leaf temperature, plant diameter, number of leaves per plant, fresh mass and incidence of root gall. The data were submitted to analysis of variance (ANOVA) and an F-test and the means were compared by the Scott-Knott test. Genetic diversity was represented by a dendrogram that was obtained using the hierarchical method of UPGMA and the optimization method of Tocher. We found genetic divergence and agronomic potential among the evaluated genotypes. Specifically, 199#1#1-E, 199#2#1-E, 199#2#2-E, 199#3#1-E, 199#6#1-E and 75#2#2-E presented good agronomic potential, were rich in carotenoids and showed resistance to the root-knot nematode.