F4 families of crispleaf lettuce with tolerance to early bolting and homozygous for resistance to Meloidogyne incognita race 1

Abstract

The objective of this study was to evaluate yield, commercial characteristics, tolerance to early bolting and resistance to the root-knot nematode Meloidogyne incognita race 1 in 25 F4 families of crispleaf lettuce, obtained out of crosses between cultivars Grand Rapids, Regina 71, and Verônica. In the first experiment, we evaluate leaf blade and borders characteristics, aboveground fresh weight, and number of days from sowing to the anthesis of first flower (tolerance to early bolting). In the second experiment, we evaluated the resistance to Meloidogyne incognita race 1 via gall index and number of galls and egg masses per root system. Five families had scores for leaf blade and borders similar to cultivars Verônica and Grand Rapids. Furthermore, 84% of the families were as tolerant to early bolting as cultivar Veronica, while 92% of the families were homozygous for resistance to Meloidogyne incognita race 1.