Diseases

Root rots of lettuce

Lactuca sativa L.

A complex of lettuce diseases caused by soil-borne fungi, oomycetes, and bacteria, leading to root system damage, stunted growth, and plant wilting.

In the reference 43 varieties crop Lettuce, where this is mentioned in the description.

The primary causal agents of the disease are Pythium spp., Fusarium oxysporum f. sp. lactucae, Rhizoctonia solani, Aphanomyces cladogamus, Phoma anethi, Alternaria spp., Phytophthora spp., Verticillium spp., as well as specific pathogens Berkeleyomyces rouxiae, B. basicola, and Rhizomonas suberifaciens, which causes corky root rot.

Symptoms include darkening and necrosis of the roots, sliminess of the root system in the case of Pythium, corky texture of the tissues when infected with Rhizomonas, and the formation of dark lesions in black root rot. The presence of Race 1 is known for Fusarium oxysporum f. sp. lactucae.

In breeding for resistance to corky root rot, the recessive gene cor has been identified, and for black root rot, a monogenic dominant trait has been discovered, notably in the cultivar La Brillante.

General information about the subject — on the page Root rots.

Sources8

Varieties of Lettuce mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.