Diseases

Gray Mold — Head Lettuce

Lactuca sativa L. var. capitata L.

A fungal disease of lettuce caused by Botrytis cinerea, manifested by chlorotic spots and a gray fuzzy mold on leaves and heads. The pathogen leads to tissue softening, while the crop's resistance is quantitative and polygenic in nature.

In the reference 5 varieties crop Head lettuce, where this is mentioned in the description.

The causative agent of the disease is the necrotrophic fungus Botrytis cinerea, which acts as a wound parasite. Primary symptoms include the appearance of yellowish spots on leaves and stems, which progress into necrosis, followed by the development of conidial sporulation in the form of a gray fuzzy mold. The disease is accompanied by the softening and decomposition of tissues, leading to the wilting and destruction of the head during the growing season and in storage.

Unlike specialized lettuce pathogens, B. cinerea has a wide host range and lacks distinct races, which complicates breeding for immunity. The crop's resistance is polygenic and not labeled with specific gene indices. Current research is focused on searching for quantitative trait loci (QTL) and studying regulatory genes, such as LsBOS1 and LsNAC53, responsible for defensive transcriptional rearrangements in plant tissues.

General information about the subject — on the page Grey mold.

Sources8

Varieties of Head 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.