Thicket
ActiveLactuca sativa L. · Lettuce
Nunhems Netherlands B.V.
NL
10 records
Diseases
Downy mildew of lettuce
Lactuca sativa L.
A fungal disease of lettuce caused by the obligate oomycete Bremia lactucae, characterized by high pathogen variability and the appearance of chlorotic angular spots with sporulation on the underside of leaves.
In the reference 2 007 varieties crop Lettuce, where this is mentioned in the description.
The disease is caused by the oomycete Bremia lactucae Regel, which exhibits high genetic variability. Pathogen populations include numerous physiological races, designated by the code Bl followed by a sequence number, the composition of which is constantly changing, making it difficult to maintain cultivar resistance.
Symptoms appear as chlorotic angular spots on the upper side of the leaf, restricted by veins. On the underside, a characteristic loose whitish, gray, or violet sporulation layer forms. Affected tissues become necrotic, leading to leaf desiccation and stunted seedling growth.
Breeding for resistance is based on the use of Dm-genes (Downy mildew) and quantitative trait loci (QTL). Cultivar resistance is determined by the ability to withstand specific races of the pathogen; however, the effectiveness of protection is limited due to the ability of local Bremia lactucae populations to overcome genetic resistance.
General information about the subject — on the page Downy mildew.
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.
Luceris
ActiveLactuca sativa L. · Lettuce
BEJO ZADEN
NL
4 records
Abrinas
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Digitale
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
6 records
Kerilis
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
4 records
Yoannina
Application submittedLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
5 records
Groovin
Application submittedLactuca sativa L. · Lettuce
Nunhems Netherlands BV
NL
5 records
Helvius
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Firmino
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer
NL
6 records
Freesol
ActiveLactuca sativa L. · Lettuce
Seminis Vegetable Seeds
FR
4 records
Wengen
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Cantrell
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
7 records
Clavelina
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 records
Keona
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Kitsch
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
5 records
Stonsay
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
6 records
Stylist
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 records
Ice Blues
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
6 records
Trival
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
4 records
Suyai
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Azaronas
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Lebrion
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
4 records
Bemole
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
8 records
Blastex
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
7 records