Immensal
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
6 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.
Rosaine
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Roxy
ActiveLactuca sativa L. · Lettuce
ENZA ZADEN
NL
4 records
Lorenzo
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
6 records
Judita
Protection expiredLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
5 records
Brice
ActiveLactuca sativa L. · Lettuce
BEJO ZADEN
NL
7 records
Kireve
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
6 records
Pursuit
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
6 records
Firstkin
ActiveLactuca sativa L. · Lettuce
NUNHEMS
NL
7 records
Kingita
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
10 records
Rockita
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
6 records
Tranvia
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Walha
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan, NL
NL
7 records
Yves
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
7 records
Funfix
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
6 records
Antedis
ActiveLactuca sativa L. · Lettuce
BEJO ZADEN
NL
5 records
Extratos
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
6 records
Theras
ActiveLactuca sativa L. · Lettuce
NUNHEMS
NL
6 records
Azulita
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
7 records
Traper
ActiveLactuca sativa L. · Lettuce
MORAVOSEED
CZ
SK
4 records
Daywalt
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Adelita II
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
7 records
Vidotex
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
8 records
Mesclita
ActiveLactuca sativa L. · Lettuce
Syngenta UK Ltd
NL
7 records