Katusa
ActiveLactuca sativa L. · Lettuce
NUNHEMS
NL
9 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.
Ozwald
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
10 records
Templin
ActiveLactuca sativa L. · Lettuce
Nunhems B.V., Nunhems B.V.
NL
8 records
Grenadine
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
8 records
Tendita
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
9 records
Ice Hielo
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
8 records
Barcelona
ActiveLactuca sativa L. · Lettuce
NUNHEMS ZADEN B.V.
NL
7 records
Malenita
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan, NL
NL
8 records
Capitan
TerminatedLactuca sativa L. · Lettuce
S&G SEEDS B.V.
ES
FR
NL
6 records
Tevion
ActiveLactuca sativa L. · Lettuce
Enza Zaden, NL
NL
11 records
Galatea
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Xapia
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
7 records
Ezra
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
7 records
Crackita
ActiveLactuca sativa L. · Lettuce
Syngenta UK Ltd
NL
7 records
Jonction
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
5 records
Insignia
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
7 records
Alpinas
ActiveLactuca sativa L. · Lettuce
RIJK ZWAAN Z.Z. B.V.
ES
4 records
Asmara
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
8 records
Redflash
ActiveLactuca sativa L. · Lettuce
NAPOLEONSWEG 152
NL
5 records
Albanas
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Tamarindo
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
7 records
Rawley
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Vindicate
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
7 records
Drake
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records