Seneca
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel 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.
Tirole
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
9 records
Ofelia
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
5 records
Exfiles
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
7 records
Bloomquist
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
7 records
Humboldt
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Elfos
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
7 records
Sadawi
ActiveLactuca sativa L. · Lettuce
ENZA ZADEN
NL
4 records
Guayabita
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Lianabel
ActiveLactuca sativa L. · Lettuce
Bejo Zaden, NL
NL
9 records
Minestrone
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
5 records
Ice Palace
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
7 records
Recilia
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
6 records
Xavier
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
7 records
Clearwater
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
7 records
Albara
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
7 records
Lilybel
ActiveLactuca sativa L. · Lettuce
BEJO ZADEN
NL
10 records
Canagio
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
7 records
Antonet
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
7 records
Yacht
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Pivotal
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
8 records
Barcia
ActiveLactuca sativa L. · Lettuce
NUNHEMS
NL
6 records
Krilda
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
5 records
Lukasz
ActiveLactuca sativa L. · Lettuce
NUNHEMS
NL
7 records