Sefana
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 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.
Jessica
ActiveLactuca sativa L. · Lettuce
Panora s.p.a.
FR
NL
5 records
Silvana
ActiveLactuca sativa L. · Lettuce
ANIELLO ANTONIO CUTOLO FILHO / KATIA REGIANE BRUNELLI BRAGA / ROMULO FUJITO KOBORI_
NL
3 records
Lucbee
ActiveLactuca sativa L. · Lettuce
Nunhems B.V., 6083 AB Nunhem
NL
5 records
Octo
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 records
Alamer
ActiveLactuca sativa L. · Lettuce
MORAVOSEED
CZ
3 records
Takoda
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 records
Crispagio
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
7 records
Carterham
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
6 records
Casey
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer
NL
7 records
Arganda
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Colanzi
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
8 records
Hungarina
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
4 records
Mathix
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
6 records
Kismy
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 records
Quefir
TerminatedLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
4 records
Aferdita
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 records
Vladan
TerminatedLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
5 records
Kinesic
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Matute
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Faramir
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer
NL
6 records
Tokapie
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
4 records
Treslia
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
6 records
Pacification
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
5 records