Gonzaga
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 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.
Egery
TerminatedLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Azerix
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Ezfilan
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Icedancer
TerminatedLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
3 records
Tigagon
Application submittedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
3 records
Lollopio
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Queenbee
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
4 records
Alfonsina
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Caelius
WithdrawnLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
3 records
Silonis
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Queence
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Bonola
TerminatedLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
5 records
Jaypur
ActiveLactuca sativa L. · Lettuce
MERIDIEM SEEDS S.L.
ES
3 records
Colibry
TerminatedLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Stefina
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records
Rosinski
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
3 records
Este
ActiveLactuca sativa L. · Lettuce
MARALDI SEMENTI S.r.l.
FR
3 records
Vitraï
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records
Sveva
ActiveLactuca sativa L. · Lettuce
Consorzio Sativa Societa Cooperativa Agricola
IT
2 records
Bonor
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Pigale
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Ice Folk
Application submittedLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Rimaya
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records