Noventa
ActiveLactuca sativa L. · Lettuce
MARALDI SEMENTI S.r.l.
IT
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.
Lovanice
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Lagollo
ActiveLactuca sativa L. · Lettuce
Nunhems B.V.
NL
4 records
Dalila
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Bivouac
ActiveLactuca sativa L. · Lettuce
Monsanto Vegetable IP Management B.V.
FR
3 records
OLOF
TerminatedLactuca sativa L. · Lettuce
Nunhems Zaden BV (NL)
FR
HR
2 records
Jankowski
Application submittedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
3 records
Gido
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Palomis
TerminatedLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Largo
Protection expiredLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
NL
3 records
Crispita
WithdrawnLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
3 records
Gianina
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
3 records
Biwa
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
3 records
Parrales
ActiveLactuca sativa L. · Lettuce
RAMIRO ARNEDO, S.A.
ES
2 records
Cavale
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Quercita
ActiveLactuca sativa L. · Lettuce
MARALDI ANDREA
IT
2 records
Accalon
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records
Tamburo
TerminatedLactuca sativa L. · Lettuce
Nickerson Zwaan
ES
2 records
Vilandry
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Gordini
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Balakai
Application submittedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
3 records
Sesmaria
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Abrivado
Application submittedLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
2 records
Jaïone
ActiveLactuca sativa L. · Lettuce
Vilmorin-Mikado SAS (FR)
FR
3 records