Alcira
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.
Lobetina
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 records
Calorice
TerminatedLactuca sativa L. · Lettuce
Vilmorin SA (FR)
FR
HR
3 records
Chiara
ActiveLactuca sativa L. · Lettuce
ISI SEMENTI SPA
NL
3 records
Nisava
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
5 records
Multired 1
TerminatedLactuca sativa L. · Lettuce
Nunhems B.V.
NL
5 records
Semplice
ActiveLactuca sativa L. · Lettuce
BEJO ZADEN
NL
5 records
Pueblo
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 records
Elizium
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer
NL
6 records
Volumia
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Caledonas
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Starsky
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
4 records
Dynamo
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records
Colbiana
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 records
Pereion
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
FR
4 records
Parole
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
7 records
Augita
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Taco
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
6 records
Larsen
ActiveLactuca sativa L. · Lettuce
MORAVOSEED
CZ
3 records
Ivy
Application submittedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
6 records
Tahamata
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
5 records
Claudita
ActiveLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
8 records
Cobain
ActiveLactuca sativa L. · Lettuce
Nunhems B.V., 6083 AB Nunhem
NL
5 records
Litska
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
5 records