Armonizia
TerminatedLactuca sativa L. · Lettuce
Vilmorin-Mikado S.A.S.
FR
3 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.
Rubygo 1
ActiveLactuca sativa L. · Lettuce
Gautier Semences S.A.S
SV3543LK
ActiveLactuca sativa L. · Lettuce
Monsanto Vegetable IP Management B.V.
FR
3 records
Rubygo 2
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Exenture
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records
Tiktial
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Solagon
TerminatedLactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
NL
4 records
Rubygo I
TerminatedLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Eztoril
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Flouran
TerminatedLactuca sativa L. · Lettuce
Syngenta Seeds B.V.
NL
3 records
Veteran
TerminatedLactuca sativa L. · Lettuce
LARRY D. KNERR
NL
3 records
Pomery
ActiveLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Isasa
ActiveLactuca sativa L. · Lettuce
RAMIRO ARNEDO, S.A.
ES
2 records
Annelie
TerminatedLactuca sativa L. · Lettuce
Novartis Seeds B.V.
NL
3 records
Morfeo
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
3 records
Nazare
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
7 records
Bionda Colosseo 4
ActiveLactuca sativa L. · Lettuce
MINISTERO DELLE POLITICHE AGRICOLE E FORESTALI - DIREZIONE GENERALE DELLE POLITICHE AGRICOLE ED AGROINDUSTRIALI NAZIONALI
IT
2 records
Stratous
Application submittedLactuca sativa L. · Lettuce
Nunhems B.V.
NL
2 records
Clerac
ActiveLactuca sativa L. · Lettuce
Monsanto Vegetable IP Management B.V.
FR
3 records
Ezuma
TerminatedLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Ikarina
ActiveLactuca sativa L. · Lettuce
Syngenta Crop Protection AG
NL
4 records
Agrela
ActiveLactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
NL
4 records
Albanice
TerminatedLactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
FR
2 records
Morrigan
ActiveLactuca sativa L. · Lettuce
MERIDIEM SEEDS S.L.
ES
2 records