|
Laboratory
Evaluation of Lettuce Seedlings ABNORMAL
SEEDLING DESCRIPTION
Association of Official
Seed Analysts (AOSA),
Seedling Evaluation Handbook
Description of
abnormal lettuce seedlings tested for 7 days at constant 68°F.
Cotyledons
- less than half of the original cotyledon tissue remaining
attached.
- less than half of the original cotyledon tissue free of
necrosis or decay.
Epicotyl
- missing (may be assumed to be present if cotyledons are
intact).
- any degree of necrosis or decay.
Hypocotyl
- deep open cracks extending into the conducting tissue.
- severely twisted or grainy.
- watery.
Root
- none.
- primary root tip blunt, swollen and discolored.
- primary root with splits or lesions.
Seedling
- swollen cotyledons associated with extremely short or
vestigial hypocotyl and root.
- one or more essential structures impaired as a result of decay
from primary infection.
- albino.
|
