Abstract
Leaf spot of carrot, caused by the fungus Alternaria dauci , is a common disease of carrot throughout the world. To assess the disease response in different genotypes an in vitro method of assay has been developed. The terminal portion of excised mature leaves from carrot are incubated under lights at 25–26°C for 6 days with spores of A. dauci . After 6 days, chlorophyll and total soluble polyphenol contents of the leaves decline to a low level, whereas in the uninoculated control leaves levels of these compounds are largely unchanged. Electron microscope studies of the effect of infection on the ultrastructure of leaves from both cv. Fancy and wild plants show disintegration of the cell wall, plasmalemma and chloroplast membranes in the region close to the invading fungus. The response to A. dauci shows characteristics compatible with the presence of a phytotoxin. Seedling hypocotyls of the carrot cv. Fancy are used as a source of explants to initiate callus tissue and regenerate embryos. Regenerant somaclone plants show variation in morphology (crown number, height, leaf number, leaf shape and flowering time) and susceptibility to the pathogen as measured by the loss in chlorophyll from infected detached leaves after a 6‐day period. Potentially susceptible and resistant regenerant plants are identified by the low and high chlorophyll levels, respectively, in excised leaves 6 days after infection. Selected high‐ and low‐chlorophyll regenerant plants and seedling‐derived cv. Fancy are self‐pollinated, then the seeds are used to produce a progeny generation, which is assessed for morphological changes and disease resistance as before. The response of leaves of progeny plants to infection shows that the plants derived from high‐chlorophyll regenerants still show a higher chlorophyll level after infection compared with leaves derived from low‐chlorophyll and control plants. High chlorophyll levels in the presence of infection in the progeny of high‐chlorophyll regenerants suggest that the capacity to resist infection in the selected somaclones is inherited.
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Claims 10
Claim · model-written summary
An excised-leaf assay was developed to assess carrot disease response.
- Taxon
- carrot
Daucus carotat0 - Outcome
- method of assaye0
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Disease response of carrot and carrot somaclones to Alternaria dauci”
e0“an in vitro method of assay has been developed”
Claim · model-written summary
Infected carrot leaves lost chlorophyll and total soluble polyphenols after six days.
- Taxon
- carrotDaucus carotat0
- Organ / stage
- leavese0
- Treatment
- infectede1
- Interactor
- Alternaria dauciAlternaria daucit0pathogen
- Outcome
- chlorophyll and total soluble polyphenol contentse0
- Direction
- declinee0
- Comparator
- uninoculated control leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Disease response of carrot and carrot somaclones to Alternaria dauci”
e0“After 6 days, chlorophyll and total soluble polyphenol contents of the leaves decline to a low level, whereas in the uninoculated control leaves levels of these compounds are largely unchanged”
e1“susceptibility to the pathogen as measured by the loss in chlorophyll from infected detached leaves after a 6‐day period”
Claim · model-written summary
Uninoculated carrot leaves retained chlorophyll and polyphenol levels.
- Taxon
- carrotDaucus carotat0
- Organ / stage
- leavese0
- Outcome
- levels of these compoundse0
- Direction
- largely unchangede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Disease response of carrot and carrot somaclones to Alternaria dauci”
e0“in the uninoculated control leaves levels of these compounds are largely unchanged”
Claim · model-written summary
Infection disintegrated cell wall, plasmalemma and chloroplast membranes near the fungus in Fancy and wild carrot leaves.
- Taxon
- carrotDaucus carotat0
- Material
- cv. Fancy and wild plantse0
- Interactor
- Alternaria dauciAlternaria daucit0pathogen
- Outcome
- disintegration of the cell wall, plasmalemma and chloroplast membranese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Disease response of carrot and carrot somaclones to Alternaria dauci”
e0“Electron microscope studies of the effect of infection on the ultrastructure of leaves from both cv. Fancy and wild plants show disintegration of the cell wall, plasmalemma and chloroplast membranes in the region close to the invading fungus”
Claim · model-written summary
The carrot response to A. dauci was compatible with a phytotoxin.
- Taxon
- carrotDaucus carotat0
- Interactor
- A. dauciAlternaria daucie0pathogen
- Outcome
- response to A. daucie0
- Qualifier
- compatible with the presence of a phytotoxine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Disease response of carrot and carrot somaclones to Alternaria dauci”
e0“The response to A. dauci shows characteristics compatible with the presence of a phytotoxin”
Claim · model-written summary
Regenerant carrot somaclones varied in morphology.
- Taxon
- carrotDaucus carotat0
- Material
- Regenerant somaclone plantse0
- Outcome
- variation in morphologye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Disease response of carrot and carrot somaclones to Alternaria dauci”
e0“Regenerant somaclone plants show variation in morphology (crown number, height, leaf number, leaf shape and flowering time)”
Claim · model-written summary
Regenerant carrot somaclones varied in susceptibility to the pathogen.
- Taxon
- carrotDaucus carotat0
- Interactor
- Alternaria dauciAlternaria daucit0pathogen
- Outcome
- susceptibility to the pathogene0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Disease response of carrot and carrot somaclones to Alternaria dauci”
e0“susceptibility to the pathogen as measured by the loss in chlorophyll from infected detached leaves after a 6‐day period”
Claim · model-written summary
High-chlorophyll regenerants were identified as potentially resistant and low-chlorophyll regenerants as potentially susceptible.
- Taxon
- carrotDaucus carotat0
- Interactor
- Alternaria dauciAlternaria daucit0pathogen
- Outcome
- susceptible and resistant regenerant plantse0
- Comparator
- low and high chlorophyll levelse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Disease response of carrot and carrot somaclones to Alternaria dauci”
e0“Potentially susceptible and resistant regenerant plants are identified by the low and high chlorophyll levels, respectively, in excised leaves 6 days after infection”
Claim · model-written summary
Progeny of high-chlorophyll regenerants retained higher chlorophyll after infection than progeny of low-chlorophyll and control plants.
- Taxon
- carrotDaucus carotat0
- Material
- high‐chlorophyll regenerantse0
- Interactor
- Alternaria dauciAlternaria daucit0pathogen
- Outcome
- chlorophyll levele0
- Direction
- highere0
- Comparator
- low‐chlorophyll and control plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Disease response of carrot and carrot somaclones to Alternaria dauci”
e0“plants derived from high‐chlorophyll regenerants still show a higher chlorophyll level after infection compared with leaves derived from low‐chlorophyll and control plants”
Claim · model-written summary
Resistance capacity in selected carrot somaclones appeared inherited.
- Taxon
- carrotDaucus carotat0
- Material
- selected somaclonese0
- Interactor
- Alternaria dauciAlternaria daucit0pathogen
- Outcome
- capacity to resist infectione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Disease response of carrot and carrot somaclones to Alternaria dauci”
e0“High chlorophyll levels in the presence of infection in the progeny of high‐chlorophyll regenerants suggest that the capacity to resist infection in the selected somaclones is inherited”
The same questions in other papers
infection · Alternaria dauci · Daucus carota (carrot)Positive and negative results
1 paper in the same direction as this paper · 1 in the opposite direction
- positive
- negative
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.