Abstract
SUMMARY Culture filtrates of Leptosphaeria maculans (Desm.) Ces. & De Not. inhibited the germination of seeds of Brassica napus ssp. oleifera (Metzg.) Sinsk., winter oilseed rape. The toxicity of filtrates was broadly correlated with the pathogen icily of the isolates of L. maculans from which they were obtained, and the sensitivity of seeds of different cultivars was broadly correlated with the known resistances ot those cultivars to the fungus. Culture filtrates of B. maculans , when incorporated into culture media, were also toxic to secondary embryoids of B. napus ssp. oleifera , as also was Sirodesmin P.L., a putative pathotoxin of L. maculans. Variation for the ability to grow in culture in the presence of toxic levels of culture filtrate and Sirodesmin P. L. was detected among populations of secondary embryoids, and the proportion of resistant embryoids present in the population was increased by successive rounds of re‐selection on toxic, selective media. However, when embryoids were removed to non‐selective media, resistance to toxic culture filtrates and to Sirodesmin P.L. was rapidly lost. Plants regenerated from secondary embryogenic lines selected for resistance to toxic culture filtrate or Sirodesmin P.L. were no more resistant to infection by L. maculans then were plants regenerated from unselected, control secondary embryoids, and were consistently more susceptible than were plants grown from seed. It was concluded, firstly, that the rate of stable, heritable somatic variation may be insufficiently high in the secondary embryogenic lines to he of value in attempts to select in vitro for novel resistance to L. maculans secondly, that although the seed germination tests indicated that toxic culture filtrates may have potential as screening agents for detecting novel resistance to L. maculans in vitro , no evidence in support of this view was obtained in the experiments with secondary embryoids; and, finally, that because a relatively high level of resistance to L. maculans already exists in cultivars of H. napus ssp. oleifera , any novel variation m disease reaction that does occur m secondary embryogenic lines is likely to be towards greater susceptibility rather than increased resistance.
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Claims 14
Claim · model-written summary
Leptosphaeria filtrates inhibited oilseed rape seed germination.
- Taxon
- Brassica napus ssp. oleifera
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Brassica napus var. napuse0 - Treatment
- Culture filtrates of Leptosphaeria maculanse0
- Interactor
- Leptosphaeria maculans
Plenodomus lingame0pathogen - Outcome
- germination of seedse0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Culture filtrates of Leptosphaeria maculans (Desm.) Ces. & De Not. inhibited the germination of seeds of Brassica napus ssp. oleifera (Metzg.) Sinsk., winter oilseed rape.”
Claim · model-written summary
Filtrate toxicity broadly correlated with isolate pathogenicity.
- Taxon
- Brassica napus ssp. oleiferaBrassica napus var. napust0
- Interactor
- L. maculansPlenodomus lingame0pathogen
- Outcome
- toxicity of filtratese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“toxicity of filtrates was broadly correlated with the pathogen icily of the isolates of L. maculans from which they were obtained”
t0“Brassica napus ssp. oleifera”
Claim · model-written summary
Cultivar seed sensitivity broadly correlated with known fungal resistance.
- Taxon
- Brassica napus ssp. oleiferaBrassica napus var. napust0
- Material
- different cultivarse0
- Outcome
- sensitivity of seedse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“sensitivity of seeds of different cultivars was broadly correlated with the known resistances ot those cultivars to the fungus.”
t0“Brassica napus ssp. oleifera”
Claim · model-written summary
B. maculans culture filtrates were toxic to secondary embryoids.
- Taxon
- B. napus ssp. oleiferaBrassica napus var. napuse0
- Treatment
- Culture filtrates of B. maculanse0
- Interactor
- B. maculanse0pathogen
- Outcome
- toxic to secondary embryoidse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Culture filtrates of B. maculans , when incorporated into culture media, were also toxic to secondary embryoids of B. napus ssp. oleifera”
Claim · model-written summary
Sirodesmin P.L. was toxic to secondary embryoids.
- Taxon
- B. napus ssp. oleiferaBrassica napus var. napuse0
- Treatment
- Sirodesmin P.L.e0
- Outcome
- toxic to secondary embryoidse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“toxic to secondary embryoids of B. napus ssp. oleifera , as also was Sirodesmin P.L.”
Claim · model-written summary
Embryoid populations varied in ability to grow under toxic filtrate and Sirodesmin P. L.
- Taxon
- Brassica napus ssp. oleiferaBrassica napus var. napust0
- Organ / stage
- secondary embryoidse0
- Outcome
- ability to grow in culturee0
- Qualifier
- toxic levels of culture filtrate and Sirodesmin P. L.e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Variation for the ability to grow in culture in the presence of toxic levels of culture filtrate and Sirodesmin P. L. was detected among populations of secondary embryoids”
t0“Brassica napus ssp. oleifera”
Claim · model-written summary
Successive reselection increased the resistant embryoid proportion.
- Taxon
- Brassica napus ssp. oleiferaBrassica napus var. napust0
- Treatment
- successive rounds of re‐selection on toxic, selective mediae0
- Outcome
- proportion of resistant embryoidse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“proportion of resistant embryoids present in the population was increased by successive rounds of re‐selection on toxic, selective media.”
t0“Brassica napus ssp. oleifera”
Claim · model-written summary
Resistance to toxic filtrates was rapidly lost after transfer to nonselective medium.
- Taxon
- Brassica napus ssp. oleiferaBrassica napus var. napust0
- Treatment
- removed to non‐selective mediae0
- Outcome
- resistance to toxic culture filtratese0
- Direction
- loste0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“when embryoids were removed to non‐selective media, resistance to toxic culture filtrates and to Sirodesmin P.L. was rapidly lost.”
t0“Brassica napus ssp. oleifera”
Claim · model-written summary
Resistance to Sirodesmin P.L. was rapidly lost after transfer.
- Taxon
- Brassica napus ssp. oleiferaBrassica napus var. napust0
- Treatment
- removed to non‐selective mediae0
- Outcome
- resistance to toxic culture filtrates and to Sirodesmin P.L.e0
- Direction
- loste0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“when embryoids were removed to non‐selective media, resistance to toxic culture filtrates and to Sirodesmin P.L. was rapidly lost.”
t0“Brassica napus ssp. oleifera”
Claim · model-written summary
Selected regenerated plants were no more resistant to L. maculans than unselected regenerated plants.
- Taxon
- PlantsViridiplantaee0
- Treatment
- selected for resistance to toxic culture filtrate or Sirodesmin P.L.e0
- Interactor
- L. maculansPlenodomus lingame0pathogen
- Outcome
- resistant to infection by L. maculanse0
- Direction
- no more resistante0
- Comparator
- plants regenerated from unselected, control secondary embryoidse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plants regenerated from secondary embryogenic lines selected for resistance to toxic culture filtrate or Sirodesmin P.L. were no more resistant to infection by L. maculans then were plants regenerated from unselected, control secondary embryoids”
Claim · model-written summary
Selected regenerated plants were consistently more susceptible than seed grown plants.
- Taxon
- Brassica napus ssp. oleiferaBrassica napus var. napust0
- Treatment
- selected for resistance to toxic culture filtrate or Sirodesmin P.L.e0
- Outcome
- susceptiblee0
- Direction
- more susceptiblee0
- Comparator
- plants grown from seede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plants regenerated from secondary embryogenic lines selected for resistance to toxic culture filtrate or Sirodesmin P.L. were no more resistant to infection by L. maculans then were plants regenerated from unselected, control secondary embryoids, and were consistently more susceptible than were plants grown from seed.”
t0“Brassica napus ssp. oleifera”
Claim · model-written summary
Authors conclude stable heritable somatic variation may be too rare for in vitro resistance selection.
- Taxon
- Brassica napus ssp. oleiferaBrassica napus var. napust0
- Outcome
- rate of stable, heritable somatic variatione0
- Direction
- insufficiently highe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“rate of stable, heritable somatic variation may be insufficiently high in the secondary embryogenic lines to he of value in attempts to select in vitro for novel resistance to L. maculans”
t0“Brassica napus ssp. oleifera”
Claim · model-written summary
Seed germination tests suggested filtrates might screen novel resistance, but embryoid experiments did not support it.
- Taxon
- Brassica napus ssp. oleiferaBrassica napus var. napust0
- Outcome
- screening agents for detecting novel resistancee0
- Comparator
- experiments with secondary embryoidse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“toxic culture filtrates may have potential as screening agents for detecting novel resistance to L. maculans in vitro , no evidence in support of this view was obtained in the experiments with secondary embryoids”
t0“Brassica napus ssp. oleifera”
Claim · model-written summary
Authors infer novel disease variation in embryogenic lines would likely increase susceptibility.
- Taxon
- Brassica napus ssp. oleiferaBrassica napus var. napust0
- Outcome
- disease reactione0
- Direction
- greater susceptibilitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“any novel variation m disease reaction that does occur m secondary embryogenic lines is likely to be towards greater susceptibility rather than increased resistance.”
t0“Brassica napus ssp. oleifera”
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See all 7 papers →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.