Abstract
Abstract Dormancy in achenes (seeds) of wild sunflower ( Helianthus ) species ensures that they do not germinate in temperate climates until conditions are optimal for seedling survival. However, high achene dormancy results in low germination of achenes, precluding utilization of many wild species for domestic purposes. Interest in the use of native Helianthus species for domestic purpose such as low‐maintenance ornamentals, revegetation, cut flowers, and genetic improvement of cultivated sunflower has recently increased. The objectives of this study were to evaluate germination media to overcome dormancy and enhance germination of two annual species, H. annuus L. and H. petiolaris Nutt., and to evaluate the influence of achene maturity and storage time and temperature on germination. A 1 m M gibberellic acid (GA 3 ) medium was the most effective stimulant in laboratory tests for enhancing germination of H. annuus . Germination of treated achenes was 81%, compared with 38% for the control. Germination of H. petiolaris achenes was 60% with the 1 m M GA 3 medium, compared with 9% for the water control. This GA 3 medium enhanced germination regardless of achene maturity, storage time, or storage temperature. When averaged over all media, achene maturities, and storage times and temperatures, H. annuus had a germination of 41%, compared with only 21% for H. petiolaris . The age of the achenes at harvest influenced germination. Achenes harvested 20 d after flowering generally had greater germination than those harvested 40 d after flowering, especially for H. petiolaris . Storage time and temperature could not overcome the dormancy imposed prior to germination in either species. Utilization of germination media to enhance germination of wild Helianthus species will facilitate their use for domestic purposes.
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Claims 6
Claim · model-written summary
Gibberellic acid raised H. annuus germination to 81% versus 38% control.
- Taxon
- H. annuus
Helianthus annuuse0 - Treatment
- 1 m M gibberellic acid (GA 3 ) mediume0
- Outcome
- Germination of treated achenese0
- Direction
- enhancinge0
- Value
- 81%e0
- Qualifier
- 38%e0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A 1 m M gibberellic acid (GA 3 ) medium was the most effective stimulant in laboratory tests for enhancing germination of H. annuus . Germination of treated achenes was 81%, compared with 38% for the control”
Claim · model-written summary
Gibberellic acid gave H. petiolaris 60% germination versus 9% water control.
- Taxon
- H. petiolaris
Helianthus petiolarise0 - Treatment
- 1 m M GA 3 mediume0
- Outcome
- Germination of H. petiolaris achenese0
- Direction
- increaseinferrede0
- Value
- 60%e0
- Qualifier
- 9%e0
- Comparator
- water controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Germination of H. petiolaris achenes was 60% with the 1 m M GA 3 medium, compared with 9% for the water control”
Claim · model-written summary
GA3 enhanced germination regardless of maturity, storage time or temperature.
- Taxon
- wild sunflowere1
- Treatment
- GA 3 mediume0
- Outcome
- germinatione0
- Direction
- enhancede0
- Qualifier
- regardless of achene maturity, storage time, or storage temperaturee0
Not reportedComparator
Verbatim
e0“This GA 3 medium enhanced germination regardless of achene maturity, storage time, or storage temperature”
e1“wild sunflower ( Helianthus ) species”
Claim · model-written summary
H. annuus averaged 41% germination versus 21% for H. petiolaris.
- Taxon
- H. annuusHelianthus annuuse0
- Outcome
- germinatione0
- Direction
- higherinferrede0
- Value
- 41%e0
- Qualifier
- 21%e0
- Comparator
- H. petiolarise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“H. annuus had a germination of 41%, compared with only 21% for H. petiolaris”
Claim · model-written summary
Achenes harvested at 20 days generally germinated more than at 40 days.
- Taxon
- H. petiolarisHelianthus petiolarise0
- Organ / stage
- Achenese0
- Outcome
- germinatione0
- Direction
- greatere0
- Qualifier
- 20 d after floweringe0
- Comparator
- 40 d after floweringe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Achenes harvested 20 d after flowering generally had greater germination than those harvested 40 d after flowering, especially for H. petiolaris”
Claim · model-written summary
Storage time and temperature did not overcome dormancy in either species.
- Taxon
- wild sunflowere1
- Treatment
- Storage time and temperaturee0
- Outcome
- dormancy imposed prior to germinatione0
- Direction
- could not overcomee0
Not reportedComparator
Verbatim
e0“Storage time and temperature could not overcome the dormancy imposed prior to germination in either species”
e1“wild sunflower ( Helianthus ) species”
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See all 36 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.