Abstract
The ability of Rhizobium to fix N 2 in legume root nodules is a property that requires a great deal of further study. A rapid assay for N 2 ‐fixing ability that can be used for screening many plants certainly will be utilized for work on this important symbiosis. We have modified the acetylene‐reduction technique to assay for N 2 fixation in nodulated legumes. Inoculated seedlings are grown in sterile conditions in small vials capped with plastic bags. The vials contain vermiculite wetted with an N‐free medium. The effectiveness assay is completed within 2 weeks after seedlings have germinated and several thousand seeds can readily be tested in 1 month. Nitrogen‐fixing ability is monitored by observing the reduction of acetylene to ethylene by gas chromatography. Cultivars of soybean, Glycine max (L.) Merr., were assayed with this technique and major varietal differences were found. Nitrate and ammonium prevent nodulation and acetylene reduction in the effectiveness assay. Results from screening soybean cultivars and introduction lines may have value for plant‐breeding programs and host‐ Rhizobium interaction studies. This effectiveness assay is useful for screening mutant plants or rhizobia that have defects in their ability to synthesize factors responsible for the establishment of an N 2 ‐fixing root nodule.
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Claims 4
Claim · model-written summary
The modified acetylene-reduction effectiveness assay for N2 fixation is completed within 2 weeks after seedlings germinate.
- Taxon
- Glycine max
Glycine maxe2 - Outcome
- effectiveness assaye1
- Value
- within 2 weekse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“The effectiveness assay is completed within 2 weeks after seedlings have germinated and several thousand seeds can readily be tested in 1 month”
e2“Cultivars of soybean, Glycine max (L.) Merr., were assayed with this technique and major varietal differences were found”
Claim · model-written summary
Several thousand seeds can readily be tested in 1 month with the assay.
- Taxon
- Glycine maxGlycine maxe2
- Outcome
- several thousand seeds can readily be testede1
- Value
- in 1 monthe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“The effectiveness assay is completed within 2 weeks after seedlings have germinated and several thousand seeds can readily be tested in 1 month”
e2“Cultivars of soybean, Glycine max (L.) Merr., were assayed with this technique and major varietal differences were found”
Claim · model-written summary
Soybean cultivars assayed with the technique show major varietal differences in N fixation.
- Taxon
- Glycine maxGlycine maxe2
- Material
- Cultivars of soybeane2
- Outcome
- varietal differencese2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Cultivars of soybean, Glycine max (L.) Merr., were assayed with this technique and major varietal differences were found”
Claim · model-written summary
Nitrate and ammonium prevent nodulation and acetylene reduction in the effectiveness assay.
- Taxon
- Glycine maxGlycine maxe2
- Treatment
- Nitrate and ammoniume3
- Outcome
- nodulation and acetylene reductione3
- Direction
- prevente3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Cultivars of soybean, Glycine max (L.) Merr., were assayed with this technique and major varietal differences were found”
e3“Nitrate and ammonium prevent nodulation and acetylene reduction in the effectiveness assay”
The same questions in other papers
nitrogen · symbiosis · Glycine max (soybean)Positive and negative results
86 papers in the same direction as this paper · 59 in the opposite direction
- positive
- positive
- positive
142 papers more in this group
See all 146 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.