Abstract
Abstract The legume pigeon pea [Cajanus cajan (L.) Millsp.] is an important rainfed crop in many areas of the world. Production can be reduced when high nitrogen is present and symbiotic activity is low. A field experiment was conducted to determine the effects of nitrogen rate on nodulation, nodule carbon, and nitrogen fixation in 40 pigeon pea genotypes. Nitrogen was applied as urea at 40 (N40) and 120 kg·ha−1 of N (N120). Shoot biomass, root nodulation, amounts of nitrogen and carbon fixed, nitrate reductase activity in roots and nodules, and nitrite content in roots and nodules were determined. Genotype, N rate, and the interaction affected results. The genotypes Pusa-2001 and Sel-90306-11-4 had the most nodule mass at N40. Nitrogen rate did not affect nodule nitrogen-fixing effectiveness. Genotype Pusa-2001 had higher biomass at N120. Genotype Sel-90306-11-4 had high phosphoenol pyruvate carboxylase activity even at N120; which likely reduces host carbon dependence for nodule nitrogen function and improves carbon diversion to the reproductive sink. At N40 ‘Sel-24’ formed large nodules with effective nitrogen fixation, which was impaired at N120. ‘RG-01-69N’ had lower numbers of nodules, nodule mass, and nitrogen fixation but more shoot biomass than the majority of the pigeon pea lines. N-response of pigeon pea was evident for nodule N2 fixation. Genotypes with improved nodule CO2 fixation may lead to increased yield and quality in monocropped and intercropped pigeon pea. Keywords: Cajanus cajan Nitrate reductaseNitrogenase activityPhosphoenol pyruvate carboxylase activityIndia Acknowledgments Financial support of the project by the Indian Agricultural Research Institute is acknowledged.
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Claims 11
Claim · model-written summary
Pusa-2001 had the most nodule mass at N40.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The genotypes Pusa-2001 and Sel-90306-11-4 had the most nodule mass at N40”
e1“pigeon pea [Cajanus cajan (L.) Millsp.]”
Claim · model-written summary
Sel-90306-11-4 had the most nodule mass at N40.
- Taxon
- pigeon pea
Cajanus cajane1 - Material
- Sel-90306-11-4e0
- Treatment
- N40e0
- Outcome
- nodule masse0
- Direction
- moste0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The genotypes Pusa-2001 and Sel-90306-11-4 had the most nodule mass at N40”
e1“pigeon pea [Cajanus cajan (L.) Millsp.]”
Claim · model-written summary
Nitrogen rate did not affect nodule nitrogen-fixing effectiveness.
- Taxon
- pigeon peaCajanus cajane1
- Treatment
- Nitrogen ratee0
- Outcome
- nodule nitrogen-fixing effectivenesse0
- Direction
- did not affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen rate did not affect nodule nitrogen-fixing effectiveness”
e1“pigeon pea [Cajanus cajan (L.) Millsp.]”
Claim · model-written summary
Pusa-2001 had higher biomass at N120.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Genotype Pusa-2001 had higher biomass at N120”
e1“pigeon pea [Cajanus cajan (L.) Millsp.]”
Claim · model-written summary
Sel-90306-11-4 retained high phosphoenol pyruvate carboxylase activity at N120.
- Taxon
- pigeon peaCajanus cajane1
- Material
- Sel-90306-11-4e0
- Treatment
- N120e0
- Gene
- phosphoenol pyruvate carboxylasee0
- Outcome
- phosphoenol pyruvate carboxylase activitye0
- Direction
- highe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Genotype Sel-90306-11-4 had high phosphoenol pyruvate carboxylase activity even at N120”
e1“pigeon pea [Cajanus cajan (L.) Millsp.]”
Claim · model-written summary
Sel-24 formed large nodules at N40.
- Taxon
- pigeon peaCajanus cajane1
- Material
- Sel-24e0
- Treatment
- N40e0
- Outcome
- large nodulese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At N40 ‘Sel-24’ formed large nodules with effective nitrogen fixation”
e1“pigeon pea [Cajanus cajan (L.) Millsp.]”
Claim · model-written summary
Sel-24 had effective nitrogen fixation at N40, impaired at N120.
- Taxon
- pigeon peaCajanus cajane1
- Material
- Sel-24e0
- Treatment
- N120e0
- Outcome
- nitrogen fixatione0
- Direction
- impairede0
- Comparator
- N40e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At N40 ‘Sel-24’ formed large nodules with effective nitrogen fixation, which was impaired at N120”
e1“pigeon pea [Cajanus cajan (L.) Millsp.]”
Claim · model-written summary
RG-01-69N had fewer nodules, less nodule mass and lower nitrogen fixation than most pigeon pea lines.
- Taxon
- pigeon peaCajanus cajane1
- Material
- RG-01-69Ne0
- Outcome
- numbers of nodules, nodule mass, and nitrogen fixatione0
- Direction
- lowere0
- Comparator
- majority of the pigeon pea linese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“‘RG-01-69N’ had lower numbers of nodules, nodule mass, and nitrogen fixation but more shoot biomass than the majority of the pigeon pea lines”
e1“pigeon pea [Cajanus cajan (L.) Millsp.]”
Claim · model-written summary
RG-01-69N had more shoot biomass than most pigeon pea lines.
- Taxon
- pigeon peaCajanus cajane1
- Material
- RG-01-69Ne0
- Outcome
- shoot biomasse0
- Direction
- moree0
- Comparator
- majority of the pigeon pea linese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“‘RG-01-69N’ had lower numbers of nodules, nodule mass, and nitrogen fixation but more shoot biomass than the majority of the pigeon pea lines”
e1“pigeon pea [Cajanus cajan (L.) Millsp.]”
Claim · model-written summary
Genotype, nitrogen rate and their interaction affected the measured responses.
- Taxon
- pigeon peaCajanus cajane1
- Treatment
- N ratee0
- Outcome
- resultse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Genotype, N rate, and the interaction affected results”
e1“pigeon pea [Cajanus cajan (L.) Millsp.]”
Claim · model-written summary
The authors suggest genotypes with improved nodule CO2 fixation may increase pigeon pea yield and quality.
- Taxon
- pigeon peaCajanus cajane0
- Outcome
- Genotypes with improved nodule CO2 fixation may lead to increased yield and qualitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Genotypes with improved nodule CO2 fixation may lead to increased yield and quality in monocropped and intercropped pigeon pea”
The same questions in other papers
nitrogen · symbiosis · Cajanus cajan (pigeon pea)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- positive
- negative
- 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.