Nitrogen-Fixing Activity of Root Nodules in Relation to Their Size in Peanut (Arachis hypogaea L.)
The nitrogen-fixing activity of root nodules was examined with reference to the nodule size in peanut. Root nodules of field-grown peanut were collected at flowering through harvesting stages and classified into five groups of size using a circle template. Then acetylene reduction activity was measu...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Taylor & Francis Group
2007-01-01
|
| Series: | Plant Production Science |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1626/pps.10.423 |
| _version_ | 1811237117897998336 |
|---|---|
| author | Ryosuke Tajima O New Lee Jun Abe Alexander Lux Shigenori Morita |
| author_facet | Ryosuke Tajima O New Lee Jun Abe Alexander Lux Shigenori Morita |
| author_sort | Ryosuke Tajima |
| collection | DOAJ |
| description | The nitrogen-fixing activity of root nodules was examined with reference to the nodule size in peanut. Root nodules of field-grown peanut were collected at flowering through harvesting stages and classified into five groups of size using a circle template. Then acetylene reduction activity was measured to evaluate nitrogen-fixing activity for respective size groups. In addition, the diameter of the cross-section of each root nodule and rhizobium-infected areas on the cross-section were measured. The results showed that the nitrogen-fixing activity of root nodules is closely related with their size. In the root nodules in the medium size group (1.5− 2.0 mm in diameter), nitrogen-fixing activity per unit fresh weight of nodule was highest at the flowering stage and rapidly decreased thereafter. The nitrogen-fixing activity of root nodules larger than 2.0 mm in diameter did not vary significantly with their size. Colors of rhizobium-infected zones varied with their size: white in small nodules; red in medium-sized nodules; and greenish in larger nodules, which suggests that the concentration of leghemoglobin is highest in the medium-sized nodules. Nitrogen-fixing activities of the medium-sized nodules might determine the amount of nitrogen fixation in the whole root system during pod-filling because medium-sized nodules had high activity and were large in number. Classification of root-nodule size based on the circle template is a simple, rapid, and useful method to evaluate nitrogen-fixing activity of root nodules. |
| first_indexed | 2024-04-12T12:20:38Z |
| format | Article |
| id | doaj.art-f67995c529a848c7b4273676100e08b8 |
| institution | Directory Open Access Journal |
| issn | 1343-943X 1349-1008 |
| language | English |
| last_indexed | 2024-04-12T12:20:38Z |
| publishDate | 2007-01-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | Plant Production Science |
| spelling | doaj.art-f67995c529a848c7b4273676100e08b82022-12-22T03:33:19ZengTaylor & Francis GroupPlant Production Science1343-943X1349-10082007-01-0110442342910.1626/pps.10.423111644971Nitrogen-Fixing Activity of Root Nodules in Relation to Their Size in Peanut (Arachis hypogaea L.)Ryosuke Tajima0O New Lee1Jun Abe2Alexander Lux3Shigenori Morita4Field Production Science Center, Graduate School of Agricultural and Life Sciences, The University of TokyoField Production Science Center, Graduate School of Agricultural and Life Sciences, The University of TokyoGraduate School of Agricultural and Life Sciences, The University of TokyoField Production Science Center, Graduate School of Agricultural and Life Sciences, The University of TokyoField Production Science Center, Graduate School of Agricultural and Life Sciences, The University of TokyoThe nitrogen-fixing activity of root nodules was examined with reference to the nodule size in peanut. Root nodules of field-grown peanut were collected at flowering through harvesting stages and classified into five groups of size using a circle template. Then acetylene reduction activity was measured to evaluate nitrogen-fixing activity for respective size groups. In addition, the diameter of the cross-section of each root nodule and rhizobium-infected areas on the cross-section were measured. The results showed that the nitrogen-fixing activity of root nodules is closely related with their size. In the root nodules in the medium size group (1.5− 2.0 mm in diameter), nitrogen-fixing activity per unit fresh weight of nodule was highest at the flowering stage and rapidly decreased thereafter. The nitrogen-fixing activity of root nodules larger than 2.0 mm in diameter did not vary significantly with their size. Colors of rhizobium-infected zones varied with their size: white in small nodules; red in medium-sized nodules; and greenish in larger nodules, which suggests that the concentration of leghemoglobin is highest in the medium-sized nodules. Nitrogen-fixing activities of the medium-sized nodules might determine the amount of nitrogen fixation in the whole root system during pod-filling because medium-sized nodules had high activity and were large in number. Classification of root-nodule size based on the circle template is a simple, rapid, and useful method to evaluate nitrogen-fixing activity of root nodules.http://dx.doi.org/10.1626/pps.10.423Acetylene reduction activityNitrogen-fi xing activityNodule diameterPeanut (Arachis hypogaea L.)Rhizobia |
| spellingShingle | Ryosuke Tajima O New Lee Jun Abe Alexander Lux Shigenori Morita Nitrogen-Fixing Activity of Root Nodules in Relation to Their Size in Peanut (Arachis hypogaea L.) Plant Production Science Acetylene reduction activity Nitrogen-fi xing activity Nodule diameter Peanut (Arachis hypogaea L.) Rhizobia |
| title | Nitrogen-Fixing Activity of Root Nodules in Relation to Their Size in Peanut (Arachis hypogaea L.) |
| title_full | Nitrogen-Fixing Activity of Root Nodules in Relation to Their Size in Peanut (Arachis hypogaea L.) |
| title_fullStr | Nitrogen-Fixing Activity of Root Nodules in Relation to Their Size in Peanut (Arachis hypogaea L.) |
| title_full_unstemmed | Nitrogen-Fixing Activity of Root Nodules in Relation to Their Size in Peanut (Arachis hypogaea L.) |
| title_short | Nitrogen-Fixing Activity of Root Nodules in Relation to Their Size in Peanut (Arachis hypogaea L.) |
| title_sort | nitrogen fixing activity of root nodules in relation to their size in peanut arachis hypogaea l |
| topic | Acetylene reduction activity Nitrogen-fi xing activity Nodule diameter Peanut (Arachis hypogaea L.) Rhizobia |
| url | http://dx.doi.org/10.1626/pps.10.423 |
| work_keys_str_mv | AT ryosuketajima nitrogenfixingactivityofrootnodulesinrelationtotheirsizeinpeanutarachishypogaeal AT onewlee nitrogenfixingactivityofrootnodulesinrelationtotheirsizeinpeanutarachishypogaeal AT junabe nitrogenfixingactivityofrootnodulesinrelationtotheirsizeinpeanutarachishypogaeal AT alexanderlux nitrogenfixingactivityofrootnodulesinrelationtotheirsizeinpeanutarachishypogaeal AT shigenorimorita nitrogenfixingactivityofrootnodulesinrelationtotheirsizeinpeanutarachishypogaeal |