Effect of CO2enrichment and nitrate application on growth and dinitrogen fixation of wild and cultivated soybean plants during pod-filling stage
Year: 1989
Type: article
Abstract: A wild soybean variety (Glycine soja Sieb. and Zucc. line Nakei-No. 1) and a cultivated soybean variety (Glycine max L. Merr. cv. Tamahomare) were subjected to treatments of CO2 enrichment and/or 50 ppm nitrate (NO3-N) application during the pod-filling period and the growth and dinitrogen fixation of the plants were examined. 1. The whole plant weight of the soybean cultivar was increased by CO2 enrichment and did not change by NO3-N application, whereas the wild soybean variety responded neither to CO2 enrichment nor to NO3-N application. In the wild soybean variety, CO2 enrichment promoted yellowing and death of leaves, while NO3-N application prevented those phenomena from occuring. 2. In the absence of NO3-N in the culture medium, the dinitrogen-fixing activity in the soybean cultivar increased by CO2 enrichment, whereas it decreased in the wild soybean variety. In the soybean cultivar, the adverse effect of NO3-N on the dinitrogen fixation was alleviated by CO2 enrichment. 3. The whole plant N increment of the soybean cultivar increased by CO2 enrichment and/or NO3-N application, whereas the reverse trend was observed in the wild soybean variety. In the presence of NO3-N in the culture medium, CO2 enrichment led to an increase in the accumulation of fixed-N and to a decrease in the combined-N accumulation in both varieties. 4. The concentration of sugars and starch in the leaves of both varieties increased by CO2 enrichment, especially the starch concentration in the leaf blades of the soybean cultivar and that in the yellow leaves of the wild variety. For the nodules, CO2 enrichment tended to increase the concentration of sugars and starch in the cultivar but to decrease that of the wild variety. 5. CO2 enrichment led to an increase in the export rate of photosynthetically fixed 14C from leaves to other parts in the cultivar, but did not affect it in the wild variety. The l4C distribution percentage in nodules decreased only in the wild variety by CO2 enrichment. Based on these results, it is assumed that during the pod-filling period, the growth of the cultivar is limited by photosynthate supply, while that of the wild variety is limited mainly by the low ability to receive photosynthates and N.
Source: Soil Science & Plant Nutrition
Authors: Taizo Masuda, Kounosuke Fujita, Shoitsu Ogata
Institution: Hiroshima University
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W1982130021