| Autor: |
Hunter, W. J., Fahring, C. J., Olsen, S. R., Porter, L. K. |
| Zdroj: |
Crop Science; September 1982, Vol. 22 Issue: 5 p944-948, 5p |
| Abstrakt: |
The amount of NO3‐in xylem sap from 11 soybean (Glycine maxL. Merr.) cultlvars was examined to determine if nitrate was being reduced in the shoot or root. Rhizobiumfree plants were grown hydroponically in the greenhouse with NO3‐as a sole N source. In one study using 5‐week‐old plants, NO3‐—N in the sap was found to vary with cultivar, with NO3‐accounting for 42 to 79% of the sap N. Presumably a high proportion of NO3‐in the sap indicates a high reduction of NO3‐in the shoot. In another study, weekly sap analysis with ‘Tracy’ showed that shoot reduction of the N in the xylem sap dominated in young plants ( 4 to 6 weeks of age), but root reduction dominated in older plants (7 to 14 weeks). A different pattern was seen with ‘Swift’ in which root and shoot NO3‐reduction were about equal in younger plants (4 to 6 weeks), but root reduction dominated in older plants (7 to 13 weeks). A comparison of nitrate reductase enzyme activities in older plants (7 to 13 weeks) showed Swift to have a large amount of activity in the shoot and Tracy to have a large amount in roots. These studies suggested that soybean cultivars differ in the location of nitrate reduction. |
| Databáze: |
Supplemental Index |
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