Nitrogen fixation by hybrids of white clover (Trifolium repens L.) and Trifolium nigrescens

Citation
Mt. Abberton et al., Nitrogen fixation by hybrids of white clover (Trifolium repens L.) and Trifolium nigrescens, J AGRON CR, 183(1), 1999, pp. 27-33
Citations number
30
Categorie Soggetti
Agriculture/Agronomy
Journal title
JOURNAL OF AGRONOMY AND CROP SCIENCE-ZEITSCHRIFT FUR ACKER UND PFLANZENBAU
ISSN journal
09312250 → ACNP
Volume
183
Issue
1
Year of publication
1999
Pages
27 - 33
Database
ISI
SICI code
0931-2250(199907)183:1<27:NFBHOW>2.0.ZU;2-4
Abstract
Development of hybrids between white clover (Trifolium repens L.) acid Trif olium nigrescens provides a novel route for genetically improving the repro ductive capacity of white clover, provided the hybrids are agronomically vi able, particularly with respect to N-2 fixation. A comparative study of gro wth and rates of N-2 fixation over 21 days was conducted with the parental species, F-1 hybrids and backcross hybrids, in flowing solution culture, wi thout a supply of mineral N to the plants. T. nigrescens was unable to fix N-2 in association with the strains of Rhizobium leguminosarum biovar. trif olii selected for inoculation. Rates of Nz fixation per plant increased in the order T. nigrescens < F-1 hybrid < T. repens < backcross 1. Specific ra tes of N-2 fixation (days 0-21) increased in the order T. nigrescens < F-1 hybrid < backcross 1 < T. repens. Dry matter production and nodule biomass per plant increased at a higher rate in backcross 1 hybrids than in T. repe ns. The results suggest that the potential for N-2 fixation by backcross 1 hybrids is at least as great as that by T. repens.