Abstract:

Boron efficiency of 16 oilseed rape genotypes was tested using both hydroponic and pot-soil growing techniques. From the nutrient solution experiment (0.1 and 10 µM B), 4 representative contrasting genotypes were selected based on relative root and shoot growth. These were then grown in pots with low-B soil (0.25 mg kg-1). From the nutrient solution experiment, 2 genotypes selected as B-inefficient did not show any growth disorders, and the concentration of B in the shoots was above critical. Furthermore, 4 contrasting genotypes were subjected to the stable 11B isotope-enriched uptake solution for 6 h to verify possible low B-induced active uptake by roots and xylem loading of B. The concentration of 11B in either root cell sap or xylem exudate was higher than in the external nutrient solution, which indicated the presence of low B-induced active uptake for all tested genotypes, and, to some extent, their efficiency with low B. In conclusion, a combination of different growing techniques under controlled environmental conditions together with different parameters including relative root and shoot weight, shoot B concentration, and B uptake provided reliable B efficiency results in oilseed rape genotypes.

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