Nitrate reductase activity (in vivo and in vitro) of ditelosomic stocks of wheat (Triticum aestivum L.)

The nitrate reductase activities (NRA) of 31 ditelosomic stocks were compared with that of the control plant [Chinese Spring (CS) euploid], using in vivo and in vitro assay procedures that had been optimized with respect to the euploid. Fourteen stocks exhibited significant differences in in vivo NRA from that of the euploid; the effect of removal of a chromosome arm was always to increase NRA. Eight of these stocks showed similar effects in vitro, although in three, a casein-sensitive factor had to be eliminated before the difference was expressed. Homoeologous group effects were evident among ditelosomics of groups 2, 4, and 7, while for three chromosomes (2D, 7A, and 7B), removal of either arm resulted in a similar increase in NRA in vivo and probably in vitro.