CARBON AND NITROGEN FLOWS IN HYBRID WHEATS AND THEIR PARENTS DURING GRAIN FILLING [French]

摘要

Carbon and nitrogen flows were studied between anthesis and maturity on 29 hybrid wheats and their 23 parents examined in a complete block design, the basic plot measuring 7 m(2). Heterosis expressed not only for grain yield but also for nitrogen yield. With the same nitrogen filling rate per m(2), F1 had a greater duration of grain filling for nitrogen than inbred lines. For the hybrids and their parents, 65% of grain nitrogen was already in the plant at anthesis, when only 18% of grain glucides came from water-soluble carbohydrate remobilization. There was no difference between hybrids and inbred lines for remobilization, but post-anthesis assimilation of nitrogen was greater for the Fl hybrids than for their parents. Some assumptions regarding carbon-nitrogen relationships are proposed to explain the more favorable 'sink-source' relationship demonstrated for the hybrids.