NITROGEN-CONTENT, OIL CONTENT AND OIL COMPOSITION OF OAT CULTIVARS (AVENA-SATIVA) AND WILD AVENA SPECIES IN RELATION TO NITROGEN FERTILITY,YIELD AND PARTITIONING OF ASSIMILATES

Three European and three North American oat cultivars (Avena sativa) a nd 10 wild Avena species were grown to maturity in pots at three nitro gen fertility levels. The yield and nitrogen content of plant parts, a nd the production and partitioning of dry matter and nitrogen were mea sured. Greats were also analysed for oil content and composition. Some wild species had high great oil(12-13%). Great nitrogen was higher in wild species (2.9-6.3%) than cultivars (1.5-2.7%). Increases in total yield and total nitrogen yield closely corresponded with increases in nitrogen fertility level. Two wild species, with great nitrogen conte nts significantly greater than those of all the cultivars at all ferti lity levels (A. maroccana, A. canariensis), also had total plant dry m atter yields and total plant nitrogen yields that were not significant ly different from those of a number of cultivars. The hull contributed substantially to dry matter and nitrogen yield in some wild species, and in two (ii. canariensis, A. maroccana) partitioning of both dry ma tter and nitrogen to the grain was not significantly different from th ose for most cultivars. There were significant genotype x fertility in teractions for a number of characteristics, but there was no evidence that wild species had superior nitrogen economies at any fertility lev el. In a comparison of cultivars, however, variation in great nitrogen content was associated with variation in nitrogen partitioning. (C) 1 997 Academic Press Limited.