Evaluation of yielding of high oleic forms of winter oilseed rape in conditions of different nitrogen fertilization level

The paper presents the reaction of three genotypes with changed fatty acid composition (PN 412 and PN 438 - developed through mutagenesis and the line PN 1261 developed through selection of inbred lines population) and two currently grown varieties (open pollinated variety Starter and hybrid restored variety Poznaniak), on two spring nitrogen doses (100 and 180 kg N.ha(-1)). The effect of spring nitrogen fertilization on yield and quantitative characters of seeds and oil of all cultivars studied in the experiment was similar. Increasing nitrogen dose from 100 to 180 kg N. ha(-1) caused an increase of seed yield (average of 9%) and a significant reduction of crude fat content in seeds, however had not significant effect on fatty acids content in oil. Independently from the dose of nitrogen the high oleic lines: PN 412, PN 438 and PN 1261 yielded not significantly better (about 3-8 %) than open pollinated variety Starter (4.31 t.ha(-1)), but significantly lower (except the line PN 412) than the hybrid restored variety Poznaniak (5.13 t.ha(-1)). In relation to both open pollinated varieties (Starter and Poznaniak F1) forms with changed fatty acid composition (PN 412, PN 438 and PN 1261) had a significantly higher content of oleic acid (respectively 72.9, 72.6 and 73.0%), lower content of linoleic (10.9, 11.4 and 11.8%), linolenic (8.88, 8.83 and 7.61%) and palmitic acid (3.94, 3.76 and 3.96%).