Influence of Meteorological Factors on Oil Content and Major Fatty Acids of Rapeseeds (Brassica napu

A study on the influence of meteorological factors on oil content and major fatty acids of rapeseeds was conducted based on latitudinal location experiments and years of varietal investigations. Negative correlation was found between the latitudes and erucic acid content, and positive correlations were found between the latitudes and oil content, oleic acid and linoleic acid contents of rapeseeds. No significant correlation was observed between the latitudes and lionlenic acid content of rapeseeds. The oil content of rapeseeds varied from 34.00 % to 44.90 % and was concentrated within 39.00 %～40.90% in the Yangtze River lower basin. The difference of oil content between years was observed to be 3. 00% ～5.00%. The regional variation of the same varieties had ravealed a 0. 4432 % increase of oil content per 1 increase of the latitudes.The seed formation was the key growth stage in which the oil content and stagemajor fatty acid contents of rapeseeds were influenced by the meteorological factors. The following correlations were observed:( 1 )positive correlation between oil content and the daylength; (2) negative correlations between erucic acid content and daily mean temperature, ≥3℃ effective accumulated temperature, and the daylength; (3)positive correlation between oleic acid content and the daylength; (4) negative correlation between linoleic acid content and daily mean temperature, and positive one between linoleic acid content and ≥3℃ effective accumulated temperature;(5) no significant correlation between linolenic acid content and these meteorological factors. The experiments also estimated the key meteorological factors which affected oil content and major fatty acid contents of rapeseeds, and established the stepwise regression equations between the key meteorological factors and oil content, and major fatty acid contents of rapeseeds. The experimental results formed important bases for the selection of low erucic acid rape breeding area and for the development and expansion of high quality rape.