Study of Correlations and regression analysis between quantitative and qualitative characteristics in different cultivars of rapeseed (Brassica napus L.)in different planting pattern

Planting pattern is a crucial factor in grain yield and oil crop quality characteristics of rapeseed, for this purpose a factorial experiment in a randomized complete block design with three replications was conducted in 2014 in Ardabil. The first factor was canola cultivars at three levels (Hyola 308, Hyola 401 and R.G.S 003), second factor row of three levels (20, 30 and 40 cm) and third factor was plants interval on row at two levels including 5 and 10 cm. The triple effect of cultivars × distance between rows × between plants on row was significant on number of pods per plant, seeds number, one thousand seeds weight, seed yield, biological yield, harvest index, protein percentage, protein yield and grain nitrogen content. The highest seed yield (3875 kg/ha) obtained in plant spacing of 5 cm × 20 cm row spacing × Hyola308. Oil yield was highest in row spacing 20 and 30 cm and highest protein content obtained in Hyola 308 with plants interval of 30 × 5 cm, respectively. Seed yield had significant positive correlation with biological yield (r=0.85**), harvest index (r=0.44**), oil percentage (r=0.38*), oil yield (r=0.84**), protein percentage (r=0.46**), protein yield (r=0.89**) and seed nitrogen (r=0.47**). Stepwise regression analysis, grain yield as dependent trait is influenced by the three variables, protein yield, protein percentage and oil yield regression model, totally 95% of the variations in grain yield was related to these three traits.