Seed coat color determines seed germination, seedling growth and seed composition of canola (brassica napus)

Canola (Brassica napus L.) seeds were sorted based on seed coat color into black (BL), dark brown (DBR) and light brown (LBR). Germination, seedling growth and seed composition (oil, protein and soluble sugar contents) were evaluated among seeds of different categories. From dark to light seed coat colors, germination percentage and germination index (GI) declined and mean germination time (MGT) increased; emergence percentage, seedling vigor index (SVI), shoot and root length decreased; seed oil content decreased but protein and soluble sugar content increased. Correlation matrix indicated that oil content was positively, but the protein and soluble sugar content were negatively correlated to seed germination and seedling growth. Almost all seed germination characteristics were either negatively or positively correlated to those of seedling growth (r = -0.94 to 0.99, P=0.00 to 0.03) with the exception between germination percentage and shoot length (r = 0.52, P = 0.08). It was concluded that seeds in the BL category showed fast germination, high emergence percentage and high seedling establishment, and the science behind this is that seed coat color determines seed composition, which further affects seed germination and seedling growth. © 2013 Friends Science Publishers.