Tocopherols accumulation in developing seeds and pods of rapeseed ( Brassica napus L.)

The accumulation of dry matter, chlorophyll, and tocopherols was monitored in developing seeds and pods of three rapeseed genotypes with contrasting tocopherol profiles from shortly after anthesis to maturity. Three phases of tocopherols accumulation were observed. Phase I, from 12 to 41 days after flowering (DAF), was characterized by a slow accumulation of both α- and γ-tocopherol. Phase II, from 41 to 53 DAF, showed the highest tocopherols accumulation rates, with more active accumulation of γ- than α-tocopherol in the lines characterized by an α- to γ-tocopherol ratio below the unity. Final differences in the α- to γ-tocopherol ratios among genotypes were caused by different accumulation rates between both tocopherol derivatives in Phase II. Both total tocopherols content and the α- to γ-tocopherol ratio remained constant in Phase III, from 53 DAF to maturity. Changes on chlorophyll and tocopherols contents in pods during development were similar to those previously reported in senescing leaves. No export of tocopherols from pods to seeds throughout seed development was detected.