Sinapine Leakage for Detection of Seed Quality in Brassica

Abstract

Sinapine leakage has been developed as a rapid seed viability test in cruciferous seeds on a single seed basis, in which non-viable seeds leak fluorescent sinapine while viable seeds do not. Sinapine leakage was used to predict germination for 11 seed lots (cabbages, broccoli, cauliflowers and radishes), and the prediction was significantly correlated with the actual germination. The major source of error in this test is false-negatives (F-), i.e. those seeds that do not leak and do not germinate. The sinapine leakage index (SLI) was calculated to assess F- for any seed lot by dividing the number of non-germinable seeds that leaked by the total number of non-germinable seeds. The SLI was related to seed coat permeability. Chemical analyses of seed coats were conducted on 4 lots with different SLI values. Cutin content was negatively correlated with SLI, and cutin may restrict the diffusion of sinapine throughout the seed coat. Sinapine leakage provided the basis for the development of a novel seed coating system to detect and upgrade seed quality. Seeds were first imbibed and then coated with a cellulose filler to adsorb sinapine leakage. The coated seeds are then dried and sorted by UV colour sorting equipment to upgrade seed quality by removal of fluorescent coated seeds.