A simple and rapid procedure for identification of seed coat colour at the early developmental stage of Brassica juncea and Brassica napus seeds: Early identification of seed coat colour in Brassica

The yellow seed is a desirable trait in oilseed Brassica species. However, seed coat colour cannot be observed until the maturation of the seed. Identification of seed coat colour at early seed development will allow for the early detection of yellow-seeded individual plants in the segregating populations at the same generation and thus speed up yellow-seeded rapeseed breeding programme. Colour of seed coats from Brassica juncea and Brassica napus can precisely be determined as early as 15 days after pollination by staining with 0.5% vanillin-HCl solution for 5 min, which is shown to be simple, rapid and reliable. Flowering duration of an individual plant usually lasts for approximately 25-35 days in Brassica species and so the seed coat colour of an individual plant can be determined 10-20 days before the end of its flowering. Through this technique, breeding for the yellow-seeded trait can now be advanced one generation earlier by vanillin staining than by conventional visual observation of testa colour of mature Brassica seeds.