Raffinose content and viability and vigour of wheat grains

Abstract

Twenty-one samples of wheat grains graded at different vigour levels by the Official Seed Testing Station, Cambridge (OSTS) were screened for germination, vigour and raffinose and sucrose contents of the embryos prior to germination. The samples exhibited a wide range of vigour as measured by seedling length attained in standard tests, in agreement with the scores obtained from OSTS. Samples having lower vigour ranking also showed lower germination rates and germination capacity, ie viability. High-vigour, high-viability samples had a wide range of raffinose and sucrose contents and R:S ratios whereas all the low-viability, low-vigour batches had low values of raffinose and R:S ratios. Analysis of a low viability sample indicated that non-viable embryos had a raffinose content at least 2-3 times less than that of viable embryos. In enforced ageing tests, samples having relatively low raffinose contents and R:S ratios lost viability more readily than the high-raffinose, high R:S ratio samples.

These findings strongly suggest that the potential longevity and the vigour of wheat grains is closely associated directly with the raffinose content and R:S values.