INFLUENCE OF TESTA CONDITION ON THE IMBIBITION AND VIGOR OF PEA-SEEDS

Seed lots of peas with high rates of water uptake which contained a large proportion of seeds with at least one crack in the testa and were low in vigour, as indicated by electrolyte leakage and poor field emergence. Comparisons of the tetrazolium chloride staining of the cotyledons after imbibition in water and polyethylene glycol of two seed lots both with and without scarification showed that cracks in the testa could cause cell death by increasing the rate of water uptake. Although the major cause of poor seed vigour appeared to be the incidence of cracks in the testa which resulted in rapid water uptake, cell death, and solute leakage, the condition of the embryo also influenced the response to water uptake. The practical significance of these observations to the problems of field emergence and seed production in peas is discussed. © 1979 Oxford University Press.