Annals of Botany 25: 197-205, 1961
© 1961 Annals of Botany Company
RESEARCH-ARTICLE |
Studies on the Germination of Cereals
4. The Oxygen Requirement for Germination of Wheat Grains during Maturation
Official Seed Testing Station Cambridge
1Part of a thesis submitted to the University of London for the Ph.D. Degree in 1958
The oxygen required by the wheat embryo, for germination at different stages of maturation, has been determined by the number of grains with the embryo exposed which germinated in different oxygen concentrations. Some embryos required only 0.5 per cent., and the majority required less than 5 per cent., but there was also a proportion which required a concentration approaching the level in air. There were more embryos in the last category in the grains of a red variety than in those of a white variety but this did not account for the varietal difference in germination when the grains were intact.
The effect of the covering layers was also determined in each atmosphere by the difference in germination between intact grains and grains with the embryo exposed. The covering layers were sufficiently impermeable to prevent germination in both varieties when the external oxygen concentration was very low; when the concentration was increased from 5 to 60 per cent., however, the inhibiting effect of the covering layers was reduced in the white variety but not in the red. The delayed germination of the red grains was therefore attributed to some factorother than the impermeability of the covering layers to oxygen.