Soil moisture conditions affect the sensitivity of Bromus catharticus dormant seeds to light and the emergence pattern of seedlings.

摘要: The soil moisture regime may affect dormancy of seeds and their sensitivity to signals that promote germination. We studied the effect on light dormant Bromus catharticus seeds, emergence pattern seedlings. Seeds were incubated under continuously hydrated, dehydrated, or fluctuating regimes in a controlled environment (25°C, darkness) for 2 months. After treatments, exposed red far-red pulses, darkness, determine germinability. In addition, grassland mesocosms with intact seed bank vegetation irrigated subjected drought glasshouse at summer temperatures. months, temperature was reduced correspond temperatures autumn; canopy removed half covered filters exclude light. Density B. seedlings evaluated after weeks. Dormancy decreased hydrated but they still required contrast, an important fraction experienced dehydrated germinated darkness pulses. had drought, higher density emerged absence than daily mesocosms. This indicates acquired capability germinate canopy, especially regime. Results indicate during affects as well