Drought tolerance of germinating seeds and young seedlings of Anastatica hierochuntica L.

Drought tolerance of germinating seeds and young seedlings of Anastatica hierochuntica L. was studied under controlled conditions. When seeds at various stages of germination were air-dried, or alternatively were desiccated over CaCl2 to the same or a lower water level than in the air-dried seeds, and after various periods of storage were rewetted, they readily continued germination or growth. Similarly, 60% of dried young seedlings with rootlets 4-6 mm long that had been dehydrated for one week, renewed their growth 8 h after wetting, their shrivelled, dried rootlets imbibing water. Recovery was adversely affected by both longer periods of germination prior to the dehydration, or by the longer duration of storage of the redried seeds/seedlings. The higher rate of dehydration also reduced recovery. It is argued that despite this tolerance of seedlings to drought, the Rose of Jericho cannot be considered a resurrection plant. Compared with other desert annuals, this behavior is specific for Anastatica. However, it may occur also in other annual species of populations sequestered within the driest of desert habitats.