Reactions of Adansonia digitata L. provenances to long-term stress at seedling stage

摘要

The effects of drought stress on growth parameters and dry matter partitioning of seven provenances (six from West Africa and one from East Africa) of Adansonia digitata L. were assessed in a seedling experiment in Burkina Faso. Three water regimes corresponding to 100 % (control), 75 % and 50 % of field capacity were applied over a period of 18 months. While survival was unaffected by the stress treatments, provenances and water regimes significantly affected growth parameters, and plant dry matter accumulation was significantly reduced by water stress. Provenances had growth rates of diameter and height in response to stress. The fresh weight/dry weight ratio increased with increasing stress. In response to stress, shoot/root ratios decreased at the start of the experiment, but increased at the end, compared to the control. Differences between provenances were not correlated to environmental parameters of the site of origin, and the hypothesis about better resistance of seedlings from drier sites to drought stress was not confirmed. However, the provenance from East Africa was in several aspects different from the West African provenances.