Assessment of sexual vs asexual reproduction in Prosopis cineraria in the United Arab Emirates using seed pod observations

摘要

Distribution of Prosopis cineraria in the United Arab Emirates(UAE)varies from open forests in gravelly wadi beds to tight clusters in low sand dunes.Observations of pod production were used to test the hypothesis that clustering was due to asexual reproduction,while open forests were derived sexually.Flowers are self-incompatible and insect pollinated,thus requiring pollination from a genetically different tree to produce fruit.Observations of pod distributions on 591 trees in open,clustered,and mixed forests could all be explained by the hypothesis.Findings indicate that large clusters containing hundreds of genetically identical trees are common,and that asexual reproduction is far more frequent in the region than is sexual.Conservation efforts should facilitate both forms of reproduction within the species' natural range.Food sources for native wildlife,and for livestock,could both be enhanced by increasing the rate of outcrossing during pollination in clonal forests.