Evolution of seed dormancy due to sib competition: Effect of dispersal andinbreeding

The effect of dispersal and inbreeding on the evolution of seed dormancy to avoid sib competition is theoretically investigated, using a model which a ssumes a plant population with patchy spatial structure in a constant envir onment. Applying the inclusive fitness method, the evolutionarily stable do rmancy rates are analytically derived for three cases: (a) an asexual haplo id population (b) a diploid-hermaphrodite population in which the dormancy rate is controlled by seeds, and (c) a diploid-hermaphrodite population in which the dormancy rate is controlled by mother plants. The evolutionarily stable dormancy rates decrease in the order of case (c), case (a), and case (b). In all the cases, the evolutionarily stable dormancy rates increase w ith decreasing the dispersal rate. Although inbreeding generally increases the evolutionarily stable dormancy rates, inbreeding due to selfing reduces the rate exceptionally in case (c). (C) 2000 Academic Press.