Ecology of fruit-colour polymorphism in Myrtus communis and differential effects of birds and mammals on seed germination and seedling growth

摘要: Summary 1 The fruit-colour polymorphism of Myrtus communis, a common Mediterranean shrub, is examined. We investigate whether frugivores affect the maintenance polymorphism, morphs differ in germination or seedling growth, and passage through frugivores’ gut affects seed behaviour growth. 2 Blue berries are very similar morphological traits nutrient composition to rarer white morph. Rates fruit removal by birds, main dispersers this species, did not between morphs, suggesting that colour preference involved polymorphism. 3 Seeds two showed same germinability (final percentage germination) as well rates under controlled conditions (in growth chamber greenhouse). Outdoors, seeds from blue tended germinate slightly faster (which might give them an early advantage) but differences disappeared after several weeks growth. 4 The myrtle differently affected digestive tract which appeared significantly increase germinability, carnivorous pine marten, Martes martes, not. The different retention time chemical food ingested along with may be responsible for such differences. 5 The detection positive effect bird ingestion outdoor conditions, greenhouse, demonstrates importance performing tests natural habitat. 6 Seed size, irrespective morph, response gut. Large seeds, more rapidly ejected, thus less abraded, germinated at speed non-ingested controls. Variation size within single species should considered future studies.