Greater mycorrhizal colonization of unisexual morphs than of hermaphroditic morphs of Jacaratia mexicana during flowering and fruiting in central Mexico

Different sexual morphs of dimorphic and trimorphic populations of plants have different demands for resources correlating with phenotypic and ecological dissimilarities among morphs. Few studies have investigated the variations in mycorrhizal symbiosis across the sexual morphs of trimorphic plant populations. Here, we report seasonal variations in the mycorrhizal colonization of the roots of female, male and hermaphroditic trees of Jacaratia mexicana under field conditions in central Mexico. Mycorrhizal colonization was low in the rainy season, when J. mexicana bears only leaves, but high in the dry season when it flowers and fruits. In the dry season, the mycorrhizal colonization of female and male trees was over twofold higher than that of the hermaphroditic trees, and all three morphs had low mycorrhizal colonization in the rainy season. The lack of seasonal variation in the mycorrhizal colonization of hermaphroditic trees, together with other available evidence, supports the idea that hermaphroditic trees of J. mexicana might have some physiological disadvantages compared with male and female trees.