Pollen-ovule relation in Adesmia tristis and reflections on the seed–ovule ratio by interaction with pollinators in two vertical strata

Abstract

The vertical distribution of pollinators is an important component in the foraging pattern of plants strata, and it influences the reproductive system (pollen/ovule ratio) and seed/ovule ratio. Niches in two different strata from Adesmia tristis Vogel were evaluated in these aspects. This plant is an endemic shrub from the Campos de Cima da Serra in Southern Brazil. The studies were carried out from January 2010, to January 2011, at Pró-Mata/PUCRS (Catholic University of Rio Grande do Sul) (29°27'-29°35'S and 50°08'-50°15'W), São Francisco de Paula, sate of Rio Grande do Sul, Brazil. Breeding system of A. tristis is mandatory allogamy. The vertical profile in A. tristis has differentiated foraging niches among the most common pollinators. Bees of Megachile genus forage in the upper stratum, and representative bees of the Andrenidae family explore the lower stratum. The upper stratum of the vertical profile had more contribution to seed production. Adesmia tristis showed evidence of pollination deficit.

Compatibility in pollen-pistil interaction of interspecific crossings with Passiflora spp.

“…Probably such restrictions to fruit development in some crossings can result in some degree of genetic incompatibility or any zygotic barrier in pre or post fertilization. It can have a rejection mechanism in pollen recognition process under the stigma, style or ovary, which proteins block the germination of pollen grains or inhibit/suspend the development and growth of the pollen tube, besides the ratio pollen:ovary, which can influence on the efficacy of the pollen grain to reach the compatible stigma (Bugallo et al 2011, Jones et al 2012, Ferreira et al 2014.…”