Pollination Ecology ofPolylepis tomentella(Rosaceae), an Andean Anemophilous Tree Presenting a Potential Floral Fungal Infection

Pollen limitation and reproductive incompatibility system in a critically endangered tree, Polylepis incarum (Bitter) M. Kessler & Schmidt-Leb (Rosaceae)

“…Pollen supplementation increased seed set in hand pollinated flowers, regardless of the source of the pollen, as hand self-and cross-pollinated flowers produced a higher percentage of seeds than openly pollinated flowers. Our results contrast with studies in P. australis and P. tomentella where pollen supplementation did not increase seed set [30,31]. Despite P. incarum possess several demographic and reproductive strategies that could ensure fertilization of female flowers, such as high density of reproductive individuals in the same population and high synchronization of flowering during the dry season, our results suggest that the amount of pollen available may not be sufficient to guarantee sexual reproduction [34,37].…”

“…The results of the hand pollination and the stigmatic receptivity experiments in P. incarum also showed evidence of prezygotic compatibility, which has also been previously reported in P. australis and P. tomentella [30,31]. The flowers set fruits and seeds whether they were pollinated with pollen from the same plant or pollen from another plant.…”

“…High production of non-viable seeds has been commonly found in the genus, which has been attributed to pollen limitation and parthenocarpy as well as to habitat degradation and resource limitation [27][28][29]. However, the breeding system of Polylepis has been studied in very few species [30,31] and it could include a diversity of breeding systems, from obligate outcrossing species to autonomously selfing species. Here, we focus on understating the reproductive system of Polylepis incarum (Bitter) M. Kessler & Schmidt-Leb by testing if seed production is limited by pollen availability and by characterizing the incompatibility system of the species.…”

Evaluating the fitness effects of seed size and maternal tree size onPolylepis tomentella(Rosaceae) seed germination and seedling performance

“…The species flowers annually during the dry season (May-October) and produces fruits from late August to December (Domic et al 2013). The species possess a prezygotic self-compatible system and flowers produce a single winged achene, dispersed by wind on maturation (Domic et al 2017).…”

“…In this study, we conducted greenhouse experiments to evaluate the functional influence of seed size on germination and offspring performance in the wind-dispersed highland tropical tree Polylepis tomentella Weddell (Rosaceae). We selected P. tomentella because this species is adapted to semiarid high-altitude conditions and is known to experience low rates of seedling recruitment, partially associated with low production of viable seeds (Arrazóla et al 2012, Domic et al 2014, 2017. It is unclear how these effects are a consequence of evolutionary tradeoffs related to high-elevation adaptation or to increasing population decline (Cierjacks et al 2007, Renison et al 2004Velez et al 1998).…”