Data/hora: 03/06/2024 08:48:18

Provedor de dados: | Acta Botanica Brasilica
País: | Brazil
Título: | Pollination of two species of Vellozia (Velloziaceae) from high-altitude quartzitic grasslands, Brazil
Autores: | Jacobi,Claudia Maria; del Sarto,Mário César Laboissiérè.
Data: | 2007-06-01
Ano: | 2007
Palavras-chave: | Pollen limitation; Geitonogamy; Rocky grasslands; Self-incompatibility; Serra do Cipó.
Resumo: | The pollinators and breeding system of two species of Vellozia (Velloziaceae) from high-altitude quartzitic grasslands in SE Brazil were studied. Vellozia leptopetala is shrubby and grows solely on rocky outcrops, V. epidendroides is herbaceous and grows on stony soils. Both bear solitary, hermaphrodite flowers, and have massive, short-lasting annual blooms. We evaluated the level of self-compatibility and need for pollinators of 50 plants of each species and 20-60 flowers per treatment: hand self- and cross-pollination, spontaneous pollination, agamospermy and control. The behavior of floral visitors on flowers and within plants was recorded. Both species are mostly self-incompatible, but produce a small number of seeds by self-fertilization. The pollen-ovule ratio suggests facultative xenogamy. They were visited primarily by bees, of which the most important pollinators were two leaf-cutting bees (Megachile spp.). Vellozia leptopetala was also pollinated by a territorial hummingbird. Low natural seed production compared to cross-pollination seed numbers suggests that pollen limitation is the main cause of low seed set. This was attributed to the combined effect of five mechanisms: selfing prior to anthesis, enhanced geitonogamy as a result of large floral displays, low number of visits per flower for the same reason, pollen theft by many insect species, and, in V. leptopetala, delivery of mixed pollen loads on the stigma as a consequence of hummingbird promiscuity.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062007000200007
Editor: | Sociedade Botânica do Brasil
Relação: | 10.1590/S0102-33062007000200007
Formato: | text/html
Fonte: | Acta Botanica Brasilica  v.21 n.2 2007
Fonte: | info:eu-repo/semantics/openAccess