Biologia reprodutiva de Pseudolaelia corcovadensis (Orchidaceae): melitofilia e autocompatibilidade em uma Laeliinae basal

Abstract

-(Reproductive biology of Pseudolaelia corcovadensis Porto & Brade (Orchidaceae): melittophyly and selfcompatibility in a basal Laeliinae). The floral biology, mating systems and phenology of Pseudolaelia corcovadensis (Orchidaceae), in the "Estação de Pesquisa e Desenvolvimento Ambiental de Peti", São Gonçalo do Rio Abaixo, Minas Gerais state was studied. This species flowers from April to September, with a higher availability of flowers in June and July. The flowers are dark-pink, strongly zygomorphic, and have osmophores and nectar-guides absorbing ultraviolet light. However, the flowers of P. corcovadensis do not present nectar and are pollinated by Bombus (Fervidobombus) atratus Franklin, 1913 (Hymenoptera: Apidae) by deceit. Apparently, the flowers do not form a model-mimic pair with other species in the community, but mimic a generalized melittophilous food-flower. As a consequence, visits are very rare and fruit set is low (18%). Pseudolaelia corcovadensis is self-compatible and presents inbreeding depression in the early stages of development. The phylogenetic position of the genus Pseudolaelia and studies on floral biology in related genera suggest that melittophyly and selfcompatibility are basal characters in the subtribe Laeliinae, with subsequent adaptive radiation to pollination by hummingbirds, Lepidoptera, Diptera and other Hymenoptera.

Biologia floral, melitofilia e influência de besouros Curculionidae no sucesso reprodutivo de Grobya amherstiae Lindl. (Orchidaceae: Cyrtopodiinae)

“…A porcentagem de sementes potencialmente viáveis em frutos originados das autopolinizações manuais (99,35%) não apresentou diferenças significativas em relação aos formados através de polinizações cruzadas (99,36%), nem tampouco em relação aos provenientes de condições naturais, com 99,6% e 99,7% nas populações A e B, respectivamente (tabela 1). O alto percentual de sementes viáveis em Grobya amherstiae não é comum em Epidendroideae, que geralmente apresenta espécies com alto número de sementes sem embrião (Lock & Profita 1975, Stort & Martins 1980, Stort & Galdino 1984, Borba et al 2001, Borba & Braga 2003. Outras Epidendroideae, como Xylobium squalens (Lindl.…”

Reproductive biology of Cyrtopodium polyphyllum (Orchidaceae): a Cyrtopodiinae pollinated by deceit

“…The occurrence of a high percentage of potentially viable seeds after manual pollinations and rain‐assisted self‐pollinations of C. polyphyllum is uncommon in Epidendroideae, whose species present a great number of seeds without embryos (Lock & Profita 1975; Stort & Martins 1980; Stort & Galdino 1984; Borba et al. 2001; Borba & Braga 2003). As reported here for C. polyphyllum, G. amherstiae (Mickeliunas et al.…”

Is the pollination efficiency of long-lived orchid flowers affected by age?

“…In this case, it was found that pollination efficiency was not affected by the flower age. Most studies using hand-pollination, however, provide no information on the age of the flowers in the tests (Stort & Galdino, 1984;Calvo, 1990;Galetto et al, 1997;Singer & Sazima, 1999;Singer, 2001Singer, , 2002Singer & Sazima, 2001;Borba & Braga, 2003;Gale, 2007;Peter & Johnson, 2009;Micheneau et al, 2010;Srimuang et al, 2010). In studies mentioning the flower age, hand-pollinations were performed on the first (Borba et al, 1999;Pansarin & Amaral, 2006;Li et al, 2008;Pansarin & Amaral, 2008;Aguiar et al 2011) or second day of floral anthesis (Vieira et al, 2007).…”