Pollination biology and breeding system of Zeyheria montana (Bignoniaceae)

Abstract

The reproductive biology of Zeyheria montana was studied through field observations of flower visitors and floral events, controlled manual pollinations, and observations of pollen tube growth and ovule penetration by fluorescence microscopy. Analysis of secretory areas of the nectar chamber was made by flower dissections and histology of serial sections. The flower lasted 6-8 days, but pollen exposure and stigma receptivity occurred only up to the end of the first and second days, respectively. Pollination was effected by several species of hummingbirds, especially Colibri serrirostris. The flowers present a rudimentary, non-functional disc, and secretion of nectar is performed by corolla-borne glandular trichomes. Only hand cross-pollinated and natural-pollinated flowers set fruits. Artificially selfpollinated and non-pollinated flowers dried off after anthesis without presenting any swelling of the ovary. Almost all the ovules in selfed and crossed pistils were penetrated 96 h after pollination. However, a delay in ovule penetration in self-pollinated pistils was verified, which indicates the occurrence of late-acting self-incompatibility.

Sistema reprodutivo do Ipê-Branco: Tabebuia roseo-alba (Ridley) Sandwith (Bignoniaceae)

“…1999), Tabebuia nodosa (Gibbs & Bianchi 1999), Spathodea campanulata , Zeyheria montana (Bittencourt & Semir 2004), Handroanthus umbellatus, H. impetiginosus, H. vellosoi (Bittencourt & Semir 2005 e Jacaranda racemosa (Bittencourt & Semir 2006), confi rmando a hipótese de que a autoesterilidade em espécies de diferentes gêneros de Bignoniaceae apresenta uma série de características em comum e representa um caráter basal do grupo. Por sua vez, a autofertilidade em Bignoniaceae (Bittencourt & Moraes 2010) parece ser um caráter derivado que pode ter emergido diversas vezes na família a partir de ancestrais autoincompatíveis.…”

“…Apesar da diversidade de espécies existente em Bignoniaceae -cerca de 827 espécies (Lohmann 2006) distribuídas em 82 gêneros (Olmstead et al 2009), das quais aproximadamente 620 são espécies neotropicais (Spangler & Olmstead 1999) -, investigações sobre os seus sistemas reprodutivos são relativamente escassas, tendo sido realizadas em pouco mais de 6% (51 espécies) da família (Gibbs & Bianchi 1999;Dutra & Machado 2001;Bittencourt et al 2003;Bittencourt & Semir 2004;2006;Correia et al 2005;2006;Carvalho et al 2007;Yanagizawa & Maiomni-Rodella 2007;Guimarães et al 2008;Maués et al 2008;Srithongchuay et al 2008;Polatto & Alves 2009;Sampaio 2010). Esses estudos indicaram que, com exceção de Pyrostegia venusta (Gobatto-Rodrigues & Stort 1992), Astianthus viminalis (Bullock 1985), Tecoma stans (Singh & Chauhan 1996;Dutra & Machado 2001), Handroanthus chrysotrichus (syn.…”

Floral visitors and reproductive strategies in five melittophilous species of Bignoniaceae in Southeastern Brazil

“…In some bignon species that share the same pool of pollinators, mainly bees, seasonal separation would also be an important isolating mechanism (Gentry 1974a(Gentry , 1974b. The floral biology of bignon species has been investigated in some communities in Brazil (Yanagizawa and Gottsberger 1983, Amaral 1992, Gobatto-Rodrigues and Stort 1992, Barros 2001, Dutra and Machado 2001, Lopes et al 2002, Bittencourt Jr. and Semir 2004, 2005. In the Botucatu region, São Paulo State, Southeastern Brazil, species of Bignoniaceae occur in vegetation fragments (GromboneGuaratini and Maimoni-Rodella 1995;Silberbauer-Gottsberger and Eiten 1983).…”

Pollination biology in Jacaranda copaia (Aubl.) D. Don. (Bignoniaceae) at the "Floresta Nacional do Tapajós", Central Amazon, Brazil

“…Mart. (Bittencourt Júnior & Semir 2004), but in J. copaia these agents were considered simply occasional pollinators, due to their low frequency and unspecialized bird syndrome flower traits. Cornucopia flowering phenology also contributes to long distance pollinators' attraction.…”

“…But despite low density and sometimes asynchronous flowering, which have led to misconceptions about the ability of these plants to attract pollinators and have allogamous fruit set (Corner 1954, Fedorov 1966, they do attract efficient long distance pollinators as large solitary or subsocial bees (Bawa et al 1985, Dick et al 2004. For the tropical Bignoniaceae, a diverse assemblage of pollinators seems to have influenced flowering morphology and guaranteed fruit-set of these largely self-incompatible plants (Gentry 1974a, Gibbs & Bianchi 1999, Bittencourt Júnior & Semir 2004, Gottsberger & Silberbauer-Gottsberger 2006. Flowering phenology patterns, defined according to the duration and intensity, were also related with pollination biology (Gentry 1974b, Van Schaik et al 1993, Morellato et al 2000.…”