Contrasting bee pollination in two co-occurring distylic species of Cordia (Cordiaceae, Boraginales) in the Brazilian semi-arid Caatinga: generalist in C. globosa vs. specialist in C. leucocephala

Abstract

In this study we compare the reproductive biology of Cordia globosa and C. leucocephala (Cordiaceae, Boraginales; formerly referred to Boraginaceae) to understand the functioning of the floral morphs and the relations with their effective pollinators. The species are synchronopatric, distylic, and self-incompatible. Though they share melittophilous traits, the main visitor and pollinator of C. globosa was the generalist and exotic bee Apis mellifera, while the only one of C. leucocephala was the oligoletic bee Ceblurgus longipalpis. These two latter species are restricted to the Caatinga of NE Brazil, contrasting with the wide distribution of Cordia globosa. While the fruit-set for C. globosa was high, independently if the pollen donor/stigma receptor was a pin (long-styled) or thrum (short-styled) individual, in C. leucocephala the fruit-set was low and occurred only when a thrum individual was the pollen donor. This raises the possibility of this species moving towards dioecy. The high natural fruit-set of C. globosa confirms the generalist bee as its effective pollinator. The low fruit-set after manual crosses in C. leucocephala may be due to low pollen viability. Additionally, the low natural fruit-set (two times lower than after crosses) may be related with the foraging behavior of the specialist pollinator.

The genus Cordia: botanists, ethno, chemical and pharmacological aspects

“…C. sellowiana and C. myxa are species found in the temperate regions of the whole world and in the tropics . C. flavescens, C. globosa and C. goeldiana are widely distribute in various regions including: Florida, Caribbean, Central America and northeastern South America, it is limited to the Caatinga (Machado et al, 2010). C. laurecea and C. leucocephala are species endemic to Northeast Brazil and are widely cultivated for ornamental purposes (Machado et al, 2010;Milet-Pinheiro and Schlindwein, 2010).…”

“…C. flavescens, C. globosa and C. goeldiana are widely distribute in various regions including: Florida, Caribbean, Central America and northeastern South America, it is limited to the Caatinga (Machado et al, 2010). C. laurecea and C. leucocephala are species endemic to Northeast Brazil and are widely cultivated for ornamental purposes (Machado et al, 2010;Milet-Pinheiro and Schlindwein, 2010). C. macleodii and C. nodosa have a wide distribution in tropical America (Izzo and PetInI-BenellI, 2011).…”

Heterostyly and the possibility of its breakdown by polyploidization

“…and Arroyo (1982);Sobrevila et al (1983);Feinsinger and Busby (1987);Jung-Mendançolli and Melhem (1995);Ree (1997);Coelho and Barbosa (2003);Mendonça and Anjos (2006);Pereira et al (2006);Hernández and Ornelas (2007);Machado et al (2010a);Silva et al (2010);Valois-Cuesta et al (2011) …”

Distylous traits in Cordia dodecandra and Cordia sebestena (Boraginaceae) from the Yucatan Peninsula

“…In the present study, intramorph incompatibility was confi rmed for C. dodecandra at the fruit level. Under natural conditions, higher fruit production was observed in long-styled fl owers indicating that pollinators exert an effect on the success of intermorph cross-pollination as it was observed in C. globosa and C. leucocephala from Brazil (Machado et al, 2010). Hummingbirds are the principal pollinators in both the studied Cordia species, suggesting that the probability of the stigma touching the pollen-impregnated head of a hummingbird is greater in long-styled than in short-styled fl owers.…”