Abstract
ABSTRACT In heterantherous flowers, some anthers have an attraction and feeding function, while others are related to plant reproduction. Microlicia cordata has dimorphic stamens organized in two cycles: the antesepalous one with large stamens and pink anthers, and the antepetalous one with small stamens and yellow anthers. Division of labor was analyzed using the parameters of structure, composition, amount and estimated viability of pollen, and the color of floral parts. The anthers of the pollinating stamens were larger than the anthers of the feeding stamens, although anatomically similar. There was a difference in the amount of pollen produced by the anthers of the two cycles, but no difference was found in pollen viability. Considering a bee color vision model, the color of the anthers of the pollinating stamens contrasted less with that of the corolla, and thus is probably less attractive to visitors. Conversely, the anthers of the feeding stamens and the ventral appendage of the connective of the pollinating stamens contrasted more with the corolla, presenting the same color to the pollinators. These results are in accordance with the idea of division of labor among anthers of heterantherous flowers, especially regarding the quantity of pollen and the color of the floral parts.
Highlights
Among the Angiosperms, approximately 20,000 species contain pollen as the only reward for their pollinators in the so-called pollen flowers (Vogel 1978; Buchmann 1983; Luo et al 2009)
The study was conducted at the Private Natural Heritage Reserve (RPPN) of the Clube Caça e Pesca de Uberlândia, Minas Gerais, Brazil (18 ̊59’S 48 ̊18’W), an area of 640 hectares on the banks of the Uberabinha river covered with a cerrado sensu stricto, dry grasslands and palm swamp areas (Apolinário & Schiavini 2002)
The pollinating anthers are larger than the feeding anthers (p
Summary
Among the Angiosperms, approximately 20,000 species contain pollen as the only reward for their pollinators in the so-called pollen flowers (Vogel 1978; Buchmann 1983; Luo et al 2009). The occurrence of two or more types of stamens in the same flower, or heteranthery, is understood as a mechanism for the solution of this conflict since it generates specialization of stamen types with different and specific functions in the pollination process (Luo et al 2008; VallejoMarín et al 2009; Barrett 2010) These stamens differ in shape, position, size and/or color, a condition that has arisen in at least 16 angiosperm families (Buchmann 1983; Luo et al 2009; Vallejo-Marín et al 2009; 2010; Barrett 2010).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
