Abstract Detail

Reproductive Processes

Perez-Barrales, Rocio [1], Sa, Tulio [2], Matias, Rapahel [3], Rodrigues, Ebenezer [4], Consolaro , Hélder [5], Cardoso de Castro, Cibele [6].

Does pollinator preference and flower traits affect reproduction in co-flowering species?.

Flowering phenology affects plant-to-plant interactions and reproductive success through pollinator preference and behaviour. These interactions in seasonal climates are constrained by the length of the flowering season, which often creates overlapping flowering phenologies of species in the community. Diverse communities can attract and maintain a wider diversity of pollinators, but if closely related species co-flower, they might share pollinators, in turn generating complex ecological dynamics of pollen delivery and deposition. We investigated the variation of flower traits of co-flowering Palicourea coriacea and P. officinalis, two Rubiaceae species that flower from mid-October to January, and from end-November to February respectively in the Brazilian Cerrado. We studied pollinator behaviour and preference at different moments of the flowering (before and during co-flowering, the later in single species and co-occurring patches) to describe patterns of pollen delivery and deposition in P. coriacea. Early in the season, P. coriacea was visited by Bombus atratus, and occasionally by hummingbirds. During the co-flowering period, B. atratus visited single species patches of P. coriacea and patches with the two species, but hummingbirds only visited the later, and B. atratus visitation was higher in the single patches of P. coriacea. Pollen delivery was higher in the single species patches, but pollen deposition on the stigmas was higher in the patches where both Palicourea species co-occur. Both species have similar flowers, but P. coriacea has a shorter flower tube, with less nectar than P. officinalis. Our results indicate that B. atratus preferred P. coriacea as evidenced by the higher visitation in solitary patches during the co-flowering period, that in turn correlated with higher pollen delivery rates. The lower visitation rate in patches with the two species may reflect a decrease in the probability of finding nectar. This could be due to finding flowers with less nectar as a result of the hummingbird activity. Alternative, because patched with the two species have on average longer flower tubes (12 mm), B. atratus might be less likely to reach the nectar (average proboscis length of 6.2 mm). Either way, uncertainty in finding nectar would increase the time per flower to find nectar and contact rate with the stigmas, resulting in higher rates of pollen deposition in patches with the two species. These results revealed complex pollen dynamics, creating reproductive conflicts of interest in P. coriaceae with closely related species, that could be solved by shifting flowering peaks to decrease pollinator competition.

1 - University Of Porstmouth, School Of Biological Sciences, King Henry Building, King Henry 1st Street, Portsmouth, HAM, PO1 2DY, United Kingdom
2 - Universidade Federal de Pernambuco, Biology department, Botany area
3 - QI 11, Bloco E, Apto 215, Guará, DF, 71020350, Brazil
4 - Universidade Federal de Uberlândia, Instituto de Biologia, Brazil
5 - Federal University of Catalão, Catalão, Goiás, Biotechnology Institute, Brazil
6 - Universidade Federal de Pernambuco, Academic Unit of Garanhuns, Brazil

Keywords:
pollination
reproductive biology
Flower morphology
nectar
flowering phenology.

Presentation Type: Oral Paper
Session: REP2, Reproductive Processes 2
Location: Virtual/Virtual
Date: Wednesday, July 29th, 2020
Time: 2:00 PM
Number: REP2007
Abstract ID:726
Candidate for Awards:None