Dynamics of closely related invading plant species can be governed by the interaction between their shared pollinators and the plants breeding systems. Difference in pollinator behaviour and plant breeding systems underpin the patterns of interspecific hybridization and asymmetrical gene flow in a plant community. Hybridization between co-invading species has major impacts on invasion outcomes and it can be facilitated by pollinators visitation. In particular, one-directional bias in pollinators visitation can change the rate of interspecific pollen transfer between species. Hence, it can affect species succession and eventually alter population dynamics. In this research, we aimed to elucidate how increased pollinator visitation on distinct floral traits would result in increased pollen transfer of that particular species in the population. Hence, we have constructed a population of Cakile sp. (Brassicaceae) involved 8 C.maritima, 8 C.edentula and 8 F1 hybrid plants. Then, we monitored pollinators behaviour using a high-resolution video recorder.
Results/Conclusions
The results retrieved from analysing 3 hours of recorded videos illustrated that out of 2771 visits, almost 44% of pollinators movement assigned to maritma-maritima direction. The second direction which had the highest traffic was movement between F1 hybrids (36%). The lowest traffic was assigned to the movement between the parental species, maritima-edentula direction (0.87%). As expected, backcrossing between maritima parents and hybrids in both directions was almost 6 times higher compared to backcrossing with edentula parents, ~6.5% and ~1% respectively.
Our experimental studies showed that pollinator preference strongly affected by floral attractiveness and it caused a biased intraspecific movement between C.maritima species as well as F1 hybrid plants. Another major consequence was higher bi-directional movement between the one of the parental species and the F1 progenies. Indeed, F1 hybrids were more attracted to backcross with C.maritima than with C.edentula because they have greater floral traits than C.edentula. These findings, in combination with measuring relative allele frequency in the next generation would explain the effects of pollinator visitation history and pollen dispersal on mating patterns and geneflow in a population. To assess successful cross-fertilisation under open-pollination, we show how differences in pollinators' behaviour will be translated into the genotypes of the seeds produced. To elucidate the genetic basis of hybrids between the out breeder (C.maritima) and the inbreeder (C.edentula), all F2 progenies generated from our population will be genotyped using MinION sequencing.