Breeding system variability, pollination biology, and reproductive success of rare Polemonium caeruleum L. in NE Poland

Beata Ostrowiecka,Ada Wróblewska,Katarzyna Roguz,Izabela Tałałaj,Paweł Mirski,Justyna Ryniewicz,Emilia Brzosko,Marcin Zych,Edyta Jermakowicz

doi:10.5586/aa.1709

Beata Ostrowiecka, Ada Wróblewska + Show 7 more

Open Access

https://doi.org/10.5586/aa.1709

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Journal: Acta Agrobotanica	Publication Date: Mar 31, 2017
Citations: 3	License type: CC BY 4.0

Affiliation: University of Białystok, University of Warsaw

Abstract

Polemonium caeruleum (Polemoniaceae) represents a very interesting system of compatibility transition. Studies of its biological and ecological properties in the context of the breeding system of various populations may help to understand the evolutionary mechanism of this process. We investigated some aspects of the breeding system, diversity and foraging behavior of the visitors, and relationship between population properties and fruit set in three populations from NE Poland. We found distinct compatibility systems in two studied populations and showed that if a population is self-compatible (SC), selfing is mediated by insects via geitonogamous pollen transfer. Despite the population properties (compatibility, visitor diversity and activity, population size, density, or floral display), P. caeruleum is not pollen limited and pollinators are highly important as a key factor determining the high reproductive success. Visitor assemblages (including key pollinators, bumblebees, and honey bees) and their foraging behavior on inflorescences vary between the populations, which may influence differences in the breeding system. The self-incompatible population was visited by a more diverse group of insects from Hymenoptera, Diptera, Lepidoptera, Heteroptera, and Coeloptera, which may favor effective cross-pollen transfer, whereas the SC population was pollinated mainly by Apis mellifera, which may promote mixed-mating. Studies on a wider range of P. caeruleum populations are needed to determine selective factors responsible for compatibility transition.

Highlights

Recent studies have shown that the majority of angiosperms suffer from pollen limitation [1,2,3] and most of them are self-compatible (SC), which enables selfing and protects against pollinator deficiency [4,5,6]
We examined three populations of P. caeruleum located in NE Poland, in which we attempted to determine: (i) their compatibility system, (ii) visitor diversity and activity within inflorescences, (iii) the relationship between population properties and fruit set
We detected no significant differences in fruit set between supplemental outcross and controlled pollination (Fisher’s exact probability test, p > 0.05) and no significant differences in seed number obtained from both treatments in the OP and KO populations

Summary

Introduction

Recent studies have shown that the majority of angiosperms suffer from pollen limitation [1,2,3] and most of them are self-compatible (SC), which enables selfing and protects against pollinator deficiency [4,5,6]. Because selfing progeny usually suffers strongly from inbreeding depression, plants may protect themselves against excessive share of selfing in the overall breeding system. These adaptations are connected with the spatial and temporal separation of male and female structures within the flower and inflorescence [9] or with modification of pollinators’ behavior due to, e.g., floral display or deception [10,11,12,13]. Self-compatible plants are distinguished by higher reproductive success and lower quality of offspring than self-incompatible species [5,11]

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