Microsatellites of Primula vulgaris in translocated golf course populations

Background and Aims
Species forced back into intensively used agricultural landscapes face severe disturbance and random destruction, making alternative restoration measures necessary. In Western Europe, Primula vulgaris, a perennial heterostylous herb, is nowadays restricted to fragmented habitats in arable landscapes. Translocations were conducted at five locations on a golf course area, using outcrossed juveniles originating from remnant populations. This study aimed to: (i) evaluate the golf course’s contribution to species conservation; (ii) assess source population suitability; and (iii) determine the translocation network's impact on genetic diversity and gene flow of neighbouring populations.

Methods
We conducted a demographic (census size, demographic structure, morph ratio) and genetic study (genetic diversity and structure, connectivity network, barrier and parentage analyses), using 13 microsatellite loci across adult and juvenile generations of translocated, adjacent, and remote metapopulations, for pre- and post-translocation periods.

Key Results
Golf translocated populations nearly doubled the local census size, provided 1/3 of the breeders, harboured similar genetic diversity to agricultural metapopulations, and were representative of source populations. Most populations, even translocated and large ones, were senescent. There was overall genetic erosion and local increases in inbreeding over time, threatening long-term population sustainability. Genetic erosion was associated with flowering size and pin proportion, and exacerbated in juveniles, suggesting S Allee and genetic drift effects, but also illegitimate pollination. Translocations enhanced pollen flow and potential connectivity among adjacent populations, although barriers between remnant populations persisted.

Conclusions
Using recreational infrastructures as alternative sites for plant translocations, at distances that enable effective pollen flow to integrate new populations into the local network, can contribute to preserving species' regional demographic and genetic pools, while increasing connectivity. However, management control of landscape elements where the remnant populations occur remains highly desirable, not only for safeguarding existing old, still genetically diverse adults, but also to guarantee balanced morph ratios and population rejuvenation.

Methods
Translocations were conducted at five locations on a golf course area, using outcrossed juveniles originating from remnant populations.

Only transplants obtained from legitimate outcrosses (between morphs) were used. Translocations were conducted (1) in G1 in 2007 with 1-year old transplants (N =180); (2) in G2 and G3 in 2008, with plantlets taken from G1 –that had rejuvenated and increased in size– (N = 100); (3) in 2009 in G4 with plantlets from G1 (N = 140), and for enlarging G2 (an additional N = 25); and (4) in 2013 in G5, with plantlets taken from various previously translocated Golf populations (N = 30).