Abstract Detail

Conservation Biology

EDWARDS , CHRISTINE E [1], Weekley, Carl W. [2], Menges, Eric S. [2], Smith, Stacy A. [2].

Parentage analysis of ex-situ reintroductions of the federally endangered, self-incompatible Ziziphus celata reveals disproportionate contributions of genotypes and asymmetry of parental role.

Ziziphus celata (Rhamnaceae) is a federally endangered shrub endemic to central Florida. Z. celata is currently known in the wild from only 15 populations, and within those populations, very few extant wild genotypes remain. The species is also highly clonal; for example, 9 of the 15 wild populations are uniclonal (i.e. each population comprises a single genetic individual). Further complicating the recovery of this species is the reproductive failure of most experimental crosses due to gametophytic self-incompatibility. Because of high clonality, self-incompatibility, and low numbers of wild extant genotypes, currently no natural seedling recruitment occurs in the wild. Recovery efforts for Z. celata have therefore focused on augmentation of uniclonal populations and ex-situ reintroduction of genetically diverse populations into publicly protected sites. An ex-situ population in Bok Tower Gardens containing individuals of several different mating types has produced a large number of seedlings, which have been transplanted in a series of augmentations and ex-situ reintroductions. In this study, our goal was to carry out parentage analysis of the seedlings used in the augmentations and ex-situ reintroductions to understand the overall contribution of genotypes to the gene pool and to assess the relative roles of each genotype as pollen donors and recipients. Twelve microsatellite loci were used to genotype and ascertain the parentage for over 600 individuals of Z. celata. Analysis of parentage data revealed that certain parental pairs disproportionately contributed to the gene pool. Significant asymmetry in parental role was also detected; some individuals were more likely to be the pollen donor, while others were more likely to be the pollen recipient.  Two genotypes were the pollen donor in the vast majority of crosses, suggesting that differences in pollen viability among genotypes may be affecting mating success.  For one new ex-situ reintroduction, parentage analysis was carried out prior to transplantation, allowing for the spatial structuring of genotypes in the field to maximize the proximity of cross-compatible genotypes to increase the potential for sexual reproduction.  These results demonstrate that parentage analysis is an important tool to help understand the reproductive biology of endangered plant species and the genetic composition of ex-situ reintroductions.  Parentage analysis prior to transplantation may be vital to create self-sustaining populations in plant species with reproductive hurdles.

1 - Missouri Botanical Garden, Center for Conservation and Sustainable Development, PO Box 299, St. Louis, MO, 63166, USA
2 - Archbold Biological Station, 123 Main Drive, Venus, FL, 33960, USA

Keywords:
ex situ conservation
parentage analysis
conservation genetics
Microsatellite
reproductive biology
Self-incompatibility
Endangered species
Rhamnaceae.

Presentation Type: Oral Paper:Papers for Topics
Session: 27
Location: Firs North/Boise Centre
Date: Tuesday, July 29th, 2014
Time: 2:30 PM
Number: 27005
Abstract ID:608
Candidate for Awards:None