December 2012 Number 1 - Utah Native Plant Society

Utah Native Plant Society
Figure 1. Collection sites for four species of Phacelia included in the AFLP (Amplified Fragment Length Polymorphism)
study. Tissue samples were field-collected or greenhouse-grown tissue for P. argillacea and P. glandulosa
for Site 2, while samples from the other P. glandulosa sites and for P. argylensis were obtained from specimens in
the Brigham Young University herbarium. (Inset shows Spanish Fork Canyon, Utah, with extant P. argillacea subpopulations
in black, reintroduction sites in green).
Through U.S. Fish and Wildlife funding, a working
group was organized in 2004 to focus on the introduction
of P. argillacea into suitable and presumably previously
occupied habitat on public land in Spanish Fork
Canyon, an action recommended in the recovery plan
for this species (US Fish and Wildlife Service 1989).
Because many endangered plants with small population
sizes and fragmented populations, such as P. argillacea,
suffer higher risk of extinction due to genetic drift and
inbreeding as well as stochastic environmental effects,
an introduction program is almost essential for rare
plants like P. argillacea (Kang et al. 2005). In 2007,
seeds produced from greenhouse-grown individuals
from the Tucker site were introduced at two new sites
on US Forest Service land. The inset in Figure 1 depicts
the location of the reintroduction sites (Mill Fork and
Tie Fork) with reference to the extant P. argillacea
populations.
Analysis of the genetic diversity within and between
the P. argillacea populations was also necessary because
the species had never been studied at the molecular
level. Analysis of the genetic diversity of an endan-
gered plant species is a key element in the estimation of
the viability of a population and can assist in conservation
programs (Ronikier 2002, Kang et al. 2005). Data
were also needed to address the question of whether P.
argillacea was truly a distinct species or simply a disjunct
population of P. glandulosa. Amplified Fragment
Length Polymorphism (AFLP) was the molecular
marker chosen to quantify genetic diversity. AFLPs
were chosen because they have the potential to resolve
genetic differences for individual identification and require
no prior sequence knowledge of the organism. In
this study AFLP analysis was used to address the following
questions with regard to reintroduction of P. argillacea:
(a) What is the level of genetic diversity in the
two populations? (b) Is there genetic differentiation between
the two populations? (c) Do samples collected
within a population within a single year represent a random
sample of genetic variation, or is there genetic differentiation
between years? (d) Is P. argillacea genetically
distinct from its close congeners P. argylensis and
P. glandulosa? The answers to these questions should
help to inform reintroduction efforts for this organism.
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