Habitat, Seed Dormancy, and Allozyme Variation of the Rare Endemic Phacelia cookei (Boraginaceae)

We conducted habitat, germination, and population genetic studies to inform management priorities for Phacelia cookei Constance & Heckard (Boraginaceae), a diminutive annual herb known from only four populations near Mt. Shasta in Siskiyou Co., California. Habitat surveys characterized soil, veg...

Full description

Saved in:
Bibliographic Details
Published in:Madroño 2013-01, Vol.60 (1), p.11-23
Main Authors: Patterson, M. E., Ivey, C. T., Edwards, A. L., Schierenbeck, K. A., De Queiroz, T. Forbis, Nelson, J. K.
Format: Article
Language:English
Subjects:
Boraginaceae
Conservation
Conservation biology
Ecological genetics
endemism
Genetic diversity
Germination
habitat
Habitat conservation
Habitats
Nama densum
Phacelia cookei
Plants
Population genetics
rarity
Research s
seed dormancy
Seeds
Volcanic rocks
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We conducted habitat, germination, and population genetic studies to inform management priorities for Phacelia cookei Constance & Heckard (Boraginaceae), a diminutive annual herb known from only four populations near Mt. Shasta in Siskiyou Co., California. Habitat surveys characterized soil, vegetation, and ground cover of extant populations and attempted to identify potentially suitable, but uncolonized, habitat. We were unable to distinguish any sites based on tests of soil characteristics. Nama densum Lemmon occurred at all sites where P. cookei was present. We identified several areas near existing populations that appeared to be suitable, but uncolonized, habitat. We tested the effects of various factorial combinations of after-ripening, scarification, stratification, and variable germination temperatures on breaking seed dormancy. Seed viability by tetrazolium tests ranged between 89% and 93%, but the highest germination from any treatment combination was 14% after adjusting for seed viability. We resolved 19 putative allozyme loci, two of which were polymorphic. Apparent genetic diversity was low both within and among the three sampled populations compared to similar endemic species, and populations were genetically similar. Management plans could consider attempting to expand existing populations by sowing seeds from existing populations into similar habitat.
ISSN:0024-9637
1943-6297
DOI:10.3120/0024-9637-60.1.11