TITLE:
Outlier Stands of Quaking Aspen in the Davis Mountains of West Texas: Clone or Clones?
AUTHORS:
Jerritt Nunneley, O. W. Van Auken, John Karges
KEYWORDS:
Populus tremuloides, Genetic Diversity, PCR, SSRs, Conservation
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.15,
July
9,
2014
ABSTRACT:
Populus tremuloides (quaking aspen) is found from the Pacific to the
Atlantic Ocean in the northern United States and Canada, and at higher
elevations in the western United States and northern Mexico. While P.
tremuloides can reproduce
sexually or asexually, it is primarily a clonal species in the intermountain
west, reproducing vegetatively via root sprouts, yielding genetically identical
stems or ramets. In west Texas, isolated, outlier stands occur in the
Guadalupe, Davis, and Chisos Mountains at an elevation of approximately 2300 m.
This study utilized seven microsatellites or simple sequence repeats (SSRs) to
examine leaf samples from 10 widely separated stems in 10 isolated P.
tremuloides individual stands
within the Davis Mountains to determine the level of clonal and genetic
diversity. We then examined differentiation among stands. Each stem sampled
within a stand was genetically identical to all stems examined in that stand or
was part of a clone. There were eight genetically identical clones from these
ten stands, with three stands being genetically identical or part of the same
clone. Many of the genotypes shared several of the same alleles and the
remaining alleles were only a few base pairs apart. Some of these alleles have
been previously identified in other western North American P. tremuloides stands.
Microsatellites identified several triploid patterns consistent with possible
aneuploidy, which is concurrent with previous studies.