Lk. Massey et Jl. Hamrick, GENETIC DIVERSITY AND POPULATION-STRUCTURE OF YUCCA-FILAMENTOSA (AGAVACEAE), American journal of botany, 85(3), 1998, pp. 340-345
Using 19 allozyme loci we studied genetic diversity in 18 populations
of Yucca filamentosa (Agavaceae) from the southeastern United States.
Of the 19 loci surveyed, 17 (89.5%) were polymorphic in at least one a
f the populations sampled. There was considerable variation among popu
lations in the percentage of polymorphic loci (range = 31.6-84.2%, mea
n = 67.6%). Similar heterogeneity among populations was observed for m
ean number of alleles per polymorphic locus (range = 2.0-3.0; mean = 2
.48) and mean expected heterozygosity (range = 0.113-0.288: mean = 0.2
13). On average, 83% of the total genetic diversity was found within p
opulations. Duplications of three allozyme loci were detected in sever
al populations. The life-history characteristics of Y. filamentosa (a
long-lived, semiwoody. predominantly outcrossing monocot with a large
geographical range) may contribute to the maintenance of such high lev
els of genetic diversity. These results contradict expectations of the
genetic structure of Y. filamentosa based on observations of the disp
ersal and pollination behavior oi its sole pollinator, Tegeticula yucc
asella, the yucca moth.