VARIATION IN ALLOZYMES AND STOMATAL SIZE IN PINYON (PINUS-EDULIS, PINACEAE), ASSOCIATED WITH SOIL-MOISTURE

Citation
Jb. Mitton et al., VARIATION IN ALLOZYMES AND STOMATAL SIZE IN PINYON (PINUS-EDULIS, PINACEAE), ASSOCIATED WITH SOIL-MOISTURE, American journal of botany, 85(9), 1998, pp. 1262-1265
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences
Journal title
ISSN journal
0002-9122
Volume
85
Issue
9
Year of publication
1998
Pages
1262 - 1265
Database
ISI
SICI code
0002-9122(1998)85:9<1262:VIAASS>2.0.ZU;2-F
Abstract
Microgeographic allozyme variation was examined in pinyon pine, Pinus edulis, among five collection sites in Owl Canyon, Colorado. Relativel y dry and moist sites were identified by associated plant communities and the sizes and densities of trees. Three moist sites and two dry si tes were compared, and because all sites were within 600 m of one anot her, isolation by distance was not considered as a viable explanation of genetic differentiation between sites. Allelic frequencies at glyce rate dehydrogenase (Gly) differed by 14% between moist and dry areas, and the pattern of microgeographic variation found here-allele 3 highe r in frequency on dry sites-was consistent with previous studies of mi crogeographic variation in contrasting moist and dry sites. Trees with in one of the dry sites were examined to test the hypothesis that stom ata sizes and densities are heterogeneous among Gly genotypes. Heteroz ygotes had the longest and widest stomata; the stomatal area of hetero zygotes was 28% greater than the stomatal area of homozygotes. Whereas the stomatal areas of the two homozygotes were similar, their shapes did not overlap when projected on a bivariate plot of length and width . These results suggest that stomatal shape may play a role in adaptin g pinyon to heterogeneity in soil moisture.