Genet structure and determinants of clonal structure in a temperate deciduous woodland herb, Uvularia perfoliata

Kudoh, H Shibaike, H Takasu, H Whigham, DF Kawano, S

H. Kudoh et al., Genet structure and determinants of clonal structure in a temperate deciduous woodland herb, Uvularia perfoliata, J ECOLOGY, 87(2), 1999, pp. 244-257

69

INGLESE

Article

Environment/Ecology

JOURNAL OF ECOLOGY

0022-0477 → ACNP

87

2

1999

244 - 257

ISI

0022-0477(199904)87:2<244:GSADOC>2.0.ZU;2-M

1 We used isozyme variation to examine the genet structure of Uvularia perf oliata patches in gap and closed canopy habitats in a temperate deciduous f orest in Maryland, USA. 2 A large patch in a gap habitat was composed of a small number of widely s pread genets with many ramets, and a large number of genets with more restr icted distribution and few ramets, Genets with many ramets were patchily di stributed at a metre scale. Analysis of genet structure on a scale of squar e centimetres, however, revealed that the genets were highly intermingled w ith no clear boundaries between them. The presence at both scales of sampli ng of many genets with unique multilocus genotypes indicated continuing gen et recruitment within the population. 3 In the closed canopy habitat, the patches examined were each composed of a single unique multilocus genotype, suggesting that each had developed by asexual propagation following the establishment of a single genet. 4 The clonal structure of U. perfoliata patches in both gap and closed cano py habitats therefore appears to depend on recruitment patterns of genets. Populations in closed canopy habitats are characterized by a 'waiting' stra tegy, in which asexual ramet production maintains populations until genet r ecruitment by seed production can occur under the more optimal conditions a ssociated with canopy gaps. Extended sampling suggests that the genetic div ersity of U. perfoliata populations is primarily controlled by the disturba nce regime of the forest canopy.