| Autor: |
Nassar JM; University of Miami, Biology Department, PO Box 249118, Coral Gables, FL 33124, USA. jnassar@oikos.ivic.ve, Hamrick JL, Fleming TH |
| Jazyk: |
angličtina |
| Zdroj: |
Heredity [Heredity (Edinb)] 2001 Jul; Vol. 87 (Pt 1), pp. 69-79. |
| DOI: |
10.1046/j.1365-2540.2001.00910.x |
| Abstrakt: |
Genetic diversity was measured in the mixed-mating cactus, Melocactus curvispinus, in Venezuela. Allozyme diversity was surveyed in 19 putative loci over 18 populations. Compared to other plant taxa, this cactus is rich in polymorphic loci (Ps=89.5%), with high numbers of alleles per polymorphic locus (APs=3.82), but moderate levels of heterozygosity (Hes=0.145). Substantial levels of inbreeding were detected across loci and populations at macrogeographic (FIS=0.348) and regional levels (FIS=0.194-0.402). Moderate levels of genetic differentiation among populations were detected at macrogeographical (FST=0.193) and regional (FST=0.084-0.187) scales, suggesting that gene flow is relatively restricted, but increases within regions without topographic barriers. The population genetic structure observed for this cactus was attributed to, at least, three factors: short-distance pollination and seed dispersal, the mixed-mating condition of the species, and genetic drift. High genetic identities between populations (I=0.942) supported the conspecific nature of all populations surveyed. The levels and patterns of genetic structure observed for M. curvispinus were consistent with its mating system and gene dispersal mechanisms. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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