Open AccessGenetic variation and population structure of the mixed‐mating cactus, Melocactus curvispinus (Cactaceae)
Author(s) -
Nassar Jafet M.,
Hamrick J. L.,
Fleming Theodore H.
Publication year - 2001
Publication title -
heredity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.441
H-Index - 118
eISSN - 1365-2540
pISSN - 0018-067X
DOI - 10.1046/j.1365-2540.2001.00910.x
Subject(s) - biology , inbreeding , gene flow , genetic structure , genetic diversity , population , biological dispersal , cactus , locus (genetics) , genetic variation , mating system , evolutionary biology , population genetics , genetic drift , seed dispersal , allele , mating , genetics , ecology , gene , demography , sociology
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 ( P s =89.5%), with high numbers of alleles per polymorphic locus ( AP s =3.82), but moderate levels of heterozygosity ( H es =0.145). Substantial levels of inbreeding were detected across loci and populations at macrogeographic ( F IS =0.348) and regional levels ( F IS =0.194–0.402). Moderate levels of genetic differentiation among populations were detected at macrogeographical ( F ST =0.193) and regional ( F ST =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.