The epiphyte bromeliad Catopsis berteroniana (Schult. & Schult. f) Mez was classified in the Norma Oficial Mexicana 059 (NOM-059-ECOL-2001) as a species that requires special protection. In Oaxaca, México, it is commonly sold in the local markets as an ornamental plant for several religious festivities. Plants are collected by settlers in the localities of El Cerezal and Reynoso in the Santa Catarina Ixtepeji municipality, where the vegetation is a dry fragmented shrub and disturbed oak forest respectively. Because of its collection and forest reduction and fragmentation, we expected a pauperized genetic diversity in these localities. We analyzed the genetic diversity of this bromeliad using starch gel electrophoresis and tested for a recent bottlenecks using the model of Luikart and Cornuet 1998. Change of vegetation was analysed using Sensor MSS maps for 1979 and Sensor SPOT 5 maps for 2005
Results/Conclusions
Contrary to our expectations, C. berteronina displayed one of the highest levels of genetic diversity in the family. Nine out of the ten loci analyzed were polymorphic, the mean number of alleles per locus was 3.4 and mean observed heterozygosity was 0.402 (expected heterozygosity was 0.292). Although we calculate a Fis value of 0.256 showing a small endogamy among populations, the populations of El Cerezal and Reynoso were not genetically differentiated (Fs t= 0.021, ns). We did not find evidence of recent bottleneck despite the high levels of forest fragmentation and collection. The rate of deforestation in this region was calculated as 9.1 % per decade. Although the total forest area is being severely reduced, the perimeter of the forest fragments has increased, probably favoring gene flow and establishment, as this species appears to grow better in forest edges. This result shows that some plant species may benefit to certain extent with forest fragmentation
