Testing the effectiveness of DNA-barcoding for species discrimination in tropical montane cloud forest vascular plants (Oaxaca, Mexico) using BLAST, genetic distance, and tree-based methods.

DNA-barcoding is a species identification tool that uses a short section of the genome that provides a genetic signature of the species. The main advantage of this novel technique is that it requires a small sample of tissue from the tested organism. In most animal groups, this technique is very effective.

DNA barcoding ferns in an unexplored tropical montane cloud forest area of southeast Oaxaca, Mexico.

DNA barcoding can be useful for species identification and phylogenetic analysis, but its effectivity has not been verified in most neotropical cloud forest plants. We tested three plastid barcodes, rbcLa, matK, and trnH-psbA, in selected pteridophytes, a well-represented group in these forests, from a little-explored area in Oaxaca, Mexico, applying the CBOL criteria for barcoding. We used BLASTn, genetic distance, and monophyly tree-based analyses employing neighbor-joining (NJ), maximum likelihood (ML), and Bayesian inference methods.

On the possible role of nonreproductive traits for the evolution of unisexuality: Life-history variation among males, females, and hermaphrodites in (Cactaceae).

In angiosperms, dioecy has arisen in 871-5,000 independent events, distributed in approximately 43% of the flowering families. The reproductive superiority of unisexuals has been the favorite explanation for the evolution of separate sexes. However, in several instances, the observed reproductive performance of unisexuals, if any, does not seem to compensate for the loss of one of the sex functions.

Possible combined effects of climate change, deforestation, and harvesting on the epiphyte Catopsis compacta: a multidisciplinary approach.

Climate change, habitat loss, and harvesting are potential drivers of species extinction. These factors are unlikely to act on isolation, but their combined effects are poorly understood. We explored these effects in Catopsis compacta, an epiphytic bromeliad commercially harvested in Oaxaca, Mexico.

Genetic factors associated with population size may increase extinction risks and decrease colonization potential in a keystone tropical pine.

Pioneer species are essential for forest regeneration and ecosystem resilience. Pinus chiapensis is an endangered pioneer key species for tropical montane cloud forest regeneration in Mesoamerica. Human activities have severely reduced some P.

Reproductive implications of combined and separate sexes in a trioecious population of Opuntia robusta (Cactaceae).

Opuntia robusta has hermaphroditic, dioecious, and trioecious populations. To enhance our understanding of this breeding system diversity, we compared the reproductive output of males, females, and hermaphrodites in a trioecious population using field evaluations, controlled crosses, and progeny tests. Unisexuals were fully sterile in one sex function.