Phylogeny of Opuntia s.s. (Cactaceae): Clade delineation, geographic origins, and reticulate evolution

Abstract

Opuntia s.s. is a well-supported clade that includes Nopalea. The clade originated in southwestern SA, but the NA radiation was the most extensive, resulting in broad morphological diversity and frequent species formation through reticulate evolution and polyploidy.

Genetic divergence between Mexican Opuntia accessions inferred by polymerase chain reaction-restriction fragment length polymorphism analysis

“…However, we found no variability in the sequence of this gene in the Mexican Opuntia species studied here. Majure et al (2012b) identified 20 informative characteristics in an 861-bp fragment of the atpB-rbcL region in Opuntia species, but we did not find any polymorphisms in this region with any of the eight enzymes used, suggesting that Mexican accessions conserve the same sequence in this region. It is noteworthy that we also conducted the PCR-RFLP analysis for the ITS region in 70 genotypes and digested with four restriction enzymes (EcoRI, HaeIII, HhaI, and HinfI); however, no polymorphisms were detected among these accessions either (data not shown).…”

“…However, some problems limit its use in phylogenetic studies, such as frequent indels, microsatellites, inversions, a high degree of homoplasy, and the presence of inversions in the middle of the sequence, which can lead to incorrect alignments; however, psbA-trnH may still be a successful marker due to its high interspecific variability (Korotkova et al, 2011). Korotkova et al (2011) stated that the psbA-trnH spacer is the most successful individual region for operational taxonomic unit identification at the intraspecific level, and the intergenic spacer trnL-trnF has been the most frequently used locus in phylogenetic studies of the Opuntioideae (Griffith and Porter, 2009;Hernández-Hernández et al, 2011;Majure et al, 2012b). ppc and ycf1 have been sequenced in the Opuntieae tribe, and are moderately informative Majure et al, 2012b).…”

“…Korotkova et al (2011) stated that the psbA-trnH spacer is the most successful individual region for operational taxonomic unit identification at the intraspecific level, and the intergenic spacer trnL-trnF has been the most frequently used locus in phylogenetic studies of the Opuntioideae (Griffith and Porter, 2009;Hernández-Hernández et al, 2011;Majure et al, 2012b). ppc and ycf1 have been sequenced in the Opuntieae tribe, and are moderately informative Majure et al, 2012b). Amplification of the mitochondrial cox3 gene in Opuntia is reported here for the first time; in addition, the phytochrome C gene (PhyC) was found to be invariable in all of the genotypes investigated in the present study.…”

“…ficus-indica, O. hyptiacantha, O. lasiacantha, O. robusta, and O. streptacantha (Yesson et al, 2011);O. lasiacantha (Hernández-Hernández et al, 2011);and O. megacantha (Majure et al, 2012b). These were represented by one specimen from each species in all the studies mentioned above, except for O. ficus indica in Griffith (2004).…”

“…They sampled 110 specimens using ITSs and the chloroplast trnL-trnF regions. Majure et al (2012b) studied 98 species of Opuntioideae, and sequenced the plastid intergenic spacers atpB-rbcL, ndhF-rpl3, psbJ-petA, and trnL-trnF, the plastid genes matK and ycf1, the nuclear gene ppc, and ITSs to reconstruct the phylogeny of the Opuntieae tribe, including Opuntia s.s., which is a well-supported clade but includes Nopalea (Majure et al, 2012b). However, Opuntia s.s. has the signature of a clade that has undergone a rapid radiation (i.e., broad distribution, high morphological and species diversity, and low molecular marker divergence) (Helsen et al, 2011).…”