Showing papers by "Salvador Arias published in 2018"
TL;DR: A new sectional classification for Echinocereus is proposed based on the eight recovered clades, which is supported by a combination of morphological and molecular characters.
Abstract: Echinocereus is a morphologically diverse genus that includes 64 species grouped into eight taxonomic sections based on morphological traits. In previous molecular phylogenetic analyses, the relati...
17 citations
TL;DR: In vitro propagation protocols were established for endangered species of cacti Mammillaria hernandezii, M. dixanthocentron, and M. lanata and three in vitro culture cycles were performed to validate the propagation protocols and to verify genetic stability.
Abstract: In vitro propagation protocols were established for endangered species of cacti Mammillaria hernandezii, M. dixanthocentron, and M. lanata. In vitro-germinated seedlings were used as the explant source. Three explant types were evaluated as apical, basal, and lateral stem sections. Shoot multiplication was achieved using Murashige and Skoog (MS) medium supplemented with benzyladenine, kinetin, meta-topolin, and thidiazuron in equimolar concentrations (0.0, 0.4, 1.1, 2.2, 4.4, and 8.9 μM). Shoot regeneration was obtained primarily in the lateral stem section explants. In M. hernandezii, an average of 7.4 shoots was regenerated in MS medium with 2.2 μM meta-topolin. M. dixanthocentron and M. lanata averaged 16.7 and 17.9 shoots/explant, respectively, in MS medium supplemented with 1.1 μM meta-topolin. Rooting occurred in MS medium without growth regulators. Three in vitro culture cycles were performed to validate the propagation protocols and to verify genetic stability. Shoots were collected in each cycle and genomic DNA was extracted. Amplified microsatellites were used to compare each genotype with its respective donor plant. Polymorphic information content analysis showed low levels of intra-clonal polymorphisms—M. hernandezii 0.04 and M. dixanthocentron and M. lanata both 0.12. More than 95% of the plants were successfully acclimatized in the greenhouse. After 12 months, plants of M. hernandezii reached the flowering stage; M. dixanthocentron and M. lanata flowered at 24 mo.
14 citations
TL;DR: It is proposed that heterochrony controls male sterility by accelerating the process of programmed cell death in tapetal cells during anther development in female flowers, which mediates both seed and pollen abortion.
Abstract: Premise of research. Dioecy has evolved numerous times among unrelated Cactaceae taxa. Changes in ontogenetic patterns determine final floral morphology and breeding system. It has not been establi...
11 citations
TL;DR: It is unequivocally demonstrate the funicular origin and aerenchymatic structure of the seed appendage, the aril in S. corregidorae, which shows that further genetic, phylogenetic and comparative ontogenic studies that include the three taxa of Strombocactus and the nearest genera are required in order to determine if this structure was gained or lost during evolution.
4 citations