Molecular based assessment of genetic diversity of xoconostle accessions (Opuntia spp.)

Abstract

Xoconostle or acidic prickly pear is an important fruit in Mexico; it is produced by a group of Opuntia plants known for their nutritional qualities and adapted to harsh environmental conditions. In this study, we report for the first time the estimation of genetic diversity within a set of 24 xoconostle accessions using inter simple sequence repeats (ISSR) markers. Five ISSR primers were selected to detect DNA polymorphisms in these plants. Broad genetic diversity was detected (0.41-0.82, Dice coefficient) and the unweighted pair group method with the arithmetic averaging (UPGMA) analysis allowed discriminating all genotypes and enabled their clustering into six groups; the 'Matizado' accession was significantly divergent from all tested genotypes. In addition, as shown by the clustering analysis and principal component analysis (PCA), the tested genotypes did not group according to their origin, to culture conditions, or to the current species classification. This work, on one hand, demonstrates the high genetic variation among genotypes of xoconostles, and on the other hand, it suggests a taxonomic revision and raises doubts about the number of species reported for these plants.

Morfología de semillas de siete especies del género Opuntia (Cactaceae) del sureste de Coahuila (México)

“…El análisis morfológico de semillas de diferentes especies del género Opuntia funcionaría en la conservación ex situ como un criterio en la diferenciación de especies, cuando lo que se tiene es semilla, en especial entre especies cercanas taxonómicamente, ya que el potencial de un banco de germoplasma radica en las introducciones que permitan evitar duplicados e identificar accesiones para procesos de selección y conservación (Fischer et al, 2000), los caracteres con potencial discriminante como GT y GCFV podrían ser de utilidad en la clasificación taxonómica del género Opuntia, pues son caracteres que no se han tomado en cuenta, también se podrían adicionar caracteres morfológicos confiables en la descripción de las especies (Caruso et al, 2010;Valadez-Moctezuma et al, 2014;Helsen et al, 2009), por la variación morfológica que presentan (Bravo-Hollis, 1978;…”

Assessment of genetic relationship in Persea spp by traditional molecular markers

“…Genomic DNA was extracted from young leaves (200 mg) using a slightly modified cetyltrimethylammonium bromide method (Saghai-Maroof et al, 1984). Genetic markers were developed using random-amplified polymorphic DNA (RAPD) and the inter simple sequence repeat (ISSR) (with anchor) techniques, both of which scan the whole genomes (Fontaine et al, 2004;Valadez-Moctezuma et al, 2014;Valadez-Moctezuma et al, 2015). Polymerase chain reaction (PCR) for RAPD comprised of 100 ng genomic DNA, 1.5 U Taq DNA polymerase (Fermentas, USA), 200 mM dNTPs, 1X Taq buffer, 2.0 mM MgCl 2 , and pM primer in a 25-µL total volume.…”

“…DNA markers have been used successfully to discern genealogies, design breeding strategies, and support systematization and conservation in germplasm banks (Zietkiewicz et al, 1994;Gilbert et al, 1999;Valadez-Moctezuma et al, 2014;Valadez-Moctezuma et al, 2015). Using these tools, races of P. americana and some hybrids have been distinguished (Davis et al, 1998;Clegg et al, 1999;Ashworth and Clegg, 2003).…”