Diversidade genética entre e dentro de espécies de Opuntia spp. revelada por marcador molecular ISSR

Abstract

The forage palm Opuntia spp., belonging to the Cactaceae family, which has 130 genera and more than 2,000 species, has Mexico as its center of origin, but is distributed throughout the different regions of the world, as it easily adapts to adverse weather and climate conditions. , from areas with high temperatures to the lowest. It constitutes an economically important crop for arid and semi-arid areas, as it enables the regeneration of vegetation, the deceleration of deforestation, the increase of biodiversity and the reduction of soil degradation and erosion. The cactus pear, in addition to being used as a source of animal and human food, has medicinal properties and is also used as an ornamental plant. Due to their economic attributes, it is essential to know even more about their genetic characteristics to help genetic improvement programs for these species. One of the most used techniques are molecular markers. The ISSR (Inter Simple Sequence Repeats) is widely used to determine the genetic diversity between and within species. Within this context, the objective of this work was to evaluate the genetic diversity of 40 genotypes of Opuntia spp. from the INSA BAG, using ISSR molecular markers. DNA extraction from the accessions was performed using the DNeasy Plant Mini® Kit (Qiagen). Eleven ISSR oligonucleotide primers (primers) were used. After (PCR) reactions, the amplified DNA fragments were separated in a 2% agarose gel and photodocumented. A total of 839 fragments were amplified, distributed in 91 loci, of which 86 were polymorphic and 5 monomorphic, with a polymorphism of 94.50%. The genetic dissimilarity matrix was obtained from the genetic distance between pairs of accessions that ranged from 0.32 to 1.00. Based on the genetic distances, the 40 accessions were grouped into nine groups using Ward's method and into ten groups using Tocher. It was concluded that there is high genetic diversity between and within the evaluated species and it was possible to establish the phylogenetic relationships between accessions of Opuntias spp. studied. This information is useful to define the basis for new collections represented by Opuntia spp. and to expand the genetic base of the segregating populations, intraspecific crossing between accessions 87 and 117 and interspecific with accessions 1 x 119, 86 x ?(101), 86 x 135, 88 x 135, ?(101) are suggested. x 135.