Genetic Diversity of Local Peach (Prunus persica) Accessions from La Palma Island (Canary Islands, Spain)

Abstract

Peach (Prunus persica) is an economically important temperate fruit crop due to its edible fruits. Due to the need to develop new varieties better adapted to climate change, it is of great interest to find germplasm adapted to warmer conditions, such as those found in the Canary Islands. Peach was an important crop during the last century in one of those islands (La Palma), but its cultivation has been abandoned in recent years. Currently, commercial production is relict and isolated trees are relegated to family orchards with little management. With the objective to characterize and prevent the loss of local varieties of this crop, peach trees were sampled along La Palma. A total of 89 local peach accessions were prospected and analyzed with 10 single-sequence repeat (SSR) loci, which permitted 28 different genotype profiles to be detected. These genotypes were compared to 95 Spanish peach landraces conserved in an ex situ collection, and 26 additional samples from eight different countries. Results showed that the peach genetic diversity found in La Palma was low. In addition, a relation between La Palma samples and other Spanish peaches was observed, which could indicate the arrival of genetic material from the Iberian Peninsula and subsequent intercrossing and local selection of the genotypes more adapted to the subtropical climate of the island. The population structure reflects a grouping of the samples based on fruit type and geographic origin.

Genetic diversity and population structure of Chilean blueberry Gaultheria pumila (L.f.) D.J. Middleton (Ericaceae)

“…These variability levels are similar to those reported in species with high economic and ornamental values, such as cherry Prunus pseudocerasus Lindl. (Chen et al, 2015) and Prunus persica (Pérez et al, 2020). Bantawa et al (2011) found a high level of polymorphism (68.52%) in Gaultheria fragantissima using RAPD.…”

Exploring Genome-Wide Diversity in the National Peach (Prunus persica) Germplasm Collection at CITA (Zaragoza, Spain)

“…In a different study also using SSR markers, Bouhadida et al [11] found results similar to ours, identifying 'Pigat' and 'Rojo Amarillo Septiembre' as genetically close accessions. Our phenotypic records have not shown considerable differences among the three members of the clone group 12 in terms of harvest time and fruit traits, which may indicate that if the genotype differences found by Pérez et al [34] really exist, these changes can occur in noncoding regions and do not influence gene expression and fruit phenotype.…”

“…Lack of genetic differences among samples could be due to lack of SNPs in the array from specific regions of the peach genome, although the amount of markers used in this study is clearly higher than in previous studies [8]. Some of the clones detected in the present study have been characterized previously with SSRs [11,21,24,26,27,34]. The clone groups detected here (clone groups 1, 2, 4, 5, 6, 7, 8, 10, 13) are in agreement with the genetic proximity observed in previous works, in which small differences in one or two markers, genetically close, were observed.…”

“…Regarding clone group 12, the accessions 'Fulla' and 'Rojo Amarillo Septiembre' were placed genetically far away in a previous neighbor-joining dendrogram by Pérez et al [34] using a set of 10 SSR markers. However, both accessions had a high admixture coefficient for the same cluster in their population structure analysis.…”

“…Genetic diversity analysis through SNP detection using RAD-seq on the whole genome was assessed in apricot and showed a decrease in genetic diversity during the domestication process [33]. Although the Spanish National Peach Germplasm Collection at CITA has been studied and genetically characterized with SSR markers [11,34], it has never been characterized with a set of SNP markers.…”