Genetic diversity of Brazilian and introduced olive germplasms based on microsatellite markers

Abstract

ABSTRACT. Olive trees have been grown since the beginning of civilization, and the consumption of olives and olive products is increasing worldwide, due to their health benefits and organoleptic qualities. To meet the growing market for olives, commercial cultivation of this species is expanding from traditional areas to new regions. Although the Brazilian olive industry has just begun to be established, breeding programs are already developing cultivars that are more adapted to local conditions. We used 12 microsatellite markers to evaluate 60 olive accessions, including several cultivars that were developed in Brazil. The analyses identified 72 distinct alleles; the largest number of alleles per locus were at the markers Genetic diversity in olive germplasms GAPU 101 and GAPU 71B, which contained 10 and 9 alleles, respectively. The largest allelic diversity and polymorphic information contents were also found at the GAPU 101 and GAPU 71B markers, with values of 0.8399/0.8203 and 0.8117/0.7863, respectively. Additionally, the 12 microsatellite markers generated a cumulative identity probability of 1.51 x 10 -10 , indicating a high level of accuracy of accession identification. The set of markers that we used allowed the identification of 52 of the 60 olive genotypes, in addition to the recognition of several varietal synonyms. The components of a two-dimensional principal coordinate analysis explained 48.6% of the total genetic variation. The results obtained from the microsatellite markers showed a substantial degree of genetic diversity in the olive tree accessions used in Brazil.

Myrciaria dubia, an Amazonian fruit: population structure and its implications for germplasm conservation and genetic improvement

“…The efficiency of using Bayesian statistics for the genetic diversity and populations structure analyses is well-known and has been used in different crops, such as olive (do Val et al, 2012), coffee (Setotaw et al, 2010), and strawberry (Nunes et al, 2013). In our study, the 94 accessions were grouped into three clusters that agreed with the geographical distribution of the populations.…”

SNP Discovery by Illumina-Based Transcriptome Sequencing of the Olive and the Genetic Characterization of Turkish Olive Genotypes Revealed by AFLP, SSR and SNP Markers

“…The synonyms and homonyms among fruit trees have been widely reported [104]–[108]. Several previous studies noted several synonyms and homonyms in the olive collection, making it difficult to identify the reference of olive cultivars [29], [36], [53], [96], [100], [109]–[112]. Our results indicated that a number of accessions known by the same names were genetically different, suggesting that these were homonyms.…”

“…Slightly higher PIC values (0.47 to 0.91) were registered by Belaj et al [31] between local cultivars and wild olive trees from 3 important Spanish olive-growing regions. Do Val et al [100] reported that the informativeness of the 12 loci (PIC) were highly variable (0.12–0.72), of which eight loci showed PIC values ≥0.50. These results are partially similar to ours.…”

Genetic Structure and Core Collection of Olive Germplasm from Albania Revealed by Microsatellite Markers

“…Oleaster genotypes were admixed much more with the ancient than with the current olive cultivars ( Figure 2C,D). The analysis of molecular variance (AMOVA) performed to evaluate the partitioning of molecular variance among native cultivars, oleasters, and foreign olive cultivars, showed that 93% of variation is due to genetic variation within groups, with only 7% of genetic variance being observed among groups, indicating the high heterozygous nature and mixed genetic structure of the olive genotypes [47]. The calculated PhiPT (analogue of Fst index) (0.074) was significant, p < 0.001, indicating low genetic differentiation among groups.…”