Genetic variability among local apricots (Prunus armeniaca L.) from the Southeast of Spain

Abstract

The fast rotation of new cultivars demanded by modern fruit growers implies the loss of many old varieties with valuable characters. Then, the need arises to keep and characterize this germplasm for future breeding projects. The region of Murcia, together with Valencia, in the East and Southeast of Spain respectively, are important and ancient producers of apricot (Prunus armeniaca L.), and many local cultivars have appeared and diversified in this area. A collection of 28 of these old cultivars, plus eight clonal selections of the cultivar 'Búlida', is maintained at the Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario (IMIDA, Murcia, Spain). In order to characterize their genetic diversity and to identify the collection with molecular markers, 17 microsatellite primers pairs were used. Thirteen of these primers produced polymorphic repeatable amplification patterns, and 31 genotypes were identified among the 36 apricot accessions. In addition to this, an evaluation of the genetic diversity found in the field within the cultivar 'Búlida' was made, the predominant cultivar for the canning industry in the region. For this, 66 field samples were analyzed with seven microsatellite markers. The results suggest that all the samples could derive from four closely-related genotypes, one of them accounting for 89% of the samples.Additional key words: cultivar identification, genetic relationships, microsatellites, molecular diversity, molecular markers. Resumen Variabilidad genética entre cultivares de albaricoquero tradicionales (Prunus armeniaca L.) del sureste españolLa rápida rotación de nuevas variedades que exige la fruticultura moderna, implica la pérdida de muchas variedades antiguas con caracteres potencialmente valiosos. En consecuencia, surge la necesidad de mantener y caracterizar este germoplasma para futuros proyectos de mejora. La región de Murcia, junto con la de Valencia, en el este y sureste de España respectivamente, son importantes y antiguas productoras de albaricoque (Prunus armeniaca L.), y muchos cultivares autóctonos han aparecido y se han diversificado en la zona. En el Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario (IMIDA, Murcia, España) se mantiene una colección de 28 de estas antiguas variedades más 8 selecciones clonales del cv. 'Búlida'. Para caracterizar molecularmente la diversidad e identidad genética de esta colección, se emplearon 17 marcadores microsatélite. En 13 de ellos se detectaron pautas de amplificación polimórficas y reproducibles, y se pudieron identificar 31 genotipos. Además de la evaluación de la colección, se planteó la evaluación de la diversidad genética en campo del cv. 'Búlida', que es la predominante para uso en la industria conservera de la región. Para ello se analizaron 66 muestras de campo con 7 marcadores microsatélite. Los resultados sugieren que todas las muestras de campo podrían derivar de cuatro genotipos estrechamente relacionados, agrupando uno de ellos al 89% de las muestras.

Molecular Characterization of Apricot Germplasm from an Old Stone Collection

“…The mean value of 4.27 alleles per locus obtained was higher than the 3.10 alleles per locus reported previously with 11 SSRs and 40 cultivars from different areas around the world [11] . It was similar to the 4.1 alleles per locus reported with 20 SSRs and 48 genotypes from diverse geographical areas [10] and the 4 alleles per locus obtained with 36 accessions from different areas of Murcia (Spain) [17] . However, it was lower than the value of 7.64 alleles per locus in 74 cultivars analyzed with 12 loci [12] , 12.3 alleles per locus in 44 cultivars [16] and 13.3 alleles per locus in 133 accessions [13] .…”

Molecular Characterization of Genetic Diversity in Apricot Cultivars: Current Situation and Future Perspectives

“…Additionally, the diversity indexes were studied for each group of landraces, commercial cultivars and recent releases (Table 3). The mean number of alleles found in landraces (6.50) was higher than those obtained in previous reports for traditional cultivars in Spain (4.00 [23]; 4.27 [15]) or Iran (4.62 [47]; 3.01 [27]) resulting presumably from the larger and diverse number of accessions analyzed in this work. However, the number of alleles was lower than those obtained in reports that include wild apricots (23.00 [48]; 16.75 [20]), probably due to not having included cultivars from China, the center of origin [20], as reported by Bourguiba et al [3].…”

“…The mean observed heterozygosity was lower in the landraces (0.68) compared to the recent releases (0.77) and commercial cultivars (0.77) although without significant differences (p < 0.05). These values are higher than those in previous studies of diversity in apricot (0.51 [22]; 0.32 [51]; 0.52 [52]; 0.63 [19]; 0.58 [53]; 0.68 [23]; 0.65 [54]; 0.39 [15]; 0.52 [27]; 0.63 [55]; 0.36 [26]; 0.72 [20]; 0.65, 0.66 [21]). In the landraces, the expected heterozygosity ranged from 0.57 to 0.84, with a mean value of 0.73.…”

“…Microsatellites have been used to characterize numerous Prunus species [18]. In apricot, they have been used to study the evolutionary history of the crop [3,5,[19][20][21], and to characterize traditional [22] and local cultivars from Spain [15,23], Turkey [24], Tunisia [25,26] and Iran [27].…”

Molecular characterization of some apricot Prunus armeniaca L. and plum Prunus domistica L. cultivars grown in northern Iraq using RAPD markers

“…In order to assess the genetic similarity of forty-three Indian apricot cultivars, Mir et al[24] studied the genetic variation of apricot cultivars in genetic banks in India using RAPD genetic indicators. Martínez-Mora et al[25] noted the use of genetic traits of several cultivars of apricots grown in Spain. Lisek et al[26] were able to use RAPD technology extensively among the sweet cherry cultivars in Poland, where it showed great effectiveness in distinguishing between cultivars[16] also demonstrated the efficiency of RAPD technology in showing obvious differences between cultivars of Prunus cerasia spread overland in Syria, and conducted PCR on DNA strands with eighteen random primers and demonstrated high efficiency in detecting genetic differences between the studied cultivars.…”