Phenotypic and molecular characterization of apple (Malus × domestica Borkh) genetic resources in Greece

Abstract

ABSTRACT:The phenotypic and genetic analysis of apple (Malus × domestica Borkh) genotypes is essential for breeding species. Information on the morphology and genetic structure of apple offers significant help for germplasm maintenance and selection of suitable material to breed superior cultivars. This study shows the results of an investigation on the morphology and the genetic diversity for 19 apple cultivars, which are preserved in an ex situ collection in Naoussa, Central Macedonia, Greece. Information was recorded over a 5-year period for 47 traits describing plant morphology and phenotype, as well as leaf and fruit quality. Data were analyzed using the principal component analysis (PCA) method. The Euclidean distance metric and the Ward's agglomeration method were used in an unsupervised hierarchical cluster analysis of all cultivars. The cultivars were grouped into four main clusters, suggesting that the characterized apple collection has a high potential for specific breeding goals. Furthermore, the cultivars were genotyped using seven microsatellite primers. Moderate levels of polymorphism were detected, and 38 distinctive alleles (5.4 alleles per primer pair) were identified. Both multivariate clustering approach (phenotypic data) and the genetic distance clustering approach (genetic data) grouped the apple cultivars according to their type. Hence, these data could be used for protection or patenting processes of existing or new apple cultivars carried out by the EU-Community Plant Variety Office.

Molecular characterization of apple (Malus × domestica Borkh.) genotypes originating from three complementary conservation strategies

“…It was shown that the number of alleles obtained by amplification with the 11th SSR primer was 1-3, with an average of 1.6. The set of microsatellite markers used showed a low level of polymorphism among the studied genotypes (Table 6), which is in agreement with similar studies (Guilford et al, 1997;Silfverberg-Dilworth et al, 2006), but it was lower than the amount reported in other studies for apple inbred lines and hybrids (Zhang et al, 2007;Gharghani et al, 2009;Farrokhi et al, 2011;Sikorskaite et al, 2012;Pérez-Romero et al, 2015;Ganopoulos et al, 2017). The lower value obtained in our study may be due to the use of agarose gel electrophoresis for the screening of SSR markers compared to polyacrylamide gel electrophoresis or automated analysis that would be able to resolve allelic variation at a finer scale than gel electrophoresis analysis.…”

“…Neighbor-joining tree based on Dice coefficient calculated by SSR markers of apple genotypes originating from three conservation strategies: field collection (ex situ), in vitro collection (v1, v2, v3), and cryocollection (c1, c2, c3). Bouhadida et al, 2011;Sikorskaite et al, 2012;Pérez-Romero et al, 2015;Ganopoulos et al, 2017).…”

“…SSR markers have been successfully applied not only for evaluation of genetic diversity within germplasm collections (Guarino et al, 2006;Pereira-Lorenzo et al, 2007;Sikorskaite et al, 2012) but also for apple tree cultivars (Galli et al, 2005;Pérez-Romero et al, 2015;Ganopoulos et al, 2017) or for parent identification (Kitahara et al, 2005;Király, 2013). Although molecular characterization by SSR markers of apple cultivars from the United States (Hokanson et al, 1998) and some European countries (Galli et al, 2006;Patocchi et al, 2009;Sikorskaite et al, 2012;Király, 2013;Pérez-Romero et al, 2015;Ganopoulos et al, 2017) was accomplished, to the best of our knowledge there are no records regarding molecular characterization by SSR markers of apple genotypes commonly bred in Romania originating from 3 complementary conservation strategies. Structural changes in genomic DNA from leaves of apple trees grown in a field collection and in vitro-grown plants have been investigated using surface-enhanced Raman spectroscopy (Muntean et al, 2011a(Muntean et al, , 2011b.…”

Comparison of Old and Landraces Varieties of the Apple Tree (Malus domestica Borkh) in the Variability of Some Morphological Characters of Leaves and Flowers

“…S ohľadom na ich dlhodobé pestovanie v rôznych oblastiach sa adaptovali na určité špecifické pestovateľské podmienky, čím nadobudli vysoký stupeň tolerancie proti nepriaznivým faktorom prostredia. Predstavujú výrobné prostriedky pre rozvoj agroekosystémov a poľnohospodárstva v špecifických podmienkach, zdroje pre estetizáciu životného prostredia, krajinotvorbu a rozvoj kultúrnych tradícií (Brindza, 2001;Tóth et al, 2004;Ganopoulos et al, 2017). Zakladanie klonových repozitórií s cieľom záchrany ohrozeného genofondu rastlín má u nás uplatnenie pri mnohých ovocných druhoch akými sú hruška, čerešňa, slivka, gaštan atď.…”

Characterization of the Genetic Diversity Present in a Diverse Sesame Landrace Collection Based on Phenotypic Traits and EST-SSR Markers Coupled With an HRM Analysis

“…To identify agro-morpho-physiological traits that contribute to the total diversity and characterize the levels of similarity among cultivars, an investigation of the phenotypic diversity and structure is essential [ 14 , 15 , 16 , 17 ]. Morphological traits such as growth habit, plant height, primary and secondary branches, leaf arrangement, leaf shape, hairiness of the stem flower and capsule, number of flowers per leaf axil, number of capsules, number of carpels per capsule, days to maturity, seed yield and seed coat color [ 10 , 18 , 19 ] were considered as the most representative agro-morphological traits used to estimate the genetic diversity in sesame.…”