In situ and ex situ assessment of morphological and fruit variation in Scandinavian sweet cherry

Abstract

Sweet cherry is a tall, deciduous tree producing stone fruits. This diploid outcrossing species was domesticated in Asia but has been grown in orchards and home gardens in Scandinavia for many years. In situ and ex situ assessments of phenotypic variation in sweet cherry accessions were performed to determine the reliability of such assessments, and to determine relationships between Nordic populations. Principal component analysis (PCA) based on in situ data revealed that accessions were mostly clustered according to their country of origin. PCA based on ex situ assessment of accessions that were propagated by seed at Hornun (Denmark) did not agree with the PCA based on in situ data. These contrasting results suggest that phenotypic assessment in sweet cherry depends on the environment, genotype, and the interaction between them. Phenotypic diversity accounted for by in situ assessment may not be always true, while phenotypic differences determined by ex situ assessment may be confounded by the genotype-by-environment interaction, or could depend on the new genotypes arising from open pollination after seed propagation. Our research also suggests that ecotype differentiation could occur in wild Scandinavian sweet cherry. Fruit descriptors were among the best to distinguish between Scandinavian populations. Previously reported monogenic characteristics showed intermediate narrow-sense heritability, as suggested by the percentage of total variation accounted by the half-sib populations.

Morphological characterization of sweet and sour cherry cultivars in a germplasm bank at Portugal

“…The endocarp represents in most of the cases less than 10% of the fruit volume being relatively larger in the three 'D'Ó bidos' varieties; these values correspond to those obtained in an evaluation of sour cherry cultivars in Denmark (Christensen 1970(Christensen , 1977. Fruit size, peduncle length and maturation time are the three main descriptors for characterization (Christensen 1970;Hjalmarsson and Ortiz 2000) because of their relevance to commercial growing. As expected, the total acidity is more marked in all sour cherries, with values from 9 to 20 g/l, being 'Seixas', 'Garrafal negra' and 'Garrafal' the ones with lower acidity.…”

Multivariate analysis of Prunus subgen. Cerasus germplasm in Iran using morphological variables

“…Previously, PCA had been used to establish genetic relationships among cultivars, to study correlations among tree traits and to evaluate germplasm of different Prunus species: apricot (Badenes et al 1998;Ruiz and Egea 2008), peach (Perez et al 1993;Esti et al 1997;Wu et al 2003;Nikolic et al 2010), cherry plum (Horvath et al 2008), mahaleb (Ganji Moghadam and Khalighi 2007), sweet cherry (Hjalmarsson and Ortiz 2000;Beyer et al 2002), sour cherry (Hillig and Iezzoni 1988;Krahl et al 1991;Rakonjac et al 2010) and some Cerasus genotypes (Shahi-Gharahlar et al 2010).…”

Morphological characterization of cherry rootstock candidates selected from Samsun Province in Turkey

“…PCA was used to identify the most significant variables in the data set. PCA has been used until now to evaluate germplasm of different Prunus species, including peach (Perez et al, 1993;Esti et al, 1997;Wu et al, 2003;, apricot (Badenes et al, 1998;Ruiz and Egea, 2008;Yılmaz et al, 2012), mahaleb Khalighi, 2006, 2007), cherry plum (Horvath et al, 2008;Sedaghathoor et al, 2009;Aran et al, 2012), sour cherry (Krahl et al, 1991;Onal, 2002;Rakonjac et al, 2010), cherry (Hillig and Iezzoni, 1988;Hjalmarsson and Ortiz, 2000;Beyer et al, 2002, Rodrigues et al, 2008Perez Sanchez et al, 2008;Lacis et al, 2009, and Prunus incana (Nazari et al, 2012). Morphological characterization is necessary for germplasm description and classification, and statistical methods such as PCA are useful tools for screening the accessions of a collection (Cantini et al, 1999;Badenes et al, 2000).…”