Morphometric and Molecular Analysis of the Three Arbutus Species of Greece

Abstract

Arbutus andrachne, A. unedo and A. × andrachnoides found in the Greek macchia are promising species for reforestations, ornamental use, as well as for medicinal use and the food industry. Μorphological traits and molecular markers (RAPD) were used to identify and distinguish these Arbutus species to facilitate their exploitation. Since there are no descriptors established for Arbutus spp., 23 qualitative morphological characteristics of crown, foliage, bark, flowering, fruiting, and four quantitative morphological characteristics of leaf and fruit were selected and used to define differences and similarities between sampled individuals of A. andrachne, A. unedo and individuals with intermediate characteristics sampled as A. × andrachnoides. Twenty eight individuals representative of three Arbutus taxa were sampled in two typical macchia forest areas of the prefecture of Attica, Greece. Cluster analysis based on morphological characteristics separated the individuals in three distinct groups, and this was confirmed by molecular analysis. Τhe intermediate form was indicated as A. × andrachnoides, a natural hybrid of A. andrachne and A. unedo. Fifteen 10-mer oligonucleotide arbitrary primers used to amplify genomic DNA generated 166 reproducible polymorphic fragments, which revealed that A. × andrachnoides has higher degree of genetic similarity with A. andrachne than A. unedo. The applied morphometric characteristics are suggested as a basis to develop a complete list of discriminating descriptors for Arbutus genus.

Seed Germination Behavior, Molecular Analysis of Four Populations of Arbutus andrachne Species from Greece, and Cultivation Practice for Producing High-Quality Plants

“…× andrachnoides, were genetically more similar to A. andrachne than to A. unedo. Between the two populations of A. andrachne, from Kalamos and Varympompi, no groupings were observed as in the present work, probably due to the small distance in which the plants were located [24]. In a study carried out on the related species A. unedo originating from nine countries using nine AFLP markers, two populations originating from Greece (specifically from Athens and Sithonia), it was found that the populations have a genetic uniformity among them, and they could be distinguished from the Atlantic and Mediterranean groups [26].…”

“…Since it is the first time that remote populations of A. andrachne have been genetically studied using molecular markers, no comparison can be made with other works. In another paper by Bertsouklis and Papafotiou [24], two populations of A. andrachne were studied, but they grow naturally close among them (Kalamos and Varympompi, distance about 12 km). In this paper, the relationship among species A. andrachne, A. unedo, and their natural hybrid A.…”

“…A research gap also exists considering the variance of A. andrachne both on morphological and molecular level. Considering the morphological traits, A. andrachne has been studied in Greece [23,24] as well as in the south part of North Macedonia [4]. Most studies focus on the genetic analysis of A. unedo using isozyme markers [25], amplified fragment length polymorphism (AFLP) [26,27], simple sequence repeat (SSR) [28,29], and randomly amplified polymorphic DNA (RAPD) [24,28,30,31].…”

“…Considering the morphological traits, A. andrachne has been studied in Greece [23,24] as well as in the south part of North Macedonia [4]. Most studies focus on the genetic analysis of A. unedo using isozyme markers [25], amplified fragment length polymorphism (AFLP) [26,27], simple sequence repeat (SSR) [28,29], and randomly amplified polymorphic DNA (RAPD) [24,28,30,31]. In the present study, inter-simple se-quence repeat (ISSR) markers have been used for the genetic analysis of A. andrachne [31], the only related paper is that of Betsouklis and Papafotiou [24], where the genetic relationship among A. andrachne, A. unedo, and their natural hybrid A.…”

Next-Generation Sequencing (NGS) Identified Species-Specific SSR and SNP Markers, Allow the Unequivocal Identification of Strawberry Tree (Arbutus unedo L.) Germplasm Accessions and Contribute to Assess Their Genetic Relationships

“…Strawberry tree studies using genomic tools, particularly DNA markers techniques, are relatively scarce and generally use randomly amplified markers: RAPD, ISSR, and AFLP, to assess the genetic variability and population structure of the species at the regional level [ 17 , 18 , 19 ] or covering its whole geographic range [ 20 ], or for discrimination from related species [ 21 ]. In one of these studies [ 19 ], cross-species SSR markers developed for Vaccinium spp.…”