ANALYSIS OF THE GENETIC DIVERSITY OF "LOVRAN MARRON" (Castanea sativa Mill.) USING MICROSATELLITE MARKERS

Maruni (maroni) su sorte europskog pitomog kestena (Castanea sativa Mill.) dobivene selekcijom, koje se od davnina uzgajaju radi proizvodnje krupnih i kvalitetnih plodova. Maruni su u Hrvatskoj sađeni na privatnim posjedima istočnih padina Učke, u okolici Lovrana i poznati su pod nazivom "lovranski marun". Do sada nije bilo znanstvenih istraživanja lovranskog maruna te nije poznato s kojim su biljnim materijalom nasadi podignuti, odnosno koliko je različitih genotipova zastupljeno. Ta saznanja ključna su za sve daljnje korake koje treba poduzeti kako bi se očuvali postojeći genetski izvori. Cilj ovoga istraživanja bila je analiza genetske raznolikosti stabala lovranskog maruna u postojećim nasadima, korištenjem mikrosatelitnih biljega. Istraživanje je rađeno na uzorku od 72 stabla, korištenjem 5 mikrosatelitnih biljega. Analiza je pokazala prisutnost 11 multilokusnih genotipova, što govori u prilog raznovrsnosti i bogatstvu svojti pitomog kestena na lovranskom području, koje još uvijek nisu taksonomski određene, a vode se pod kolektivnim nazivom "lovranski marun". Većina uzorkovanih stabala, 58, pripada istom genotipu, što se može tumačiti statičnošću u smislu introdukcije novih svojti na istraživano područje i forsiranjem, tj. ekstenzivnim uzgojem.Marrons are varieties of the European chestnut (Castanea sativa Mill.) obtained through selection, which have been grown since antiquity for the production of large and high quality fruits. In Croatia, marrons were planted on private properties on the eastern slopes of the Učka mountain, in the environs of Lovran, and are hence known as the "Lovran marron". There has been no scientific research of the Lovran marron to date, and it is unknown which plant material was used to raise the plantations, or how many different genotypes are represented. Those insights are crucial for any further steps to be undertaken in order to conserve the existing genetic resources. The aim of this study was to analyze the genetic diversity of the Lovran marron trees in the existing plantations, by using microsatellite markers. The study was conducted on a sample of 72 trees, using 5 microsatellite markers (Table 1). The analysis demonstrated the presence of 11 multilocus genotypes, pointing to the diversity and abundance of sweet chestnut taxa in the Lovran area, which have not yet been taxonomically defined and bear the collective name of the "Lovran marron". The majority of analyzed trees, specifically 58 individuals, had a uniform genetic structure and areassigned to the MG01 cultivar, which is therefore the most represented cultivar in the researched area, i.e. the one most often grown. However, not all trees are uniform, which is proven by the fact that the remaining 14 analyzed trees belong to 10 different gene pools. Of the 14 trees, 2 had not been grafted, but are found in the plantations together with the grafted marrons and are genetically specific as is to be expected. The remaining 12 grafted trees belong to 9 gene pools. Out of those, 5 trees share common alleles on all loci and are assigned the MG02 cultivar, whereas 7 trees were genetically unique and classified into 7 different cultivars (Tables 2, 3, 4 and Figure 1). Consequently, with regard to the "Lovran marron" operational taxonomic unit grown in the area of the Municipality of Lovran, although it is not taxonomically specified, on the basis of the genetic diversity analysis conducted using 5 microsatellite markers, it can be said to include several different genotypes, or cultivars, one of which (MG01) is present at a much higher frequency than others

Alive and kicking, or, living on borrowed time? – Microsatellite diversity in natural populations of the endangered Ulmus minor Mill. sensu latissimo from Croatia

The main objective of this research was to assess the genetic diversity of 5 natural field elm populations in Croatia. The study results suggest that the observed populations are characterized by a satisfactory amount of heterozygosity, and that the impact of the Dutch elm disease on the amount of genetic diversity in the sampled populations is currently negligible. However, one population displayed a significant excess of heterozygosity, implying a genetic bottleneck. The existence of a very clear genetic differentiation between the continental and the Mediterranean populations of Ulmus minor in Croatia was noticed

Asymmetric Introgression and Cryptic Natural Hybridization between Two Species of Teucrium Section Polium (Lamiaceae) on the Balkan Peninsula

In this work, we analyzed the morphology and genetic structure of Teucrium montanum, T. capitatum and their hybrid T. × rohlenae from three syntopic populations. A morphometric study showed that the parents and their hybrids exhibited continuous morphological variation, with the hybrid positioned exactly between the parents. Genetic analysis revealed that plants morphologically identified as T. × rohlenae are fertile hybrids that produce hybrid swarms dominated by later-generation hybrids. This suggests that introgression, rather than speciation, is the more likely outcome of hybridization between these plant species. The extent and direction of gene flow between the two species differed markedly between the three syntopic localities. At the Trilj locality, it was clearly unidirectional, with T. capitatum playing the dominant role. At the Sićevo locality, gene flow was slightly asymmetric, favoring the genetic background of T. capitatum, while at the Sliven site, it was completely asymmetric in the opposite direction. The extreme case of unidirectional gene flow was observed at the Trilj locality where plants morphologically identified as T. montanum could not be genetically distinguished from T. capitatum. This suggests that interspecific hybridization occurred long ago, leading to introgression and cryptic hybrids, blurring of species boundaries and generating evolutionary noise

Synergistic Effects of Combining Morphological and Molecular Data in Resolving the Intraspecific Classification in O. basilicum L.

High levels of both morphological and chemical variability exist within the O. basilicum L. species. Long-term traditional uses and wide distribution throughout the world, as well as traditional selection and breeding efforts, have contributed to variability within the species. Morphological traits according to UPOV descriptor list and AFLP markers were utilized to define the extent of existing variation in the species analyzing 24 accessions. Phenotypic dissimilarities between pairs of accessions were calculated and the UPGMA dendrogram was constructed. A number of clearly defined clusters have been detected, giving a good representation of traditional taxonomic relationships. Genetic relationships were determined by Neighbour-Joining cluster analysis based on Dice’s distance matrix between accessions. Generally, morphologically similar accessions grouped together and a high congruence between trees was observed. Our analyses revealed a certain degree of correspondence between morphological and molecular data among O. basilicum L. accessions. Both AFLP markers and morphological descriptors can contribute in resolving existing problems concerning intraspecific classification in O. basilicum

INTERNATIONAL LEGISLATION CONCERNING CONSERVATION OF BIOLOGICAL DIVERSITY: AGENDA 21 AND CONVENTION ON BIOLOGICAL DIVERSITY

U ovom se radu govori o dva međunarodna dokumenta u svezi očuvanja biološke raznolikosti: Program za 21. stoljeće i Konvencija o biološkoj raznolikosti. Raspravljena je svrha i cilj ovih dokumenata.The paper deals with two international documents concerning conservation of biological diversity: Agenda 21 and Convention on Biological Diversity. The background, aims and prospects of these documents have been discussed

Comparison of Different Methods for Classification of Gene Bank Accessions

The objective of this study was to group common bean (Phaseolus vulgaris L.) accessions originating from different collection sites according to their morphological similarity. Classification based on genetic diversity should improve the maintenance of the collection of bean accessions and enhance its use as a valuable source of desirable traits in plant breeding. Materials used in this study are accessions of common bean, collected at various locations in Croatia, and Bosnia and Herzegovina, and stored in the Croatian Bank of Plant Genes (HBBG). In order to use a number of qualitative and quantitative morphological traits, scored according to IPGRI (International Plant Genetic Resources Institute, Rome), and HBBG descriptor lists, we followed the method of classification described by Franco and Crossa (2003). Results obtained from this study reveal some weaknesses as well as advantages of methods used for classification of gene bank accessions