Assessment of morphological and molecular similarity of Hungarian white grape varieties

The aim of this paper was to find possible link between molecular and morphological similarities of 38 Hungarian white grape varieties. Three aspects of morphological and molecular similarity were assessed in the study: comparison of the ordered variety pairs, assessment of molecular and morphological mean similarity differences and separation of varieties into similar groups by divisive cluster analysis to define (DIANA). Molecular similarity was calculated from binary data based on allele sizes obtained in DNA analysis. DNA fingerprints were determined at 9 SSR loci recommended by the European GrapeGen06 project. Morphological similarity was calculated on the basis of quantitative morphological descriptors. Morphological and molecular similarity values were ordered and categorized after pairwise comparison. Overall correlation was found to be weak but case by case assessment of the variety pairs confirmed some coincidence of molecular and morphological similarity. General similarity position of each variety was characterized by Mean Similarity Index (MSI). It was calculated as the mean of n-1 pair similarity values of the variety concerned. Varieties were ordered and compared by the difference of the index. Five varieties had low morphological and high molecular MSI meaning that they share several SSR marker alleles with the others but seems relatively distinct according to the expression of their morphological traits. Divisive cluster analysis was carried out to find similar groups. Eight and twelve cluster solutions proved to be sufficient to distinct varieties. Morphological and molecular similarity groups partly coincided according to the results. Several clusters reflected parent offspring relations but molecular clustering gave more realistic results concerning pedigree.

Intra- and interspecific molecular polymorphism of thrips species

Molecular polymorphism of six species of Thysanoptera of both sexes, collected from different locations and host plants in Hungary was studied by using RAPD-PCR technique. The specimens were classified according to sampling sites (Gödöllö, Nagykovácsi and Valkó), host plants (Lathyrus tuberosus, Medicago sativa, Taraxacum officinale, Trifolium pratense), sexes, and larvae in case of Aeolothrips intermedius. On the basis of the total of 103 fragments generated by 15 RAPD primers the genetic distances were calculated by cluster analysis using simple matching method. The dendrogram resulted in two main groups: Aeolothripidae (Aeolothrips intermedius) and Thripidae (Frankliniella intonsa, Kakothrips robustus, Odontothrips confusus, Thrips dilatatus and T. tabaci). Within the family Thripidae two subgroups were observed including (i) F. intonsa, T. dilatatus and T. tabaci, and (ii) K. robustus and O. confusus. Two population-specific and one sex-linked fragments were identified by the RAPD primers, OPQ 14, NO11 and OPA08, respectively.

Evaluation of genetic diversity of poplar genotypes by RAPD and AP-PCR analysis

RAPD (randomly amplified polymorphic DNA) and AP-PCR (arbitrarily primed PCR) were utilized to establish the genetic diversity of 19 Populus genotypes. A set of 40 primers of random sequence was tested, of which 35 exhibited polymorphism. Eighteen primers generated 162 easily detectable bands between 250 and 2,500 base pairs in size, sufficient to distinguish between the genotypes. Similarity measures, cluster and multidimensional scaling analysis were performed to evaluate the RAPD and AP-PCR data. Our study demonstrated that in most instances similarity in the RAPD and AP-PCR banding patterns reflected the relationship due to origin. Nineteen primers gave a species or hybrid-specific pattern. One primer generated a specific pattern in P. euramericana. Ten primers produced specific fragments in VIF (P. alba), 4 primers in KOR (P. pyramidialis x P. berolinensis) and 4 primers in UNA and RAS (P. trichocarpa x P. deltoides). The results of this study demonstrated that RAPD or AP-PCR can be used to distinguish between poplar genotypes.