Iva Viehmannová

In vitro Conservation of Smallanthus sonchifolius under Slow-Growth Conditions

Abstract The aim of this work was to optimize in vitro storage of yacon (Smallanthus sonchifolius) under slow-growth conditions. Mediumterm conservation was tested on ½ MS supplemented with mannitol and sorbitol (1-3%), BAP (5 mg l-1), or MS and ½ MS medium free of plant growth regulators. Within 60 days, height of plants, number of nodes, number of roots and their length were measured in all of these treatments. The results revealed that there was a decline in plant growth along with the increase in the concentrations of mannitol (1.88, 1.49 and 1.07 cm for 10, 20 and 30 g l-1 mannitol) and sorbitol (3.66, 3.19 and 1.74 cm for 10, 20 and 30 g l-1 sorbitol), and along with the decrease of nutrient concentration in the cultivation medium (4.74 and 2.24 cm for MS and ½ MS medium). The survival of explants was found to be minimal at the highest concentrations of osmotic regulators (70% in mannitol and 50% in sorbitol) and on the medium supplemented with BAP (60%), while maximal on MS medium, ½ MS medium and on ½ MS medium with addition of 10 g l-1 mannitol (in all cases 100%). On full-strength MS medium and medium with addition of BAP plant growth was rapid, suggesting that these media could be rather used for multiplication of yacon. On the basis of our results it can be concluded, that for medium-term conservation of yacon can be satisfactory used ½ MS medium and media supplemented by 10 or 20 g l-1 mannitol or sorbitol.

Dealing with AFLP genotyping errors to reveal genetic structure in Plukenetia volubilis (Euphorbiaceae) in the Peruvian Amazon

An analysis of the population structure and genetic diversity for any organism often depends on one or more molecular marker techniques. Nonetheless, these techniques are not absolutely reliable because of various sources of errors arising during the genotyping process. Thus, a complex analysis of genotyping error was carried out with the AFLP method in 169 samples of the oil seed plant Plukenetia volubilis L. from small isolated subpopulations in the Peruvian Amazon. Samples were collected in nine localities from the region of San Martin. Analysis was done in eight datasets with a genotyping error from 0 to 5%. Using eleven primer combinations, 102 to 275 markers were obtained according to the dataset. It was found that it is only possible to obtain the most reliable and robust results through a multiple-level filtering process. Genotyping error and software set up influence both the estimation of population structure and genetic diversity, where in our case population number (K) varied between 2–9 depending on the dataset and statistical method used. Surprisingly, discrepancies in K number were caused more by statistical approaches than by genotyping errors themselves. However, for estimation of genetic diversity, the degree of genotyping error was critical because descriptive parameters (He, FST, PLP 5%) varied substantially (by at least 25%). Due to low gene flow, P. volubilis mostly consists of small isolated subpopulations (ΦPT = 0.252–0.323) with some degree of admixture given by socio-economic connectivity among the sites; a direct link between the genetic and geographic distances was not confirmed. The study illustrates the successful application of AFLP to infer genetic structure in non-model plants.

Genetic Diversity Of Plukenetia Volubilis L. Assessed By ISSR Markers

Abstract The diversity and genetic relationships in 173 sacha inchi samples were analyzed using ISSR markers. Thirty ISSR primers were used, only 8 showed variability in tested samples. ISSR fragments ranged from 200 to 2500 bp. The mean number of bands per primer was 12 and the average number of polymorphic bands per primer was 11. The lowest percentages of polymorphic bands (27%), gene diversity (0.103), and Shannon’s information index (0.15) were exhibited by the Santa Lucia population, which was also geographically most distant. This fact may be attributed to a very small size of this group. In contrast, the Dos de Mayo population exhibited the highest percentage of polymorphic bands (78%), and the Santa Cruz population the highest Nei’s gene diversity index (0.238) and Shannon’s information index (0.357). The obtained level of genetic variability was 36% among tested populations and 64% within populations. Although the diversity indices were low, a cluster analysis revealed 8 clusters containing mainly samples belonging to individual populations. Principal coordinate analysis clearly distinguished Chumbaquihui, Pucallpa, Dos de Mayo, and Aguas de Oro populations, the others were intermixed. The obtained results indicated the level of genetic diversity present in this location of Peru, although it is influenced by anthropological aspects and independent on the geographical distances.

Genetic diversity of eight millet genera assessed by using molecular and morphological markers

Abstract. In this study, the genetic diversity and relationships among eight millet genera were investigated by molecular and morphological data analyses. Sixty-nine millet accessions were analysed by using amplified fragment length polymorphism (AFLP) markers, and evaluated for morphological traits. Eight AFLP primer pairs were amplified successfully and 779 bands were scored for all accessions, with a high level of polymorphism detected. Nei’s genetic distance among all accessions varied from 0.0123 to 0.4246 and the Shannon’s index was estimated at 0.9708. The neighbour joining tree, using the unweighted neighbour-joining method and Dice’s dissimilarity coefficient, was constructed. The AFLP markers revealed the close relatedness between the Eragrostis and Panicum genera, whereas the greatest distance was found the Pennisetum and Echinochloa genera. Cluster analysis based on the AFLP profiles revealed that the majority of accessions of a given millet genus tend to group together. Clustering from morphological data allocated individuals into three main clusters with high variation. The genetic variability found between the analysed accessions was weakly negatively correlated (r = –0.074) with their morphological attributes. However, high molecular and morphological variability indicated that this collection includes rich and valuable plant materials for millet breeding.