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The invasive ascomycete fungus Hymenoscyphus fraxineus has caused large scale population decline of European ash (Fraxinus excelsior) throughout much of its distribution range in Europe. Large genotypic variation in susceptibility to the pathogen exists in the natural population, albeit resistance occurs at a low level. Damage traits associated with the pathogen are strongly genetically controlled, which suggests that considerable gain can be achieved through selection and breeding. Large potential exists for utilizing modern approaches or tools that can quantitatively identify phenotypes and help explain the genetic basis of important plant traits, such as disease resistance. One main obstacle to making such advances is the lack of viable tools for rapid resistance phenotyping. Vibrational spectroscopy is one approach that has been used successfully for rapid phenotyping for plant resistance. In this study, we used Fouriertransform Infrared (FT-IR) spectroscopy coupled with a chemometric model to discriminate between resistant and susceptible European ash genotypes. Non-infected leaves and stem samples from known susceptible and resistant F. excelsior genotypes were collected from six European countries. Purified phenolic extracts were analyzed on a FT-IR spectrometer and soft independent modeling of class analogy (SIMCA) was used to discriminate between resistant and susceptible trees. The model built with stem samples, and subsequently validated using random blind samples, gives powerful evidence that FT-IR can clearly discriminate between susceptible and resistant genotypes. These results suggest that spectroscopic phenotyping tools may allow for superior genotypes to be quickly identified and employed in restoration efforts.

Klimatinėse kamerose atlikti paprastojo uosio (Fraxinus excelsior L.) pusiausibų palikuonių šeimų iš trijų populiacijų augimo skirtingų ozono dozių poveikyje tyrimai parodė, kad poveikis buvo nepatikimas uosiukų aukščiui, skersmeniui ir aukščio prieaugiui, bet patikimas lapų pažeidimo požymiams – nekrozei, taškuotumui ir džiūvimui (P

Magistro darbe tiriama eksperimentiniuose želdiniuose įveistų paprastojo uosio adaptacinių požymių genetinė variacija. Darbo objektas - paprastojo uosio populiacijų pusiausibų palikuonių eksperimentiniai želdiniai. Darbo tikslas - ištirti paprastojo uosio adaptacinių požymių genetinę variaciją ir jos pasiskirstymą bei priklausomybę nuo ekologinių sąlygų juvenaliniame amžiuje. Darbo metodai – Trijuose specialaus dizaino palikuonių genetinio testavimo eksperimentiniuose želdiniuose įvertinta paprastojo uosio iš 140 palikuonių šeimų iš 10 Lietuvos populiacijų ir 180 šeimų iš 14 vakarų Europos populiacijų (27000 medelių) fenologija pagal pumpurų sprogimą ir medelių būklę balais nuo 1 iki 5. Surinkti duomenys apdoroti SAS statistinio paketo programomis ir ����vertinti svarbiausi genetiniai parametrai – genetinių veiksnių (populiacijų ir šeimų) įtaka, genetinė variacija, paveldėjimas, genotipo ir aplinkos sąveika, ekovalentingumas, ir kt. Darbo rezultatai. Atlikus tyrimus buvo nustatyti patikimi ir stipriai išreikšti tarppopuliaciniai genetiniai skirtumai pagal palikuonių adaptacinius požymius. Adaptacinių požymių adityvinės genetinės variacijos koeficientas buvo labai aukštas - skirtinguose želdiniuose siekė 30,3-36,8 %, kas rodo, kad genetiniai skirtumai tarp šeimų labai stipriai išreikšti. Didžiausia adaptacinio požymio - pumpurų sprogimo fenologijos adityvine genetine variacija, ir todėl – genetinės adaptacijos galimybėmis, pasižymėjo Šakių, Telšių, Pakruojo ir Kupiškio... [toliau žr. visą tekstą] This study aimed at evaluation of genetic variation of adaptive traits of common ash at juvenile age, its distribution and dependence upon ecological conditions. The study was performed in three progeny plantations on 140 open pollination families from 10 Lithuanian populations and 180 families from 14 West European populations. Data on bud flushing phenology, health condition and height growth was collected on 27000 trees and analyzed with Statistical procedures of SAS software, estimating main genetic parameters: influence of genetic factors (populations and families), additive genetic variation, heritability, genotype by environment interaction, ecovalency, etc. Statistical analysis revealed significant genetic differences among populations in adaptive traits of its progeny. Additive genetic variation of traits studied was very high, in different experimental plantations it reached from 30,3 to 36,8 %, thus indicating strongly expressed genetic differences among families. The highest genetic variation of most important adaptive trait, bud flushing phenology, and thus the highest adaptive capacity had progeny from Šakiai, Telsiai, Pakruojis and Kupiškis populations. The levels of genetic variation were not the same in different experimental progeny test plantations established in different environmental conditions. The genotype by environment interaction (G x E) was weak, thus indicating that changes of traits of populations’ progenies are rather small: three Lithuanian... [to full text]

Aim of the study – to evaluate the phenotypic variability of the wild apple and the wild pear in the aspect of the species’ natural regeneration and survival. The research sites have been chosen in the typical forest habitats of the species. The data on the mature trees were collected in the forests of south-western and central Lithuania in 1997-2005. The data on taxonomic identity of self-spreading pears were obtained after the evaluation of clone collection at the Lithuanian Institute of Horticulture. SAS and STATISTICA procedures were used for mathematical-statistical analysis of the data. With an aim to determine whether the wild apple may be able to produce viable apomictic seeds, seven progenies have been selected for peroxidase analysis according to the evaluation results of different female-trees at their natural habitats. The results of K-means clustering of pear clones were the sampling basis for peroxidase analysis of self-spreading pears. The novelty of the study is presented by: the evaluation of the phenotypic differences among trees at their natural habitats within the wild apple; the determination of the critical traits of the wild apple indicative for vigorousness of tree growth and survival; the determination of wild genotypes of the apple and the pear with the aid of peroxidase analysis for the first time in Lithuania; the definition of traits for taxonomic identification of self-spreading pears; the conceptualization of conservation and promotion of the... [to full text]