Perekond robirohu (Rhinanthus) geneetiline mitmekesisus ja taksonoomia

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Meie planeedi bioloogiline mitmekesisus kahaneb kiiresti. Tänaseks on teada, et liikide ellujäämiseks on oluline geneetiline varieeruvus. Geneetilise diversiteedi uurimine võib aidata lahendata keerukate liigikomplekside taksonoomiat ning annab infot tänapäeva liigirikkuse, liikide mineviku ja evolutsiooni kohta. Lisaks sellele mõjutab geneetilist mitmekesisust ka taimede paljunemisviis ning populatsioonide suurused. Seega on oluline hinnata liikide geneetilist mitmekesisust. Käesolevad doktoritöös uurisin isoensüümide ja mikrosatelliitidega seitsme liigi geneetilist varieeruvust perekonnast Rhinanthus. Uuritud liigid kuulusid kolme erinevasse sektsiooni: Eesti endeem R. osiliensis, R. rumelicus, R. wagneri, R. angustifolius, R. alectorolophus sektsiooni Cleistolemus, R. minor sektsiooni Rhinanthus ning Bulgaaria endeem R. javorkae sektsiooni Anoectolemi. Lisaks sellele võrdlesime esmakordselt geneetiliselt Rootsi saarelt Gotlandilt leitud ebaselget robirohu taksonit morfoloogiliselt sarnase Eesti endeemiga R. osiliensis. Tulemused näitasid laialdast sugulusristumist enamuses uuritud populatsioonidest hoolimata liigilisest kuuluvusest. Endeemidel (R. osiliensis ja R. javorkae) ning kitsa levikuga Gotlandilt leitud ebaselgel taksonil on madalam geneetiline mitmekesisus võrreldes laialt levinud liikidega (R. rumelicus, R. wagneri, R. angustifolius). Siiski, madal geneetiline mitmekesisus leiti samuti laialt levinud liigil R. minor, mis ilmselt on tingitud liigi õie morfoloogiast. Geneetiliselt eristusid hästi eraldi sektsioonidesse kuuluvad R. minor ja bulgaaria endeem R. javorkae. Uuritud sektsiooni Cleistomus liigid on geneetiliselt teineteisele sarnased välja arvatud R. alectorolophus, mis eristus märkimisväärselt teistest sama sektsiooni liikides. Seega on sektsiooni Cleistolemus monofüleetilisus küsitav. Lõpetuseks näitasid tulemused, et Rootsist Gotlandi saarelt leitud robirohi on geneetiliselt märkimisväärselt erinev morfoloogiliselt sarnase Saaremaa robirohuga R. osiliensis ning tegemist ei ole ühe liigiga. Minu doktoritöö näitab mlekulaargeneetiliste uuringute tähtsust aitamaks selgitada keerulisi liikidevahelisi suhteid, hinnata populatsioonide jõulisust.Biological diversity is rapidly decreasing. Evaluation of genetic diversity and assessment of genetic differentiation are essential for estimate boundaries between species. Different aspects of genetic diversity provide valuable information about the species delimitation, relationships and species boundaries. Genetic diversity and differentiation levels of seven Rhinanthus species from three different sections and one unclear taxon were studied in this thesis Estonian endem R. osiliensis, R. rumelicus, R. wagneri, R. angustifolius and R. alectorolophus belonging to section Cleistolemus, R. minor to section Rhinanthus and Bulgarian endem R. javorkae to section Anoectolemi. In addition, taxonomically unclear individuals found from Sweden were studied and compared with R. osiliensis, R. angustifolius and R. minor from Estonia. Two different molecular techniques - allozymes and microsatellites - were used for analyses. We found high level of non-random mating and inbreeding in most of the studied populations. Low genetic diversity was found in unknown Rhinanthus sp., endemics R. osiliensis and R. javorkae with restricted geographic range. Widespread R. minor showed also low level of genetic variation and high inbreeding mode due to flower morphology. Our results of genetic differentiation were in concordance with previous taxonomy where R. minor and R. javokae belong to two different sections were well differentiated from other studied species. Surprisingly, R. alectorolophus that belongs to section Cleistolemus together with R. osiliensis, R. rumelicus, R. wagneri and R. angustifolius was strongly differentiated from those species and monophyly of this section is questionable. Low genetic differentiation of R. osiliensis, R. rumelicus, R. wagneri and R. angustifolius shows their close affinity and weak genetic structure of section Cleistolemus. Finnaly, we clearly showed that the unknown Rhinantus sp. found from Gotland, while morphologically similar to R. osiliensis, does not belong to the same taxon. Both R. osiliensis and Rhinanthus sp. are genetically more close to R. angustifolius. We suggest that these two cryptic species originated from two independent island colonization events and may be even from different refugia. Further genetic comparison between unknown Rhinanthus sp. and local Rhinanthus species from Gotland is necessary to determine the species status and to check for possible alternative hypotheses about the origin of this unclear taxon

Preparation of onion-like multilayered particles comprising mainly poly(iso-butyl methacrylate)-block-polystyrene by two-step AGET ATRP

The role of dietary fiber in supporting healthy gut microbiota and overall well-being of the host has been revealed in several studies. Here, we show the effect of a bacterial polyfructan levan on the growth dynamics and metabolism of fecal microbiota in vitro by using isothermal microcalorimetry. Eleven fecal samples from healthy donors were incubated in phosphate-buffered defined medium with or without levan supplementation and varying presence of amino acids. The generation of heat, changes in pH and microbiota composition, concentrations of produced and consumed metabolites during the growth were determined. The composition of fecal microbiota and profile of metabolites changed in response to substrate (levan and amino acids) availability. The main products of levan metabolism were acetic, lactic, butyric, propionic and succinic acids and carbon dioxide. Associated growth of levan-degrading (e.g. Bacteroides) and butyric acid-producing (e.g. Faecalibacterium) taxa was observed in levan-supplemented media. The study shows that the capacity of levan and possibly also other dietary fibers/prebiotics to modulate the composition and function of colon microbiota can be predicted by using isothermal microcalorimetry of fecal samples linked to metabolite and consortia analyses

Effects of lake sediment on soil chemical composition, dehydrogenase activity and grain yield and quality in organic oats and spring barley succession

In organic farming, it is important to maintain soil fertility with organic fertilisers; often organic compost, manure, or slurry is used. However, the effects of lake sediment in maintaining and improving soil fertility are less studied. The direct and residual effects of a one-time application of 50 t ha-1 or 100 t ha-1 of lake sediment were compared to an unfertilised control for oats (Avena sativa) (2015) followed by spring barley (Hordeum vulgare) in 2016, under organic farming conditions. Soil chemical composition, microbial activity in the 0–20 cm soil layer, grain yield, and grain quality were tested. The application rate, 100 t ha-1 , increased (P < 0.05) the soil organic carbon (SOC), the amount of mobile calcium (Ca), total nitrogen (Ntot), and boron (B) content in soil. Both application rates increased (P < 0.05) the amount of magnesium (Mg), copper (Cu), and manganese (Mn) content in the soil. The application rate had no effect on soil pH. Soil dehydrogenase activity (DHA) was higher (P < 0.05) at 100 t ha-1 than the control and the lower application rate. Both rates of lake sediment application significantly (P < 0.05) increased the grain yield and test weight for oats in 2015. Positive residual effects on spring barely yield only occurred in the 100 t ha-1 treatments in 2016. No residual impact of lake sediment was found on spring barely quality

The evolution of spring fen ecotypes in Rhinanthus : genetic evidence for parallel origins in Scandinavia after the last ice age

Locally adapted ecotypes can constitute an important part of the biodiversity, especially in young floras with few endemic species. However, the origins, distinctness and conservation value of many ecotypes remain uncertain because genetic data are lacking or no common-garden study has been carried out. In the present study, we evaluated the distinctness and genetic structure of a phenotypically deviating morph of Rhinanthus angustifolius, growing in calcareous spring fens on the Baltic island of Gotland. Using data from a common-garden experiment and analyses of nuclear microsatellite variation, we compared fen populations on Gotland with conspecific populations from habitats more typical of the study species. We also included the fen specialist R. osiliensis from the Baltic island of Saaremaa in the molecular analyses to make further inferences about the origin of the Gotlandic fen morph. Our data indicate that the Gotlandic fen populations constitute a phenotypically and genetically distinct ecotype that most likely has evolved at least two times on Gotland after the last ice age. In congruence with previous studies, we also infer that fen ecotypes have evolved independently on Gotland and Saaremaa. We propose a varietal status for the Gotlandic fen ecotype and give recommendations for the conservation of this taxon

Diversity and Stability of Lactic Acid Bacteria in Rye Sourdoughs of Four Bakeries with Different Propagation Parameters.

We identified the lactic acid bacteria within rye sourdoughs and starters from four bakeries with different propagation parameters and tracked their dynamics for between 5-28 months after renewal. Evaluation of bacterial communities was performed using plating, denaturing gradient gel electrophoresis, and pyrosequencing of 16S rRNA gene amplicons. Lactobacillus amylovorus and Lactobacillus frumenti or Lactobacillus helveticus, Lactobacillus pontis and Lactobacillus panis prevailed in sourdoughs propagated at higher temperature, while ambient temperature combined with a short fermentation cycle selected for Lactobacillus sanfranciscensis, Lactobacillus pontis, and Lactobacillus zymae or Lactobacillus helveticus, Lactobacillus pontis and Lactobacillus zymae. The ratio of species in bakeries employing room-temperature propagation displayed a seasonal dependence. Introduction of different and controlled propagation parameters at one bakery (higher fermentation temperature, reduced inoculum size, and extended fermentation time) resulted in stabilization of the microbial community with an increased proportion of L. helveticus and L. pontis. Despite these new propagation parameters no new species were detected

Organic Carrot (Daucus carota L.) Production Has an Advantage over Conventional in Quantity as Well as in Quality

Organic production is one of the fastest growing food sectors globally. However, average yield in organic vegetable production is up to 33% lower than in conventional production. This difference could be due to higher fertilization rates in conventional, compared to organic, farming. We aimed to compare yield and quality characteristics of carrots produced under equal nitrogen fertilization rates over four years in organic and conventional conditions. We found a 14.5% higher marketable, and 10.0% lower discarded, yield in the organic compared to the average conventional treatments. In addition, carrots managed organically had 14.1% lower nitrate and 10.0% higher vitamin C content than carrots managed conventionally. There were no convincing effects of cultivation system on the nitrogen, total sugar, or dry matter content of carrots. Organically managed carrots were free of pesticide residues, while several residues were found in carrots managed conventionally. Our study reveals that organic management of carrots may exceed that of conventional methods in yield and several quality characteristics, while being free of pesticide residues. Organic fertilizer gave an advantage over mineral fertilizer, when equal rates of nitrogen were used in both production systems

The effect of cover crops on biomass and nitrogen accumulation and on spring barley yield

Saabunud / Received 27.05.2023 ; Aktsepteeritud / Accepted 21.06.2023 ; Avaldatud veebis / Published online 15.08.2023 ; Vastutav autor / Corresponding author Merili Toom ; [email protected] crops play an important role in preventing nutrient loss, reducing agricultural inputs, improving soil quality and environmental sustainability. The objectives of the study were to determine the biomass and nitrogen accumulation of cover crops and their effect on the following spring barley (Hordeum vulgare L.). Field trials with cover crop species winter rye (Secale cereale L), winter turnip rape (Brassica rapa spp. oleifera L.), forage radish (Raphanus sativus L. var. longipinnatus), hairy vetch (Vicia villosa Roth), and berseem clover (Trifolium alexandrinum L.) were carried out during four growing seasons (2016/17, 2017/18, 2018/19, and 2019/20) at the Estonian Crop Research Institute (present: The Centre of Estonian Rural Research and Knowledge, METK). Cover crop biomass and N accumulation in autumn and in spring depended on species and growing conditions. The biomass and nitrogen (N) accumulation were at their lowest in the first growing season (2016/17) due to lowest level of effective temperatures. Forage radish accumulated the highest amount of biomass and N in autumn. Berseem clover accumulated lowest amount of biomass and N in the year with drought conditions (2018) before sowing. Among overwintered cover crops, hairy vetch accumulated the highest amount of N in the spring although its biomass was similar to winter turnip rape. Winter rye had the lowest biomass and N accumulation in spring. As an average over the four years, only forage radish and hairy vetch significantly increased the yield of subsequent barley. None of the cover crops had a negative effect on barley, as the yield level following other species was similar to the control without cover crop. The knowledge about cover crop selection is useful to integrate suitable species into Estonian cropping systems

Production of organic acids, carbon dioxide and ethanol (A), biogenic amines and branched-chain fatty acids (B), and production/consumption of amino acids (C) (mmol/gDW) during growth of fecal consortia in media containing levan (in red), levan + amino acids (in green) or without added substrates (in blue).

<p>The data presents the average of all fecal samples (n = 11 with 1–4 biological replicates). Dotted line indicates the zero level (no production or consumption). *—significant difference between levan and no-substrate conditions (p-value < 0.05), **—significant difference between levan and levan + amino acids (p-value < 0.05), ***—significant difference between levan and levan + amino acids and no substrate conditions (p-value < 0.05).</p

Proposed scheme for levan degradation and product formation on the basis of our experimental data and information from the literature.

<p>Proposed scheme for levan degradation and product formation on the basis of our experimental data and information from the literature.</p