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Thesis

University of Iceland > Verkfræði- og náttúruvísindasvið > Rannsóknarverkefni - Verkfræði- og náttúruvísindasvið >

Please use this identifier to cite or link to this item: https://hdl.handle.net/1946/16970

Title: 
  • Title is in Icelandic Greining erfðamengja xTriticoleymus og Rosa L.
  • Genome differentiation in xTriticoleymus and cytotaxonomy of Rosa species
Abstract: 
  • Abstract is in Icelandic

    Melhveiti (xTriticoleymus) er blendingur hveiti (Triticum) og melgresis (Leymus) tegunda. Erfðamengi xTriticoleymus er áhugavert vegna þess að blendingurinn er frjór og mögulega hægt að rækta hann sem nytjaplöntu. Í þessari rannsókn voru litningar einangraðir úr rótarendum xTriticoleymus og skoðaður fjöldi litninga xTriticoleymus og aðgreint hversu margir kæmu úr hvorri foreldraplöntu með genomic in situ hybridization (GISH). Auk þess voru 18S-25S rDNA gen kortlögð með fluorescence in situ hybridization (FISH). Niðurstöður sýndu að xTriticoleymus hefði 2n=6x=42 með 30 hveitilitninga og 12 melgresislitninga. Ríbósómgenin sýndu að önnur foreldraplantan væri hveiti með genamengi sem innihéldi B genamengi ásamt erfðamengi frá dúnmel (Leymus mollis). Mögulegt er að tveir Leymus mollis litningar skiptist út fyrir tvo hveitilitninga í tegundablöndunarferlinu og hveitiforeldrið sé því ferlitna með 2n=4x=28 og AB genamengi.
    Kristinn Guðsteinsson æxlaði saman tveimur rósategundum og fékk blendinginn Rosa moyesii var fargesii x Rosa ˈDornröschenˈ sem vex enn í garði hans. Rosa ˈDornröschenˈ hefur verið ræktuð á Íslandi um nokkurt skeið og er móðurplantan sem notuð var í æxlun blendingsins. Í þessari rannsókn var leitast við að ákvarða litnun og litningafjölda þessara tveggja rósaafbrigða. Það var gert með því að einangra litninga úr sprotabrumum með protoplast-dropping aðferð. Niðurstöðurnar sýndu að Rosa ˈDornröschenˈ væri tvílitna með 2n=2x=14 og að breytileiki væri í litningafjölda innan blendingsins Rosa moyesii var fargesii x Rosa ˈDornröschenˈ. Sú fruma sem var með fæsta litninga hafði 2n=28 en sú sem hafði flesta var sexlitna með 2n=6x=42. Sexlitna fruman hefur hugsanlega komið til með náttúrulegri tvöföldun litninga þríblendingsfrumna.

  • The hybrid xTriticoleymus was established from a cross between wheat (Triticum) and lymegrass (Leymus) species. The hybrid is interesting because it is a fertile amphiploid and it might possibly be viable for cultivation as a grain crop. This research utilized an enzymatic root-tip squash method of chromosome preparation which was used to discover the genome composition in xTriticoleymus. The genomic in situ hybridization (GISH) method was used to distinguish how many came from each parental species. In addition, 18S-25S rDNA genes were mapped with fluorescence in situ hybridization (FISH). The results showed that xTriticoleymus was an allohexaploid with 2n=6x=42 from which 30 chromosomes came from wheat and 12 from lymegrass. The nucleolar organizing regions (Nor) showed that one of the parent plants was in fact a wheat containing B genome, whereas the other plant was probably Leymus mollis. Substitution is likely to have taken place during the hybridization process such that two of the Leymus mollis chromosomes were replaced by two of the wheat chromosomes. The wheat parent is probably a tetraploid with 2n=4x=28 and AB genome.
    Kristinn Guðsteinsson established a hybrid from a cross between Rosa moyesii var fargesii and Rosa ˈDornröschenˈ. Now this hybrid grows in his garden. Rosa ˈDornröschenˈ, the mother plant which Guðsteinsson used in his crossing, has been cultivated in Iceland for a while now. The aim of this research was to determine the ploidy and the number of chromosomes by using a protoplast dropping method for shoot-tip chromosomes. The results showed that Rosa ˈDornröschenˈ was a diploid with 2n=2x=14 and that there was a variation in the chromosome number of the hybrid Rosa moyesii var fargesii x Rosa ˈDornröschenˈ. The cell that had the fewest chromosomes had 2n=28 and the one that had the most was hexaploid with 2n=42. The hexaploid cell has probably derived from chromosome doubling of the hybrid triploid cell by natural means.

Accepted: 
  • Dec 20, 2013
URI: 
  • http://hdl.handle.net/1946/16970


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