47 research outputs found
The role of pollen in the changing environmental conditions of Scots pine
Rapid change in climate is challenge for the adaptation of forest trees in the future. In wind pollinated tree species pollen mediated long distance gene flow may provide alleles that are (pre)adapted to a future climate.
In order to examine the long distance pollen flow in Scots pine (Pinus sylvestris L.), we measured the amount and viability of airborne pollen and flowering phenology in central, northern, and northernmost Finland during four years. Viable airborne pollen grains were detected during female flowering and before local pollen shedding in all study sites. The situation when there was nonlocal pollen in the air lasted from one to four days depending on the year and study site. The amount of nonlocal airborne pollen varied also between years and study sites, the total amount of nonlocal viable pollen in the air was 2.3% from all detected viable pollen grains.
The effect of pollen origin on seeds siring ability was studied with artificial pollination experiments. Pollen genotypes originating from southern Finland sired 76% and 48 % of the analysed seeds in competition studies where both pollen origin were introduced simultaneously into the female strobili.
We examined the importance of arrival order of pollen grains in to the strobili in a study where pollen genotypes of different origin were introduced in two hours interval. Northern genotypes sired 76% of the analysed seeds when it was injected first, but in the "southern first" experiment both pollen types sired equal amount of seeds. The first pollen grain in the pollen chamber do not always fertilizes the ovum, instead there likely is more complex way of competition between pollen grains.
To examine chemically mediated pollen-pollen interactions we conducted in vitro germination experiment where different pollen genotypes had chemical but not physical contact. Both positive and negative effects of interactions were found. We found highly negative effects in germinability of northern pollen grains when they were germinating with southern pollen, and increase in the germinability of southern pollen.
There were no variation in the size of the dry pollen grains between pollen origins, and minor variation between different genotypes. After hydration and germination northern pollen grains were larger than southern pollen. Pollen genotypes having high hydration rates had low germinability and tube growth rate, however, germinated pollen grains were larger in size than nongerminated. This supports the suggestion that the early germination and growth of pollen tube is dependent on pollen storage materialsand less dependent on water intake and hydration.
Long distance pollen movements and good competition ability of southern pollen makes gene flow possible, although rising temperature and timing of pollen movements may affect pollen competition and the amount of gene flow.Tuulipölytteisen mÀnnyn sopeutumista ilmaston lÀmpenemiseen voi helpottaa valmiiksi tuleviin olosuhteisiin sopeutuneista populaatioista siitepölyn mukana kulkeutuvat geenit. EdellytyksenÀ tÀllÀisen geenivirran syntymiseen on siitepölyn kaukokulkeutuminen, sekÀ kaukokulkeutuneen siitepölyn hyvÀ kilpailukyky paikallista siitepölyÀ vastaan. Myös siitepölyn kaukokulkeutumisen ja kohdepaikan emikukinnan on osuttava samaan aikaan.
Siitepölyn kaukokulkeutumisen mahdollisuutta ja ajoitusta emikukinnan suhteen tutkimme tarkkailemalla kukintaa, mittaamalla siitepölymÀÀriÀ ilmassa ja testaamalla ilmasta kerÀtyn siitepölyn itÀvyyskykyÀ Korpilahdella, RovaniemellÀ ja Kevolla vuosina 1997-2000. Ennen paikallista hedekukintaa ilmassa olevan itÀmiskykyisen mÀnnyn siitepölyn mÀÀrÀ oli 2.3% kaikesta ilmasta kerÀtystÀ mÀnnyn siitepölystÀ ja emikukinnoista 7,5% oli avoinna. On mahdollista ettÀ erityisesti ensimmÀisinÀ aukeavat mÀnnyn emikukat pölyttyvÀt useiden satojen kilometrien pÀÀstÀ lÀhtöisin olevalla siitepölyllÀ.
EtelÀisen ja pohjoisen siitepölyn kilpailukykyÀ tutkimme kilpailuristeytysten ja molekyylibiologisten isyystestausten avulla. Kahdessa eri tutkimuksessa etelÀiset siitepölyt hedelmöittivÀt 76% ja 48% tutkituista siemenistÀ.
EnsimmÀisenÀ kukkaan saapuneen siitepölyhiukkasen mahdollisesti saamaa kilpailuetua tutkimme pölyttÀmÀllÀ emikukkia ensin etelÀisellÀ siitepölyllÀ ja kahden tunnin kuluttua pohjoisella pölyllÀ, ja pÀinvastoin. Pohjoiset siitepölyt saivat etumatkasta huomattavan kilpailuedun, kun taas etelÀinen pöly ei siitÀ hyötynyt. Kun pölytys tehtiin etelÀisen ja pohjoisen pölyn sekoituksella, pohjoisen saama kilpailuetu katosi.
Siitepölyjen kemiallisen vuorovaikutuksen mahdollisuutta selvitimme idÀttÀmÀllÀ eri siitepölyerÀt nesteitÀ lÀpÀisevÀn kalvon eri puolilla. Havaitsimme sekÀ positiivista ettÀ negatiivista vuorovaikutusta: etelÀiset siitepölyt itivÀt kilpailutilanteessa paremmin ja pohjoiset huonommin kuin kontrolli-idÀtyksissÀ.
ItĂ€misaikaisen lĂ€mpötilan vaikutusta siitepölyn itĂ€miseen ja siitepölyputken kasvuun tutkittiin idĂ€ttĂ€mĂ€llĂ€ siitepölyeriĂ€ + 15ÂșC ja + 20ÂșC lĂ€mpötiloissa kasvatusliuoksessa. Siitepölyjen itĂ€vyys ja siitepölyputken kasvu oli nopeampaa + 20ÂșC:ssa kuin + 15ÂșC:ssa, pohjoiset siitepölyt hyötyivĂ€t korkeammasta lĂ€mpötilasta enemmĂ€n kuin etelĂ€iset pölyt.
Siitepölyn kaukokulkeutuminen ja etelÀisen pölyn kilpailukykyisyys mahdollistavat geenivirtauksen mÀnnyllÀ. LÀmpötilan nousu ja kaukokulkeutumisen ajoitus voivat kuitenkin vaikuttaa siitepölykilpailuun ja sitÀ kautta geenivirran mÀÀrÀÀn
Somatic Embryogenesis and Plant Regeneration From Primordial Shoot Explants of Picea abies (L.) H. Karst. Somatic Trees
Article 1551201
From Petri dishes to bioreactors - First experiences on optimization of Norway spruce SE-process for bioreactors
201
Development of Somatic Embryo Maturation and Growing Techniques of Norway Spruce Emblings towards Large-Scale Field Testing
201
Rooted shoot cuttings from SE donor plants in Finland â potential material for breeding and propagation
Poster presentation: IUFRO Seed Orchard Conference 2017 September 4-5, 2017, BĂ„lsta, Sweden201
Telomere Length in Norway Spruce during Somatic Embryogenesis and Cryopreservation
Telomeres i.e., termini of the eukaryotic chromosomes protect chromosomes during DNA replication. Shortening of telomeres, either due to stress or ageing is related to replicative cellular senescence. There is little information on the effect of biotechnological methods, such as tissue culture via somatic embryogenesis (SE) or cryopreservation on plant telomeres, even if these techniques are widely applied. The aim of the present study was to examine telomeres of Norway spruce (Picea abies (L.) Karst.) during SE initiation, proliferation, embryo maturation, and cryopreservation to reveal potential ageing or stress-related effects that could explain variation observed at SE process. Altogether, 33 genotypes from 25 families were studied. SE initiation containing several stress factors cause telomere shortening in Norway spruce. Following initiation, the telomere length of the embryogenic tissues (ETs) and embryos produced remains unchanged up to one year of culture, with remarkable genotypic variation. Being prolonged in vitro culture can, however, shorten the telomeres and should be avoided. This is achieved by successful cryopreservation treatment preserving telomere length. Somatic embryo production capacity of the ETs was observed to vary a lot not only among the genotypes, but also from one timepoint to another. No connection between embryo production and telomere length was found, so this variation remains unexplained