Tuija S. Aronen

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material for genetic transformation of silver birch (Betula pendula Roth) by particle bombardment. Cultivation of in vitro shoot cultures before particle bombardment and a long selection period, combined with a high concentration of selective agent after bombardment, led to the production of transformed plantlets that were stable, and no escapes were found(More)
Clonal trueness of micropropagated or cryopreserved material is essential, especially with long-living tree species. In this study, the growth rate and morphology of regenerated silver birch (Betula pendula Roth) plants growing in the nursery were evaluated after different treatments: short-term (14 months) and long-term (70 months) tissue culture periods,(More)
The aim of the study was to develop an effective cryopreservation method for Scots pine (Pinus sylvestris L.) embryogenic cultures. Altogether nine cell lines derived from three mother trees were cryopreserved after cold hardening using dimethylsulfoxide or two different mixtures of polyethyleneglycol 6000, glucose and dimethylsulfoxide as cryoprotectants.(More)
The study demonstrates the production of a transgenic Scots pine (Pinus sylvestris L.) seedling through the application of transformed pollen in controlled crossings. The pollen lots were transformed by particle bombardment, resulting in transient transformation frequencies varying from 15 to 49% of the germinated pollen grains, and bombarded pollen was(More)
An in vitro germination method was used to study variation in pollen viability, that is pollen-tube growth rate together with germination percentage, among the Picea abies genotypes in a seed orchard. The method permits easy, rapid screening of large numbers of genotypes. Significant variation in pollen viability among the genotypes was evident, the(More)
The aim of the present work was to study pollen-tube competition in Picea abies. Controlled crossings were performed with pollen mixtures including pairs of pollen lots with fast and slowly elongating pollen-tubes. Paternity analysis using isozyme markers was performed on the progenies in order to study whether the in vitro pollen-germination vigour(More)
The shortening of telomeres, the specific structures at the end of the eukaryotic chromosomes, has been associated with ageing and loss of cell replication or regeneration capacity. The aim of this study was to determine the variation in telomeric repeats during the life-span of Scots pine (Pinus sylvestris L.) by studying different tissues and age groups(More)
The effects of Agrobacterium pRiA4 rol and aux genes, controlled by their endogenous promoters, on tree growth and wood anatomy and chemistry were studied in 5- and 7-year-old silver birch (Betula pendula Roth) plants. Southern hybridization confirmed the following rol and aux gene combinations: control plants (no genes transferred); plants with rolC and(More)
Scots pine plantlets were produced via tissue culture using cotyledons excised from germinated embryos as explants. The optimum tissue culture conditions were: 1/2GDbasal medium gelled with agar-Gelrite during shoot formation and with agar during rooting, inclusion of 5.0μM benzylaminopurine (BAP) and 0.05 μM naphthaleneacetic acid (NAA) for 2 weeks for(More)
Shortening of telomeres has been connected with ageing and loss of cell replication or regeneration capacity. The aim of the present study was to examine potential variation in the length of telomeric repeats in silver birch (Betula pendula Roth) using clonal materials consisting of different-aged outdoor trees and tissue cultures of seven genotypes. The(More)