Scientific publications

This article presents the results of evaluating the effectiveness of the BpCW1 molecular marker for early detection of the ‘figured grain’ trait in vegetative progeny of curly birch Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti during clonal micropropagation in vitro. In the parent trees, this trait is typically visualized by the age of 8–10 years as bulges or thickenings on the trunk surface. Clones (in vitro) of silver birch (Betula pendula Roth), downy birch (Betula pubescens Ehrh.), and their varieties (which have predominantly decorative leaf shapes or colors) served as controls. PCR analysis showed that 87.5 % of curly birch clones contained amplification products (476 bp or 530/476 bp) corresponding to a deletion (loss) of a 54-bp DNA region associated with the ‘figured grain’ trait. The deletion allele was found to be homozygous in 62 % of clones, and heterozygous in 38 %. A comparative analysis of vegetative progeny based on their geographic provenance revealed that curly birch of Karelian provenance exhibited significantly more heterozygous alleles (>1.4 times more frequent) than homozygous alleles. Clones derived from parent trees from other Russian regions (e.g., Smolensk Oblast), Belarus, Denmark, and Finland exhibited a different allele ratio. Application of the BpCW1 marker also confirmed the absence of the allele with the 54-bp deletion in other members of the genus Betula (available in a previously created collection of in vitro clones), which is consistent with their characteristic straight-grained wood texture. These data indicate the possibility of using the BpCW1 molecular marker to detect a deletion localized on chromosome 10 in the curly birch genome, linked to the ‘figured grain’ trait, in clones cultivated in vitro, whose parent trees were selected solely on the basis of indirect exterior evidence. This will speed up the resolution of a number of issues related to the selection of curly birch, as well as the selection of initial genotypes when creating commercial plantations for growing trees with the desired characteristics.