Quantitative parameters of cenopopulations of Lobaria pulmonaria, an endangered cyanolichen, have been studied in spruce phytocenoses of Karelia recovering after disturbance through the successional...

The paper describes the ontogenesis of the epiphytic lichen Lobaria pulmonaria. The studies were carried out in the Karelian forest communities with the period since the last disturbance ranging from 80 to 450 years. Based on the concept of a discrete description of plants and lichens, four periods and 14 age-related states have been distinguished in L. pulmonaria’s ontogenesis. Each ontogenetic state of L. pulmonaria is characterized by a certain thallus size as well as by the presence and the level of development of vegetative diaspores and apothecia on the thallus surface. The possible variants of the species ontogenesis are described.

The use of biotechnological tools, in particular somatic embryogenesis (SE) for mass propagation of conifers, is relevant since this method allows to quickly replicate plant material with desired features. However, there are still a number of difficulties in obtaining an embryogenic cell culture for Pinus sylvestris. One of the important and unsolved problems is the search for SE-competent genotypes. We cultured 674 megagametophytes from 22 donor plants (16 genotypes) in vitro during the 2021 summer period. As a result of the experiment, callus formation was not recorded for the studied genotypes; however, 9.4 ± 1.0% of the explants formed plants. In addition to the genotype effect, unsuitable nutrient medium or late developmental stages of zygotic embryos could be the reasons for the lack of callus induction. To solve these problems, a number of studies were carried out: (1) the effect of the nutrient medium composition and density (MS, MSG, ½LV, DCR) on the callus initiation from mature seeds was analyzed, (2) the effect of various growth regulators concentrations on the initiation of callus formation was studied, (3) the analysis of the reproductive competence of donor plants was performed by the method of vegetative buds cultivation. As a result, several genotypes were found to have the ability for embryogenic callus formation, and the conditions for explants cultivation were selected.

The article analyzes and summarizes information on breeding and seed production of the main forest-forming and commercial species for the countries of Northern Europe and Russia: Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst). It is shown that in the last 40–50 years Sweden and Finland have completed the first (primary) cycle of plus-tree breeding, and the second cycle is being actively pursued. In terms of seed production, this means a gradual replacement of the 1st generation forest seed orchards with the forest seed orchards of enhanced genetic value (of 1.5 and 2nd generation). By the middle of the 21st century, the productivity of new artificial stands is expected to increase by 20–25 % in terms of stem wood stock due to breeding work. Successful and quite large-scale works were undertaken in plus trees phenotypic breeding and forest seed orchards (1st generation) planting in some regions of European Russia in the last third of the 20th century. However, even this first (primary) cycle of plus-tree breeding has not been fully completed. The latter makes it possible to lay out the necessary areas of multiplicative populations of increased genetic value – forest seed orchards of the 1.5 generation. Although this is impossible to achieve in many subjects of the Northwestern Federal District due to the insufficient number of selected plus trees and, most importantly, the extremely small area of progeny tests. At present, the vast majority of initially selected plus trees were not genetically tested, which hinders the possibility of further development of the plus-tree breeding system. Russia also lacks special breeding zoning of the main forest-forming species, providing a spatial organization of breeding work and the use of seeds from forest seed orchards. A federal program for the preservation and sustainable management of forest genetic resources of the Russian Federation, together with a number of subprograms for genetic research and breeding of the most important forest-forming species, should be developed to achieve progress in this direction, considering current advances in molecular genetics and biotechnology. Acknowledgments: Financial support of the research was provided by the federal budget for the state assignment of the Forest Research Institute and the Department of Multidisciplinary Scientific Research of Karelian Research Centre, Russian Academy of Sciences with partial support of the World-class Scientific and Educational Center “Russian Arctic: New Materials, Technologies and research Methods”. For citation: Raevsky B.V., Ignatenko R.V., Novichonok E.V., Prokopiuk V.M., Kuklina K.K. The Current State of Conifer Species Breeding and Seed Production. Lesnoy Zhurnal = Russian Forestry Journal, 2022, no. 6, pp. 9–37. (In Russ.). https://doi.org/10.37482/0536-1036-2022-6-9-37

The article describes the cytogenetic parameters of seed progeny of Pinus sylvestris plus trees growing in the Petrozavodsk seed orchard of the first order. P. sylvestris normal trees from the natural pine phytocenosis in the Pryazha region (Karelia) were taken as a control. The following indicators were considered: relative DNA content, number of chromosomes, frequency and types of mitosis pathologies at the metaphase, anaphase and telophase stages (in % of the total number of dividing cells at the same stages). It was found that the root meristem of the P. sylvestris seed progeny contains 24 chromosomes in the diploid set. Single aneuploid cells (2n = 23; 2n = 25) were found in the studied plants. The most frequent is monosomy (2n = 23). It made up 81 % of the total number of aneuploid cells. The relative DNA content in the young needles of pine seedlings of plus clones and normal trees was 42.07±0.21 and 42.95±0.04 pg, respectively, and the difference between the two was statistically significant (U-test, p ˂ 0.01). Cytogenetic analysis revealed 7 types of mitosis pathologies: chromosome fragmentation, chromosome bridges, chromosome overlap, isolation of chromosomes and groups of chromosomes, chromosome lagging, multipolar mitosis and complex abnormalities. Chromosome overlap was the most common pathology in the general mitotic disorders spectrum. Comparison of mitosis pathologies in two general samples of normal trees and plus tree clones showed that they significantly differ by the following mitosis abnormalities: overlap and isolation of chromosomes in metaphase, fragmentation, lagging, bridges and multipolar mitosis in the anaphase and telophase. The study shows that the proportion of cells with mitosis abnormalities in the seed progeny of normal trees was about 1.5 times higher than of plus tree clones, and is equal 3.44±0.32 and 2.38±0.14 % (U-test, p = 0.05), respectively. The data obtained demonstrate the cytogenetic stability of the seed progeny of P. sylvestris clones from the Petrozavodsk seed orchard of the first order, which in turn may indicate the high quality of the seed material. For citation: Ignatenko R.V., Ershova M.A., Galibina N.A., Raevsky B.V. Cytogenetic Characteristics of Seed Progeny of Scots Pine Plus Tree Clones in Karelia. Lesnoy Zhurnal [Russian Forestry Journal], 2022, no. 1, pp. 9–22. DOI: 10.37482/0536-1036-2022-1-9-22