Seed Germination and Seedling Growth of Robinia pseudoacacia Depending on the Origin of Different Geographic Provenances

Black locust (Robinia pseudoacacia) is recognised as a forest species of interest due to its multiple uses. The management of forest genetic resources and their efficient conservation suffer from variations in traits and start with seed germination. The aim of the current study was to investigate the germination of seeds obtained from plus trees selected in eight Romanian provenances, as well as to investigate the influence of the origin upon plants’ growth and development. Two experiments were undertaken to test seed germination: one treatment involved water-soaked seeds and heat/cold treatment, while the other treatment was based on sulphuric acid, at different concentrations (50, 70, 90%). The results were correlated with the morphological analysis of the seeds. Satu-Mare had the lowest germination rate within both treatments. Sulphuric acid did not improve seed germination as much as the heat treatment. The highest germination rate occurred for the water and temperature treatment on seeds from Bihor provenance (68.2%). The most distant provenance was Bihor, in inverse correlation with Bistrița Năsăud and grouped separately within the hierarchical dendrogram of cluster analysis based on the analysed parameters of the provenances investigated. The results demonstrated that the genotypes and environmental heterogeneity of the seed origin within the provenances may finally result in different performances.

Practical approaches to determining the dynamics of the stability of stands of breeding objects

The article analyzes the indicators that can be used to assess the biotic and ecological stability of forest stands. For breeding facilities, this issue is of relevance when prescribing reforestation measures in forest genetic reserves, assessing the stability when selecting plus stands, assessing selected permanent forest-seed plots to determine the volumes of their formation and tending activities in them and, in the future, their transfer to plus stands, as well as, in general, for isolation of a reserve fund from the forest environment. The methods for assessing the stability of forest stands are based on determining the indicators of forest stand stability, calculated on the basis of tree mensuration in the study area (based on a trial plot) and the sanitary state of the trees. The basis for the determination is the complete tree enumeration and the scale of sanitary state used in production operations (SanitaryForestsReg.Ukraine). The assessment of stand stability is based on the method of calculating the loss of stability (BC)), which was proposed to determine the stability of secondary spruce forests in fertile beech forest types (BlystivV. I. 2006) and later adapted to assess the formation of the stability of hornbeam-beech stands (Blystiv V. I., 2012). The issue of assessing the tension of a stand, using the growing space of the forest is addressed in the methods section of the dissertation work by V.M.Malyuga, 2020. Using the values of the above indicators (KC, ВбС, ВеС), stands can be divided into 3 categories of stability: stable, conditionally stable and unstable. Appropriate forestry activities are proposed according to the categories. They require a special numeric-expressed substantiation, both in relation to the economic group of forest types, forest category, and for targeted activities or research areas - in this case, loss of stability of breeding facilities. Tension studies have shown that by using factors of environmental impact, the conditions are assessed as normal, non-tensioned and tensioned. To assess the indicator values of normal and weakened states, the basic scale of the assessment of biotic stability by stand indexes will be used. For the weakened state, three indexes are identified for the purpose of detailed planning of possible activities. In forest breeding, the selection and formation of forest stands for stability will require parameter-defined indicators, in this case, the forest stand stability coefficient is used. The protective properties of the forest environment, identified with the preservation of genetic diversity, determined by the amount and quality of natural regeneration and associated with ecological stability, can be effectively assessed by its loss according to the above method. The studies on the stand tension, using the factors of environmental impact, have shown that stands growing under tension are those that are somewhat overstocked ones. Pine stands grow optimally when they have a density range of 0.7-1.0. The rest of the stands grow without tension, but they do not make full use of growing space due to varying degrees of stand density. Such medium-stocked stands can be effectively used as selected and appropriately formed permanent forest-seed plots. Assessment of the stand state by impact factors makes it possible to record quantitative changes. The dynamics of areas in accordance with the changes of these indicators by periods characterizes the ecosystem changes (stages of development by successive process) and is important for the facilities of preservation of genetic diversity - especially forest genetic reserves.

The Current State of Forest Breeding in the Russian Federation: The Trend of Recent Decades

The work is devoted to the study of the trends existing in forest breeding in Russia over the recent years, their comparison with similar achievements in foreign countries with close climatic conditions, and the assessment of the prospects for the development of this scientific and production direction in our country, based on the obtained results. The official data of State inventories over the last 25 years and national scientific publications were used. A number of foreign literature sources were also considered for comparison in addition to Russian sources. Quantitative indices of the following processes were studied: selection of plus trees; creation of clone archives, provenance trial and population-ecological plantations; allocation of forest genetic reserves and plus stands; organization of temporary and permanent forest seed plots; and creation of mother plantations, forest seed orchards and progeny field tests of plus trees. Materials on the development or degradation of forest genetic resources in Russia were analyzed by years. The analysis has shown that in Russia there is a regression of the state forest genetic and breeding complex. Over the past 25 years, there has been an average 50 % decline in individual components, with fluctuations in various indices ranging from 7 to 940 %. A comparison of the development of the unified forest genetic complex in our country with its development in a number of foreign countries (Canada, Norway, Sweden, and Finland) revealed our lag in almost all indices by several times. In particular, the selection intensity of plus trees in the countries of Northern Europe (Norway, Sweden, and Finland) is 21.0–61.7 times higher than in Russia. The provision with forest seed orchards in the Russian Federation is 2.7–12.0 times lower than in Norway and Finland. At the same time forest seed orchards of the more progressive, second order represent a large share in the Nordic countries. For instance, in Canada there are more than 30 % of them. In the Russian Federation, such plantations are practically absent and are not listed in official documents. The analysis has shown that it is time to develop a new long-term program of genetic and breeding improvement of forest tree species in order to preserve sustainable reforestation of Russian forests and their valuable gene pool, as well as to identify those responsible for its implementation. For citation: Tsarev A.P., Laur N.V., Tsarev V.A., Tsareva R.P. The Current State of Forest Breeding in the Russian Federation: The Trend of Recent Decades. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 6, pp. 38–55. DOI: 10.37482/0536-1036-2021-6-38-55

Conservation of forest genetic resources through the example of native Quercus species from the “Košutnjak” park forest in Serbia

Given the importance of urban park forests and protected natural areas in the urban environment, the implementation of the concept of genetic conservation is one of the main ways to save and improve this category of natural resources. Forests such as Košutnjak can be considered a refuge for flora and fauna and by establishing conservation programs for certain species, the entire ecosystem would be better protected. The purpose of this paper is to elaborate a systematic approach to in situ conservation of forest genetic resources in urban areas through the example of four native oak species: pedunculate oak, sessile oak, Hungarian oak and downy oak in the protected natural area “Košutnjak” in the capital of Serbia – Belgrade, to develop replicable conservation guidelines for urban park forests. The methodological framework for the development of guidelines for genetic conservation, presented in this paper, is a replicable model whose basic principles can be applied in other cases of urban park forests.

Analysis of genotype-by-environment interaction in a multisite progeny test with Scots pine for supporting selection decisions

In multisite forest genetic experiments, the presence of genotype × environment interaction (GEI) is common. GEI may negatively affect the estimates of genetic variance and hamper selection decisions in tree breeding programs. Several measures exist to evaluate the stability of tested genotypes’ performance across environments with a choice of the method likely affecting breeders’ decisions. In this study, we evaluated variation in diameter and height growth performance in the progeny test established at 4 sites with 80 open-pollinated half-sib families of Scots pine. We found significant variation among examined progeny at age 10, reaching up to 31% for diameter and 20% for height depending on site, and significant GEI in both traits. We estimated contribution of each family to GEI using various methods and tools of GEI analysis—AMMI, GGE biplots, heterogeneity of regression coefficients (bi’s), the deviation mean squares from regression (s2di) and Kang’s yield-stability index (YSi). Despite the presence of the cross-over interaction, family ranks did not vary much among sites. The selections based on the phenotype, YSi and restricted bi corresponded well to each other leading to the expected response to selection up to 7.8% on diameter and 4.4% on height, whereas those based on the AMMI stability variance were different and lead to a slight loss in both traits. We discuss our results in the context of the usefulness of those measures of genotype stability for tree breeding programs and propose the procedure to follow for making selection decisions in forest experiments with GEI.

Graft survival of Pinus engelmannii Carr. in relation to two grafting techniques with dormant and sprouting buds

Developing methods for successfully grafting forest species will be helpful for establishing asexual seed orchards and increasing the success of forest genetic improvement programs in Mexico. In this study we investigated the effects of two grafting techniques (side veneer and top cleft) and two phenological stages of the scion buds (end of latency and beginning of sprouting), in combination with other seven grafting variables, on the sprouting and survival of 120 intraspecific grafts of Pinus engelmannii Carr. The scions used for grafting were taken from a 5.5-year-old commercial forest plantation. The first grafting was performed on January 18 (buds at the end of dormancy) and the second on February 21 (buds at the beginning of sprouting). The data were examined by analysis of variance and a test of means and were fitted to two survival models (the Weibull’s accelerated failure time and the Cox’s proportional hazards model) and the respective hazard ratios were calculated. Survival was higher in the top cleft grafts made with buds at the end of latency, with 80% sprouting and an estimated average survival time of between 164 and 457 days after the end of the 6-month evaluation period. Four variables (grafting technique, phenological stage of the scion buds, scion diameter and rootstock height) significantly affected the risk of graft death in both survival models. Use of top cleft grafts with buds at the end of the latency stage, combined with scion diameters smaller than 11.4 mm and rootstock heights greater than 58.5 cm, was associated with a lower risk of death.

Growth and genetic parameters of progenies of Cordia trichotoma in the juvenile phase

Increasing the productive potential of native species is a challenge for forest genetic improvement. Progeny tests are efficient tools to determine the reproductive capacity of individuals and to assist with the selection of superior genotypes. Cordia trichotoma (Vell.) Arrab. ex Steud, is a native species of commercial interest due to its high potential for sawn wood. The performance of seedling production from different progenies was the objective of this work. Seeds were collected from 34 matrices selected phenotypically and georeferenced in the region of Lavras - MG. The experiment was conducted in a completely randomized design with 4 replications of 12 plants. Germination after 70 days of sowing, survival and height at 170 days after germination were evaluated. Height and genetic parameters were estimated according to mixed REML / BLUP models using the Selegen software model 82. Progeny 104 (70.8%) was superior in germination and progenies 86 (35.42%), 92 (35.42%) and 111 (43.75%) had the highest survival rates. Height shows high values for the individual additive genetic variation coefficient (49.18%) and genotypic variation coefficient between progenies (24.59%) and moderate values of heritability in the restricted individual sense (0.45) and heritability within progenies (0.38). Due to high values for the coefficient of genotypic variation and moderate values of heritability, there is a potential for height improvements. Progenies 104 stand out in the germination and the progenies 86, 92 and 111 in the seedlings survival). Regarding height, progeny 95 is the only one that stands out negatively.

State of in situ forest genetic resources of broadleaved tree species in the Right-Bank Forest-Steppe of Ukraine

Forest genetic resources (FGRs) are an important source of biodiversity conservation and forest restoration. Today, more than 600 genetic reserves (GRs) of more than 30 main forest tree species have been allocated in Ukraine. The main aim of the work is to reveal the features of the distribution, environmental condition and the trends of state of in situ gene sources of broadleaved tree species in the Right-Bank Forest-Steppe of Ukraine. Based on the research results, it has been established that the share of FGR in situ is only 0.3–0.5% of the total forest area of the region. The predominant species of forest stands of the region are English oak (Quercus robur L.) – 37.7%, European beach (Fagus sylvatica L.) – 26.8% and Common ash (Fraxinus excelsior L.) – 7.6%. The in situ locations of Black alder (Alnus incana L.), Sessile oak (Quercus petraea (Matt.) Liebl.), English oak and Common ash are characterized by the highest average annual temperature (8.1–8.2°С), the accumulated temperatures for the growing season (3111.9–3237.1°С). Stands with the European beech predominance are allocated in better moisture conditions by the precipitation-temperatures ratio (Selianinov Hydrothermal Index (HTI) – 1.769–1.802; climatic index by Vorobyov – 2.707–2.951). The in situ gene pool conservation units are defined by 12 soil types that are included in the 7 main groups according to the FAO international classification. The largest number of sites, 67 (56.8%), is concentrated on grey and dark-grey forest soils (Haplic Greyzems) (47%). According to the research results, GRs are not evenly distributed, they do not fully reflect the environmental diversity, and their area is negligible. We indicated the unsatisfactory condition of most genetic reserves. It was caused by reducing the share of main tree species, decrease in relative stocking density of stands and tree-breeding structure and deterioration of tree stands condition. This requires the development and implementation of an integration strategy based on the established concept of developing a national ecological network on both national and pan-European levels.

Culturile comparative – elemente esențiale de verificare a comportamentului diferitor proveniențe de arbori

Depending on the general or specific objectives, for the improvement of forest species and to assess performance of proveniences in different environmental conditions, it is necessary to install comparative trials. These comparative trials include descendants of Forest Genetic Resources (RGF) from three provenance regions (A, B, C) of the Republic of Moldova, and are being intended to monitor the performance of descendants over time. The performance of descendants will be evaluated through different statistical approaches of biometric parameters. The study of comparative cultures will contribute to establish over time most adapted and stable proveniences for region where permanent trials are installed. The selection of most adapted proveniences is the first mandatory stage in any tree improvement program, because in addition to estimating provenances ability to adapt, are also evaluated quantitative traits such as growth performances and wood quality and plasticity.