Comparative analysis of genetic diversity in Norway spruce (Picea abies) clonal seed orchards and seed stands

Norway spruce, Picea abies (L.) Karst. is the most important conifer species in Romania and the most planted tree species in the Carpathian Mountains. Here we compare the genetic diversity of four Norway spruce clonal seed orchards and two seed stands located in the Eastern Carpathians. A set of highly polymorphic nuclear microsatellite markers was used. The analysis of genotypic identity of ramets for each Norway spruce clone in all seed orchards indicated that nearly all sampled ramets (97%) were genetically identical. The genetic diversity in seed orchards (He=0.700) was slightly smaller compared to the seed stands (He=0.718). Allelic richness was higher in seed stands (10.874), compared to clonal seed orchards (8.941). The Bayesian analysis indicated a genetic structure with two clusters, one corresponding to the clonal seed orchards and a second one consisting of the two seed stands. Our results provide valuable information for the management of Norway spruce seed orchards in Romania.

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

Variation in Platycladus orientalis (Cupressaceae) Reproductive Output and Its Effect on Seed Orchard Crops’ Genetic Diversity

The genetic efficiency of seed orchards is crucial for determining seed crops’ genetic gain and diversity. Platycladus orientalis is a conifer tree of important ecological value in China. Here, we assessed the reproductive output (fertility) variation for 166 clones in a first-generation P. orientalis seed orchard over five years and across three years for each gender (female: 2017, 2018, and 2020 and male: 2017, 2019, and 2021). Fertility variation and genetic diversity parameters were estimated for each gender-year combination. The reproductive output (fertility) variation differed among years, provinces, clones nested within provinces, and ramets within clones. We observed asymmetry in the gender reproductive output and parental imbalance and determined their profound effects on the genetic diversity of these seed crops. The maleness index revealed the existence of female-biased or male-biased clones. When seeds from multiple individuals and years were blended, we found an increase in the effective number of parents (Np) and in genetic diversity (GD), and a reduced fertility variation (Ψ) in the seed orchard. When we set the effective number of parents (Np) to 30, the GD of the seed orchard could be maintained at more than 95%. Thus, achieving genetic diversity balance in seed production can be accomplished through monitoring the fertility variation of orchards and through the utilization of the thereby generated information for the advanced generation of seed orchards.

Peculiarities in Scots pine (Pinus sylvestris L.) clones seeding on CSP (Cloning seed plantation) in western Polissya of Rivne region

The main purpose of seed orchards is to obtain regularly seeds of the highest genetic value for forest plantations. Long-term research in Ukraine and foreign experience show that there is a significant reduction in the cone yield on orchards that are over 26–28 years old even with free spacing of ramets. The aim of the study was to identify peculiarities in reproduction of Scots pine on Clonal Seed Orchards (CSO), based on comparison for performances of flowering intensity and seed production from different clones, their groups and CSO in Rivne region. The object of the study is the clonal seed orchards of Scots pine (Pinus sylvestris L.). The subject of research is the reproduction of clones on clonal seed orchards of Scots pine. The intensity of «flowering» and seeding of clones on CSO was determined by continuous list of each ramet. To assess the intensity of female «flowering», we determined the growth and the reproductive layer of the crown, the rank position of pine clones on plantations, which we divided into three groups: high, medium and weak. We analyzed the intensity of growth, «flowering» and seed production of Scots pine clones (Pinus silvestris L.) for many years on the plantations of 1977 and 1984. At CSP of 1977, the «flowering» within clones is characterized by a mixed-sexual type; on the plantation of 1984, the most clones (54.2%) were dominated by female «flowering». The rate of microstrobiles formation in clones on the younger plantation (CSP-1984) is lower than the intensity of megastrobiles formation by 4.0%, while on the older one (1977), on the contrary, the intensity of microstrobiles formation was dominant by 118.2%. The average yield of strobiles from the number of megastrobiles on the CSP of 1977 and 1984 was 70.1 and 74.3%, respectively. The close correlations were found between the number of megastrobiles and the number of strobiles (r = 0.94 and 0.84). The variation in the number of strobiles per tree over the years of observation is quite high and varied in clones of 1977 from 40.2% in 2004 to 70.7 in 2003 and averaged 52.6%; clones of 1984 ranged from 43.6% in 2004 to 78.8% in 2005 and averaged 59.3%. The number of female strobiles for the six-year period at CSP of 1977 averaged 45.8% from the number of male ones; for three years — 4.0% in clones of 1984. Their number ranged from 25.5 to 61.3% in clones of 1977; in clones of 1984 – from 16.5 to 77.5%. Depending on the clone and the weather conditions of the growing season, the ratio between the number of female and male strobiles within each clone is from 29.8 to 166.7% on CSP of 1977 and from 49.4 to 1005.4% of 1984. The correlation between the number of mega- and microstrobiles on CSP of 1977 is weak (r = 0.17), and the ones of 1984 – high (r = 0.77). No dependences were found between the preservation of megastrobiles by their number (abundance of «flowering») in clones of 1984 and the average correlation (r = 0.33) was found in clones of 1977. According to long-term data on CSP of 1977, the most productive is clone No 22. The highest yield of strobiles from the number of megastrobiles on the plantation of 1984 – in clone No 130 (88.1%), the lowest — No 121 (46.7%). Only two clones (No 22 and 97) and eight clones of 1984 (No 116, 118, 127, 129, 130, 137, 138, 139) are included into the group of clones of 1977 with abundant «flowering», harvest and high yield of strobiles). The clones that have the high and medium growth intensity, with high and medium flowering intensity, with high and medium yield of strobiles are perspective for seed plantations among the selected groups.

Genetic diversity of seeds from four German Douglas fir (Pseudotsuga menziesii) seed orchards

In Germany, Douglas fir (Pseudotsuga menziesii Franco) is seen as a valuable species for future cultivation in times of climate change. Local seed production in seed stands and seed orchards may secure that local adaptation is transferred to the next generation, but small population sizes could lower genetic diversity and thus future adaptability. Here we analyse the transfer of genetic diversity from parent to offspring generation in four older German seed orchards. We detected low pollen contamination rates due to high levels of spatial isolation. Even with a relatively low number of 40 clones, seed orchard design with randomized and repeated planting of clones led to low selfing rates, and despite uneven parental contributions, the number of successful parents and the level of genetic intermixture were high enough to allow the transfer of an adequate part of the genetic diversity to the next generation. Larger numbers, however, might be needed to reliably conserve the entire genetic diversity over succeeding generations. Conclusions on the establishment of future seed orchards and regarding areas requiring further research are drawn at the end of the paper.

Monitoring genetic diversity across Pinus tabuliformis seed orchard generations using SSR markers

The maintenance of genetic diversity across seed orchard generations is an important management objective. Here, we used Pinus tabuliformis as a model to explore the extent of genetic diversity across the species’ breeding activities through their corresponding seed orchards generations. We utilized a large number of SSR markers selected from <i></i>Pinus tabuliformis<i></i> transcriptomic data, and then assessed the effect of marker number on genetic diversity and individuals’ genetic relationships across orchards’s generations. In total, we designed 125 simple sequence repeat (SSR) markers, from which 39 SSRs were polymorphic and used in the present study. The genetic diversity and genetic distance parameters tended to increase with thean increase ofin markerloci numbers and a stable trend was reached at 24 SSRs. The selected optimal 24 SSR markers were further used to assess the genetic diversity across seed orchards’s generations, and a decreasing trend was detected with the advancement of orchards’s generations. Genetic distance analysis indicated that individuals in the 2nd generation orchard was more closely related as compared to those of the 1st- and 1.5-generations. This study provided valuable information on the effect of selection and breeding on genetic diversity and highlighted its role for effective seed orchards management.

Genetic variability of Araucaria angustifolia Bertol. initial growth: subsidy to the formation of seed orchards

A Araucaria angustifolia Bertol. é uma espécie nativa do Brasil que, devido a ação antrópica ao longo de vários anos, a colocou sob ameaça de extinção. O objetivo do trabalho foi avaliar a variabilidade genética de Araucaria angustifolia com base em variáveis qualitativas e quantitativas de crescimento inicial em teste de procedências e progênies, selecionando-se aquelas com maior presença de superioridade como subsídio para a formação de pomares de sementes. Um teste de procedência e progênies foi instalado em casa de vegetação, utilizando-se as árvores matrizes de Guarapuava-PR e Palmeira-SC, de acordo com suas características biométricas e morfométricas. Cada matriz recebeu código de controle. As árvores matrizes foram avaliadas de acordo com as características dendrométricas e sanitárias, bem como as pinhas colhidas, quanto ao peso, volume e sanidade. Foram selecionadas 14 matrizes de Palmeira-SC e 10 matrizes de Guarapuava-PR. As pinhas de cada matriz selecionada foram avaliadas utilizando variáveis quantitativas. As sementes dessas pinhas, de acordo com a árvore matricial, foram separadas e utilizadas no experimento para avaliar a emergência das sementes e o crescimento inicial entre os genótipos. Todas as análises estatísticas foram realizadas pelos softwares GENES® e R Studio. Verificou-se que existe variabilidade genética entre as procedências e progênies para a maioria dos caracteres quantitativos estudados para a espécie e, portanto, a possibilidade de obter ganhos através da seleção entre e dentro das procedências. A seleção entre e dentro das procedências sugere a possibilidade de alcançar ganhos genéticos significativos, especialmente para caracteres de peso e diâmetro de pinhas, peso e número de sementes por pinha e crescimento das árvores.

Towards new seed orchard designs in Germany – A review

New first and 1.5 generation seed orchards are to be created in Germany based on recently assembled breeding populations of Acer pseudoplatanus, Larix sp., Picea abies, Pinus sylvestris, Pseudotsuga menziesii, and Quercus sp. To justify the high expenses in time and cost for orchard establishment and maintenance, planning should make use of consolidated knowledge and experience of both the national and international scientific community. Here, we briefly describe advances in genetic gains achieved through tree breeding, and resume population genetic aspects and design considerations to draw conclusions for clonal composition and spatial design of the new orchards. We conclude that to avoid outbreeding depression separate orchards are required for each breeding zone. The zones are species-specific and defined by ecological and climatic aspects. A minimum of 60-80 clones per orchard is recommended for native tree species with high proportions of natural regeneration in forest practice. This would allow future selective thinning based on estimated breeding values from progeny testing. It would also permit the transfer of seed orchard progenies into a naturally regenerating forest stands without the risk of a genetic bottleneck. Lower clone numbers are appropriate for non-native species and hybrids. It is important to strictly avoid inbreeding depression, achieved by using only one clone per progeny or population, from which the plus trees were selected. Further, the spatial layout should promote random mating by optimizing the neighbourhood of each clone. With all of these considerations taken into account, we expect superior quality traits and at least 10-15 % more volume from the new seed orchards.

Naohidemyces vaccinii sporulates on wild species of ground flora in Finnish Norway spruce seed orchards but Thekopsora areolata does not on other species than Prunus

Thekopsora areolata Picea abies Picea T. areolata T. areolata Vaccinium myrtillus V. vitis-idaea Empetrum nigrum Calluna vulgaris Thekopsora areolata Thekopsora 2 T. areolata V. myrtillus V. vitis-idaea V. myrtillus V. vitis-idaea V. myrtillus V. vitis-idaea Naohidemyces vaccinii Vaccinium T. areolata Prunus