scholarly journals Adaptive performance of genetically improved and unimproved seedlings of Scots pine

Silva Fennica ◽  
2021 ◽  
Vol 55 (5) ◽  
Author(s):  
Matti Haapanen ◽  
Seppo Ruotsalainen

Our main objective was to determine whether various genetically improved reproductive materials of Scots pine ( L.) differ in growth rhythm, autumn cold acclimation and resilience from unimproved materials. The study consisted of two successive indoor experiments with Scots pine seedlings representing four levels of genetic gain (unimproved natural stands, first-generation seed orchards, 1.5-generation seed orchards and seed orchards established with freezing-tested parents) and a wide range of geographical origins within Finland. The seedlings were assessed for terminal shoot elongation, growth cessation, bud set, freezing injuries and bud flushing over the first growth period. All the adaptive traits showed a latitudinal trend regardless of the genetic level. Seed orchard progenies and natural stand progenies did not differ significantly in the timing of growth cessation, bud set, and the flushing rate of the frost-injured seedlings, after the trait variation was adjusted to the latitude of origin. The differences in autumn frost hardiness were insignificant, too, except for the somewhat higher injury rate displayed by the first-generation seed orchard materials. The finding was not conclusive due to ambiguous results from the two experiments. Overall, we did not find evidence of alarming compromises in the adaptive performance of genetically improved materials.Pinus sylvestris

2015 ◽  
Vol 76 (3) ◽  
pp. 240-249
Author(s):  
Paweł Przybylski

Abstract Scots pine (Pinus sylvestris L.) is the most common species in Poland’s forest stands. The mode of pine stands renovation requires that silviculture practitioners have continuous access to seed banks. Orchard-grown seeds are predicted to constitute an increasingly larger part of the average demand for pine seeds in Poland. Seed orchards, due to a limited number of maternal trees as well as the irregularity of their blooming and pollination, enhance the risk of genetic diversity reduction in planted forest stands. This is of particular importance in the context of dynamic climate change. Markers based on microsatellite DNA fragments are effective tools for monitoring genetic variability. In the present study, three different microsatellite DNA fragments were used: SPAC 12.5, SPAG 7.14 and SPAC 11.4. The main objective of this research was to study genetic variability in one of the biggest seed orchards in Poland, located in the Forest District Susz. The obtained results indicated heterozygosity loss within the orchard, proving the existence of specimen selection effects on genetic variability. Hence, it seems quite important to take account of molecular genetic variability of maternal trees in future breeding strategies.


2008 ◽  
Vol 38 (12) ◽  
pp. 2976-2980 ◽  
Author(s):  
Saila Varis ◽  
Arja Santanen ◽  
Anne Pakkanen ◽  
Pertti Pulkkinen

Timing of pollen arrival may affect the level of seeds fertilized by pollen from outside seed orchards, especially in seed orchards of Scots pine ( Pinus sylvestris L.) established in southern Finland with stock from northern populations. We performed sequential pollination experiments with Scots pine pollen collected from seed orchard clones originating from southern and northern Finland and recipient strobili in clones originating from southern Finland. When southern pollen was introduced first, seeds were sired equally by northern and southern genotypes. When northern pollen was introduced first, northern genotypes were found in 75% of the resulting seeds. When both pollen types were introduced at the same time, the resulting seed crop was split almost equally between northern and southern genotypes. These results do not unconditionally support the idea that the first pollen grain in the pollen chamber always fertilizes the ovum; instead, they suggest a more complex way of competition between pollen grains.


Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1429
Author(s):  
Siqian Jiao ◽  
Meiyu Li ◽  
Yuanjiao Zhu ◽  
Shanshan Zhou ◽  
Shiwei Zhao ◽  
...  

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.


2012 ◽  
Vol 61 (1-6) ◽  
pp. 133-142 ◽  
Author(s):  
Wei Li ◽  
Xiaoru Wang ◽  
Yue Li

Abstract Flowering phenology in an orchard is a crucial factor affecting the gene exchange among clones and consequently changing genetic composition of the seed crop. Pinus tabuliformis is now at the crucial period from first generation clonal seed orchards to advanced generation seed orchards in China. In this study, variation and stability in floral phenological synchronization of all the clones and possible mating pairs, in terms of an index of phenological overlap, were observed in a first generation clonal seed orchard which located in northeast of China. Results showed that significant variations occurred in the clones and mating pairs. This kind of variation was apparently related with temperature and humidity of the research site. With increasing age, levels of flowering synchronization were likely to rise in the clones and mating pairs. In general, the average flowering synchronization of male parents was slightly higher than that of female parents, female management in a seed orchard should be paied more attention. Flowering time was under strong genetic control and this genetic control was stronger in the female flowering process than of the males in terms of board sense heritability and year to year correlation analysis. Flowering synchronization of female parents was positively correlated between most years and can be a reliable reference for early and late predication in Pinus tabuliformis seed orchard during stage of initial seed harvest to stable seed production. According to their average levels of flowering synchronization, 49 clones in the first generation clonal seed orchard were divided into 11 different groups. Results of this paper provided the basic information for first generation seed orchard management and advanced seed orchard establishment of Pinus tabuliformis.


2020 ◽  
Vol 62 (1) ◽  
pp. 1-12
Author(s):  
Ihor Neyko ◽  
Olena Kolchanova ◽  
Veronika Monarkh ◽  
Svitlana Poznyakova

AbstractGlobal climate change has mainly impacted the forest ecosystems in Europe. Today, it is not fully understood how these changes will affect the reproductive process of trees on seed orchards. The main aim of the study is to evaluate the growth, condition and reproductive function of Scots pine clones of Finnish origin after moving them to the southern direction of natural distribution area. Variability and seed productivity of 25-year-old clones of Scots pine of Finnish origin in the clonal seed orchard under climatic conditions of the central part of Ukraine (Vinnitsa region) was investigated. Grafted seedlings of Scots pine of Finnish origin were moved southward at a distance of over 1,500 km. Climatic conditions of Vinnytsia region, where the clones were displaced, differed by an increase in the mean and maximum temperatures by 3.3–3.6ºC, as well as an increase in the mean temperatures during the cold period and a rise in the minimum by 2.1–2.3ºC. The climate in the seed orchard location was characterized by the most significant increase in the mean temperatures in April and May (5.3–5.8ºC), which greatly influenced the intensity of the formation of microstrobili and macrostrobili. The ratio of precipitation to the amount of temperatures decreased more than twice. Analysis of the grafted trees’ vitality of Finnish origin and seed progeny of the local population, estimation of their intensity (height, diameter), state (category of the state) and reproductive processes (intensity of formation of microstrobili and cones) was carried out on the clonal seed orchard. In conditions of climate change, most of the clones of Finnish origin were characterized by a higher intensity of flowering compared to the local population. Some clones of Finnish origin (E80 and E729) dominated the local population by the seed yield. According to a comprehensive analysis of vitality, the intensity of growth and reproductive capacity, the best clones of Finnish origin were E80, E1883 and E2254. Low adaptive ability was noted in the clones E2312, K634 and K801. According to the research results, it was found that changes in climatic conditions did not significantly affect the vitality, development and condition of the clones. There was observed intensification of the formation of microstrobili and cones. Seed viability and quality of Scots pine of Finnish origin obtained on seed orchards located in the southern conditions requires further research.


Author(s):  
Natalia N. Besschetnova ◽  
Vladimir P. Besschetnov ◽  
Nikolai A. Babich ◽  
Vladimir A. Bryntcev

An important moment in the establishment of forestry seed orchards is the formation of their optimal composition, avoiding inbreeding depression in the outgoing seed material which occurs due to crossbreeding between closely related plus trees, the clones of which comprise the orchards. It is possible to minimize the negative effect of inbreeding by considering the hereditary aspect of the heterogeneous seed orchard material. The purpose of our work is to provide a comparative assessment of the formation and lignification of xylem in annual shoots of the plus trees of Scots pine. We investigated the formation and lignification of xylem in the annual shoots of the plus trees of Scots pine (Pinus sylvestris L.), found in natural forests in the Nizhny Novgorod region of the Russian Federation. Their vegetative progeny were cultivated in the clone archive stationed in the same region. Analyzing the one-type of the 1-year shoots, the time that the shoots were cut from the branches corresponded to the presence of plants in the characteristic phenological phases of seasonal development. A histochemical study of xylem was conducted, using the qualitative reactions of phloroglucinol to lignin. The power of xylem development was estimated by counting, in the radial direction, the cell rows from the core to the cambium in the microscope’s field of view. A significant differentiation of plus trees was revealed in a complex of signs characterizing the level of xylem development and the degree of xylem cell lignification in the tissues of annual shoots. Phenotypic differences in the physiological state of plus trees appeared given a leveled ecological background, indicating their genotypic determinism. This was confirmed by an analysis of variance. The share of the influence of differences between the proper plus trees was between 25.16%  ± 8.91% and 53.98%  ± 5.48% of the total phenotypic variance of the signs of the seasonal state of xylem. Factor analysis was used to reduce the number of considered indicators of xylem physiological state. The results allowed a cluster analysis to be carried out on the basis of the normalized values of the initial xylem features as well as the principal components derived from them. The association of plus trees was done on the basis of the similarity of the multidimensional estimates of xylem seasonal condition. The objects that were the most remote from the others were identified. This information provides a reasonable approach to the formation of an assortment of Scots pine seed orchards.


2014 ◽  
Vol 63 (1-6) ◽  
pp. 41-46 ◽  
Author(s):  
Huwei Yuan ◽  
Zhexin Li ◽  
Pan Fang ◽  
Wei Li ◽  
Yue Li

AbstractSeed orchards of Chinese pine, Pinus tabuliformis, are in a transition period from first generation to advanced generation. During this crucial period, evaluation of seed production in seed orchards is essential. Female strobili production is an important factor in seed production. This study examined the variation and stability in female strobili production in a first-generation clonal seed orchard of Chinese pine in years 9, 10, 13, 14, 20 and 21 after grafting in 1974. The results showed significant variation in female strobili production among clones, years, and interactions between clones and years. Correlations in female strobili production between years were significant. The repeatability for female strobili production within the examined years ranged from 0.47 to 0.87. The relative stability of female strobili production varied among clones, with regression coefficients among individual clones and an environmental index ranging from 0.13 to 2.81. The productivity index in different clones ranged from -1.09 to 1.83. Yield stability of female strobili among clones could be estimated from female strobili production. Clones could be divided into three groups according to their stability and productivity parameters. The results of this research provide guidance for evaluating clones in existing seed orchards, as well as some basic information for seed orchard management and advanced-generation seed orchard establishment.


2019 ◽  
Vol 25 (1) ◽  
Author(s):  
Ernest Bielinis ◽  
Jacek Kwiatkowski ◽  
Sergii Boiko

Allelopathy is a kind of interaction between plants in which the inhibitory effect on growth and germination can play an important role during the struggle for existence in interspecific competition. The species (or clone of one species) with a higher allelopathic potential might win the competition and place themselves in a better biosocial position for growth. Also, the clones with a lower allopathic potential might be useful in agroforestry, e.g.  as trees useful for shading the crops. The allelopathic potential of Scots pine (Pinus sylvestris L.), the tree species with a wide range of distribution in Europe and of great economic importance, was estimated in this study. To this end, needles from trees growing in a clonal seed orchard were collected and used as a material to obtain water leachates. The leachates were diluted to 25 and 50% and used in allelopathy tests. The differences between potentials of leachates from Scots pine clones to inhibit germination and growth of the test plant (Sinapis alba L. cv. Borowska) were assessed. The clones 1702 and 1703 were characterized as highly allelopathic, with the potential confirmed in two independent allelopathic tests. The clones 355 and 2209 were characterized as clones with a moderate allopathic potential. The possibility of selecting clones with the known allelopathic potential for the successful use in forestry was discussed.


Author(s):  
Anna-Maria Hartmann

Mythographies were books that collected, explained, and interpreted myth-related material. Extremely popular during the Renaissance, these works appealed to a wide range of readers. While the European mythographies of the sixteenth century have been utilized by scholars, the short, early English mythographies, written from 1577 to 1647, have puzzled critics. The first generation of English mythographers did not, as has been suggested, try to compete with their Italian predecessors. Instead, they made mythographies into rhetorical instruments designed to intervene in topical debates outside the world of classical learning. Because English mythographers brought mythology to bear on a variety of contemporary issues, they unfold a lively and historically well-defined picture of the roles myth was made to play in early modern England. Exploring these mythographies can contribute to previous insights into myth in the Renaissance offered by studies of iconography, literary history, allegory, and myth theory.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1027
Author(s):  
Vincenzo De Leo ◽  
Francesco Milano ◽  
Angela Agostiano ◽  
Lucia Catucci

Liposomes are consolidated and attractive biomimetic nanocarriers widely used in the field of drug delivery. The structural versatility of liposomes has been exploited for the development of various carriers for the topical or systemic delivery of drugs and bioactive molecules, with the possibility of increasing their bioavailability and stability, and modulating and directing their release, while limiting the side effects at the same time. Nevertheless, first-generation vesicles suffer from some limitations including physical instability, short in vivo circulation lifetime, reduced payload, uncontrolled release properties, and low targeting abilities. Therefore, liposome preparation technology soon took advantage of the possibility of improving vesicle performance using both natural and synthetic polymers. Polymers can easily be synthesized in a controlled manner over a wide range of molecular weights and in a low dispersity range. Their properties are widely tunable and therefore allow the low chemical versatility typical of lipids to be overcome. Moreover, depending on their structure, polymers can be used to create a simple covering on the liposome surface or to intercalate in the phospholipid bilayer to give rise to real hybrid structures. This review illustrates the main strategies implemented in the field of polymer/liposome assembly for drug delivery, with a look at the most recent publications without neglecting basic concepts for a simple and complete understanding by the reader.


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