Annual Seedlings Research Articles

Influence of growth stimulants on the cultivation of annual Mongolian oak (Quercus Mongolian Fisch. ex Ledeb.) seedlings

Growth stimulants are substances that provide the growth and development of plants. The aim of this study was to assess the effect of growth stimulants Albit, Energen and Epin-Extra on the cultivation of annual seedlings of Mongolian oak (Quercus mongolica Fisch. ex Ledeb.) in a forest nursery of Primorye Territory. These stimulants were used as a pre-sowing seed treatment in various concentrations of solutions. Control – seeds which have not been treated with preparations. At the end of the growing season, the parameters of seedlings were determined: height, diameter of the root neck, length of the root system, number of leaf blades, leaf surface area and dry mass. It was revealed that the growth stimulator Albit had a more positive effect on the height of seedlings, and Epin-Extra was more effective on the diameter of the root neck. The total dry mass was influenced by Energen. The rest of the parameters were within the control group, or their decrease was observed. In the future, it is planned to study the effect of these stimulants on the subsequent growth of oak seedlings.

Использование жидких комплексных микроудобрений для роста и развития робинии псевдоакации и сосны крымской в засушливых условиях

The article presents data on the results of testing complex micronutrients when sowing seeds of Robinia pseudoacacia L. and Pinus nigra subsp. pallasiana (Lamb.) Holmboe. at a production nursery. Stratification provides seeds with rapid germination under optimal conditions of oxygen access and maintaining a humidity level and temperature of 10°C. Fertilizers “Volski Biochem” are able to increase the energy of germination of seeds of the studied species, increase their growth rate and contain all the necessary nutrients for plants. The highest content of trace elements is found in the preparation “Microel”. Established that the best option for planting seeds are RCL‑81 forest cassettes, which naturally and correctly distribute the root system of seedlings, increase their ability to form active root tips, provide oxygen to plants and eliminate waterlogging with improper watering. The percentage of safety for seedlings in the first and second year was almost the same. Pine seeds require de-spraying on the VSG‑01 air gravity apparatus before processing and planting. The possibility of using tools for tillage and crops is provided by an ordinary method with the location of narrow sowing lines along the tapes. Proven that the use of complex micro fertilizers allows pine and robinia seedlings to have an optimal ratio of the aboveground part and the root system, accelerated growth and development, and an even stem. The maximum growth of robinia was 71–98 cm, pine trees 10–29 cm, which fully met the standards and requirements for the cultivation of planting material of woody species. Revealed that the differentiation of robinia and pine seedlings in height begins in the second half of June, in the variant of the experiment with sowing seeds in a box, the largest gains of seedlings were observed in the third decade of June, after which there was a noticeable decrease in growth. As a result, the best growth and development indicators were observed in Crimean pine in the 1st variant of the experiment, in robinia pseudoacia in the 1st and 2nd variants. The growth rates of two-year-old seedlings of the studied species are identical to those of annual seedlings

АГРОТЕХНИЧЕСКИЕ ПРИЁМЫ ДЛЯ ПОЛУЧЕНИЯ КАЧЕСТВЕННЫХ ОДНОЛЕТНИХ САЖЕНЦЕВ ЯБЛОНИ

The article presents an analysis of the collection and structuring of information on the methods of crowning annual seedlings of fruit crops in the nursery. The most effective and affordable agricultural practices for obtaining high-quality branched seedlings of fruit crops, as well as the effectiveness of their combinations, are analyzed. To improve the technology for the production of crowned annual seedlings, it is necessary to take into account the biological tendency of varieties to branch, the quality of cuttings of rootstocks in the first field of the nursery, apply mechanical methods of influencing the central conductor in combination with treatments of the seedling growth tip with plant growth regulators based on 6-benzylaminopurine or 6-benzyladenine and gibberellic acids.

Growth and Development Law of Annual Sown Seedings of <i>Photinia prunifolia</i> and Preliminary Exploration on Seeding Breeding Technology

In this paper, we studied the height and ground diameter growth of annual seedlings of <i>Photinia prunifolia, </i>and introduced its the morphological characteristic and geographical distribution. At the same time, through the seedling sowing and breeding experiment, we used the ordered sample clustering analysis method to analyze the high growth process of seedlings sown in <i>Photinia</i> <i>prunifolia</i>. We divided the growth of seedlings into four different growth periods, seedling stage, growth stage, rapid growth stage and later growth stage according to the experimental investigation. The seedling stage and growth stage of <i>Photinia prunifolia </i>were 30 days. The initial growth period lasted for about 48 days. The rapid growth stage lasted for 120 days, which was 10.1 times and 5.2 times higher than the seedling height and ground diameter growth in initial growth period, respectively. In later growth stage, the seedling height and ground diameter grew quite slowly. The simulation correlation coefficient was as high as 0.99 by simulating seedling height growth and seedling age. The fitting degree was high. It showed that the relationship seedling height growth and seedling age of <i>Photinia prunifolia</i> was highly consistent with the Logistic population growth model. Meanwhile, by using the Logistic population growth curve model to fit the high and diameter growth of <i>Photinia prunifolia</i>, we elucidated the growth law of annual seedlings. Since the seedlings grew in the rapid growth stage, that is, the high growth rate of seedlings grew rapidly with the increase of seedling age, enough nutrient fertilizer should be supplemented at this stage to satisfy the rapid growth of seedlings. Annal seedling biomass accounted for 62.5% of the total biomass, and the fresh-weight ratio of above-ground biomass was 1.67. Therefore, this species has better lodging resistance and is suitable for seedling afforestation. The study provided references for the rational cultivation and utilization of new afforestation tree species.

PINUS SYLVESTRIS L. БІРЖЫЛДЫҚ СЕППЕ КӨШЕТТЕРІНЕ AGRO-MIX, AGRARKA ЖӘНЕ ЭПИН БИОПРЕПАРАТТАРЫН ҚОЛДАНУ

This article presents studies of the effect of biological products "Agro-MIKS", "Agrarka" and "Epin" on the growth of annual seedlings of Scots pine (Pinus sylvestris L.) in 2022 with the financial support of KATU named after. S. Seifullin of young scientists about research work carried out within the framework of internal grant funding No. 2VGF/21. The research work was carried out in a forest nursery located in the city of Schuchinsk, Burabay district, Akmola region. In the forest nursery, a total area of 0,4 ha was surveyed, of which 0.2 ha was pre-treated and sown with seeds of Pinus sylvestris L. Some details of this research work were published in other publications, but in this paper only one object of study, seedlings of Pinus sylvestris, was fully analyzed. L. The composition of chlorophyll was studied to assess seasonal growth and physiological development, as well as the biochemical activity of seedlings. The biological products used in the experimental samples were compared with each other and with control options. The biomass, growth and viability of seedlings were analyzed. Soil cultivation, sowing and care were carried out according to generally accepted methods of experimental work. The samples were built according to the linear-diagonal method, and the data were collected throughout the season. Statistical data were processed using the SPSS, STATISTICA 13, and SNEDECOR programs.

Effects of NaCl Stress on the Growth, Physiological Characteristics and Anatomical Structures of Populus talassica × Populus euphratica Seedlings.

In order to elucidate the salt tolerance mechanism of Populus talassica × Populus euphratica, the growth, physiology and anatomical characteristics of P. talassica × P. euphratica were studied under different concentrations of NaCl-stress treatments. In this study, the annual seedlings of Populus talassica × Populus euphratica were used as the test material in a field potted control experiment. The basic salt content of the culture soil was the control (CK), and two NaCl treatments of 200 mmol/L and 400 mmol/L were established. The pot experiment showed that: (1) Compared with CK, the 200 mmol/L NaCl-stress treatment significantly increased the growth parameters of P. talassica × P. euphratica, such as leaf area, plant height, ground diameter, biomass, root length, root surface area, root fork number and root-shoot ratio. However, compared with CK, the 400 mmol/L NaCl-stress treatment significantly reduced most growth parameters. (2) The 200 and 400 mmol/L NaCl-stress treatments significantly decreased various physiological parameters such as relative water content (RWC), chlorophyll content, water potential, stomatal opening and photosynthetic parameters and increased the accumulation of MDA and Pro compared with CK. The 200 mmol/L NaCl-stress treatment significantly increased the activity of antioxidant enzymes, and the 400 mmol/L NaCl-stress treatment significantly decreased the activity of antioxidant enzymes. (3) Compared with CK, 200 and 400 mmol/L NaCl-stress treatments significantly improved the leaf palisade tissue thickness and palisade-to-sea ratio, as well as the stem xylem and stem phloem thickness and pith diameter, and significantly increased the root xylem thickness, root phloem thickness, and root cross-cutting diameter of P. talassica × P. euphratica. The growth, physiological characteristics and anatomical characteristics of P. talassica × P. euphratica under NaCl-stress treatments showed that it had good salt tolerance and adaptability, and the 200 mmol/L NaCl-stress treatment promoted the growth of P. talassica × P. euphratica to a certain extent. This study provided a theoretical basis for the study of the salt-tolerant mechanism of P. talassica × P. euphratica.

Development of elements of technology for growing branched sweet cherry seedlings

The results of two-year studies on the influence of rootstocks, physiologically active substances and mechanical techniques on biometric indicators of annual seedlings of two varieties of cherries (Tyutchevka and Chermashnaya) are presented. The research was carried out in 2020-2021 in the experimental nursery of the Federal State Budgetary Research Center of Horticulture in the conditions of the Moscow region. The scheme of the experiment included 5 options: I – removal of apical leaves; II – treatment with Apllin (0.6 g/l); III – removal of apical leaves with treatment with Apllin (0.6 g/l); IV – pinching of the tip at a height of 60 cm; st – control, without processing and pinching. The eyepieces were sprayed twice, with an interval of 10 days. It was found that treatment with the preparation Apllin, removal of the apical leaves and their combined use contributed to a significant improvement in the biometric indicators of annual cherry seedlings of weakly branching varieties, increased the number of branches by 2.7-4.6 times and provided in most combinations an increase in the yield of first-class seedlings up to 90-100%. The greatest effect from mechanical and chemical influences was achieved when using the Izmailovsky rootstock. Pinching the top at a height of 60 cm caused a decrease in the linear and radial growth of annuals, an increase in the number of lateral shoots by 1.43 times, but only 50 % of seedlings obtained in this variant corresponded to 1 commercial grade.

Germination of acorns and growth of one-year common oak seedlings in conditions of the Volga-Akhtuba floodplain, Astrakhan region

Seed germination and development of common oak ( Quercus robur L.) during the first year of growing under conditions of the Volga-Akhtuba floodplain, Astrakhan region, were studied in the research. Currently, the floodplain forests of the Astrakhan region are experiencing a very high load from the grazing of farm animals and wild tourism. Therefore, it is necessary to restore degraded forest phytocenoses to increase species diversity. The aim of the study was to study the effect of flooding duration on oak germination of in the soil and climatic conditions of the Volga-Akhtuba floodplain in the north of the Astrakhan region. Sowing seeds were carried out according to the Sukachev method (1961). According to the results of the three-year research (2019-2021), it was revealed: the germination of seeds (acorns) of common oak ( Quercus robur L.) averaged 31 % of the total sown seeds. In 2019 and 2021, germination of oak in non-flooded areas was 5 % higher compared to other variants of the experiment (short-term and long-term flooding), resulted from seed loss due to prolonged flooding. In 2020, as a result of short flooding period, germination had an insignificant difference in variants. The height of annual seedlings of common oak in the variant of prolonged flooding differed significantly (35 cm higher) from other variants.

SUITABILITY OF COMMERCIAL APPLE VARIETIES ON DWARF ROOTSTOCKS FOR GROWING ACCORDING TO DENSIFIED PATTERNS

In order to assess the suitability of apple varieties that differ in the type of fruiting and genetic potential for productivity&#x0D; of apple varieties on dwarf rootstocks for growing according to densified patterns and to identify the optimal placement&#x0D; pattern for each scion-rootstock combination in the experimental orchard of RUE “Institute of Fruit Growing”, an orchard&#x0D; was planted with annual seedlings of three commercial varieties on dwarf rootstocks: Belorusskoe Sladkoe on M-9 and PB-4,&#x0D; Imant on 62-396 and PB-4, Nadzejny on 62-396, M-9 and PB-4 in the spring of 2010. Planting schemes for all scion-rootstock&#x0D; combinations are 3.5 × 1.5 m (1904 trees/ha) and 3.5 × 1.0 m (2857 trees/ha). The full realization of the productivity potential of varieties was ensured by denser placement of trees according to the planting pattern of 3.5 × 1.0 m (2857 trees/ha) and dwarf rootstock 62-396 – for Imant and Nadzejny varieties, dwarf rootstock M-9 – for Belorusskoe Sladkoe and Nadzejny varieties. Rootstock PB-4 did not solve the problems of intensive commercial fruit growing.

Comparative Transcriptome Analysis Revealing the Potential Mechanism of Low-Temperature Stress in Machilus microcarpa.

Machilus microcarpa is a rare national tree species in China and possesses important ornamental and ecological value. M. microcarpa can be planted in low-temperature areas, depending on whether its seedlings can withstand the harm. To face this problem, the annual seedlings of M. microcarpa were subjected to five temperature treatments, and eight physiological indicators were measured. Furthermore, comparative transcriptome analysis was performed between M. microcarpa leaves treated at 25°C and −2.8°C. A total of 9,385 differentially expressed genes (DEGs) were involved in low-temperature stress in M. microcarpa. An upregulated (cobA) and five downregulated (HEM, CHLM, CRD, CLH, and PORA) genes associated with the porphyrin and chlorophyll metabolism pathway may reduce chlorophyll synthesis under low-temperature stress. Upregulation of six DEGs (two GAPDHs, PFK, PGAM, PDC, and PK) involved in the glycolysis/gluconeogenesis pathway provided energy for M. microcarpa under adverse cold conditions. Thirteen upregulated and seven downregulated genes related to antioxidant enzymes were also observed under low-temperature stress. Candidate transcription factors (TFs) played key roles in signal transduction under low-temperature stress in M. microcarpa, and quantitative real-time PCR (qRT-PCR) analysis validated the RNA-seq data. The results provide valuable information for further studies on the cold response mechanisms for low-temperature stress in M. microcarpa.

Genomes and demographic histories of the endangered Bretschneidera sinensis (Akaniaceae).

Background Bretschneidera sinensis is an endangered relic tree species in the Akaniaceae family and is sporadically distributed in eastern Asia. As opposed to its current narrow and rare distribution, the fossil pollen of B. sinensis has been found to be frequent and widespread in the Northern Hemisphere during the Late Miocene. B. sinensis is also a typical mycorrhizal plant, and its annual seedlings exhibit high mortality rates in absence of mycorrhizal development. The chromosome-level high-quality genome of B. sinensis will help us to more deeply understand the survival and demographic histories of this relic species.ResultsA total of 25.39 Gb HiFi reads and 109.17 Gb Hi-C reads were used to construct the chromosome-level genome of B. sinensis, which is 1.21 Gb in length with the contig N50 of 64.13 Mb and chromosome N50 of 146.54 Mb. The identified transposable elements account for 55.21% of the genome. A total of 45,839 protein-coding genes were predicted in B. sinensis. A lineage-specific whole-genome duplication was detected, and 7,283 lineage-specific expanded gene families with functions related to the specialized endotrophic mycorrhizal adaptation were identified. The historical effective population size (Ne) of B. sinensis was found to oscillate greatly in response to Quaternary climatic changes. The Ne of B. sinensis has decreased rapidly in the recent past, making its extant Ne extremely lower. Our additional evolutionary genomic analyses suggested that the developed mycorrhizal adaption might have been repeatedly disrupted by environmental changes caused by Quaternary climatic oscillations. The environmental changes and an already decreased population size during the Holocene may have led to the current rarity of B. sinensis.ConclusionThis is a detailed report of the genome sequences for the family Akaniaceae distributed in evergreen forests in eastern Asia. Such a high-quality genomic resource may provide critical clues for comparative genomics studies of this family in the future.

Влияние низкочастотного электромагнитного поля на анатомическое строение стебля однолетних сеянцев сосны обыкновенной (Pinus sylvestris L.) и дуба красного (Quercus rubra L.)

The study determines the influence of a low-frequency electromagnetic field on the anatomical stem structure of the annual seedlings of Scots pine (Pinus sylvestris L.) with a root-balled system, carried out in the nursery of the Ustyansky forest seed breeding center of the Arkhangelsk region, and annual seedlings of red oak (Quercus rubra L. ) carried out in the forest nursery of the Donskoy forestry of the Forestry Department of the Lipetsk region, when planting in open ground with the introduction of a hydrogel. Experimental samples of annual seedlings of Scots pine and red oak were treated with a low-frequency electromagnetic field using the patented POSEP technology (pre-sowing treatment of seeds and seedlings with an electromagnetic field) using the «Rost-Active» device (low-frequency generator). Untreated seedlings served as control. Conducted in the laboratory of the Department of Forest Plantations, Breeding and Dendrology of the BMSTU (Mytishchi branch), histometric analyzes of experimental and control samples of annual seedlings of Scots pine and red oak showed a positive effect of a low-frequency electromagnetic field on the anatomical characteristics of their stems.

First Report of Needle Blight on Pinus thunbergii Parl. Caused by Fusarium proliferatum in China.

Pinus thunbergii Parl. (Japanese black pine), an evergreen species, is distributed along the seacoasts of China. In addition, this species has been planted along seacoasts as a windbreak to prevent soil erosion due to its resistance to salt and various environmental stresses. It can also be found in public parks and gardens due to its exquisite appearance and toughness. In August 2020, needle blight symptoms were found on several black pine trees in Sichuan Province, China. Further surveys showed that these symptoms are common. The disease incidence is less than 30% while severity of the disease is high. The tips of old needles first turn grayish green that developed into brown bands ranging from 1 to 2 mm. To determine the pathogen, small needle pieces (3-4 mm2 long) from the margin of fresh lesions were surface-sterilized for 30 s in 75% ethanol, follow by 1% NaOCl for 90 s, then washed three times with sterile water, and then were placed on potato dextrose agar (PDA) with 0.1 mg/mL ampicillin and incubated at 25°C. Pure cultures of 8 isolates were obtained by monosporic isolation, and a representative isolate (SC03) was deposited in the Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University. When cultured on Spezieller Nährstoffarmer Agar medium (Leslie and Summerell, 2006), the SC03 colony was beige-white, cottony from top view and pale orange near the center on the reverse side. The daily growth rate was 11.8 mm/day at 25°C in the dark. Microscopic observations showed hyaline and septate hyphae, slightly curved macroconidia with two to three septa measuring 17.5 - 30 × 3.7 - 7.5 μm (23.2 × 5.7 on average), and aseptate microconidia measuring 7.5 - 12.5 × 2.5 - 5.0 μm, (9.7 × 4.3 on average). The morphological characteristics of conidia and other structures of SC03 matched those of the Fusarium fujikuroi species complex (FFSC) (Abdalla et al. 2000). For accurate identification, translation elongation factor 1-alpha（TEF-1α） , and the second largest RNA polymerase subunit (RPB2) were amplified and sequenced using the primer pairs EF1 and EF2, RPB5f2 and RPB7cr. The sequences were deposited in GenBank [Accession TEF-1α: ON049647, RBP2: ON049648]. A Blast search of GenBank showed that TEF-1α and RPB2 sequences of SC03 matched Fusarium proliferatum (Matsush) Nirenberg at a high level (>99%). Phylogenetic analysis using neighbor joining and concatenated sequences (TEF-1α and RPB2) with MEGA X placed SC03 in F. proliferatum. For the pathogenicity test, a conidial suspension was prepared with a concentration of 2.0 × 107 conidia/ml. The suspension was sprayed onto 3 annual seedlings' needles, and the control was sprayed with sterile water. Inoculated and uninoculated plants were kept in humid chambers in a glasshouse where the average humidity was 60% and the average temperature was 27℃. After 10 days, typical symptoms appeared on inoculated needles, whereas control needles remained symptomless. These symptoms were similar to those observed in field. The fungus, F. proliferatum, was reisolated from those lesions, confirming Koch's postulates. No symptoms were observed on control plants. Fusarium proliferatum is a ubiquitous saprophytic fungus on cankers and very rarely reported to cause disease on pine needles. It has been reported to cause leaf blight of Polygonatum cyrtonema (Zhou et al. 2021) and Majesty palm (Polizzi and Vitale 2003). To our knowledge, this is the first report of needle blight on P. thunbergii caused by F. proliferatum in China. The disease represents a threat to producers and more research on the biology and management is needed.

Comparative characteristics of planting material of silver birch grown from seeds of autumn and spring sowing

Annual seedlings of silver birch ( Betula pendula Roth.), grown from seeds of autumn and spring sowing period, were analyzed. Planting material was kept in protected ground. Before sowing, various growth substances were incorporated into the soil - mineral and organic fertilizers, forest soil. It was revealed that autumn sowing increased the height of seedlings 1.031.66-fold in the variants compared to the control, except for the variants with the use of nitrogen and phosphorus fertilizers, where the largest number of plants per unit area was observed. In the variants with Humatophosphate, boric acid, Trichocin, humus and forest soil, from 60 to 100 % of seedlings reached standard values in a year. A similar experiment with the same growth substances, but spring sowing of seeds, showed a significant lag in seedling growth. The use of nitrogen fertilizer in spring, in contrast to the autumn period, had a positive effect on plant height, annual seedlings had the highest height in the experiment - 14.1 cm. Seedlings in variants with humus and forest soil also had good indicators. All variants overtook the control seedlings in height by 1.062.68 times. Therefore, the time of sowing seeds is important - all indicators of autumn seedlings significantly exceed the similar ones of spring seedlings. This fact is explained by several reasons: during the autumn period, the seeds are sown freshly harvested, they undergo pre-sowing preparation (snowing and stratification) in natural conditions, the seeds are not stored, in case of violation of which the seeds significantly lose their germination capacity. In addition, the seeds begin to germinate and shoots begin to grow much earlier than if they were sown in the spring. Shoots are not exposed to late spring frosts, as they are protected by covering material.

Responses of Physiology, Photosynthesis, and Related Genes to Saline Stress in Cornus hongkongensis subsp. tonkinensis (W. P. Fang) Q. Y. Xiang.

Cornus hongkongensis subsp. tonkinensis (W. P. Fang) Q. Y. Xiang is a native evergreen species with high ornamental value for abundant variations in leaf, bract, fruit, and tree gesture. To broaden its cultivation in coastal saline soil, salt damage and survival rate, physiological responses, photosynthetic performance, and related genes were evaluated for annual seedlings exposed to 0.3% salt (ST) concentrations for 60 days. Syndromes of salt damage were aggravated, and the survival rate decreased with prolonged stress duration; all stressed seedlings displayed salt damage, and 58.3% survived. Under short-term saline stress (5 d), marked increases in malondialdehyde (MDA), relative electrical conductivity (REC), and decreases in superoxide dismutase (SOD), photosynthetic rate (Pn), stomatal conductance (gs), and internal carbon dioxide concentration (Ci) were recorded. The stable leaf water use efficiency (WUE) and chlorophyll content were positive physiological responses to ensure photosynthetic performance. Meanwhile, the expression levels of genes related to photosystem II (psbA) and photorespiration (SGAT and GGAT) were upregulated, indicating the role of photorespiration in protecting photosynthesis from photoinhibition. After 30 days of stress (≥30 d), there was a significant increase in MDA, REC, soluble sugar (SS), soluble protein (SP), and Ci, whereas descending patterns in Pn, gs, WUE, the maximal photochemical efficiency of photosystem II (Fv/Fm), and potential activities of PSII (Fv/F0) occurred in salt-stressed seedlings, compared with CK. Meanwhile, the expression levels of related genes significantly dropped, such as psbA, LFNR, GGAT, GLYK, and PGK, indicating photoinhibition and worse photosynthetic performance. Our results suggest that the moderate salt tolerance of C. hongkongensis subsp. tonkinensis mostly lies in a better photosynthetic system influenced by active photorespiration. Hence, these results provide a framework for better understanding the photosynthetic responses of C. hongkongensis subsp. tonkinensis to salt stress.

Характеристика формирования древесного вещества при выращивании сеянцев сосны обыкновенной с использованием химических маркеров

Currently, seedlings of the main silvicultural species are grown in greenhouses by the technology of ball-rooted planting material production. The process features raise the issue of the resulting planting material sustainability in relation to environmental conditions. Seedling growth and development in multi-rotation growing schemes will be influenced by both greenhouse and hardening site conditions. This makes assessing the planting material readiness for transfer to the open ground an urgent scientific task. Secondary metabolites (end products of biosynthesis) are one of the most suitable indicators for such an assessment from a chemical point of view. This study aims to explore chemical markers of wood substance formation as a criterion for completion of the annual development cycle of seedlings (at summer sowing dates) and their readiness for planting in the open ground. Scots pine is a good model object for the research, since it is a typical representative of coniferous forests, has an extensive range of growth as well as a high adaptive potential. Pine seedlings are usually highly sensitive to environmental conditions in the early stages of development. Physicochemical methods were used for the analysis of the biosynthesis processes of the main wood substance components. The seasonal dynamics of phenolic compounds content in different parts of annual Scots pine seedlings showed that the plants adapt to the temperature changes when they are brought to the hardening site. The adaptation includes a decrease in the content of low-molecular phenolic compounds preventing the development of uncontrolled oxidative processes when plant is exposed to adverse and stressful environmental conditions. It was found that the changes in the content of coniferyl alcohol as a precursor of lignin structures of coniferous wood can serve as a marker of lignification in the studied vegetation process. The content of phenolic compounds (at least 120–140 mg/g of TOC) and the peroxidase activity in needles (0.1–0.3 units of activity) may serve as criteriа for the completion of the annual cycle of seedling formation and the degree of its readiness for planting in the natural environment. For citation: Gusakova M.A., Bogolitsyn K.G., Krasikova A.A., Selivanova N.V., Khviyuzov S.S., Samsonova N.A. Characteristics of Wood Substance Formation during Growing of Scots Pine Seedlings Using Chemical Markers. Lesnoy Zhurnal [Russian Forestry Journal], 2022, no. 1, pp. 36–48. DOI: 10.37482/0536-1036-2022-1-36-48

Photosynthetic Characteristics of Wild Plant Species with Extremely Small Populations &lt;i&gt;Cycas Shiwandashanica&lt;/i&gt;

Cycas Shiwandashanica &nbsp;is classified as an extremely small populations of cycads&nbsp;due to its fragmented habitat and scarce wild resources.&nbsp;The growth indexes of annual and biennial seedlings from Cycas Shiwandashanica &nbsp;were determined, and diurnal photosynthetic changes and photosynthetic response curves of biennial seedlings were measured by Li-6400 portable photosynthetic apparatus. The results showed that the seedling height, ground diameter and crown width of the biennial seedlings were significantly higher than those of the annual seedlings, it can be grown well in this habitation. The daily change of net photosynthetic rate P n &nbsp;of Cycas Shiwandashanica &nbsp;was bimodal curve, with the two peaks appearing at 10:30 am and 14:30 pm, and the net photosynthetic rates were 1.73 &mu;mol&middot;m -2 &middot;s -1 &nbsp;and 1.76 &mu;mol&middot;m -2 &middot;s -1 , respectively, and the net photosynthetic rate was limited by stomatal factors and non-stomatal factors.&nbsp;It belongs to the mesophytic plant, with a light compensation point (LCP) of 3.68 &mu;mol&middot;m -2 &middot;s -1 , a light saturation point (LSP) of 1023.67 &mu;mol&middot;m -2 &middot;s -1 &nbsp;and a maximum photosynthetic rate ( P max ) of 3.57&nbsp;&mu;mol&middot;m -2 &middot;s -1 . This study by measuring the growth potential and photosynthetic characteristics, reveals the photosynthetic characteristics of the Cycas Shiwandashanica &nbsp;for the first time. It provides technical support for the protection, introduction and cultivation of Cycas Shiwandashanica , provides theoretical support for the mitigation of the endangered status of Cycas Shiwandashanica , and has theoretical value and guiding significance for the protection research of it.

Comparing the Effects of N and P Deficiency on Physiology and Growth for Fast- and Slow-Growing Provenances of Fraxinus mandshurica

With the continuous increase in atmospheric carbon dioxide emissions, nitrogen (N) and phosphorus (P) as mineral elements increasingly restrict plant growth. To explore the effect of deficiency of P and N on growth and physiology, Fraxinus mandshurica (hereafter “F. mandshurica”) Rupr. annual seedlings of Wuchang (WC) provenance with fast growth and Dailing (DL) provenance with slow growth were treated with complete nutrition or starvation of N (N-), P (P-) or both elements (NP-). Although P- and N- increased the use efficiency of P (PUE) and N (NUE), respectively, they reduced the leaf area, chlorophyll content and activities of N assimilation enzymes (NR, GS, GOGAT), which decreased the dry weight and P or N amount. The free amino acid content and activities of Phosphoenolpyruvate carboxylase (PEPC) and acid phosphatase enzymes were reduced by N-. The transcript levels of NRT2.1, NRT2.4, NRT2.5, NRT2.7, AVT1, AAP3, NIA2, PHT1-3, PHT1-4 and PHT2-1 in roots were increased, but those of NRT2.1, NRT2.4, NRT2.5, PHT1-3, PHT1-4, PHT2-1 and AAP3 in leaves were reduced by P-. WC was significantly greater than DL under P- in dry weight, C amount, N amount, leaf area, PUE, NUE, which related to greater chlorophyll content, PEPC enzyme activity, N assimilation enzyme activities, and transcript levels of N and P transporter genes in roots and foliage, indicating a greater ability of WC to absorb, transport and utilize N and P under P-. WC was also greater than DL under N- in terms of the above indicators except the transcript levels of N and P assimilation genes, but most of the indicators did not reach a significant level, indicating that WC might be more tolerant to N- than DL, which requires further verification. In summary, WC was identified as a P-efficient provenance, as the growth rate was greater for the genetic type with high than low tolerance to P-.

Planting dates and placement of the Sophora plantation on the irrigated lands of the Tashkent oasis

This article is very relevant to set out organizing plantations in the conditions of the Tashkent oasis. Climatic zones of desert and semi-desert under the influence of new conditions (abundance of light and thermal solar energy, a very long growing season, artificial irrigation), the growth and development of sophora is favorable. Annual seedlings under the influence of mineral fertilizers reach a height of up to 110 cm, the growth of lateral shoots of seedlings in the first year after planting is 33 cm.In the conditions of the Tashkent oasis, sophora favorably tolerates short-term winter low air temperatures (up to 30°C), tolerates soil compaction and has established itself gas-, dust-resistant decorative breed. The number of inflorescences on one tree ranges from 16 to 60 pieces, depending on the layout of the seats. Abundant flowering of sophora was noted with a planting pattern of 5.0x4.0, 5.0x3.0 with sufficient sunlight. The content of rutin in fruit elements ranges from 3.9 to 14.7% and depends on agrotechnical care, the state of the plantings themselves and their location.

First Report of Brown Spot Needle Blight on Pinus thunbergii Parl. Caused by Aureobasidium pullulans in China.

Pinus thunbergii Parl., known as black pine, is widely distributed all over China. This pine variety can prevent soil desertification and promote soil conservation and is excellent for constructing fast-growing forests and shelter belts. The timber of this species can be used for infrastructure construction and furniture production. In August 2020, needle blight symptoms were found on several trees of black pine in Sichuan Province, China. Further surveys showed that these symptoms are common while the disease incidence is less than 30% which indicated the severity of the disease is mild. The tips of old needles first turn grayish green and developed into brown bands ranging from 1 to 2 mm. To determine the pathogen, 20 needle samples with typical symptoms were disinfected with 75% alcohol, and sections of the tissue were cut from joints of diseased and healthy tissues (visually healthy) with a sterilized scalpel, surface sterilized for 45 seconds in 75% alcohol, soaked for 90 seconds in 1.5% NaCIO, rinsed in sterilized water and dried. Small cut tissues were placed on potato dextrose agar (PDA) at 25℃ for 10 days. Pure cultures were obtained by monosporic isolation. The colonies initially appeared white to cream, yeast-like, and later turned to pink and remained at least 10 days. Conidia were hyaline, smooth-walled, single-celled, and ellipsoidal with variable shape and size, 7.5 to 16 × 3.5 to 7 µm (Zalar et al. 2008). DNA was extracted from the mycelium of the isolate by the cetyltriethylammonium bromide (CTAB) method and amplified through polymerase chain reaction (PCR) with the internal transcribed spacer (ITS) region of rDNA and partial β-tubulin genes of a representative isolate (SC05) were amplified using the ITS1/ITS4 and Bt2a/Bt2b primer pairs, respectively(Wu et al. 2017). The sequences submitted to GenBank (Accession Nos. MW228368 for ITS and MW256762 for β-tubulin) showed high similarity with BLAST sequences of Aureobasidium pullulans (ITS, KR704881 [100%]; β-tubulin, MT671934 [99.49%]). For the pathogenicity test, a conidial suspension was prepared with a concentration of 2.0 × 107 conidia/ml. The suspension was sprayed onto 3 annual seedlings' needles, and the control was sprayed with sterile water. Inoculated and non-inoculated plants were kept in humid chambers in a glasshouse. After 10 days, typical symptoms appeared on inoculated needles, whereas control needles remained symptomless. The fungus, A. pullulans, was reisolated from those lesions, confirming Koch's postulates. No symptoms were observed on control plants. Aureobasidium pullulans, a ubiquitous saprophytic fungus on many fruits and very rarely reported to cause disease on pine needles. Only reported invasion of Ozone-injured needles in P. strobus (Costonis and Sinclair 1972) and needles damaged by acid rain in P. sylvestris (Ranta 1990). To our knowledge, this is the first report of brown spot needle blight on P. thunbergii caused by A. pullulans in China. The disease represents a threat to pine manufactures and more research on the pathogenesis and management is needed. .