Angustifolia Seedlings Research Articles

The efficiency of Thymus vulgaris, Lavandula angustifolia, and Cupressus sempervirens essential oils in suppression of Hymenoscyphus fraxineus on Fraxinus angustifolia seedlings

AbstractDue to intense ash dieback, this research tested the bioactivity of Thymus vulgaris, Lavandula angustifolia, and Cupressus sempervirens essential oils (EO) against Hymenoscyphus fraxineus. In vitro testing showed that EOs had a pronounced fungitoxic effect on H. fraxineus. The most effective EO was extracted from T. vulgaris, while EOs obtained from L. angustifolia and C. sempervirens were less effective and showed the same effect. At a concentration of 1%, all tested EOs inhibited mycelial growth, while 0.01% and 0.1% concentrations of EO extracted from T. vulgaris also inhibited the growth of H. fraxineus. The in planta test of EO extracted from T. vulgaris conducted on three‐year‐old Fraxinus angustifolia seedlings showed a reduction in the size of necrotic lesions and a better crown condition compared to untreated seedlings. This research demonstrates, for the first time, the efficiency of EOs in suppressing ash dieback making a path for the development of new biological protection measures against H. fraxineus.

Arbuscular mycorrhizal fungi and phosphorus affect Araucaria angustifolia seedling growth

Symbioses between plants and arbuscular mycorrhizal fungi (AMF) provide many advantages, including a reduced need for fertilization. In this study, the effects of AMF inoculation and phosphorus application on the growth and nutritional status of Araucaria angustifolia seedlings were evaluated. The treatments included inoculation with AMF (Gigaspora margarita, Rhizophagus intraradices, Acaulospora colombiana, Acaulospora scrobiculata, or Dentiscutata heterogama), inoculation with a mixture of AMF in 100 g of 50-year-old araucaria forest soil, application of two doses of P2O5 (25 or 100 mg kg-1), and the control. A completely randomized design was used, with seven replicates per treatment. The growth parameters, macronutrient and micro-nutrient contents, root colonization, and mycorrhizal effects on the extracted nutrients were evaluated at 75 and 150 d post germination. Analysis of variance, correlations, and principal component analysis (PCA) were used to evaluate that data. Inoculation with AMF had favorable effects on growth parameters, root colonization, and the extraction of macronutrients and micro-nutrients. In particular, the mixture of AMF from the 50-year-old araucaria forest soil, R. intraradices, and A. colombiana were beneficial. Similarly, the application of 25 mg of P2O5 significantly affected the growth of A. angustifolia seedlings compared to other treatments and increased the efficiency of root colonization.

Effect of cadmium (Cd) and lead (Pb) soil contamination on the development of Hymenoscyphus fraxineus on Fraxinus excelsior and F. angustifolia seedlings

Effect of cadmium (Cd) and lead (Pb) soil contamination on the development of Hymenoscyphus fraxineus on Fraxinus excelsior and F. angustifolia seedlings

Salt Tolerance Strategies of Nitraria tangutorum Bobr. and Elaeagnus angustifolia Linn. Determine the Inoculation Effects of Microorganisms in Saline Soil Conditions

Increasing salinization threatens the normal growth of halophytes in saline habitats, especially at the seedling stage. Soil beneficial microorganisms have the potential to promote salt tolerance of halophytes, but less attention has been paid to the various responses between different halophytes with microbial inoculations. Here we performed pot experiments to assess the responses of Nitraria tangutorum Bobr. and Elaeagnus angustifolia Linn. to arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) inoculation in saline soil conditions. The results showed that neither a single AMF inoculation nor a single PGPR inoculation promoted the growth of N. tangutorum. In contrast, co-inoculation not only promoted biomass accumulation but also promoted the absorption of P, K+, and Ca2+ in the roots, and the accumulation of N, Na+, K+, and Ca2+ in the leaves. Co-inoculation also increased the K+/Na+ ratio in the roots as well as the Ca2+/Na+ ratio in both roots and leaves of N. tangutorum. Na+ is an important inorganic osmolyte, essential for both efficient osmoregulation and biomass accumulation in N. tangutorum. PGPR inoculation alone could not promote the growth of E. angustifolia. AMF inoculation, solely or combined with PGPR, was beneficial to the absorption of K+ and Ca2+ in the roots, the accumulation of N and K+ in the leaves, the maintenance of the K+/Na+ ratio and Ca2+/Na+ ratio in the leaves, the selective transportation of K+ and Ca2+ from roots to leaves, and the accumulation of proline and glycine betaine in the leaves of E. angustifolia. Increased nutrient absorption, ion homeostasis, and K+ and Ca2+ selective transportation in AMF-inoculated E. angustifolia helped reduce the toxic effects of Na+ and the damage caused by osmotic stress in saline soil conditions. “Plant-microbe specificity” leads to the different responses of N. tangutorum and E. angustifolia seedlings to AMF and PGPR inoculation in saline soil conditions. The different salt tolerance strategies for osmoregulation, nutrient acquisition, ion homeostasis, and ion transportation determine the differential responses in N. tangutorum and E.angustifolia to AMF and PGPR inoculations under saline soil conditions.

Water use efficiency and photosynthesis of Calamagrostis angustifolia leaves under drought stress through CO2 concentration increase

ABSTRACT The effects of elevated CO2 concentration on photosynthetic gas exchange parameters and chlorophyll fluorescence parameters in leaves of Calamagrostis angustifolia seedlings under drought stress were studied through control of different CO2 concentrations (370 and 700 μmol·mol−1) with an artificial OTC climate chamber. The results demonstrated that: Under non-drought conditions, although the stomatal conductance (G s) and transpiration rate (T r) decreased slightly as the CO2 concentration increased, while the net photosynthetic rate (P n) increased significantly, resulting in a significant increase in leaf water use efficiency (WUE). However, the effect of elevated CO2 concentration on PSII reaction center activity was insignificant under non drought conditions. Under severe drought stress, the amount of active reaction centers per unit area and the proportion of PSII absorbed light energy for photosynthetic electron transfer increased, while the proportion of PSII absorbed light energy for heat dissipation decreased, providing energy guarantee for effective fixation of CO2 as dark reaction. In conclusion, elevated CO2 concentration could improve the water use efficiency of C. angustifolia seedlings under normal water and drought stress, and the elevated CO2 concentration could improve the drought resistance ability of C. angustifolia seedlings through PSII function improvement under severe drought stress.

The growth of one-year-old narrow-leaved ash seedlings is strongly related to the leaf area parameters

The leaf area of plant leave scan be considered as an indicator of the plant growth conditions, and its variability is usually associated with adaptation and response to the changing environment. The aim of this study is to investigate the relation of the leaf area parameters on growth of the narrow-leaved ash 1+0 seedlings from the nursery trial and determining variability between the 18 half-sib lines. The seedlings were obtained from seeds collected from 18 maternal trees found in the area of the special nature reserve Upper Danube Region. Ten randomly selected 1+0 seedlings per half-sib line were selected for further study, and all leaves per seedling were collected, herbarized and scanned. The leaf area of each leaf (LACL) was measured using an open-source image processing program – ImageJ, and the total leaf area per seedling (TLA) was calculated. Also, the number of leaves per plant (NCL) as well as the number of leaflets within each imparipinnate compound leaf (NLCL) were counted. The results showed that differences between studied attributes were statistically significant among 18 selected half-sib lines (p < 0.05). The most variable parameter was the total leaf area per seedling (TLA; CV=68.98%), which is strongly correlated to the leaf area per each leaf (LACL; r=0.95) and the number of leaflets (NLCL; r=0.94). In this study, we confirmed that leaf parameters were highly correlated to the growth of one-year-old Fraxinus angustifolia seedlings.

First report of Verticillium wilt caused by Verticillium dahliae on Russian olive (Elaeagnus angustifolia) in Iran.

Russian olive, also known as, Persian olive or oleaster (Elaeagnus angustifolia L.) is a species in the Elaeagnaceae family native to western and central Asia. In some orchards in Iran, intercropping Russian olive or Prunus trees with vegetables is a common practice. In 2018, about 130 ha of E. angustifolia orchards in Shahrood, Semnan Province, Iran showed branch wilting and dieback. Symptoms on affected trees started with yellowing of the lower leaves, followed by wilting and finally death of affected branches. Sections of stems indicated brown or black streaks in the vascular tissues under the bark. Isolations were made from discolored vascular tissues by surface-disinfesting small pieces of tissue with 0.5% sodium hypochlorite for 2 min, plating them onto potato dextrose agar amended with 25 mg/l streptomycin sulfate and incubated in the dark for 14 days at 25°C. Fungi consistently isolated from symptomatic tissues. Fungal isolates were identified as Verticillium dahliae Kleb. based on characteristics of verticillate conidiophores, hyaline, elliptical, single celled conidia measuring 4.7-6.0 × 2.3-3.4 μm (n = 100) and irregular, dark microsclerotia measuring 27-34 × 22-26 μm (n = 50) that developed after 14 days of growth at 25°C in the dark. The identification of two isolates was further confirmed by performing real-time PCR assay using a pair of specific primers for internal transcribed spacer (ITS) region of V. dahliae as previously described (Hiemstra et al. 2013). In addition, the molecular subdivision of isolates was further determined to discriminate D and ND molecular types (Keykhasaber 2017). According to molecular assays, isolates were identified as V. dahliae and grouped with ND types. The pathogenicity of isolates was evaluated by root-dipping one-year E. angustifolia seedlings (10 seedlings) into conidial suspensions of 1×107 cfu/ml. Inoculated plants were transplanted in pots containing autoclaved soil and maintained in a greenhouse at 25°C until symptoms appearance. Two seedlings were treated with sterile distilled water as controls. All inoculated seedlings started to show wilting symptoms similar to those present in naturally affected trees within 30 days after inoculation and died thereafter. Furthermore, V. dahliae was consistently isolated from symptomatic tissues. No symptoms were observed on the control plants. The pathogenicity test was repeated twice with similar results. To the best of our knowledge, this is the first report of Verticillium wilt on Russian olive trees in Iran. In Iran, Verticillium wilt is the cause of serious losses in many woody and herbaceous plants with economic importance including many trees belonging to the genus Prunus that are highly susceptible to the disease. In Shahrood (Semnan Province), most agricultural fields have a potato- or tomato- growing history. Verticillium wilt may become an important economic problem in many Russian olive and Prunus orchards in the future since their cultivation is expanding rapidly in many agricultural areas previously dedicated to tomato and potato crops, the majority of which are infested with V. dahliae. References Hiemstra, J. A., Korthals, G. W., Visser, J. H. M., Dalfsen, P. v., Sluis, B. J. v. d., and Smits, A. P. 2013. Control of Verticillium in tree nurseries through biological soil disinfestation. Pages 62-62 in: 11th International Verticillium Symposium, Georg-August-Universität,Göttingen, Germany, 5-8 May 2013, B. Koopmann and A. von Tiedemann, eds. DPG Spectrum Phytomedizin, Göttingen. Keykhasaber, M., Faino L., van den Berg, G.C.M., Hiemstra, J. A., Thomma, B. P. H. J. 2017. A robust method for discriminating defoliating and the non-defoliating pathotypes of V. dahliae. . In; Keykhasaber M. thesis 62-84. Sun, M., and Lin, Q. 2010. A revision of Elaeagnus L. (Elaeagnaceae) in mainland China. J. Systematics and Evolution 48:356-390.

Temperature affected the formation of arbuscular mycorrhizas and ectomycorrhizas in Populus angustifolia seedlings more than a mild drought

Arbuscular mycorrhizal (AM) plants and fungi associate with lower soil organic matter, higher pH, lower phosphorus and higher nitrogen than ectomycorrhizal (EM) ones. However, soil conditions correlate with climatic factors, and we suggest that temperature and humidity have also direct roles in the success of mycorrhiza types. The hypothesis here is that EM perform better at low temperatures than AM, and AM resist drought better than EM.Narrowleaf cottonwood (Populus angustifolia E. James) forms both AM and EM. We grew seedlings in soil at 14, 20 and 26 °C in factorial combinations with adequate watering and a cyclic mild drought for 4 and 7 weeks.As hypothesized, the percent of EM root tips was largest at 14 °C, while the proportional root length with AM was largest at the two higher temperatures. However, unlike expectations, drought increased EM formation slightly, while the AM colonization was lower in the dry treatment. Plant growth was reduced more by low temperature than drought. Root branching was more prominent at low temperature and root length and mass growth at higher temperatures.Soil nutrient availability did not provide a direct explanation to the results, as both soluble soil N and P were the same in 14 and 20 °C, while the change in mycorrhiza colonization took place between these temperatures. Differences in root morphology (root branching vs length) may affect the proportions of the mycorrhiza types at different temperature regimes. The most likely explanation to the differential colonization is that temperature affects AM and EM fungi in a different way. In nature, temperature and humidity regimes are tightly correlated, and temperature as such may be a stronger determinant for the success of mycorrhiza types than has been previously considered. The poorer performance of AM in low-temperature and drought conditions may reflect stress avoidance rather than stress tolerance by AM fungi.

The presence of moderate salt can increase tolerance of Elaeagnus angustifolia seedlings to waterlogging stress

ABSTRACTHigh salinity and waterlogging are two stress factors that often occur simultaneously in nature, particularly during the rainy season in the Yellow River Delta (YRD) of China. An attractive approach to improve the saline-alkali soil produced by waterlogging and high salt is to use plants for wetland ecosystem restoration. In this work, we examined the ecological adaptability of Elaeagnus angustifolia L. under combined waterlogging and salt stress, to evaluate the potential of this species for introduction to the YRD. We monitored the effects of salt plus waterlogging co-stress on the anatomy, physiology, and enzymatic systems in E. angustifolia seedlings. Salt alone and waterlogging alone inhibited the growth of the seedlings, while salt plus waterlogging co-stress reduced this growth inhibition. Furthermore, E. angustifolia seedlings resisted the salt plus waterlogging co-stress by increasing porosity, accumulating more inorganic ions and organic solutes, and increasing antioxidant enzyme activities to maintain high photosynthetic rates and membrane stability and thus avoid damage. These findings support the inclusion of E. angustifolia in the ecological restoration of the YRD.

Variations in the water potential of stem xylem in Russian olive (Elaeagnus angustifolia) seedlings treated with mycorrhizal fungi under drought conditions

Measures must be taken to reduce the stress caused by water scarcity, which is the greatest obstacle to increasing the success of afforestation in arid areas. Precautions such as site preparation and species change do not ensure sufficient benefits. For this, it is necessary to try alternative methods such as using mycorrhization of seedlings for afforestation. The aim of the present study was to obtain Russian olive (Elaeagnus angustifolia) seedlings with high resistance to water stress and ascertain the effects of mycorrhizae on the water potential of water- stressed seedlings. Accordingly, we determined the water potentials of seedlings inoculated with arbuscular mycorrhizal fungi. Reduction in soil water content caused a reduction in the water potential of seedlings in all treatment variants. Mycorrhization reduced stress by increasing the water potential of seedlings in drought conditions, thereby enhancing their resistance to water stress.

An orthogonal test of the effect of NO3−, PO43−, K+, and Ca2+ on the growth and ion absorption of Elaeagnus angustifolia L. seedlings under salt stress

Excess salts in soil severely inhibit plant growth and yield. Various nutrients can relieve the inhibitory effect of salt on plants. Elaeagnus angustifolia is a tree species that is utilized in landscaping and ecological restoration in China and shows tolerance to saline soils. In this experiment, we first determined the optimal concentration of single-nutrient inputs for promoting growth of E. angustifolia seedlings and alleviating salt stress. The optimal nitrogen (NO3−), phosphorus (PO43−), potassium (K+), and calcium (Ca2+) concentrations under salt stress were 2, 0.6, 2, and 2 mM, respectively. Based on this result, we carried out an optimum nutrient ratio experiment by a four-factor and three-level orthogonal experiment. The results showed that under normal growth conditions, the optimal nutrient combinations for NO3−, PO43−, K+, and Ca2+ were 2, 0.6, 5, and 1 mM; 5, 0.2, 5, and 2 mM; and 5, 0.6, 1, and 5 mM, respectively, which increased plant height, biomass, and the chlorophyll content of E. angustifolia seedlings. Under salt stress, the optimal nutrient combinations were 5, 0.2, 5, and 2 mM; and 5, 0.6, 1, and 5 mM, respectively. This study provides a theoretical basis for optimal fertilization of E. angustifolia seedlings in saline-alkali soils.

The effect of Rhizophagus irregularis on salt stress tolerance of Elaeagnus angustifolia roots

We assessed the effects of arbuscular mycorrhizal fungi (AMF) Rhizophagus irregularis inoculation on salt stress tolerance in roots of the drought-tolerant plant Elaeagnus angustifolia. We studied a plant growth index, spore density and hyphal length density of AMF, the Na+ contents and ultrastructure of root cells, as well as rhizosphere soil enzyme activities of mycorrhizal and non-mycorrhizal E. angustifolia seedlings under different salt stress. Under salt stress, growth of E. angustifolia with mycorrhizal inoculation was higher than that of non-inoculated treatments. The spore density and hyphal length density decreased significantly under salt stress in rhizosphere soil of mycorrhizal E. angustifolia seedlings (p < 0.05). The root cells of E. angustifolia seedlings inoculated with R. irregularis at 300 mmol L−1 salt had more organelles, greater integrity, and lower root Na+ contents than those of non-inoculated seedlings. In addition, the results showed notably higher activities of catalase, phosphatase, urease and saccharase in rhizosphere soil of the mycorrhizal seedlings in response to salinity compared to those of the non-mycorrhizal seedlings. Therefore, AMF inoculation could enhance salt stress tolerance in roots of E. angustifolia.

Growth and quality of Brazilian pine tree seedlings as affected by container type and volume

Abstract Araucaria angustifolia (Bert.) O. Kuntze (Araucariaceae), commonly known as araucaria and Brazilian pine tree, can be grown for their edible pine nuts (pinhões), medicinal properties, and ornamental purposes. The aim was to assess the shoot and root growth and the overall quality of A. angustifolia seedlings grown in containers with different sizes, shapes and composition. Seeds were sowed in five containers: I – 126cm3 polypropylene cone-tainers (small cone-tainers); II – 290cm3 cone-tainers (large cone-tainers); III – 879cm3 polyethylene black bags; IV- 275 cm3 nonwoven fabric (TNT) containers (small TNT container) and; 493 cm3 nonwoven fabric (TNT) containers (large TNT container). Seedlings were evaluated 210 days after sowing, regarding the following variables: aboveground height (cm), root collar diameter (mm), shoot dry mass (g), roots dry mass (g), total dry mass (g), leaf area (cm2), roots area (cm2), roots volume (cm3), sturdiness quotient, root-shoot ratio and Dickson quality index. Height was superior for seedlings grown in the plastic bags (27.6 cm) and the large TNT containers (27.02 cm) when compared to the small and large cone-tainers (21.75 and 21.78 cm, respectively). Plastic bags also presented greater values of root-collar diameter, shoots, roots and total biomass and Dickson Quality index. Small and large TNT containers promoted lower root area and volume when compared to large polyethylene cone-tainers, but allowed for the same or better aboveground growth. Taking all results analyzed together, the polyethylene black bag promoted better growth and quality of Brazilian pine tree seedlings in comparison to the other containers.

Phytohormone involved in salt tolerance regulation of Elaeagnus angustifolia L. seedlings

ABSTRACTSoil salinization is a serious problem for plant growth worldwide. Understanding the tolerance mechanisms of salt-tolerant plants is essential for development and utilization of saline-alkali land. The salt-tolerant tree species Elaeagnus angustifolia is utilized in landscaping and ecological restoration projects such as afforestation. In this work, we examined the changes in phytohormone levels and the expression of phytohormone-related genes in E. angustifolia seedlings under salt stress. We observed no changes in the biomass, leaf area, and the size of epidermal cells of E. angustifolia seedlings under low levels of NaCl (50 mM); however, when the NaCl concentration was increased, these parameters were significantly reduced. Comparison of the transcriptome data of the species seedlings under 0 and 150 mM NaCl showed that many hormone pathways are involved in the salt-tolerance response. Under salt stress, abscisic acid (ABA) and jasmonate (JA) contents increased significantly, whereas the contents of auxin (IAA), gibberellin (GA), cytokinins (CKs), and brassinosteroids (BRs) decreased significantly. We conclude that these changes could be responsible for the growth inhibition and increased salt resistance of E. angustifolia seedlings.

Use of raw and acidified biochars as constituents of growth media for forest seedling production

In plant nurseries devoted to the propagation of shrubs and trees for landscaping, gardening or forestry it is first concern to produce robust seedlings which resist the stress of transplanting to soil. The selection of appropriate growth media is crucial. Biochar, the product of pyrolysis of organic matter, has been suggested as a new organic amendment for soil or for soilless growth media. Biochar is usually strongly alkaline. We studied the possibility of acidifying biochar with nitric and phosphoric acids. The effects of raw and acidified biochars in peat-based substrates on rooting and growth of cuttings of Rosmarinus officinalis and in sandy soil-based substrates on growth of Phillyrea angustifolia seedlings were compared. The physical and chemical characteristics of the growth media, and the growth and nutrient content of seedlings were analysed. Results showed that biochar acidification with nitric and phosphoric acids improves the pH and enriches the biochar with N and P without excessively increasing electrical conductivity. However, a column experiment showed that nitrate was readily leached whilst phosphate was tightly retained by biochar, which questioned the practical availability of these nutrients to plants. The agronomical assays showed that both raw biochar and acidified biochar improved rooting and growth of Rosmarinus cuttings. In Phillyrea, however, the acidified biochar did not affect plant growth whilst the raw biochar gave satisfactory results both for shoot and root growth. Results led to the conclusion that biochar without further treatment might be successfully used as growth medium constituent, even at large proportions, both in organic and in mineral substrates.

Proteomics Analysis of E. angustifolia Seedlings Inoculated with Arbuscular Mycorrhizal Fungi under Salt Stress.

To reveal the mechanism of salinity stress alleviation by arbuscular mycorrhizal fungi (AMF), we investigated the growth parameter, soluble sugar, soluble protein, and protein abundance pattern of E. angustifolia seedlings that were cultured under salinity stress (300 mmol/L NaCl) and inoculated by Rhizophagus irregularis (RI). Furthermore, a label-free quantitative proteomics approach was used to reveal the stress-responsive proteins in the leaves of E. angustifolia. The result indicates that the abundance of 75 proteins in the leaves was significantly influenced when E. angustifolia was inoculated with AMF, which were mainly involved in the metabolism, signal transduction, and reactive oxygen species (ROS) scavenging. Furthermore, we identified chorismate mutase, elongation factor mitochondrial, peptidyl-prolyl cis-trans isomerase, calcium-dependent kinase, glutathione S-transferase, glutathione peroxidase, NADH dehydrogenase, alkaline neutral invertase, peroxidase, and other proteins closely related to the salt tolerance process. The proteomic results indicated that E. angustifolia seedlings inoculated with AMF increased the secondary metabolism level of phenylpropane metabolism, enhanced the signal transduction of Ca2+ and ROS scavenging ability, promoted the biosynthesis of protein, accelerated the protein folding, and inhibited the degradation of protein under salt stress. Moreover, AMF enhanced the synthesis of ATP and provided sufficient energy for plant cell activity. This study implied that symbiosis of halophytes and AMF has potential as an application for the improvement of saline-alkali soils.

Adaptive growth response of exotic Elaeagnus angustifolia L. to indigenous saline soil and its beneficial effects on the soil system in the Yellow River Delta, China

Our manuscript showed that Elaeagnus angustifolia L. can be introduced to the Yellow River Delta of China and planting E. angustifolia was beneficial effects on the soil system. The saline soil of the Yellow River Delta of China is not suitable for the growth of crop and afforestation seedlings due to high salt content, high underground water level, and deficiencies in organic matter, nitrogen and phosphorus, which limits urban road greening around the Yellow River Delta. Elaeagnus angustifolia L. (E. angustifolia) is a member of the Elaeagnaceae family, which is a deciduous shrub or small tree. Due to its good resistance, E. angustifolia has been planted widely in the western region of China, and it has been used for wind breaking, landscaping and sand stabilization. Furthermore, E. angustifolia seedlings were introduced to the Yellow River Delta due to its strong stress and adaptive growth response, which were studied in 2014 and 2015. The results revealed that the seedlings of E. angustifolia grew well with high relative growth rates, big crowns, thick basal diameter, thick diameter at the breast height, and many branches, especially during the second year. Planting E. angustifolia on the Yellow River Delta significantly decreased its salt content, and increased its content of organic matter, nitrogen and phosphorus, as well as the number of fungus, bacteria, salt-tolerant bacteria, actinomycetes and salt-tolerant actinomycetes, especially after planting E. angustifolia for two consecutive years. In conclusion, E. angustifolia seedlings can grow well in the saline soil of the Yellow River Delta with a large biomass. In turn, planting E. angustifolia could improve saline soil properties. Hence, E. angustifolia can be a potential local greening tree species.

The effect of half-sib lines on morphological attributes of one-year old Fraxinus angustifolia seedlings

Aiming to produce forest reproductive material at the family level, we tested quality of twenty Fraxinus angustifolia Vahl half-sib lines in the nursery experiment. We measured height (HT) and root collar diameter (DIA) of one-year old seedlings, and we monitored germination rate and mortality during the first growing season. Seeds of 20 half-sib lines originating from Sombor area (north Serbia) were sown in seedbed on autumn 2016. The seed dormancy was not broken in all seeds equally, resulting with un-uniform germination over a two months period. All measured attributes shows a statistically significant differences, indicating a strong effect of genetic control. The highest average and DIA were measured in half-sib line 7 (22.62 cm; 5.79 mm, respectively). The lowest average DIA was measured in half-sib lines 18 (2.85 mm) and 19 (2.94 mm), which can be result of growing density effect (104 seedlings m-2 for line 18 and 126 seedlings m-2 for line 19, compared to 40 seedlings m-2 for line 7). The correlation between DIA and HT is strong and positive (R=0.90). Due to its morphological superiority, half-sib line 7 could be recommended for mass production of Fraxinus angustifolia seedlings at the family level.&#x0D; Keywords: Height; Root Collar Diameter; Seedlings Quality; Narrow leaved ash

Arbuscular Mycorrhizal Symbiosis Modulates Antioxidant Response and Ion Distribution in Salt-Stressed Elaeagnus angustifolia Seedlings.

Elaeagnus angustifolia L. is a drought-resistant species. Arbuscular mycorrhizal symbiosis is considered to be a bio-ameliorator of saline soils that can improve salinity tolerance in plants. The present study investigated the effects of inoculation with the arbuscular mycorrhizal fungus Rhizophagus irregularis on the biomass, antioxidant enzyme activities, and root, stem, and leaf ion accumulation of E. angustifolia seedlings grown during salt stress conditions. Salt-stressed mycorrhizal seedlings produced greater root, stem, and leaf biomass than the uninoculated stressed seedlings. In addition, the seedlings colonized by R. irregularis showed notably higher activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) in the leaves of the mycorrhizal seedlings in response to salinity compared to those of the non-mycorrhizal seedlings. Mycorrhizal seedlings not only significantly increased their ability to acquire K+, Ca2+, and Mg2+, but also maintained higher K+:Na+ ratios in the leaves and lower Ca2+:Mg2+ ratios than non-mycorrhizal seedlings during salt stress. These results suggest that the salt tolerance of E. angustifolia seedlings could be enhanced by R. irregularis. The arbuscular mycorrhizal symbiosis could be a promising method to restore and utilize salt-alkaline land in northern China.

Piriformospora indica, an excellent system for heavy metal sequestration and amelioration of oxidative stress and DNA damage in Cassia angustifolia Vahl under copper stress

Present investigation reveals copper induced phytotoxicity, oxidative stress and DNA damage in Cassia angustifolia Vahl and its amelioration by employing a symbiotic fungus, Piriformospora indica. Seeds were germinated on Knop's medium containing five Cu levels (0, 1, 10, 50, 100 and 200 mg L−1), with and without P. indica. Colonization with P. indica significantly (P < 0.05) ameliorated Cu induced oxidative stress. However, maximum amelioration was observed at 50 mg L−1 Cu with P. indica. Atomic absorption spectroscopy revealed that P. indica colonization significantly inhibited Cu accumulation in shoots. Maximum decline in Cu accumulation in shoots was observed at 50 mg L−1 (27.27%) with P. indica over Cu alone. Besides, P. indica colonized seedlings stored 16.86% higher Cu in roots as compared to Cu alone at 200 mg L−1. Similarly, maximum proline accumulation increased up to 19.32% over Cu alone at 50 mg L−1 Cu with P. indica. Significant elevation in antioxidant enzyme levels of superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase and glutathione reductase was seen with P. indica. Contrary to increase in antioxidant level, toxic parameters such as lipid peroxidation and hydrogen peroxide decreased significantly with P. indica. Maximum decline in lipid peroxidation (13.76%) and hydrogen peroxide (18.58%) was observed at 50 mg L−1 with P. indica over Cu alone. P. indica significantly reduced DNA damage as well as changed the protein profile in C. angustifolia seedlings. Thus, P. indica proved to be an excellent system to alleviate Cu induced oxidative stress and might be useful as a phytostabilization tool.