Black Locust Plants Research Articles

Changes in preferential flow caused by root effects in black locust plantations of different stand ages in the semi-arid region of the Loess Plateau

Preferential flow significantly influences regional water cycles, and affecting surface and subsurface runoff processes. By comparing soil infiltration characteristics across various forest ages, it can be evaluated how artificial black locust forests on the Loess Plateau contribute to the resilience of soil and water conservation. In this study, we analyzed the spatial distribution characteristics of roots of black locust plants using field investigations and statistical analyses and determined the effects of the root characteristics on the preferential flow in the semi-arid of the Loess Plateau, China. The results showed that the root biomass, root length density, and root volume ratio of young forests were significantly lower than those of middle-aged and mature forests (P < 0.05), and root characteristic parameters varied significantly among different root diameters and soil layers.. The average volume of decayed root channels in mature forests, accounting for approximately 0.16 % in a unit volume of soil, was 3.1 times that of young forests and 4.9 times that of middle-aged forests. Preferential flow increased with forest age in artificial black locust forests. 2–5 mm, 30–40 mm and > 50 mm roots promoted preferential flow to varying degrees, while roots of 5–15 mm inhibited the preferential flow. < 2 mm, 10–30 mm and 40–50 mm roots has no effect on preferential flow (P > 0.05). The size and density of decayed root channels significantly improve soil preferential flow, and the differences among forest ages are linked to the network created by rotten roots. These findings indicate that living roots of different diameters and decayed roots contribute to soil preferential flow to varying extents. The results provided a conceptual basis for understanding the potential impact of vegetation roots on surface runoff during the vegetation restoration ecosystems process in the Loess Plateau.

Exogenous chelating agents influence growth, physiological characteristics and cell ultrastructure of Robinia pseudoacacia seedlings under lead-cadmium stress.

Heavy metal pollution of soil, especially by lead (Pb) and cadmium (Cd), is a serious problem worldwide. The application of safe chelating agents, combined with the growing of tolerant trees, constitutes an approach for phytoremediation of heavy-metal-contaminated soil. This study aimed to determine whether the two safe chelators, tetrasodium glutamate diacetate (GLDA) and citric acid (CA), could improve the phytoremediation capacity of black locust (Robinia pseudoacacia L.) in a Pb-Cd-contaminated soil and to find the key factors affecting the biomass accumulation of stressed black locust. In Pb- and Cd-stressed black locust plants, medium- and high-concentration GLDA treatment inhibited the growth, chlorophyll synthesis and maximum photochemical efficiency (Fv/Fm), promoted the absorption of Pb and Cd ions and resulted in the shrinkage of chloroplasts and starch grains when compared with those in Pb- and Cd-stressed plants that were not treated with GLDA. The effects of CA on plant growth, ion absorption, chlorophyll content, chlorophyll fluorescence and organelle size were significantly weaker than those of GLDA. The effect of both agents on Cd absorption was greater than that on Pb absorption in all treatments. The levels of chlorophyll a and plant tissue Cd and rates of starch metabolism were identified as the key factors affecting plant biomass accumulation in GLDA and CA treatments. In the future, GLDA can be combined with functional bacteria and/or growth promoters to promote the growth of Pb- and Cd-stressed plants and to further improve the soil restoration efficiency following pollution by heavy metals. Application of CA combined with the growing of black locust plants has great potential for restoring the Cd-polluted soil. These findings also provide insights into the practical use of GLDA and CA in phytoremediation by R. pseudoacacia and the tolerant mechanisms of R. pseudoacacia to Pb-Cd-contaminated soil.

Effects of Rainfall and Plant Characteristics on the Spatiotemporal Variation of Soil Moisture in a Black Locust Plantation (Robinia pseudoacacia) on the Chinese Loess Plateau

Soil moisture is a key factor controlling vegetation construction and ecological restoration in arid and semiarid areas. Understanding its spatiotemporal patterns and influencing factors is essential for effective vegetation water management. In this study, we analyzed the spatiotemporal characteristics of black locust plants using field investigations and statistical analyses and determined the effects of the rainfall and plant characteristics on the soil moisture content (SMC) in a typical watershed in the Loess Plateau, China. The results show that the SMC increases with increasing distance from the tree trunk in the horizontal direction. The vertical profile of the SMC includes layers characterized by rapid decrease, decreased fluctuation, and slow increase. Temporal SMC changes exhibit higher variabilities in the surface layer than in deeper soil layers. Rainfall characteristics notably affect soil moisture. The influence of the rainfall amount is stronger than that of the rainfall duration and intensity. The diameter at breast height, tree height, and canopy width positively affects the soil moisture, whereas the leaf area index and canopy openness negatively affect it. The results of this study provide insights into soil moisture change mechanisms and theoretical references for sustainable plant water use management in arid and semiarid areas.

Effects of the vegetative propagation method on juvenility in &lt;i&gt;Robinia pseudoacacia&lt;/i&gt; L&lt;i&gt;.&lt;/i&gt;

Vegetative propagation is an important method of reproduction and rejuvenation in forestry. The growth and development of asexually propagated trees are influenced by the age and position of the propagule on the plant, effects referred to as cyclophysis and topophysis, respectively. Due to the long lifespans and large body sizes of woody trees, the selection of propagules is critically important. Here, we used three vegetative propagation methods (shoot cutting, root sprouting, and root cutting) to study the effect of different regeneration methods on juvenility of the resulting black locust plants, with seed-derived seedlings used as a control. Most characteristics of plantlets generated by root-sprouting were similar to those of seed-derived seedlings, including leaf traits and leaf anatomical structure. However, there were significant differences between the plantlets derived from shoot-cuttings and seedlings from seeds. Furthermore, the data showed that some of these age-related small RNAs and genes differed in expression among propagation methods and between plantlets/seedlings and mature trees. These age-related small RNAs, genes, and transcription factors may be used as molecular markers of juvenility and phase transitions in black locust Our results provide useful information for the optimal propagation of woody trees and for further research into the mechanisms of root regeneration.

Spectral parameters of Robinia pseudoacacia L. seeds in technogenic conditions of urban environment

Robinia pseudoacacia L. (black locust) is an invasive species with high activity in alien flora of Ukraine. Invasive potential of plants in unfavorable ecological conditions is due to the presence of adaptive mechanisms. One of the criteria for the invasive potential of foreign plants is considered to be seed productivity. For plants of black locust note a high level of seed productivity. However, it remains to be seen what factors ensure the formation of viable seeds in extreme environments. Among the factors that ensure the formation of viable plant seeds, note the barrier function of the seed coat relative to biotic and abiotic environmental factors. The physiological role of this protective barrier is realized due to the specific properties and component composition of the surface tissues of seeds. Among the metabolites with protective properties localized in the seed coat, consider proanthocyanidins (condensed tannins), which are formed during the biosynthesis of phenolic compounds. To objectively assess changes in the accumulation of proanthocyanidins in the seed coat, it is necessary to use non-destructive methods, because the isolation of these compounds destroys their native polymer structure. The influence of technogenic pollution of Dnipro city on the reflectance, colorimetric and fluorescent characteristics of Robinia pseudoacacia L. seeds is investigated in the work. Mature seeds of black locust were collected at monitoring sites in the Botanical Garden of Oles Honchar Dnipro National University (ecologically favorable zone) and at some points of linear roadside plantations of one of the main highways. It was found that the chronic effect of aerogenic pollutants on black locust plants caused an increased accumulation of proanthocyanidins in the seed coat, which may be due to changes in the biosynthesis of these compounds at the stage of oxidative polymerization of flavonoid subunits. Markers of this reaction of plants are the change of position and increase of intensity of maxima in the reflectance spectra of visible region, increase of value of dominant wavelength, decrease of conditional purity of color tone and colorimetric coefficients, increase of intensity of maxima in seed fluorescence spectra. The protective effect of these adaptive changes is associated with the strengthening of the barrier function of the seed coat to adverse environmental factors to maintain the viability of the seeds under the negative impact of technogenic pollution.

Активність та ізоферментний склад пероксидази листя Robinia pseudoacacia L. за дії Parectopa robiniella Clemens, 1963

Іn recent times R. pseudoacacia has been suffering from populations of new pests, which cause serious economic damage to this strategic species. Therefore, studying the features of plant defense responses against harmful insects is of great importance for biodiversity conservation for preserving this species in natural and artificial plantings. The aim of the study was to analyze the peculiarities of the activity and isoenzyme composition of peroxidase in R. pseudoacacia leaves during attacks by the invading insect P. robiniella. In the green plantations of Dnipro city, as the object of research, six groups of Robinia pseudoacacia L. model trees of different ages (5 and 35–40 years of age) with the existing leaf damages by P. robiniella leaf blotch miner were identified. Differences in benzidine-peroxidase activity were found in the leaves of 5- and 40-year-old R. pseudoacacia trees. In 35‒40-year-old trees with the presence of leaf blotch mi­ners, the leaves showed a tendency to increase BPOD activity by 24.6% vs control. While in young plants, a significant increase in peroxidase activity was found by 3.8 times due to mechanical damage of the leaves by the miner compared to the control. The revealed significant increase (by 63.2%) in the activity of guaiacol-peroxidase of black locust indicates its active participation in enhancing the barrier functions of leaf cells against P. robiniella, and it indicates the promising use of the enzyme as a biomarker for pest influence. The composition of benzidine-peroxidase isoenzymes was analyzed by electrofocusing. The main pattern of changes in the expressiveness of benzidine-peroxidase due to damage of leaves by a pest was a quantitative redistribution of activity between different molecular forms of peroxidase. Several enzyme isoforms from the highly acidic pH zone showed a significant activity increase in R. pseudoacacia leaves damaged by P. robiniella; this especially applies to the peroxidase system of young black locust plants. The increase in bensidine- and guajacol-peroxidase activity under the influence of leaf miner may be explained by a change in the gene expression of individual isoforms of peroxidases, which is confirmed by the results of studying the relative share of peroxidase molecular forms with isoelectrofocusing. Calculation of the internal diversity index (KD) of IEF benzidine-peroxidase spectra showed that the studied peroxidase spectra of young and medieval trees of control and experimental samples of R. pseudoacacia leaves differ significantly in the level of complexity. Under the influence of the invader the level of complexity increased. The study of the reaction of black locust and the mechanisms of its protection against mechanical damage by phytophages with the involvement of a larger range of enzymes in further research can serve as a theoretical basis for species selection and management to restore it under biotic stress.

Assessment of genetic diversity and chemical composition among seven black locust populations from Northern China

Black locust (Robinia pseudoacacia L.) is one of the important biomass sources used to produce bioenergy and bioethanol. In this study, we examined variations in chemical composition as well as genetic diversity and differentiation among 165 black locust plants from seven populations in five provinces (Beijing, Hebei, Gansu, Shanxi, Shandong) of Northern China using microsatellite markers(SSR). The contents of cellulose, hemicellulose, lignin varied widely among seven populations. Of the microsatellite markers analysed, 14 showed polymorphisms, and 45 alleles were identified. The polymorphism information content (PIC) ranged from 0.2885 (Rops4) to 0.6837 (Rp200), and most of the microsatellite loci had PIC values > 0.5. Expected heterozygosity (He), observed heterozygosity (Ho), and Shannon's information index (I) detected relatively high genetic variation among populations. The percentage of polymorphic loci in three populations was 100%, and the average among all populations were 95.92%. Analysis of molecular variance (AMOVA) indicated that the degree of genetic differentiation among the seven populations was low (GST = 0.058; Nm = 4.05), and chemical compositions had no relationship with genetic or geographic distance. This study demonstrates that microsatellite markers efficiently assess of genetic diversity and genetic differentiation in black locust populations, and all seven populations exhibit high genetic diversity. The population from Feixian has the potential to be lingo-cellulosic biomass for bioenergy and bioethanol.

Evaluating the health status of Robinia pseudoacacia L. by the root exudates

The components of root exudates released from healthy and unhealthy black locust (Robinia pseudoacacia L.) root were determined by GC-MS. The results showed that the kinds and contents of root exudates released from Black Locust are different for healthy and unhealthy plants, so it may be evaluated whether the Black Locust plants are healthy or unhealthy by the root exudates. Healthy plants can release more kinds of exudates than unhealthy plants, especially the kinds of acids, alcohol and ester. There are 46 kinds of compounds in the healthy Black Locust, but only 24 kinds in the unhealthy Black Locust. Many compounds are released from healthy plant but not from unhealthy, while many kinds of compounds are released from unhealthy plant but not from healthy one.

Investigations of microbial degradation of polycyclic aromatic hydrocarbons based on 13C-labeled phenanthrene in a soil co-contaminated with trace elements using a plant assisted approach

Co-contaminations of soils with organic and inorganic pollutants are a frequent environmental problem. Due to their toxicity and recalcitrance, the heterogeneous pollutants may persist in soil. The hypothesis of this study was that degradation of polycyclic aromatic hydrocarbons (PAHs) is enhanced if heavy metals in soil are immobilized and their bioavailability reduced. For metal immobilization and enhanced biodegradation, distinct mineral and organic soil amendments (iron oxides, gravel sludge, biochar) were deployed in an incubation batch experiment. The second part of the experiment consisted of a greenhouse pot experiment applying fast-growing and pollution-tolerant woody plants (willow and black locust). Soil amendments initially immobilized NH4NO3-extractable zinc, cadmium, and lead; after 100days of incubation, soil amendments showed reductions only for cadmium and a tendency to enhance arsenic mobility. In order to monitor the remediation success, a 13C-phenanthrene (PHE) label was applied. 13C-phospholipid fatty acid analysis (13C-PLFA) further enabled the identification of PHE-degrading soil microorganisms. Both experiments exhibited a similar PLFA profile. Gram-negative bacteria (esp. cy17:0, 16:1ω7 + 6, 18:1ω7c) were the most significant microbial group taking up 13C-PHE. Plants effectively increased the label uptake by gram-positive bacteria and increased the biomass of the fungal biomarker, although their contribution to the degradation process was minor. Plants tended to prolong PAH dissipation in soil; at the end of the experiment, however, all treatments showed equally low total PAH concentrations in soil. While black locust plants tended not to take up potentially toxic trace elements, willows accumulated them in their leaves. The results of this study show that the chosen treatments did not enhance the remediation of the experimental soil.

The Assimilate Partitioning Importance for Heartwood Extractives Formation in Robinia Pseudoacacia l. of Different Ages

ABSTRACTThis study aimed to investigate the influence of tree age on the assimilates partitioning and its significance for the formation of heartwood extractives in Robinia pseudoacacia L. (black locust). Assimilate translocation in 6- and 15-year-old plants was measured in May and August 2006 using the 14CO2 feeding method. The heartwood extractives content in the sapwood-heartwood transition zone and in individual tree rings of the pure heartwood were analysed by HPLC-chromatography. All plants, buds and young leaves showed the strongest 14C specific activity compared to other plant parts in May and August(14C specific activity in buds/leaves of 6-years old plants: 35.2-37.0%, 15-years old plants: 31.4-32.2%). However, in plants labelled in August 2006 at the sapwood-heartwood transition zone also showed a strong assimilates sink, while only small amounts of assimilates were translocated to the sapwood-heartwood transition zone in the plants labelled in May 2006. The amount of assimilates transported to the sapwood-heartwood transition zone was significantly higher in the 15-year-old plants compared to the 6-year-old plants. This was monitored by a higher content of extractives in the heartwood formed by the older plants compared to heartwood formed by the younger plants. The results indicate that uneven assimilate partitioning in younger and older black locust plants affects the heartwood extractives formation, which might lead to a lower natural durability of the heartwood formed by younger trees compared to heartwood formed by older trees.

Black locust (Robinia pseudoacacia L.) ecophysiological and morphological adaptations to drought and their consequence on biomass production and water-use efficiency

Successful plantation efforts growing Robinia pseudoacacia L. (black locust) in the drier regions of Hungary and East Germany (Brandenburg), have demonstrated the potential of black locust as an alternative tree species for short-rotation biomass energy plantations. The response of black locust to water limitation was investigated in a lysimeter experiment. Plants were grown under three different soil moisture regimes, with values set at 35%, 70%, and 100% of the soil water availability, namely WA35, WA70, and WA100. Their morphological adaptation and productivity response to water constraint were assessed together with their water-use efficiency. Furthermore, the ecophysiological adaptation at the leaf level was assessed in terms of net photosynthesis and leaf transpiration. During the growing season, plants in the WA35, WA70, and WA100 treatments transpired 239, 386, and 589 litres of water respectively. The plants subjected to the WA35 and WA70 treatments developed smaller leaves compared with the plants subjected to the WA100 treatment (66% and 36% respectively), which contributed to the total leaf area reduction from 8.03 m2 (WA100) to 3.25 m2 (WA35). The total above-ground biomass produced in the WA35 (646 g) and WA70 (675 g) treatments reached only 46% and 48% of the biomass yield obtained in the WA100 (1415 g). The water-use efficiency across all treatments was 2.31 g L−1. At vapour pressure deficit (VPD) values 2 kPa. Black locust plants can adapt to prolonged drought conditions by reducing water loss through both reduced transpiration and leaf size. However, under well-watered conditions it does not regulate its transpiration, and therefore it cannot be considered a water-saving tree species.

Induction of tetraploid poplar and black locust plants using colchicine: chloroplast number as an early marker for selecting polyploids in vitro

Tetraploid plants were produced by inducing chromosome doubling using colchicine in in vitro shoot tips of poplar and black locust clones. Many of the plants treated with colchicine showed modified morphological characteristics like stunted growth, thicker leaves and modified leaf morphology. The counting of chloroplast number in the epidermal guard cells of stomata was used for the rapid screening of tetraploids. The differences in mean chloroplast numbers between diploid and tetraploid plants were highly significant. For all plants tested, the tetraploid genotype had almost double the number of chloroplasts per guard cell compared to the diploid origin. Some plants were further analysed by flow cytometry to verify their ploidy status that was determined by chloroplast numbers. The results of this study demonstrated for the first time that chloroplast counting in poplar and black locust could be an effective and reliable method for pre-screening large numbers of plants for their ploidy level. The protocol might be applicable in a wide scope of breeding programs.

Restriction analysis of genetic variability of Polish isolates of Tomato black ring virus.

Several different isolates of Tomato black ring virus (TBRV) have been collected in Poland from cucumber, tomato, potato and black locust plants. Biological tests showed some differences in the range of infected plants and the type of symptoms, which was the basis for selection of seven the most biologically different TBRV isolates. According to the sequence of TBRV-MJ, several primer pairs were designed and almost the entire sequence of both genomic RNAs was amplified. The RT-PCR products derived from all tested TBRV isolates were digested by restriction enzymes. On the basis of the restriction patterns, the variable and the conserved regions of the TBRV genome were defined and the relationships between the Polish TBRV isolates established.

Restriction analysis of genetic variability of Polish isolates of Tomato black ring virus.

Several different isolates of Tomato black ring virus (TBRV) have been collected in Poland from cucumber, tomato, potato and black locust plants. Biological tests showed some differences in the range of infected plants and the type of symptoms, which was the basis for selection of seven the most biologically different TBRV isolates. According to the sequence of TBRV-MJ, several primer pairs were designed and almost the entire sequence of both genomic RNAs was amplified. The RT-PCR products derived from all tested TBRV isolates were digested by restriction enzymes. On the basis of the restriction patterns, the variable and the conserved regions of the TBRV genome were defined and the relationships between the Polish TBRV isolates established.

Propagation methods for black locust (Robinia pseudoacacia L.) improvement in Hungary

Black locust (Robinia pseudoacacia L.) is one of the most important stand-forming tree species in Hungary and its importance is increasing in many countries. Black locust plants are commonly produced by two methods, by seed and by root cuttings. Tissue culture propagation can be considered as a relatively new method. Growing trees from seed is a relatively simple method for reliably producing seedlings on a large scale under a variety of circumstances. Mechanization of the method is easy and the production cost is relatively low. Propagation from root cuttings and tissue culture are valuable for reproduction of superior individuals or varieties. By applying these methods, superior traits of the selected trees can be preserved in the clones. Recent experiments demonstrated that micropropagated trees could be successfully transplanted into soil, hardened and grown in the field.

Responses of Black Locust and Tomato Plants after Water Stress1

Abstract Plants of tomato (Lycopersicon esculentum Mill. cv. Roma) and black locust (Robinia pseudoacacia L.) were desiccated until continuous wilting was observed and then were irrigated to determine the effects of dehydration and subsequent rehydration on net assimilation, dark respiration, xylem pressure potential and leaf diffusive resistance. After-effects of water stress on dark stomatal aperture were observed in both species and on light stomatal aperture in black locust. Tomato plants appeared less able both to avoid and tolerate desiccation stress than did black locust plants.