Shoot Research Articles

Enhancing lavender (Lavandula angustifolia Mill.) propagation in vertical farming system: Investigating the impact of LED red-to-blue ratios and subsequent post-potting growth dynamics

This study aims to examine the influence of red-to-blue (R:B) LED light ratios on the propagation of Lavandula angustifolia within a vertical farming system. Additionally, it seeks to evaluate the persistent effects of LED lighting treatments on post-potting development in a glasshouse.The objective of this study is to assess how different R:B LED light ratios impact Lavandula angustifolia propagation in a vertical farming system and to analyze the enduring effects of these lighting treatments during the post-potting development stage in a glasshouse.The study consists of two phases. In the initial phase, an analysis was conducted on root emergence, root and shoot biomass, chlorophyll content, and flower bud emergence. Two LED treatments, labeled L1 and L2, were employed, with specific R:B ratios (7:1 and 9:1) and light intensities set at 140 µmol m−2 s−1 and 100 µmol m−2 s−1, respectively. Correlation and regression analyses were performed to understand the relationships among the various parameters.In Phase One, the L1 and L2 LED treatments significantly enhanced root emergence and biomass. Notably, the R:B ratios of 7:1 and 9:1, with corresponding intensities of 140 µmol m−2 s−1 and 100 µmol m−2 s−1, demonstrated substantial improvements. In the subsequent glasshouse phase, plants previously treated with L1 exhibited superior plant height and shoot biomass.The findings of this study highlight the intricate relationships among different parameters, providing valuable insights for lavender cultivation practices. The positive outcomes, particularly observed in the L1 treatment, emphasize the potential of vertical farming systems and LED lighting in optimizing lavender growth dynamics. This study underscores the importance of specific R:B ratios, contributing to sustainable propagation strategies, and acknowledges the space-efficient nature of vertical farming systems.

Horizontal gene transfer of the Mer operon is associated with large effects on the transcriptome and increased tolerance to mercury in nitrogen-fixing bacteria

BackgroundMercury (Hg) is highly toxic and has the potential to cause severe health problems for humans and foraging animals when transported into edible plant parts. Soil rhizobia that form symbiosis with legumes may possess mechanisms to prevent heavy metal translocation from roots to shoots in plants by exporting metals from nodules or compartmentalizing metal ions inside nodules. Horizontal gene transfer has potential to confer immediate de novo adaptations to stress. We used comparative genomics of high quality de novo assemblies to identify structural differences in the genomes of nitrogen-fixing rhizobia that were isolated from a mercury (Hg) mine site that show high variation in their tolerance to Hg.ResultsOur analyses identified multiple structurally conserved merA homologs in the genomes of Sinorhizobium medicae and Rhizobium leguminosarum but only the strains that possessed a Mer operon exhibited 10-fold increased tolerance to Hg. RNAseq analysis revealed nearly all genes in the Mer operon were significantly up-regulated in response to Hg stress in free-living conditions and in nodules. In both free-living and nodule environments, we found the Hg-tolerant strains with a Mer operon exhibited the fewest number of differentially expressed genes (DEGs) in the genome, indicating a rapid and efficient detoxification of Hg from the cells that reduced general stress responses to the Hg-treatment. Expression changes in S. medicae while in bacteroids showed that both rhizobia strain and host-plant tolerance affected the number of DEGs. Aside from Mer operon genes, nif genes which are involved in nitrogenase activity in S. medicae showed significant up-regulation in the most Hg-tolerant strain while inside the most Hg-accumulating host-plant. Transfer of a plasmid containing the Mer operon from the most tolerant strain to low-tolerant strains resulted in an immediate increase in Hg tolerance, indicating that the Mer operon is able to confer hyper tolerance to Hg.ConclusionsMer operons have not been previously reported in nitrogen-fixing rhizobia. This study demonstrates a pivotal role of the Mer operon in effective mercury detoxification and hypertolerance in nitrogen-fixing rhizobia. This finding has major implications not only for soil bioremediation, but also host plants growing in mercury contaminated soils.

Characterization of Physiological and Biochemical Attributes of Neem (Azadirachta indica A. Juss) under Salinity Stress

Salinity poses a significant threat to agricultural productivity worldwide, with its detrimental effects on plant growth and physiological processes. Understanding the mechanisms by which plants respond to salt stress is crucial for developing strategies to mitigate its impact on crop yield and sustainability. To address this issue, a pot study was conducted to determine the effect of salt stress on the physiological and biochemical attributes of neem (Azdiarchta indica A. Juss). Plants were grown for 10 months in pots filled with soil having different salinity levels of 3, 6, 9, 12, 15, and 18 dS m−1 and compared with a control of 1.7 dS m−1. The results showed that plant growth and chlorophyll contents declined as salinity levels increased. Due to oxidative stress, the contents of H2O2 increased under higher salt levels. The mitigation of oxidative stress was achieved through the activation of antioxidant enzymes (catalase, ascorbate peroxidase, peroxidase, and superoxide dismutase). Multivariate analysis indicated that Na+ accumulation in plants was positively related to H2O2 production and enzymatic activities, and negatively related to plant biomass, chlorophyll contents, root and shoot K+ concentration, and root K+/Na+. The experimental results suggest that neem plants can be grown in moderate saline soils.

Zno nanoparticles: improving photosynthesis, shoot development, and phyllosphere microbiome composition in tea plants

BackgroundNanotechnology holds revolutionary potential in the field of agriculture, with zinc oxide nanoparticles (ZnO NPs) demonstrating advantages in promoting crop growth. Enhanced photosynthetic efficiency is closely linked to improved vigor and superior quality in tea plants, complemented by the beneficial role of phyllosphere microorganisms in maintaining plant health. However, the effects of ZnO NPs on the photosynthesis of tea plants, the sprouting of new shoots, and the community of phyllosphere microorganisms have not been fully investigated.ResultsThis study investigated the photosynthetic physiological parameters of tea plants under the influence of ZnO NPs, the content of key photosynthetic enzymes such as RubisCO, chlorophyll content, chlorophyll fluorescence parameters, transcriptomic and extensive targeted metabolomic profiles of leaves and new shoots, mineral element composition in these tissues, and the epiphytic and endophytic microbial communities within the phyllosphere. The results indicated that ZnO NPs could enhance the photosynthesis of tea plants, upregulate the expression of some genes related to photosynthesis, increase the accumulation of photosynthetic products, promote the development of new shoots, and alter the content of various mineral elements in the leaves and new shoots of tea plants. Furthermore, the application of ZnO NPs was observed to favorably influence the microbial community structure within the phyllosphere of tea plants. This shift in microbial community dynamics suggests a potential for ZnO NPs to contribute to plant health and productivity by modulating the phyllosphere microbiome.ConclusionThis study demonstrates that ZnO NPs have a positive impact on the photosynthesis of tea plants, the sprouting of new shoots, and the community of phyllosphere microorganisms, which can improve the growth condition of tea plants. These findings provide new scientific evidence for the application of ZnO NPs in sustainable agricultural development and contribute to advancing research in nanobiotechnology aimed at enhancing crop yield and quality.Graphical

Mapping of flumioxazin tolerance in a snap bean diversity panel leads to the discovery of a master genomic region controlling multiple stress resistance genes.

Effective weed management tools are crucial for maintaining the profitable production of snap bean (Phaseolus vulgaris L.). Preemergence herbicides help the crop to gain a size advantage over the weeds, but the few preemergence herbicides registered in snap bean have poor waterhemp (Amaranthus tuberculatus) control, a major pest in snap bean production. Waterhemp and other difficult-to-control weeds can be managed by flumioxazin, an herbicide that inhibits protoporphyrinogen oxidase (PPO). However, there is limited knowledge about crop tolerance to this herbicide. We aimed to quantify the degree of snap bean tolerance to flumioxazin and explore the underlying mechanisms. We investigated the genetic basis of herbicide tolerance using genome-wide association mapping approach utilizing field-collected data from a snap bean diversity panel, combined with gene expression data of cultivars with contrasting response. The response to a preemergence application of flumioxazin was measured by assessing plant population density and shoot biomass variables. Snap bean tolerance to flumioxazin is associated with a single genomic location in chromosome 02. Tolerance is influenced by several factors, including those that are indirectly affected by seed size/weight and those that directly impact the herbicide's metabolism and protect the cell from reactive oxygen species-induced damage. Transcriptional profiling and co-expression network analysis identified biological pathways likely involved in flumioxazin tolerance, including oxidoreductase processes and programmed cell death. Transcriptional regulation of genes involved in those processes is possibly orchestrated by a transcription factor located in the region identified in the GWAS analysis. Several entries belonging to the Romano class, including Bush Romano 350, Roma II, and Romano Purpiat presented high levels of tolerance in this study. The alleles identified in the diversity panel that condition snap bean tolerance to flumioxazin shed light on a novel mechanism of herbicide tolerance and can be used in crop improvement.

Photosynthate transfer from an autotrophic orchid to conspecific heterotrophic protocorms through a common mycorrhizal network.

The minute 'dust seeds' of some terrestrial orchids preferentially germinate and develop as mycoheterotrophic protocorms near conspecific adult plants. Here we test the hypothesis that mycorrhizal mycelial connections provide a direct pathway for transfer of recent photosynthate from conspecific green orchids to achlorophyllous protocorms. Mycelial networks of Ceratobasidium cornigerum connecting green Dactylorhiza fuchsii plants with developing achlorophyllous protocorms of the same species were established on oatmeal or water agar before the shoots of green plants were exposed to 14CO2. After incubation for 48 h, the pattern of distribution of fixed carbon was visualised in intact entire autotrophic/protocorm systems using digital autoradiography and quantified in protocorms by liquid scintillation counting. Both methods of analysis revealed accumulation of 14C above background levels in protocorms, confirming that autotrophic plants supply carbon to juveniles via common mycorrhizal networks. Despite some accumulation of plant-fixed carbon in the fungal mycelium grown on oatmeal agar, a greater amount of carbon was transferred to protocorms growing on water agar, indicating that the polarity of transfer may be influenced by sink strength. We suggest this transfer pathway may contribute significantly to the pattern and processes determining localised orchid establishment in nature, and that 'parental nurture' via common mycelial networks may be involved in these processes.

Response of sweet potato cultivars to Bacillus velezensis T149-19 and Bacillus safensis T052-76 used as biofertilizers

The global market of sweet potato (Ipomoea batatas (L.) Lam.) is continuously growing and, consequently, demands greater productivity from the agricultural sector. The use of biofertilizers facilitates plant growth by making essential nutrients available to crops or providing resistance against different abiotic and biotic factors. The strains Bacillus safensis T052-76 and Bacillus velezensis T149-19 have previously been inoculated in the sweet potato cultivar Ourinho, showing positive effects on plant shoot growth and inhibiting the phytopathogen Plenodomus destruens. To elucidate the effects of these strains on sweet potato growth, four different cultivars of sweet potato were selected: Capivara, IAPAR 69, Rosinha de Verdan and Roxa. The plants were grown in pots in a greenhouse and inoculated with the combined strains according to a randomized block design. A control (without the inoculation of both strains) was also used. A slight positive effect of the inoculation of the two Bacillus strains was observed on the aerial parts of some of the cultivars. An increase in the fresh weight of the sweet potatoes of the inoculated plants was obtained, varying from 2.7 to 11.4 %. The number of sweet potatoes obtained from the inoculated cultivars IAPAR 69 and Roxa increased 15.2 % and 16.7 %, respectively. The rhizosphere soil of each cultivar was further sampled for DNA extraction, and the 16S rRNA gene metabarcoding technique was used to determine how the introduction of these Bacillus strains influenced the rhizosphere bacterial community. The bacterial communities of the four different cultivars were dominated by Actinobacteria, Proteobacteria and Firmicutes. Nonmetric multidimensional scaling (NMDS) revealed that the rhizosphere bacterial communities of plants inoculated with Bacillus strains were more similar to each other than to the bacterial communities of uninoculated plants. This study highlights the contribution of these Bacillus strains to the promotion of sweet potato growth.

In vitro Propagation of Alocasia baginda 'Silver Dragon’ through Direct and Indirect Organogenesis

Direct and indirect in vitro organogenesis of Alocasia baginda 'Silver Dragon' was investigated using explants of shoot tips, leaf tissue, and petiole segments. For direct shoot induction from shoot tips, MS medium containing 1.5 mg/l BAP was shown to be the most efficient (80%), producing a maximum of 6.60 ± 0.93 shoots/explant with 3.66 ± 0.38 cm in length. Directly induced shoots were multiplied using a 2.5 mg/l BAP enriched medium, where the number and length of shoots/culture were 11.60 ± 1.12 and 9.20 ± 1.01 cm, respectively. Shoots gradually increased in number and length during the 1st three sub-culture cycles in the similar medium combination but declined after 3rd cycle. Following the 3rd sub-culture cycle, there were 14.80 ± 0.58 shoots per culture, with a shoot length of 9.90 ± 0.63 cm. The greatest frequency of callus induction was 97.67% for leaf tissue and 86.67% for petiole segments when they were cultured on the media containing 3.0 mg/l 2,4-D. Impressive results regarding indirect shoot organogenesis (90%) with maximum shoot number/unit callus (16.20 ± 1.62) and shoot length (11.06 ± 0.97 cm) were noted upon transferring the callus onto MS medium containing 3.5 mg/l BAP and 3% sucrose. Within 10-12 days, 100% rooting was observed in half-strength of gelled MS medium containing 2.0 mg/l IBA, with an average of 15.40 ± 1.17 roots/culture. After being acclimatized in a potting mixture containing garden soil, compost, coco peat, and moss in a 2:1:1:1 ratio, A. baginda 'Silver Dragon' exhibited a 100% survival rate. Established plantlets seem morphologically similar to mother plants and possess fully developed root and shoot systems, along with an adequate leaf number per plant. Plant Tissue Cult. & Biotech. 34(1): 35-47, 2024 (June)

Performance and mechanistic study of biochar and magnesium-enhanced phytoremediation in cadmium-contaminated soil by alfalfa

Recently, phytoremediation has been regarded as a green and environment friendly technique to treat metals contaminated soils. Thus, in this study, pot experiments were designed to investigate the combine effects of biochar and magnesium (MPs) to purify cadmium (Cd)-contaminated soils by Medicago sativa L. (alfalfa). The results showed that the combined use of biochar and Mg significantly increased the accumulation of Cd and promoted the transport of Cd from root to shoot in alfalfa, simultaneously. Importantly, the combined use of biochar and Mg could increase the accumulation of Cd in shoot and whole plant (shoot + root) of alfalfa up-to 59.1% and 23.1%, respectively. Moreover, the enhancement mechanism can be analyzed from several aspects. Firstly, the photosynthesis was enhanced, which was beneficial to plant growth. The product of photosynthesis provided energy for uptake and transport of Cd. Meanwhile, its transport in phloem could promote the transport of Cd. Secondly, the enhancement of antioxidant capacity of alfalfa effectively protected the membrane structure of alfalfa, which indicated that Cd could enter alfalfa from the channel on the cell membrane. Lastly, the chemical form of Cd and microbial community structure in soil were changed. Overall, these changes reduced the Cd toxicity in soil, enhanced the resistance capability of alfalfa, increased the Cd uptake by alfalfa and promoted the growth of alfalfa. Thus, the obtained results suggested that the combined use of biochar and Mg is an effective approach to enhance phytoremediation performance for purifying Cd-contaminated soils.

Effects of Kinetin and Gibberellic Acid on Growth and Ion Transport of Rice Under Cadmium Stress

An experiment was conducted to analyze the effects of kinetin and gibberellic acid on growth, and ion transport of rice (Oryza sativa var. BRRI-80) under cadmium stress. Exogenous application of both kinetin (2 µM) and gibberellic acid (1 µM) alleviated the negative effects of cadmium (Cd) on growth parameters by enhancing the length of both root and shoot, and biomass of Cd stressed rice plants grown on sand culture. Kinetin and GA3 caused decrease in Na+ accumulation while increasing K+ accumulation in both root and shoot. Accumulation of NO3- and PO43- were improved under cadmium stress by kinetin and GA3 in cadmium stressed rice plants. In addition to this, kinetin and GA3 reduced Cd accumulation in the root and shoot of cadmium stressed rice plants. Both kinetin and gibberellic acid were found effective in improving relative water contents in shoots of cadmium stressed rice plants. Bangladesh J. Bot. 53(2): 209-216, 2024 (June)

Screening of sugarcane germplasm against Sporisorium scitamineum and its effects on setts germination and tillering

Sugarcane smut is the most damaging disease that is present almost across the globe, causing mild to severe yield losses depending upon the cultivar types, pathogen races and climatic conditions. Cultivation of smut-resistant cultivars is the most feasible and economical option to mitigate its damages. Previous investigations revealed that there is a scarcity of information on early detection and effective strategies to suppress etiological agents of smut disease due to the characteristics overlapping within species complexes. In this study, 104 sugarcane cultivars were screened by artificial inoculation with homogenate of all possible pathogen races of Sporisorium scitamineum during two consecutive growing seasons. The logistic smut growth pattern and the disease intrinsic rate were recorded by disease growth curve. Variable levels of disease incidence i.e., ranging from 0 to 54.10% were observed among these sugarcane cultivars. Besides, pathogen DNA in plant shoots of all the cultivars was successfully amplified by PCR method using smut-specific primers except 26 cultivars which showed an immune reaction in the field trial. Furthermore, the plant germination and tillering of susceptible sugarcane cultivars were greatly influenced by pathogen inoculation. In susceptible cultivars, S. scitamineum caused a significant reduction in setts germination, coupled with profuse tillering, resulting in fewer millable canes. Correlation analysis demonstrated that there was a positive relationship between reduction in setts germination and increase in the number of tillers. The present study would be helpful for the evaluation of smut resistance in a wide range of sugarcane germplasm, especially from the aspects of setts germination and tillers formation, and it also screened out several excellent germplasm for potential application in sugarcane breeding.

High ratio of blue:red light reduces fruit set in sweet pepper, which is associated with low starch content and hormonal changes

In sweet pepper (Capsicum annuum L.), the fruit yield is often negatively affected by fruit abortion. Here we investigated whether fruit abortion is affected by the blue:red light ratio (B:R) and the possible underlying physiological mechanisms related to carbohydrates and hormones. Sweet pepper plants were grown at B:R of 1:10, 1:3, 1:1 or 9:1 with a total photosynthetic photon flux density of 200 µmol m−2 s−1, resulting in a phytochrome photostationary state (PSS) of 0.88, 0.88, 0.86 and 0.72, respectively. For fruit set observations, each plant was allowed to retain 12 flowers on 4 main stems. Sweet pepper plants grown at the highest B:R (9:1) showed a low fruit set (around 3 fruits per plant), whereas the other three treatments resulted in higher fruit set (6–7 fruits per plant). This response matched with the changes in PSS, suggesting the B:R effect on fruit set might be controlled by phytochrome signaling, which requires further investigation. Plant shoot biomass and leaf area were reduced at B:R of 1:1 and 9:1. The reduced fruit set was associated with a drop in starch content and sucrose synthases activity; and a low auxin, high salicylic acid and high cis-Zeatin type levels in flowers. Flowers in the low fruit set treatment also failed to reduce the abscisic acid and ethylene levels after anthesis. We concluded that both the reduced starch content and the hormonal changes in flowers play a role in triggering fruit abortion at the high B:R of 9:1.

Arsenic uptake by Agrostis capillaris, as related to its genotypic diversity in the area of historical ore mining and processing

Common bentgrass Agrostis capillaris L. is known as tolerant to toxic elements. A hypothesis was examined that its ecotypes growing in historically polluted sites show a limited arsenic uptake and have genetic features that distinguish them from commercially available cultivars. The study was conducted in Złoty Stok, a historical area of arsenic mining. Additionally, two commercial cultivars were grown in pots with arsenic-rich soils. Based on arsenic concentrations in plant roots and shoots, bioconcentration and translocation factors BCF and TF were calculated. Commercial cultivars indicated many times higher BCF shoots and TF values compared to field plants. DNA analysis of leaf blades showed a clear distinction between the plants growing in some sites and patches in the field, and also a gene overlap between the plants in the field and commercial forms. The research did not allow for identification of ecotypes with exceptionally limited arsenic uptake. Moreover, there were no significant differences between the genotypic characteristics of plants growing in polluted sites and those poorly tolerant grown from commercially available seeds. Apparently, other factors, and not genetically determined features, are responsible for A. capillaris tolerance to arsenic in Złoty Stok.

Allometric estimation models for aboveground and belowground biomass of pre-fire and post-fire vegetation in Scots pine forests

Abstract Wildfires have recently destroyed large areas of forest in Central Europe. After a fire, the post-fire vegetation succession rebuilds previously lost biomass and carbon. Nevertheless, ground vegetation and tree regeneration, as well as belowground biomass, are largely neglected in allometric biomass models. Moreover, most models are calibrated for undisturbed forests, which differ from burned forests in terms of site conditions and species composition. We adapted a model using plant cover and shoot length of herb, graminoid and bryophyte species (PhytoCalc), and a single tree model using shoot length and root collar diameter of juvenile trees to estimate aboveground biomass (AGB) of post-fire species and growth groups, and extended them to estimate belowground biomass. We sampled the most dominant species from the herb and moss layer and the tree regeneration of burned and unburned Scots pine (Pinus sylvestris L.) forests in NE Germany. We successfully calibrated post-fire vegetation models and showed that models for undisturbed forests from the literature mostly underestimate post-fire AGB. Using models from the literature for clear-cuts often improved the estimation of post-fire AGB, but still failed to estimate AGB accurately for some species. Inaccurate estimation of post-fire biomass with these other models can be explained by high irradiance and increased nutrient availability on burned sites, which affect tissue and wood density. We showed that own species- and growth group-specific allometric models calibrated to post-fire vegetation are required to correctly estimate the total (above- and belowground) biomass of post-fire vegetation needed to calculate carbon storage.

Sewage sludge compost as an alternative source of phosphorus to rye in acidic sandy soil

Today, the use of chemical fertilisers is significantly determined by their production and purchase costs, which are high. In contrast, phosphorus (P) is present in sewage sludge in a form that is easy for plants to absorb. Good quality sewage sludge compost (SSC) could contain a high quantity of P, together with other macro- and microelements and organic matter. The effect of regular SSC application on soil characteristics as well as plant parameters has been studied since 2003 in Nyíregyháza in a small plot experiment. Focusing on the P in the soil-plant system, our hypothesis was that SSC covers plants’ P demand through enhancing soil P content and its plant availability in the acidic sandy soil. The effect of the SSC was examined at the doses of 0, 9, 18, and 27 t ha-1 on rye as a test crop. Some soil chemical parameters (pH, soil organic matter - SOM, ammonium lactate (AL) extractable P2O5), and the relationship between plant development (green weight, shoot length), physiological parameters (SPAD index), plant shoot P content, and soil available P content were studied. The obtained data indicated that the SOM content, pH, and available P content of the treated plots increased as a result of the long-term applied SSC compared to the control. Measurement of the relative chlorophyll content showed a strong correlation with the available P content of the soil, but surprisingly less correlation with shoot P content was found. The results of plant biomass and soil P content proved that SSC could be used as a low-cost and good source of P for plants.

Seed treatment with Bacillus bacteria improves maize production: a narrative review

Maize (Zea mays L.) is an important crop in relation to its production and consumption. Production of maize is constrained by soil infertility and poor quality seed. Microbial technologies like seed treatment with Bacillus bacteria improves the productivity of maize on infertile soil. However, due to variations in maize growth environments and Bacillus species, this review was conducted to identify the common species of Bacillus species used for seed treatment, and provide an overview of the effect of seed treatment with Bacillus on maize growth and yield. Results show that Bacillus subtilis, Bacillus pumilus and Bacillus amyloliquefaciens were the dominant species used for seed treatment. Bacillus was used as both a biofertiliser and biopesticide. The conspicuous positive effects of Bacillus were in plant height, shoot and root length, and shoot dry matter depending on the species. In terms of grain yield, Bacillus subtilis (8502 kg ha-1), Bacillus amyloliquefaciens (6822 kg ha-1) and Bacillus safensis (5562 kg ha-1) were the bacterial species that had an overall pronounced effect. The highest increase in grain yield was in the interactive effect of Bacillus megaterium + Bacillus licheniformis (18.1%) and sole Bacillus subtilis (15.6%), while Bacillus pumilus reduced grain yield by 4.8%. This shows that the improvement of maize productivity using Bacillus bacteria requires careful selection of the species for seed treatment.

The Biochar-Enhanced Phytoextraction of Heavy-Metal-Polluted Tropical Soils by Thorny Amaranth (Amaranthus spinosus)

Abstract It was suggested that some tropical plants were able to lower toxic metal concentrations in soils. The phytoextraction potential of thorny amaranth (Amaranthus spinosus) in tropical soils treated with biochar was investigated. Soil samples high in heavy metals were taken from a 22-years old experimental field treated with industrial waste at 0-60 Mg ha-1. Soil samples were evaluated with thorny amaranth for 4 weeks. Planting was also conducted in 0-10 Mg ha-1-biochar-treated soil samples. The soil heavy metals increased with the industrial waste levels but were decreased by plant and/or biochar treatments. The plant growth as well as root and shoot dry-weights were lowered by the high soil Cu and Zn but attenuated in the presence of biochar. The accumulation of Cu and Zn in plant roots and shoots and their translocation factors were also lowered by soil Cu and Zn but were increased by biochar. The accumulation of Cu and Zn were higher in plant shoots than those in roots in good correlations with their concentrations in soils. The thorny amaranth was a good Cu and Zn phytoextractor in heavy-metal-polluted tropical soils and performed better in the presence of biochar.

Development of K-Maryblyt for Fire Blight Control in Apple and Pear Trees in Korea.

K-Maryblyt has been developed for the effective control of secondary fire blight infections on blossoms and the elimination of primary inoculum sources from cankers and newly emerged shoots early in the season for both apple and pear trees. This model facilitates the precise determination of the blossom infection timing and identification of primary inoculum sources, akin to Maryblyt, predicting flower infections and the appearance of symptoms on various plant parts, including cankers, blossoms, and shoots. Nevertheless, K-Maryblyt has undergone significant improvements: Integration of Phenology Models for both apple and pear trees, Adoption of observed or predicted hourly temperatures for Epiphytic Infection Potential (EIP) calculation, incorporation of adjusted equations resulting in reduced mean error with 10.08 degree-hours (DH) for apple and 9.28 DH for pear, introduction of a relative humidity variable for pear EIP calculation, and adaptation of modified degree-day calculation methods for expected symptoms. Since the transition to a model-based control policy in 2022, the system has disseminated 158,440 messages related to blossom control and symptom prediction to farmers and professional managers in its inaugural year. Furthermore, the system has been refined to include control messages that account for the mechanism of action of pesticides distributed to farmers in specific counties, considering flower opening conditions and weather suitability for spraying. Operating as a pivotal module within the Fire Blight Forecasting Information System (FBcastS), K-Maryblyt plays a crucial role in providing essential fire blight information to farmers, professional managers, and policymakers.

Morphological and ecological traits of the rigid-leaved water crowfoot Ranunculus subrigidus (Batrachium, Ranunculaceae) in the Yenisei River (Siberia, Russia)

The study of water crowfoots in the Yenisei River confirmed the wide distribution of recently restored rigid-leaved North American-North Asian species Ranunculus subrigidus instead of previously mentioned European R. circinatus. The species identification as R. subrigidus was confirmed by the analysis of the ITS region nucleotide sequence and morphological data. In contrast to literature data, samples of this species collected in the Yenisei did not have sessile leaves, in half of the samples, the length between first and second bifurcation was greater than the maximum of 0.2 cm previously described for the species, in some of the samples, internodes were shorter than the leaves, also different types of pubescence were observed on plant shoot parts. The conditions under which this species grows in the Yenisei River differ from the previously reported ones, primarily, in such parameters as the water hardness and the flow regime. At the city of Krasnoyarsk, seasonal development of R. subrigidus is affected by the Krasnoyarsk Hydroelectric Power Plant. The paper presents a geobotanical description of the Yenisei River plant communities dominated by and containing R. subrigidus.

Susut Bobot dan Kadar Air Tajuk Tanaman Pakcoy Akibat Pengaruh Jenis Media Tanam dan Konsentrasi Nutrisi AB Mix

Pakcoy (Brassica rapa subsp. chinensis) is a type of vegetable commonly cultivated using hydroponic systems. The weight loss and moisture content of pakcoy plant shoots can be influenced by the type of growing media and the concentration of AB Mix nutrients. Each type of growing medium has distinct physical and chemical properties. The combination of different AB Mix nutrient concentrations with various growing media types results in varying weight loss and moisture content in the plant shoots. Pakcoy plants with lower weight loss and higher shoot moisture content exhibit better storage resistance. The research method employed was a Factorial Randomized Block Design with two factors: the first factor being the type of growing media (burnt rice husk, cocopeat, rockwool), and the second factor being the concentration of AB Mix nutrients (1,000, 1,200, and 1,400 ppm). The results indicated that rockwool, combined with an AB Mix nutrient concentration of 1,000 ppm, resulted in the lowest weight loss and the highest shoot moisture content compared to other treatments.