Improved Root Development Research Articles

Biological Control of Anthracnose in Capsicum annuum Using Inoculants in Hydroponics: A Mechanistic Review

The Colletotrichum species that causes anthracnose poses a significant threat to the growth of Capsicum annuum, or ringer pepper, resulting in significant yield losses. Conventional produced control systems can give rise to ecological and economic difficulties, necessitating the need for alternative, workable solutions. This study explores the feasibility and parts of natural inoculants in controlling anthracnose ailment in Capsicum annuum filled in chipped away at hydroponics structures. As organic inoculants, we utilized a wide variety of useful microorganisms, such as Trichoderma harzianum, Bacillus subtilis, and mycorrhizal parasites. At various stages of the Capsicum annuum plant's development, these inoculants were incorporated into the supplement arrangements for tank farming. Anthracnose was observed and compared to untreated controls and synthetically treated plants in terms of its severity. Plants treated with natural inoculants show a significant reduction in sickness rate and severity, as shown by our findings. In fact, Trichoderma harzianum outperformed Bacillus subtilis and mycorrhizal parasites in terms of biocontrol productivity. Through a series of biochemical and sub-atomic tests, the fundamental instruments were examined. Natural inoculants, according to important discoveries, increase the plant's intrinsic safe reaction by causing fundamental obstruction. This is affirmed by the upregulation of pathogenesis-related (PR) characteristics and extended activity of shield impetuses like peroxidase (Unit), polyphenol oxidase (PPO), and phenylalanine antacid lyase (Amigo). In addition, the inoculants improved root development and supplement absorption, enhancing overall establish health and resistance to microorganisms. This study demonstrates that natural inoculants can be a reasonable and effective method for controlling anthracnose in Capsicum annuum grown in improved tank farms. In accordance with the goals of a potential agribusiness, incorporating these biocontrol specialists into aquafarming frameworks can increase crop productivity and reduce the use of compound pesticides.

The Mutual Effects of Pinching and Promalin® on Root Architecture in Two Boxwood Species

Boxwoods are constantly pinched to shape and form hedges, and Promalin® application is used to boost their shoot yield. Having good root development is crucial for the healthy development of plants; however, the effects of such applications on plant root development have generally been ignored in previous studies. Hence, this study evaluated the effects of applications on the root growth of two boxwood species (Buxus sempervirens L. and Buxus balearica Lam.) during the summer dormancy period. Pinching and Promalin® (0, 1 000, 2 000, and 4 000 ppm) were applied to one-year-old seedlings at three different times. Results showed that pinching had a negative effect on root development in both species and both years. Root development was lower in pinched plants than in control plants, which were not pinched. Promalin® at 2 000 ppm was found to be the most effective application on the root parameter. Root development was also higher in the second year than in the first year, depending on temperature, humidity, and the duration of sunshine. It is recommended to apply 2 000 ppm of Promalin® and not prune B. sempervirens. However, if pinching is to be performed, application of Promalin® will be useful to improve root development. For B. balearica, applying pinching and Promalin® together will help increase root development depending on the application time (in periods when the temperature is high).

Effect of Zinc, Iron and Biofertilizer on Physical Property of Soil under Chickpea Cultivation

The research was conducted at the Central Research Farm of the Department of Soil Science and Agricultural Chemistry, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology, and Sciences (SHUATS) in Prayagraj during the Rabi season of 2022-23. The experimental design employed was a Randomized Block Design (RBD), with application of Zn, Iron along with standard fertilizer dose (RDF). This design aimed to systematically assess the combined effects of these factors on the specified parameters, insightful information about the potential advantages of using micronutrients in cultivation of chickpea, particularly the “Sadabahar” variety. In the study, Bulk density Mg m-3); Particle density (Mg m-3); Pore Space (%); Water holding capacity (%) was calculated by methods suggested by Muthuvel et al. [1]. The details of nano mixed micronutrients treatment given are T1 (Absolute control); T2 (RDF 100 % + Zinc @ 0 kg ha-1 + Iron @ 2.5 kg ha-1); T3 (RDF 100 % + Zinc @ 0 kg ha-1 + Iron @ 5 kg ha-1); T4 (RDF 100 % + Zinc @ 0 kg ha-1 + Iron @ 7.5 kg ha-1); T5 (RDF 100 % + Zinc @ 6.67 kg ha-1 + Iron @ 0 kg ha-1); T6 (RDF 100 % + Zinc @ 6.67 kg ha-1 + Iron @ 2.5 kg ha-1); T7 (RDF 100 % + Zinc @ 6.67 kg ha-1 + Iron @ 5 kg ha-1); T8 (RDF 100 % + Zinc @ 6.67 kg ha-1 + Iron @ 7.5 kg ha-1); T9 (RDF 100 % + Zinc @ 13.34 kg ha-1 + Iron @ 0 kg ha-1); T10 (RDF 100 % + Zinc @ 13.34 kg ha-1 + Iron @ 2.5 kg ha-1); T11 (RDF 100 % + Zinc @ 13.34 kg ha-1 + Iron @ 5 kg ha-1); T12 (RDF 100 % + Zinc @ 13.34 kg ha-1 + Iron @ 7.5 kg ha-1); T13 (RDF 100 % + Zinc @ 0 kg ha-1 + Iron @ 2.5 kg ha-1+ Rhizobium 20 g kg-1); T14 (RDF 100 % + Zinc @ 6.67 kg ha-1 + Iron @ 5 kg ha-1+ Rhizobium 20 g kg-1) and T15 (RDF 100 % + Zinc @ 13.34 kg ha-1 + Iron @ 7.5 kg ha-1+ Rhizobium 20 g kg-1).Zinc and Iron improve root development and microbial activity, enhancing soil structure and porosity. Rhizobium further promotes root nodulation and organic matter decomposition, increasing soil aggregation and moisture retention. This balanced nutrient and microbial application optimizes soil physical properties, leading to superior water holding capacity and pore space.

Genome-Wide and Transcriptome-Wide Association Analysis Identifies qRS-6D and Its Candidate Genes Regulating Root Development of Wheat Seedlings

Wheat (Triticum aestivum L.) is one of the most important cereal crops worldwide, and its production is challenged by global climate change and a shortage of resources. The root system plays a vital role in uptaking water and nutrients and sensing soil environmental signals, and it has great potential to improve the final yield and stress tolerance of wheat. In order to further explore the genes regulating root development, this study focused on qRS-6D, located on chromosome 6D and spanning from 462,701,391 to 465,068,943, which was significantly associated with the total root length, root volume, root surface, and root fresh weight in our previous GWAS analysis. Firstly, its genetic effects were validated using an F6 segregating population by comparing the root-related traits of homologous lines harboring the alternative haplotypes of this QTL. Then, the number of causal genes of this QTL was narrowed down to four with a transcriptome-wide association study. Additionally, qRS-6D has been demonstrated to have genetic effects on several yield- (kernel length, kernel width, and thousand-kernel weight) and plant structure-related traits (plant height, peduncle length, total tiller number, productive tiller number, flag leaf length, and flag leaf angle). Relatively, the frequency of the favorable haplotype increased with the wheat breeding practice. This study provides a reliable genetic locus to improve root development and structure and evaluate its application potential in wheat breeding improvement.

Assessment of Broccoli (Brassica oleracea) Cultivation under Two Irrigation Systems in Central Iraq

A field experiment was conducted in the Abbasiya area of Najaf Governorate, located in the Middle Euphrates region during the winter season of 2022-2023. The primary focus of the study was to evaluate the performance of two irrigation systems, nano-irrigation, and subsurface drip irrigation, on broccoli plants grown in clay soil. The experimental design followed a Complete Randomized Block Design (CRBD). Nano-irrigation demonstrated several advantages over subsurface drip irrigation. It exhibited a reduction inater con-sumption and lower energy requirements for water pumping opera-tions. Notably, the root length of broccoli plants was significantly greater under the nano-irrigation system, with an increase of 18.2 cm compared to the drip irrigation system. The use of nano-irrigation resulted in better water use efficiency and energy efficien-cy, leading to improved root development in the broccoli plants. The study results indicated that nano-irrigation offers benefits in terms of water conservation and plant growth promotion, ultimately leading to increased overall productivity. This makes nano-irrigation an appealing option for improving water use efficiency in agriculture, particularly in regions that face water scarcity. Moreo-ver, there was no significant difference in yield between the nano-irrigation and subsurface drip irrigation systems.

Primjena biopreparata kao alternativa kemijskim fungicidima u zaštiti pšenice

Two-year experiments were conducted on two different types of soil during 2021 and 2022, respectively. The influence of microbiological preparations Mycor-FAZOS, Vitality-FAZOS, and Super Green-FAZOS on the yield and quality parameters of wheat the Mura variety (Agrigenetics) was investigated. The experiment was set up according to the split-block scheme in four repetitions on two types of soil, in 12 different variants on each of them. The area of the basic plot amounted 40 m2, while the calculated plot amounted to 24 m2. The elements of the research were as follows: A (soil type) – A1 – humogly, A2 – eutric brown soil; B (seed treatment) – B1 – control, B2 – seed treated with biopreparation; C (protection against diseases) – C1 – control, C2 – treatment with chemical fungicides, C3 – treatment with biopreparations. The research parameters were grain yield (t/ ha), protein content in grain (%), mass of 1,000 grains (g), hectoliter mass (kg), and plant height (cm). The highest average grain yield was obtained by the B2C3 variant, where the yield was 17.42% higher than the yield obtained by the B1C2 variant. In terms of protein content, the difference between the mentioned varieties was 4.24%, in the weight of 1,000 grains 6.36%, in hectoliter weight 6,35%, and 6,87% in plant height. We can conclude that a seed treatment with the Mycor-FAZOS biopreparation has improved root development, so the plants were healthier, taller, and more robust, but it has improved a uniform growth too, so the plants were darker than the untreated seed variants (scoring an increased photosynthesis index). The protection performed with the Vitality-FAZOS and Super Green-FAZOS biopreparations (i.e., the microorganisms that have an extremely fungicidal effect but also synthesize growth hormones) ensured that the wheat remained healthy while achieving a higher seed yield and obtaining a better quality of research parameters.

Root-associated symbiotic fungi enhance waterlogging tolerance of peach seedlings by increasing flavonoids and activities and gene expression of antioxidant enzymes

Root-associated symbiotic fungi can enhance the host plant’s ability to tolerate adverse environmental conditions, but it’s unclear whether and how they enhance waterlogged peach plants. This study aimed to investigate the effects of Funneliformis mosseae (Fm), an arbuscular mycorrhizal fungus, and Serendipita indica (Si), an endophytic fungus, on plant growth, root development, reactive oxygen species (ROS) levels, total flavonoids, ROS scavenging activity of flavonoids, and activities and gene expression of antioxidant enzymes in roots of waterlogged peach seedlings. Although waterlogging treatment had little effect on root development, Fm and Si, particularly Fm, improved root development variables to varying degrees. Waterlogging significantly promoted superoxide anion radicals (O2•−) and hydrogen peroxide (H2O2) levels, whereas Fm and Si distinctly reduced O2•− and H2O2 levels under waterlogging. Waterlogging triggered an increase in total flavonoids in fungi-inoculated seedlings, and the two fungi also significantly increased total flavonoid concentrations and the scavenging activity of total flavonoids to hydroxyl radical, O2•−, and 2,2-diphenyl-1-picrylhydrazyl radical. In addition, root fungal colonization rate was negatively and significantly correlated with O2•− and H2O2, but positively with total flavonoids. Under waterlogging conditions, Fm significantly raised root superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) activities, and Si likewise elevated root SOD, CAT, GPX, and peroxidase (POD) activities, compared with uninoculated treatment. Although the expression of various antioxidant enzyme genes in roots remained mostly unchanged or were inhibited by the waterlogging, Fm up-regulated the expression of PpSOD3 and PpSOD7, whereas Si up-regulated the expression of PpSOD3, PpCAT1, PpGPX6, PpGPX8, and PpPOD1. In conclusion, low oxidative bursts in Fm- and Si-inoculated peach plants exposed to waterlogging were associated with an increase in total flavonoids as well as activities and gene expression of antioxidant enzymes.Graphical

Regeneration of Transgenic Ficus lyrata via Indirect Somatic Embryogenesis and Isolation of Variants for Development of New Cultivars

Ficus lyrata is a popular ornamental foliage plant with unique violin- or guitar-shaped green leaves. In our previous study, a grapevine gene VvMybA1 was introduced into F. lyrata via Agrobacterium-mediated transformation, which resulted in the availability of purple-leaved plants. Since VvMybA1 is a transcription factor, the regeneration of transgenic purple-leaved plants might potentially produce variants with multicolored leaves. The objective of this study was to establish a method for regenerating purple-leaved F. lyrata and determine if variants with different coloration or variegation could be isolated from regenerated populations. Leaf explants derived from a completely purple-leaved transgenic plant were cultured on Murashige and Skoog (MS) basal medium supplemented with different concentrations of 6-benzyladenine (BA) and α-naphthalene acetic acid (NAA). Callogenesis occurred in leaf explants, and a subculture of callus-borne explants on the same medium resulted in callus proliferation and the occurrence of somatic embryos. Somatic embryos were more effectively induced from callus pieces cultured on MS medium supplemented with 8.88 μM of BA and 0.27 μM of NAA. More than 30 embryos were induced per callus piece, and the embryos matured and converted to plantlets. MS medium supplemented with 4.92 μM of indolyl-3-butanoic acid (IBA) greatly improved root development. Plantlets were transplanted into soilless substrate and grown in a shaded greenhouse for morphological evaluation. Nine variants with different degrees of coloration and variegation were isolated from the regenerated populations. Our results suggest that the regeneration of transgenic plants that harbor a transcription factor, such as VvMybA1, could be an additional way of isolating novel variants for the development of new cultivars of ornamental plants.

Phenotypic Plasticity Strategy of Aeluropus lagopoides Grass in Response to Heterogenous Saline Habitats.

Understanding the response variation of morphological parameters and biomass allocation of plants in heterogeneous saline environments is helpful in evaluating the internal correlation between plant phenotypic plasticity mechanism and biomass allocation. The plasticity of plants alters the interaction among individuals and their environment and consequently affects the population dynamics and aspects of community and ecosystem functioning. The current study aimed to assess the plasticity of Aeluropus lagopoides traits with variation in saline habitats. Understanding the habitat stress tolerance strategy of A. lagopoides is of great significance since it is one of the highly palatable forage grass in the summer period. Five different saline flat regions (coastal and inland) within Saudi Arabia were targeted, and the soil, as well as the morphological and physiological traits of A. lagopoides, were assessed. Comprehensive correlation analyses were performed to correlate the traits with soil, region, or among each other. The soil analysis revealed significant variation among the five studied regions for all measured parameters, as well as among the soil layers showing the highest values in the upper layer and decreased with the depth. Significant differences were determined for all tested parameters of the morphological and reproductive traits as well as for the biomass allocation of A. lagopoides, except for the leaf thickness. In the highly saline region, Qaseem, A. lagopoides showed stunted aerial growth, high root/shoot ratio, improved root development, and high biomass allocation. In contrast, the populations growing in the low saline region (Jizan) showed the opposite trend. Under the more stressful condition, like in Qaseem and Salwa, A. lagopoides produce low spikes in biomass and seeds per plant, compared to the lowest saline habitats, such as Jouf. There was no significant difference in physiological parameters except stomatal conductance (gs), which is highest in the Jizan region. In conclusion, the population of A. lagopoides is tolerant of harsh environments through phenotypic plasticity. This could be a candidate species to rehabilitate the saline habitats, considering saline agriculture and saline soil remediation.

Poly-γ-glutamic acid promoted maize root development by affecting auxin signaling pathway and the abundance and diversity of rhizosphere microbial community

BackgroundThe root systems of higher plants play an important role in plant growth and development. In our present study, it was found that poly-γ-glutamic acid (γ-PGA), an environmentally friendly biomacromolecule, significantly improved root development in maize.ResultsAfter treatment with γ-PGA for 7 days, the fresh weight of maize roots was significantly increased and the differences between γ-PGA treated group and control group were mainly caused by the number (higher by 71.87% compared to the control) and length of lateral roots. RNAseq and RT-PCR analyses showed that γ-PGA treatment upregulated the expression of genes related to the synthesis of auxins and auxin signal in maize roots. In addition, γ-PGA promoted the accumulation of plant growth-promoting bacteria, such as Azospirillum, Azohydromonas, Ramlibacter, and Sphingobium (Proteobacteria), Streptomyces (Actinobacteria), Parasegetibacter (Bacteroidetes), and Gemmatimonas (Gemmatimonadetes) in rhizosphere soil and the secretion of auxins. The results of this study deepened our understanding of the effects and mechanism of γ-PGA on maize root development, and as well as highlighted the possibility of using γ-PGA to improve crop growth and soil environment.Conclusionsγ-PGA promotes early growth and development of maize roots by inducing the secretion and accumulation of auxin in roots and in rhizosphere soil, and increasing the abundance of plant growth promoting bacteria.

Soil water dynamics and drought stress response of Vitis vinifera L. in steep slope vineyard systems

The accessibility to water is a crucial factor for grapevine performance in vineyards. A sufficient supply of water favors vegetative growth, yield formation and fruit ripening. Under a changing climate, especially steep slope wine-growing regions may face severe problems in soil moisture conservation due to oftentimes lower soil water holding capacity and a larger radiation intake on the, usually South-facing, hill slopes, which causes a higher evaporative demand compared to vineyards in the flat. The impact of two steep slope vineyard management systems on water retention and drought stress response of grapevines was assessed. Soil water dynamics in the inter-vine space of steep slope sites planted downslope (control, C) and of terraces (T) were compared. Terraced vineyards were capable to retain up to a 40 % higher relative percentage of winter precipitation, compared to the control. Vines in the early years of their adaption phase planted on terraced vineyards generally displayed a higher drought stress response, showed lower vigour, lower yield and lower sugar yield. The older the terrace system, the better the performance compared to C became. This suggests a high competition of young grapevines to the cover cropped embankments of terraced vineyards. Therefore, means to improve root development and to reduce water and nutrient competition in the early years of terrace construction are crucial for successful grapevine adaptation, for the increase of resilience to abiotic stress factors and finally for the maintenance of valuable steep slope vineyard sites for grapevine cultivation.

The insecticidal potential of Bacillus velezensis CE 100 against Dasineura jujubifolia Jiao & Bu (Diptera: Cecidomyiidae) larvae infestation and its role in the enhancement of yield and fruit quality of jujube (Zizyphus jujuba Miller var. inermis Rehder)

Jujube (Zizyphus jujuba Miller var. inermis Rehder) is highly susceptible to jujube gall midge (Dasineura jujubifolia Jiao & Bu) larvae infestation, which causes rolled leaf damage, leaf galls, discoloration, and a decline in fruit yield. In this study, we demonstrate the larvicidal potential of cuticle-degrading chitinase and protease produced by Bacillus velezensis CE 100 against jujube gall midge larvae and the plant growth-promoting effect on jujube fruit yield. The laboratory insecticidal assay involving bacterial broth culture and crude enzymes of B. velezensis CE 100 revealed that both treatments caused gall midge larvae mortality rates of up to 85.5% and 96.7%, respectively. Both treatments caused severe degradation of the larvae cuticle, such as deformation of the exoskeleton and loss of sensilla. Foliar application of the bacterial broth culture in the jujube field reduced the rate of rolled leaf damage by 3.8-fold more than that in the control group. In addition, B. velezensis CE 100 produced indole-3-acetic acid (IAA) up to 3.5 mg/mL, which improved root development, and exhibited the potential for nitrogen-fixation and phosphate solubilization to improve nutrient availability and uptake. Compared to the control, applying the bacterial treatment in the jujube field increased the leaf chlorophyll content by 1.3-fold and improved the fruit yield by 2.4-fold. For the first time, we demonstrate the dual larvicidal and bio-stimulation potential of entomopathogenic B. velezensis CE 100 in managing gall midge larvae and the improvement of jujube fruit production, respectively.

Evaluation of colonization and mutualistic endophytic symbiosis of Escherichia coli with tomato and Bermuda grass seedlings.

Escherichia coli is generally considered a bacterium associated with animal microbiomes. However, we present evidence that E. coli may also mutualistically colonize roots of plant species, even to the extent that it may become endophytic in plants. In this study we used GFP tagged E. coli to observe its colonization and effects on tomato (Solanum lycopersicum) and Bermuda grass (Cynodon dactylon) seedling development and growth. Inoculation with the bacterium significantly improved root development of both seedlings tested. Treatment also increased the photosynthetic pigments in Bermuda grass seedlings. However, effects on shoot length in both seedlings were not significant. This bacterium was found to produce indole acetic acid (IAA) up to 8.68 ± 0.43 µg ml−1 in the broth medium amended with tryptophan. Effects on seedling root growth could, in part, be explained by IAA production. Bacteria successfully colonized the root surfaces and interiors of both seedlings. Tagged bacteria expressing the GFP were observed in the vascular tissues of Bermuda grass seedling roots. Seedlings with bacteria showed greater survival and were healthier than seedlings without bacteria, indicating that E. coli set up a successful mutualistic symbiosis with seedlings. E. coli is not commonly considered to be a plant endophyte but is more generally considered to be a crop contaminant. In this study we show that E. coli may also be an endophyte in plant tissues.

Nitrate-dependent regulation of miR444-OsMADS27 signalling cascade controls root development in rice.

Nitrate is an important nutrient and a key signalling molecule for plant development. A number of transcription factors involved in the response to nitrate and their regulatory mechanisms have been identified. However, little is known about the transcription factors involved in nitrate sensing and their regulatory mechanisms among crop plants. In this study, we identified functions of a nitrate-responsive miR444:MADS-box transcription factor OsMADS27 module and its downstream targets mediating rice root growth and stress responses. Transgenic rice plants expressing miR444 target mimic improved rice root growth. Although miR444 has the potential to target multiple genes, we identified OsMADS27 as the major miR444 target that regulates the expression of nitrate transporters, as well as several key genes including expansins, and those associated with auxin signalling, to promote root growth. In agreement with this, overexpression of miRNA-resistant OsMADS27 improved root development and tolerance to abiotic stresses, while its silencing suppressed root growth. OsMADS27 mediated robust stress tolerance in plants through its ability to bind to the promoters of specific stress regulators, as observed in ChIP-seq analysis. Our results provide evidence of a nitrate-dependent miR444-OsMADS27 signalling cascade involved in the regulation of rice root growth, as well as its surprising role in stress responses.

Poly-\u03b3-glutamic acid enhanced the drought resistance of maize by improving photosynthesis and affecting the rhizosphere microbial community

BackgroundCompared with other abiotic stresses, drought stress causes serious crop yield reductions. Poly-γ-glutamic acid (γ-PGA), as an environmentally friendly biomacromolecule, plays an important role in plant growth and regulation.ResultsIn this project, the effect of exogenous application of γ-PGA on drought tolerance of maize (Zea mays. L) and its mechanism were studied. Drought dramatically inhibited the growth and development of maize, but the exogenous application of γ-PGA significantly increased the dry weight of maize, the contents of ABA, soluble sugar, proline, and chlorophyll, and the photosynthetic rate under severe drought stress. RNA-seq data showed that γ-PGA may enhance drought resistance in maize by affecting the expression of ABA biosynthesis, signal transduction, and photosynthesis-related genes and other stress-responsive genes, which was also confirmed by RT–PCR and promoter motif analysis. In addition, diversity and structure analysis of the rhizosphere soil bacterial community demonstrated that γ-PGA enriched plant growth promoting bacteria such as Actinobacteria, Chloroflexi, Firmicutes, Alphaproteobacteria and Deltaproteobacteria. Moreover, γ-PGA significantly improved root development, urease activity and the ABA contents of maize rhizospheric soil under drought stress. This study emphasized the possibility of using γ-PGA to improve crop drought resistance and the soil environment under drought conditions and revealed its preliminary mechanism.ConclusionsExogenous application of poly-γ-glutamic acid could significantly enhance the drought resistance of maize by improving photosynthesis, and root development and affecting the rhizosphere microbial community.

Detection and analysis of novel and known plant volatile apocarotenoids.

As the climate becomes increasingly unpredictable due to global warming, plants will encounter a greater challenge to adapt to their hostile environment (e.g., drought, heat, pollution). Volatile apocarotenoids (VAs) are an integral part of this necessary adaptation. VAs are involved in diverse plant life processes such as defense against biotic or abiotic stresses and regulate various aspects of plant development. The discovery of new VAs will help enhance abiotic and biotic stress tolerance, optimize biomass and crop yield, improve root development to better search for nutrients and promote symbiotic associations. This chapter describes an optimized method, HeadSpace Solid-Phase MicroExtraction (HS-SPME) coupled to Gas Chromatography-Mass Spectrometry (GC/MS), for the sensitive, reproducible, accurate, and high-throughput detection and quantification of novel and known VAs. Further optimization of this method can be performed by (1) adapting optimal growth conditions for your plants, (2) identifying the correct SPME fiber coating chemistry for the VAs of interest, (3) adapting optimal sample HS-SPME extraction temperature and time, and the desorption time in the GC inlet, (4) identifying the correct GC column and applying the optimal GC/MS parameters for good chromatographic baseline separation of the VAs, mass spectral matching and retention index (RI) validation, and (5) performing suitable quantification and statistical analyses. With this optimized and validated analytical technique, we detected and quantified 28 VAs; 20 of these were identified for the first time in Arabidopsis.

Clonal propagation of Eucalyptus urophylla under effect of Cyperus rotundus extract and indole-3-acetic acid

Cyperus rotondus tubers possess substances with allelopathic qualities. Some of these substances can act as synergists of plant hormones and be used for root induction in cuttings. This study aimed to shed light on the development and rooting of Eucalyptus urophylla cuttings treated with C. rotondus (nutgrass) tuber extract and IAA (indole-3-acetic acid). The experiments were conducted using a completely randomized design (0; 25; 50; 75 and 100% nutgrass extract and 0; 50; 250; 500; 750 and 1000 mg L-1 of IAA), with four repetitions per treatment and four cuttings per plot. Plantlet height, stem width and root length were measured. The greatest width and height values were recorded for the control (0% nutgrass extract and 0 mg L-1 of IAA), indicating that these substances did not contribute to the development of these variables. However, treatments of nutgrass extract up to 50% were associated with greater root length. C. rotundus extract concentrations of 53% can be used to improve root development in E. urophylla cuttings, and contribute to the production of higher quality plantlets.

Biological Control of Leaf Blight Disease Caused by Pestalotiopsis maculans and Growth Promotion of Quercus acutissima Carruth Container Seedlings Using Bacillus velezensis CE 100.

Leaf blight disease caused by Pestalotiopsis maculans lead to deleterious losses in the quality of forest container seedlings. The use of plant growth-promoting bacteria provides a promising strategy to simultaneously control diseases and enhance forest seedling production. This study investigated the biocontrol of leaf blight disease and growth promotion potential of Bacillus velezensis CE 100 in Quercus acutissima Carruth seedlings. B. velezensis CE 100 produced cell wall degrading enzymes, such as chitinase, β-l,3-glucanase, and protease, which caused cell wall lysis and hyphae deformation of P. maculans, leading to mycelial growth inhibition by 54.94%. Inoculation of B. velezensis CE 100 suppressed P. maculans infection and increased seedling survival rate by 1.6-fold and 1.3-fold compared to chemical fertilizer and control, respectively. In addition, B. velezensis CE 100 produced indole-3-acetic acid, which improved root development and nutrient uptake compared to chemical fertilizer and control. Especially, inoculation with B. velezensis CE 100 increased the total nitrogen content of Q. acutissima seedlings, improved the chlorophyll index in the leaves, and increased seedling biomass by 1.3-fold and 2.2-fold compared to chemical fertilizer and control, respectively. Thus, B. velezensis CE 100 could be applied in the eco-friendly production of high-quality forest seedlings.

Evaluating Strategies to Improve Water Availability and Lateral Root Growth of Plants Grown in the Rice-Growing Lowlands of the Lower Mekong Basin

Overcoming constraints that poorly structured lowland rice-growing soils of the Lower Mekong River Basin present for growing non-rice crops during the dry season would have a significant positive impact on the livelihood of smallholder farmers. This study investigated whether the use of soil organic amendments, bed architecture (conventional, flat and narrow) and water application methods (sprinkler, furrow and over-bed irrigation) could improve plant water availability in typical rice-growing soils of Cambodia and Laos by either improving the movement of water into beds or the growth of the root system. Five experiments were conducted over two dry seasons on peanut and maize grown in a bed/furrow system. Organic amendments assessed were rice straw, cow/goat manure, biochar, manure plus rice straw and biochar plus manure. Results showed that compared with conventional bed/furrow design, narrowing beds increased soil moisture availability for peanut, whilst higher grain yield and water productivity were achieved with sprinkler irrigation than furrow irrigation. Placing a layer of sub-surface straw within beds did not consistently enhance soil moisture or improve root development. The study showed that maize grown on soil amended with biochar plus cow manure under a furrow irrigation system and on rice straw under sprinkler irrigation produced yields above the average yield that models have simulated for maize grown on these soils. These findings present opportunities to enhance maize production on lowland soils across Cambodia and Laos. The contrary was observed for peanut production, which indicates that factors other than water might be detrimentally affecting crop yields.

Efficacy of variable timing of Pythium oligandrum applications on red clover grown under field conditions

Biological control of root diseases of red clover (Trifolium pratense L.) could be effective but optimization of its application is needed to balance treatment efficacy with costs. Our objectives were to evaluate the effects of different Pythium oligandrum application treatments on root morphological development, plant root disease score and forage yield in a three-year field experiment. Red clover cv. Start was managed under a three-cut management in two harvest years with four treatments: (i) untreated control, (ii) multiple applications of P. oligandrum (intensive treatment), (iii) a single spring application, and (iv) a single autumn application. Plants from each plot were evaluated for root morphology traits and scored for root diseases in each autumn. Forage yield, compressed stand height and stem density were evaluated in each cut. All P. oligandrum treatments increased root dry matter and root potential index, but only the intensive treatment significantly improved forage yield (by 31%) in comparison with the control. This effect could be largely associated with plant growth stimulation resulting in increased stand height before cutting. Among single application treatments, autumn timing significantly reduced plant root disease score and showed higher stand height than spring application. One application later in the season seems likely to be effective for forage growth stimulation, but probably at least two applications are needed to produce maximum effect. Despite some drought stress during the first two years, this field study confirmed an effect of P. oligandrum on improved root development and a positive yield response, thus showing a high potential of this biological control treatment under field conditions.