Increased Shoot Length Research Articles

Lead-Tolerant Bacillus Strains Promote Growth and Antioxidant Activities of Spinach (Spinacia oleracea) Treated with Sewage Water

Irrigation with sewage-contaminated water poses a serious threat to food security, particularly in developing countries. Heavy metal tolerant bacteria are sustainable alternatives for the removal of wastewater contaminants. In the present study, four lead (Pb)-tolerant strains viz. Bacillus megaterium (N8), Bacillus safensis (N11), Bacillus sp. (N18), and Bacillus megaterium (N29) were inoculated in spinach and grown in sewage water treated earthen pots separately and in combination with canal water. Results showed that Pb-tolerant strains significantly improved plant growth and antioxidant activities in spinach and reduces metal concentration in roots and leaves of spinach plants irrigated with treated wastewater. Strain Bacillus sp. (N18) followed by B. safensis (N11) caused the maximum increase in shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight, and leaf area compared to the uninoculated control of sewage water treated plants. These strains also improved antioxidant enzymatic activity including catalase, guaiacol peroxidase dismutase, superoxide dismutase, and peroxidases activities compared to the uninoculated control under sewage water conditions. Strain Bacillus sp. (N18) followed by B. safensis (N11) showed the highest reduction in nickel, cadmium, chromium, and Pb contents in roots and leaves of spinach compared to the uninoculated control plants treated with the sewage water. Such potential Pb-tolerant Bacillus strains could be recommended for the growth promotion of spinach after extensive evaluation under field conditions contaminated with wastewater.

Mining the Genome of Bacillus velezensis VB7 (CP047587) for MAMP Genes and Non-Ribosomal Peptide Synthetase Gene Clusters Conferring Antiviral and Antifungal Activity.

Chemical pesticides have an immense role in curbing the infection of plant viruses and soil-borne pathogens of high valued crops. However, the usage of chemical pesticides also contributes to the development of resistance among pathogens. Hence, attempts were made in this study to identify a suitable bacterial antagonist for managing viral and fungal pathogens infecting crop plants. Based on our earlier investigations, we identified Bacillus amyloliquefaciens VB7 as a potential antagonist for managing Sclerotinia sclerotiorum infecting carnation, tobacco streak virus infecting cotton and groundnut bud necrosis infecting tomato. Considering the multifaceted action of B. amyloliquefaciens VB7, attempts were made for whole-genome sequencing to assess the antiviral activity against tomato spotted wilt virus infecting chrysanthemum and antifungal action against Fusarium oxysporum f. sp. cubense (Foc). Genome annotation of the isolate B. amyloliquefaciens VB7 was confirmed as B. velezensis VB7 with accession number CP047587. Genome analysis revealed the presence of 9,231,928 reads with an average read length of 149 bp. Assembled genome had 1 contig, with a total length of 3,021,183 bp and an average G+C content of 46.79%. The protein-coding sequences (CDS) in the genome was 3090, transfer RNA (tRNA) genes were 85 with 29 ribosomal RNA (rRNA) genes and 21 repeat regions. The genome of B. velezensis VB7 had 506 hypothetical proteins and 2584 proteins with functional assignments. VB7 genome had the presence of flagellin protein FlaA with 987 nucleotides and translation elongation factor TU (Ef-Tu) with 1191 nucleotides. The identified ORFs were 3911 with 47.22% GC content. Non ribosomal pepide synthetase cluster (NRPS) gene clusters in the genome of VB7, coded for the anti-microbial peptides surfactin, butirosin A/butirosin B, fengycin, difficidin, bacillibactin, bacilysin, and mersacidin the Ripp lanthipeptide. Antiviral action of VB7 was confirmed by suppression of local lesion formation of TSWV in the local lesion host cowpea (Co-7). Moreover, combined application of B. velezensis VB7 with phyto-antiviral principles M. Jalapa and H. cupanioides increased shoot length, shoot diameter, number of flower buds per plant, flower diameter, and fresh weight of chrysanthemum. Further, screening for antifungal action of VB7 expressed antifungal action against Foc in vitro by producing VOC/NVOC compounds, including hexadecanoic acid, linoelaidic acid, octadecanoic acid, clindamycin, formic acid, succinamide, furanone, 4H-pyran, nonanol and oleic acid, contributing to the total suppression of Foc apart from the presence of NRPS gene clusters. Thus, our study confirmed the scope for exploring B. velezensis VB7 on a commercial scale to manage tomato spotted wilt virus, groundnut bud necrosis virus, tobacco streak virus, S. sclerotiorum, and Foc causing panama wilt of banana.

Efficacy of biosynthesized silver nanoparticles from Larrea tridentata against Clavibacter michiganensis

AbstractGreen synthesis of silver nanoparticles (AgNPs) from plant extracts is simple, fast and environmentally friendly. In this study, an aqueous extract of fresh leaves from Larrea tridentata was evaluated as a possible source of reducing and stabilizing agents to obtain AgNPs. The synthesized nanoparticles were characterized by X‐ray diffraction, revealing the metallic nature of Ag nanoparticles. Transmission electron microscopy (TEM) studies showed spherical nanoparticles with sizes below 28 nm. Furthermore, its bactericidal effect against Clavibacter michiganensis subsp. michiganensis (Cmm) infection in tomato plants was determined. Forty‐two days after inoculation with Cmm, the disease incidence in plants with AgNPs did not exceed 20% at 50 mg L−1, and it also reduced disease severity by 36%, which correlates with the inhibition of bacterial growth in the tissue (up to 95%). The physiological analysis also showed the growth‐promoting effect of AgNPs in diseased plants, increasing shoot length (22.1%) and root dry weight (25.73%) compared with the pathogenic control. Congruently, AgNPs increased enzyme activity for CAT, APX, POD, and total phenol and flavonoid concentrations in the leaves. Slower symptom development and reduction in bacterial growth in AgNPs‐treated plants could be due to this bactericidal activity and the induction of an antioxidative protection system.

Efficacy of chitosan on growth and yield traits of mulberry, Morus sp

Chitosan is biopolymer of glucosamine residues, nontoxic, biodegradable and friendly to environment and it also helps to enhance crop production due to their bioactivities. The present experiment was conducted to assess the efficacy of chitosan on the growth and yield related attributes of mulberry, Morus sp. with various concentrations such as 25, 50, 75, 100 and 125 ppm. The chitosan was sprayed thrice on 15, 30 and 45 days after pruning (DAP) on the foliage of three different mulberry varieties namely V1, MR2 and G4. The result revealed that, irrespective of varieties, the foliar application of chitosan at 75 ppm significantly increased the biometric as well as yield related attributes of mulberry over other concentrations. Among the three varieties, V1 showed more response to chitosan application than G4 and MR2. At 75 ppm, chitosan showed marked effect on VI variety of mulberry and significantly increased shoot length (170.67 cm), number of shoots per plant (9.03), number of leaves per shoot (29.48), leaf area (220.26 cm2) and leaf area index (2.72) were observed when compared with control. The application of chitosan at 75 ppm significantly enhanced the yield traits namely weight of 100 leaves (448.10 g), leaf shoot ratio (1.45) and leaf yield (14.01 MT/ha/harvest) in V1.

Testing Virulence of Different Species of Insect Associated Fungi against Yellow Mealworm (Coleoptera: Tenebrionidae) and Their Potential Growth Stimulation to Maize.

This paper investigates 71 isolates of two genera of entomopathogens, Metarhizium and Beauveria, and a biostimulative genus Trichoderma, for their ability to infect yellow mealworms (Tenebrio molitor) and to stimulate maize (Zea mays) growth. Fungal origin, host, and isolation methods were taken into account in virulence analysis as well. Isolates Metarhizium brunneum (1154) and Beauveria bassiana (2121) showed the highest mortality (100%) against T. molitor. High virulence seems to be associated with fungi isolated from wild adult mycosed insects, meadow habitats, and Lepidopteran hosts, but due to uneven sample distribution, we cannot draw firm conclusions. Trichoderma atroviride (2882) and Trichoderma gamsii (2883) increased shoot length, three Metarhizium robertsii isolates (2691, 2693, and 2688) increased root length and two M. robertsii isolates (2146 and 2794) increased plant dry weight. Considering both criteria, the isolate M. robertsii (2693) was the best as it caused the death of 73% T. molitor larvae and also significantly increased maize root length by 24.4%. The results warrant further studies with this isolate in a tri-trophic system.

Combining Genetic Gain and Diversity in Plant Breeding: Heritability of Root Selection in Wheat Populations

To increase the resilience of agroecological farming systems against weeds, pests, and pathogens, evolutionary breeding of diversified crop populations is highly promising. A fundamental challenge in population breeding is to combine effective selection and breeding progress while maintaining intraspecific diversity. A hydroponic system was tested for its suitability to non-destructively select root traits on a population level in order to achieve genetic gain and maintain diversity. Forty wheat progenies were selected for long seminal root length (SRL) and 40 for short SRL from a wheat composite cross population grown in a hydroponic system. Wheat progenies were multiplied, and a subset evaluated again in a hydroponic system. Preliminary tests in soil and competition experiments with a model weed were performed. The hydroponic selection for long SRL led to an increase of SRL by 1.6 cm (11.6%) in a single generation. Heritability for selection of SRL was 0.59. Selecting for short SRL had no effect. The preliminary soil-based test confirmed increased shoot length but not increased SRL. Preliminary competition experiments point to slightly improved competitive response of wheat progenies but no improved competitive effect on mustard. These results indicate a heritable selection effect for SRL on a population level, combining genetic gain and intraspecific diversity.

The effect of silicon supply on photosynthesis and carbohydrate metabolism in two wheat (Triticum aestivum L.) cultivars contrasting in response to phosphorus nutrition

Phosphorus (P) deficiency affects agricultural systems by limiting crop quality and yield. Studies have suggested that silicon (Si) improves P uptake in plants grown under P deficiency. However, the effects of Si on photosynthesis and carbohydrate metabolism under P stress remain unclear. We performed a hydroponic study using two wheat cultivars with contrasting sensitivity to P deficiency (Púrpura, sensitive; Fritz, semi-tolerant) that were exposed to P (0, 0.01, or 0.1 mM) and Si (0 or 2 mM), and we evaluated the photosynthetic performance and metabolic alterations. In plants from the sensitive cultivar undergoing P deficiency, Si application increased sucrose levels, starch breakdown and length of shoots, and also improved plant dry weight. In Fritz (the semi-tolerant cultivar), Si exposure reduced P concentration, and increased shoot length and P use efficiency (PUE) under P shortage. Interestingly, Si application altered cell wall composition, which was associated with higher mesophyll conductance and net CO2 assimilation in Fritz plants grown under P stress. Together, our results indicate that under P deficiency, Si nutrition positively affects photosynthesis and carbohydrate levels in a genotype-dependent manner. Furthermore, these results suggest that Si plays an important role in maintaining high photosynthetic rates in wheat plants undergoing P deficiency.

Potassium mobilization and plant growth promotion by soil bacteria isolated from different agroclimatic zones of Odisha, India

Potassium is essential for plant metabolism; improves immunity to stress and increase crop productivity. Soil contains insoluble form of potassium, which is unavailable for plant absorption. Potash mobilizing bacteria (KMB) solubilise complex potassium and make it available to plant. KMB with plant growth promoting (PGP) traits could enhance growth and crop productivity. Here we attempt to screen KMBs with PGP traits from different agroclimatic zones of Odisha and study dynamics of potassium in soil. Isolation of KMB and determination of PGP traits was performed with standard protocols. Pot culture experiment was aimed to study their effect on sunflower crop. Available soil potassium was quantified using inductively coupled plasma-optical emission spectrometry (ICP-OES). Thirty KMBs were isolated from different agro-climatic zones of Odisha, out of which 6 isolates exhibited maximum PGP traits. Moreover, after adding inoculums the available soil potassium decreased over 0 to 30 days as compared to control, with increase in shoot length. T7 (consortium) reported maximum (144 %) increase in shoot length. Available soil potassium content decreased with increase in time. A maximum decrease was reported in T7 (26.31 %), suggesting potassium accumulation by plant.

Potassium mobilization and plant growth promotion by soil bacteria isolated from different agroclimatic zones of Odisha, India

<p class="042abstractstekst"><span lang="EN-US">Potassium is essential for plant metabolism; improves immunity to stress and increase crop productivity. Soil contains insoluble form of potassium, which is unavailable for plant absorption. Potash mobilizing bacteria (KMB) solubilise complex potassium and make it available to plant. KMB with plant growth promoting (PGP) traits could enhance growth and crop productivity. Here we attempt to screen KMBs with PGP traits from different agroclimatic zones of Odisha and study dynamics of potassium in soil. Isolation of KMB and determination of PGP traits was performed with standard protocols. Pot culture experiment was aimed to study their effect on sunflower crop. Available soil potassium was quantified using inductively coupled plasma-optical emission spectrometry (ICP-OES). Thirty KMBs were isolated from different agro-climatic zones of Odisha, out of which 6 isolates exhibited maximum PGP traits. Moreover, after adding inoculums the available soil potassium decreased over 0 to 30 days as compared to control, with increase in shoot length. T7 (consortium) reported maximum (144 %) increase in shoot length. Available soil potassium content decreased with increase in time. A maximum decrease was reported in T7 (26.31 %), suggesting potassium accumulation by plant.</span></p>

Endophytic Fungi Assures Tropical Forage Grass Growth by Water Stress Tolerances.

Forage plants is the base of beef and dairy cattle production. While water stress limits agricultural production worldwide, endophytic fungi can play a beneficial role for plants, such as tolerance to biotic and abiotic stresses. The objective of this work was to evaluate the effect of inoculation of the endophytic fungi Paraconiothyrium estuarinum (CML 3695, CML 3696, CML 3699) and Paraconiothyrium cyclothyrioides (CML 3697, CML 3698) on agronomic characteristics of two forage species, Brachiaria brizantha (A. Rich) Stapf. cv. Marandu and Megathyrsus maximus Jacq. cv. BRS Mombaça, under different available water capacities. The treatments simulated a long drought period (LDH) equivalent to 10% of the available water capacity (AWC) and simulated 7 (7 DH) and 14days of drought (14 DH) without water supply. The grasses were evaluated for length and dry weight of shoots and roots. All treatments reached humidity below the permanent wilting point (PWP) and the highest variation in soil moisture was observed at 14 DH, for both grass species. The endophytic fungi promoted an average 15% increase in shoot length (SL) for B. brizantha and an increase of 34% for SL, 266% for Dry Shoot Mass (SDM), and 340% for Dry Root Mass (RDM) for M. maximus treated with P. estuarinum (CML 3699) at 7 DH. Paraconiothyrium estuarinum (CML 3699) guaranteed the highest tolerance to water deficit and sustainable growth performance to both tested grasses.

MICROCLONAL PROPAGATION OF SPIRAEA JAPONICA FOR LANDSCAPING

Japanese spiraea (Spiraea japonica) is an ornamental shrub widely used in landscaping. The method of clonal micropropagation of Spiraea japonica was optimized to obtain a large number of plants from several shoots. The optimal concentrations of hormones have been established to increase multiplication and root formation. QL medium with 0,5 mg/l benzyl aminopurine (BAP) in combination with 1,0 mg/l gibberelic acid (GA); 0,01 and 1,0 mg/l indolyl butyric acid (IBA); 1,0 mg/l of naphthyl acetic acid (NAA) were tested for multiplication. For root induction, naphthyl acetic acid (NAA) was used in five doses at half the concentration of QL and MS medium. The highest multiplication of shoots (14,02±1,39) and the highest increase in shoot length (6,39) was obtained on QL medium supplemented with 0,5 mg/l BAP; 1,0 mg/l GA and IBA 0,01 mg/l. The highest rooting (100%), the maximum number of roots (6,20±0,63), the length of the longest root (4,60±0,02) was observed on ½ QL medium containing 0,1 mg/l NAA. In conclusion, for Spiraea japonica, an efficient high speed and rooting protocol is described that can be used in mass propagation.

Vegetative growth, yield, and fruit quality of guava (Psidium guajava L.) cv. Maamoura as affected by some biostimulants

The present study was performed during two successive seasons 2019 and 2020 to investigate the effect of the soil application of fulvic acid (FA), seaweed extract (SE), and their different combinations on vegetative growth, yield, and fruit quality of six-years-old guava (Psidium guajava L.) cv. ‘Maamoura’. The trees were planted 4 × 4 m2 apart in clay soil under a flood irrigation system. They were treated three times starting from mid-March with one-month intervals with the following treatments: Control (water only), 3 and 4 g/L FA, 3 and 4 g/L SE, and their different combinations; 3 g/L FA + 3 g/L SE, 3 g/L FA + 4 g/L SE, 4 g/L FA + 3 g/L SE, and 4 g/L FA + 4 g/L SE. The results clearly showed that the application of FA or SE solely or in combinations increased shoot length and diameter, as well as leaf chlorophyll compared with the control. The treatments also increased fruit set percentage, fruit yield, and fruit physical and chemical characteristics such as fruit weight, size, TSS%, total reduced and non-reduced sugars, as well as leaf mineral content, while they decreased the fruit acidity compared with the control in the two seasons.

Nanotechnology advances for sustainable agriculture: current knowledge and prospects in plant growth modulation and nutrition.

Advances in nanotechnology make it an important tool for improving agricultural production. Strong evidence supports the role of nanomaterials as nutrients or nanocarriers for the controlled release of fertilizers to improve plant growth. Scientific research shows that nanotechnology applied in plant sciences is smart technology. Excessive application of mineral fertilizers has produced a harmful impact on the ecosystem. Furthermore, the projected increase in the human population by 2050 has led to the search for alternatives to ensure food security. Nanotechnology is a promising strategy to enhance crop productivity while minimizing fertilizer inputs. Nanofertilizers can contribute to the slow and sustainable release of nutrients to improve the efficiency of nutrient use in plants. Nanomaterial properties (i.e., size, morphology and charge) and plant physiology are crucial factors that influence the impact on plant growth. An important body of scientific research highlights the role of carbon nanomaterials, metal nanoparticles and metal oxide nanoparticles to improve plant development through the modulation of physiological and metabolic processes. Modulating nutrient concentrations, photosynthesis processes and antioxidant enzyme activities have led to increases in shoot length, root development, photosynthetic pigments and fruit yield. In parallel, nanocarriers (nanoclays, nanoparticles of hydroxyapatite, mesoporous silica and chitosan) have been shown to be an important tool for the controlled and sustainable release of conventional fertilizers to improve plant nutrition; however, the technical advances in nanofertilizers need to be accompanied by modernization of the regulations and legal frameworks to allow wider commercialization of these elements. Nanofertilizers are a promising strategy to improve plant development and nutrition, but their application in sustainable agriculture remains a great challenge. The present review summarizes the current advance of research into nanofertilizers, and their future prospects.

Seed coating with plant nutrients enhances germination and seedling growth, and promotes total dehydrogenase activity during seed germination in tomato (Lycopersicon esculentum)

A lack of nutrients in the seed can be supplemented by seed coating and has the potential to improve germination and seedling growth. In this research, we studied the physiological effect of coating tomato seeds with plant nutrient formulations (PNF) on the dehydrogenase activity during germination and nutrient content of the seedlings. Two tomato seed lots were used, differing in physiological quality: the low quality seed lot had 76% germination and the medium quality seed lot had 87% germination. Seeds were coated with a complete PNF containing N, P, K, Ca, Mg, Fe, B, Mn, Cu and Zn. The PNF was applied at three concentrations, i.e., 1-fold (PF1), 4-fold (PF4) and 16-fold (PF16), and applied with 3% PVP-K90 + 1% PEG 6000 as a polymer. Coating seeds with PNF improved seed germination for both low- and medium-quality seeds. Accelerated ageing tests revealed that PF1 increased germination by 12 and 27% in low- and medium-quality seeds, respectively. All concentrations of PNF increased TDH activity after 48 hours of seed imbibition. Moreover, PF16 decreased root length but increased shoot length. All PNF treatments resulted in higher nutrient content in the seedlings.

The Effect of Trichoderma and Onion Extract on the Success of Grafting in Mango Seedlings

This study aims to determine the effect of Trichoderma asperellum Tc-Clkt-01 and shallot extract and their interaction on the success of grafting mango seedlings. The factorial experiments in this study were arranged in a completely randomized design (CRD). The first factor is Trichoderma consisting of without and with Trichoderma. The second factor was the concentration of shallot extract above: 0, 15, and 30 ml.l−1. With three replications, 18 experimental units were obtained. The variables observed were: shoot appearance time (days) and shoot growth length (mm) one to four weeks after grafting. All data from the observations were analyzed using ANOVA at the 5% level; the average of each treatment was compared with controls (without Trichoderma and without red onion extract). Trichoderma sp. isolate Tc-Clkt-01 accelerated the emergence time of shoots by 26.87% and increased shoot length growth by 41.76-43.71% compared to the control. Onion extract at a concentration of 15 ml.L−1 accelerated the emergence of shoots by 10.45% and increased shoot length increase by 20.59% compared to the control. The combination of Trichoderma and shallot extract at a concentration of 30 ml.l−1 accelerated the emergence of shoots by 23.17% and increased shoot length by 32.94% compared to the control.

Response of ‘Bignay’ [Antidesma bunius (Linn.) Spreng] to cutting origins, IBA and BioGroe treatments

The response of ‘Bignay’ [Antidesma bunius (Linn.) Spreng] to the cutting origins and different levels of plant bio-regulators consist of Indole-3-butyric Acid (IBA) and Biogroe treatments were investigated by means of 3 x 9 factorial experiment in Completely Randomized Design (CRD) using an automated mist propagator. Two hundred sixteen (216) healthy seedlings containing 9 nodes each were used in the study. Results revealed that cutting origins significantly increased shoot length but have no influence on the root number, percent rooting and percent survival. The cuttings originated from the bottom portion of the stem recorded the longest mean in terms of shoot length (12.48 mm) including the highest percent survival and percent rooting (82.41%). Highest mean number of roots were observed on the top cuttings (1.93). Indole-3-butyric Acid (IBA) and Biogroe treatments on cuttings have no effects on the different parameters evaluated. The interaction effect between cutting origins and IBA/Biogroe treatments significantly increased the percent rooting and percent survival except the shoot length and root number of Bignay cuttings. Overall, the findings inferred that A. bunius can be propagated by any cutting origin derived from the main stem of the donor plants tested. Cuttings can effectively be induced to produce roots and survive and can be economically mass propagated even without the application of different concentrations of IBA and BioGroe.

Plant growth promoting actinobacteria from rhizosphere soils of black pepper in Wayanad

Actinobacteria isolated from the rhizosphere soils of black pepper comprising both flood affected and non-flood affected areas of Wayanad district. Among different soil samples analysed, Puttad (Ptd) recorded significantly superior actinobacterial population on starch casein aga, Kenknight & Munaier’s agar and actinomycetes isolation agar. Actinobacterial colonies could not be detected in any of the flooded soil samples on any medium, even at a dilution of 10-1, except in Meppadi soil, which recorded a low population of 0.3x101cfu g-1 soil. Starch casein agar is best media to isolate actinobacteria from soil samples compared to other two media. The cultural, morphological and biochemical characterization of thirty-five isolates was carried out. Further the isolates were evaluated for their plant growth promoting traits such as IAA production, nitrogen fixation, P, K and Zn solubilization. The isolates Ptd-A and Amb-C were found to be significantly superior to all other isolates, with IAA production of 15.9 g ml-1 and 15.38 g ml-1 respectively. The four isolates viz. Ptd-A, Ptd-E, Ptd-B and Ptr-A recorded significantly superior nitrogen fixation and the phosphate solubilized was significantly higher in Ptd-E, Ptd-D, Ptr-E, Ptd-A and Ptr-A, as compared to other isolates. All isolates were negative to K and Zn solubilization. Based on in vitro evaluations, three isolates were shortlisted (Ptd-A, Ptd-E and Ptr-A) and subjected to in vivo evaluation for growth promotion in black pepper (variety Panniyur 1). Rooted plants of black pepper were raised in sterile potting mixture. Bioinoculants applied at the time of planting and 45 days after planting. The PGPR Mix-1 and Organic Package of Practices Recommendations (2017) were used for comparison with the microbial inoculants along with control. In the in-planta experiment, biometric characters were recorded at monthly intervals, up to five months. The actinobacterial treatment, T1: Ptd-E, T2: Ptd-A and T3: Ptr-A showed significant increase in shoot length, number of leaves and internode length throughout the growth period from planting to five MAP. Significantly higher root growth was observed in treatment T2: Ptd-A, with significantly higher root volume, fresh and root weight. The potential actinobacteria were identified Ptd-A and Ptr-A as Streptomyces sp. and Ptd-A as Actinobacteria bacterium using 16S r RNA gene sequencing.

Modulation of salinity impact on early seedling stage via nano-priming application of zinc oxide on rapeseed (Brassica napus L.)

Salinity stress negatively affects the plant's developmental stages through micronutrient imbalance. As an essential micronutrient, ZnO can substitute Na+ absorption under saline conditions. Therefore, nanoparticles as technological innovation, improve the plant growth efficiency under biotic and abiotic stresses. Nano-priming has become widely applicable in agricultural research during the last decade. The current study was conducted to highlight the impact of ZnONPs priming on seedling biological processes under 150 mM of NaCl using two rapeseed cultivars during the early seedling stage. All concentrations of ZnONPs increased the germination parameters i.e., FG%, GR, VI (I), and VI (II). Meanwhile, the high concentration (ZnO 100%) showed the highest increase in shoot length (9.60% and 25.63%), root length (41.64% and 48.17%) for Yang You 9 and Zhong Shuang 11 over hydro-priming, respectively, as well as biomass. Additionally, nano-priming improved the proline, soluble sugar, and soluble protein contents as a result of osmotic protection modulation. Moreover, nano-priming alleviated ROS and biosynthesis pigments through the reduction of accumulated (H2O2) and (O2−), and chlorophyll degradation, respectively, also enhanced antioxidant adjustment via improving the plant defense system. Nano-priming substituted the Na+ by Zn2+, K+, and Ca2+, and compensated the deficit of micronutrients, thus reduced the Na+ toxicity in the cell cytosol. To track the effects of priming during seed imbibition, it noticed that ZnO 100% and ZnO 100%+S increased the Linoleic and Linolenic acids among the studied fatty acids composition by 12.02%, 7.59%, 13.27%, and 10.38% (Yang You 9), 7.42%, 2.77%, 2.93%, and 1.49% (Zhong Shuang 11) over the hydro-priming, respectively. Moreover, the gene expression patterns of BnCAM and BnPER reflected the enhancement of germination levels, notably under the influence of ZnO 100% priming, which increased the level of BnCAM by 70.42% and 111.9% in Yang You 9 and Zhong Shuang 11, respectively. Consequently, ZnO nano-priming enhanced the seedling development through the biosynthesis of pigments, osmotic protection, reduction of ROS accumulation, adjustment of antioxidant enzymes, and improvement of the nutrient absorption, thus enhancing the economic yield under saline conditions.

Evaluation of Effective Microorganisms (EM®) against Root-Knot Nematode (Meloidogyne javanica) in Tomato

Introduction: Plant-parasitic nematodes cause significant yield losses in a wide range of crops (Nicol et al. 2011). Root-knot nematodes (Meloidogyne spp.) are the most important plant-parasitic nematodes, because they widely distributed all around the world and have wide host range (Chapuis-Lardy et al. 2015). Chemical nematicide is one of the primary means of control for plant-parasitic nematodes. Due to negative impact of synthetic nematicides, it will be necessary to develop other management strategies for plant-parasitic nematodes which are safe for the environment and humans (Huang et al., 2016). Latest interest in organic farming lead to substitution for conventional nematicides by low-risk compounds such as natural products derived from plants (Oka et al. 2006). Also, biological control is an interesting option to control these nematodes (Mosahaneh et al. 2020). Effective microorganisms (EM®) consist of a mixture of live cultures of microorganisms such as photosynthetic bacteria, which they are reported to reduce the incidence of pathogenic microorganisms (Condor et al., 2007). Materials and Methods: In the present study, the aerial parts of the marigold (Tagetes erecta) were collected from Shiraz, Iran. Marigold leaves dried in shade and finely grinded using an electric grinder and a stock solution (10% w/v) was prepared. Seeds of tomato (cv. Early-Urbana) were sown in plastic pots containing 1500 g of a sterilized mixture of farm soil (sandy loam soil) and cow manure. The pots were kept under greenhouse conditions with 16:8 h light to dark photoperiod and 27 ± 4 °C. Four-leaf stage seedlings were soil-drenched (50 ml per plant) with EM® or a mixture of equal amount of EM®+ marigold leaf extract at the rate of 5, 10, 15 and 20% and simultaneously inoculated with a suspension of M. javanica (6000 eggs per pot). The experiment was carried out in a completely randomized design with five replications. Sixty days after nematode inoculation, plants were harvested and the vegetative indices including shoots length, shoot fresh and dry weight and root fresh weight and the nematode population indices including the number of eggs as described by Hussey and Barker (1973), number of galls and egg masses per root system as described by Taylor and Sasser (1978) and the number of second stage juveniles (J2s) in the pot were recorded. Finally, the reproduction factor calculated as described by Sasser and Taylor (1978). Data were subjected to one-way analysis of variance (ANOVA) for plant growth parameters and two-way ANOVA for nematode population indices using SAS 9.1 program (Statistical Analysis System Institute Inc., USA). Treatment means were compared using least significance differences (LSD) at p<0.01.Results and Discussion: Results showed that soil drenching of EM® and EM®+ marigold leaf extract increased the plant growth parameters on inoculated and non-inoculated plants as compared to control. The treatment with EM®+ marigold leaf extract at the rate of 20% was the most effective treatment and increased shoot length, shoot fresh weight and shoot dry weight of non-inoculated plants by 33, 39 and 11% respectively, as compared to non-inoculted control plants. In the case of inoculated plants, shoot length, shoot fresh weight, shoot dry weight and root fresh weight of treated plats with EM®+ marigold leaf extract at the rate of 20% were 34, 31, 15 and 11% higher than inoculated control plants. The number of eggs and egg masses per root system and the reproduction factor were significantly reduced in treated plants with EM®+ marigold leaf extract at the rate of 15 and 20%. EM®+ marigold leaf extract at the rate of 20% reduced the number of eggs, galls, egg masses per root system and the reproduction factor by 28, 40, 37 and 27% respectively, as compared to control. The lowest numbers of eggmasses were observed in the root system of tomato plants treated with EM®+ marigold leaf extract at the rate of 20%. It had significant difference than other treatments, except EM® at the rate of 20%. These data for the first time in Iran, suggest that EM® might have utility in controlling root-knot nematodes. A mixture of EM® and marigold leaf extract was more effective than alone application of EM® for control of M. javanica. Findings from this study, suggest that a mixture of equal amount of EM® and marigold leaf extract at the rate of 20% reduced M. javanica reproduction rates in tomato plants grown in greenhouse.

The Effect Of Giving Various Kinds And Immersion Of ZPT On The Growth Of Tin Cuttings (Ficus carica L.).

This study aims to determine the effect of giving various kinds and duration of ZPT immersion on the growth of tin plant cuttings (Ficus carica L.). This research was carried out in October - December 2020, at the Terdana Village, Pondok Kubang District, Central Bengkulu Regency. This study used a Factorial Completely Randomized Design (CRD) with two factors, the first factor was giving various PGR (Z) which consisted of Control, Rootone-F, Shallot Solution, Bamboo Shoots Solution, while the second factor was the duration of immersion of PGR which consisted of of 12 hours, 18 hours, 24 hours, each treatment was repeated 3 times. The results of the study were analyzed using Variety Analysis and if it had a significant effect, further tests were carried out using Duncan's Multiple Range Test (DMRT) level 5%. The results showed that there was an interaction between the administration of Rootone-F and the immersion time of ZPT 12 to 24 hours on the percentage of live cuttings of Tin (Ficus carica L.) plant. 12 WAP, root length, percentage of live cuttings and leaf area on cuttings growth of Tin (Ficus carica L.) PGR immersion time treatment was not able to increase shoot length 12 WAP, number of shoots 12 WAP, number of leaves 12 WAP, root length, percentage of cuttings Life and leaf area on the growth of cuttings of Tin (Ficus carica L.) It is recommended to increase the concentration of natural PGR so that it can be used as a substitute for Rootone-F.