Dry Weight Of Seedlings Research Articles

Growth Response of Platycladus Orientalis (l.) Franco Seedling to Foliar Application of Ga3 And Chelated Nano N.p.k Fertilizer

As part of the ongoing efforts to optimize the application of Nanotechnology in forestry nurseries, the current study came to determine the efficiency of Nano N.P.K-fertilizer and Gibberellic acid in enhancing the growth of the slow-growing species Platycladus orientalis (L.) Franco seedlings. One–year old of P. orientalis seedlings grown in a  greenhouse were been subjected from September 2021 to the  end of Jun 2022 to two and four foliar sprays, four different levels of Nano-fertilizer N.P.K (20:20:20) (control, 1 g. L-1, 2 g. L-1 and 3 g. L-1) and three GA3 levels (control, 300 mg. L-1 and 600 mg.L-1). The experiment was designed according to the RCBD with 1008 seedlings arranged in three replicates with 14 seedlings in each of the 72 experimental units. Duncan's multiple-range test was used for comparing all means. for each factor individually revealed that increasing Nano N.P.K up to 3 g. L-1 and GA3 up to 300 and 600 mg.L-1 increased significantly the values of most of the studied parameters (seedling high, diameter, number of branches, total seedling dry weight, leaf chlorophyll, Protein (%), and percentage of leaf nutrients content as Nitrogen, Phosphorus and Potassium. Increasing the sprays number from two to four increased the values of the studied parameters except for the Diameter, Nitrogen, Chlorophyll, and Protein parameters. The interaction effect between four sprays,  Nano N.P.K 3 g. L-1 and GA3 at rate 600 mg.L-1  significantly increased the values of all studied parameters except Potassium (%), where two sprays,  of 3 g. L-1 Nano N.P.K with 600mg.L-1  of GA3 recorded the highest values. In general, the study revealed the positive role of the foliar application of Nano N.P.K fertilizer separately and in combination with GA3 in accelerating most growth parameters of the slow-growing P. orientalis ornamental shrub

Effects of Multi-Walled Carbon Nanotubes and Nano-Silica on Root Development, Leaf Photosynthesis, Active Oxygen and Nitrogen Metabolism in Maize.

Carbon nanotubes (MWCNTs) and nano-silica (nano-SiO2) are widely used in the field of life science because of their special physical and chemical properties. In this study, the effects of different concentrations of MWCNTs (0 mg·L-1, 200 mg·L-1, 400 mg·L-1, 800 mg·L-1 and 1200 mg·L-1) and nano-SiO2 (0 mg·L-1, 150 mg·L-1, 800 mg·L-1, 1500 mg·L-1 and 2500 mg·L-1) on maize seedling growth and relative mechanisms were explored. The main results are as follows: MWCNTs and nano-SiO2 can promote the growth of maize seedlings, and promote plant height, root length, the dry and fresh weight of seedlings, root-shoot ratio and so on. The ability to accumulate dry matter increased, the relative water content of leaves increased, the electrical conductivity of leaves decreased, the stability of cell membranes improved and the water metabolism ability of maize seedlings increased. The treatment of MWCNTs with 800 mg·L-1 and nano-SiO2 with 1500 mg·L-1 had the best effect on seedling growth. MWCNTs and nano-SiO2 can promote the development of root morphology, increase root length, root surface area, average diameter, root volume and total root tip number and improve root activity, so as to improve the absorption capacity of roots to water and nutrition. After MWCNT and nano-SiO2 treatment, compared with the control, the contents of O2·- and H2O2 decreased, and the damage of reactive oxygen free radicals to cells decreased. MWCNTs and nano-SiO2 can promote the clearance of reactive oxygen species and maintain the complete structure of cells, so as to slow down plant aging. The promoting effect of MWCNTs treated with 800 mg·L-1 and nano-SiO2 treated with 1500 mg·L-1 had the best effect. After treatment with MWCNTs and nano-SiO2, the activities of key photosynthesis enzymes PEPC, Rubisco, NADP-ME, NADP-MDH and PPDK of maize seedlings increased, which promoted the opening of stomata, improved the fixation efficiency of CO2, improved the photosynthetic process of maize plants and promoted plant growth. The promoting effect was the best when the concentration of MWCNTs was 800 mg·L-1 and the concentration of nano-SiO2 was 1500 mg·L-1. MWCNTs and nano-SiO2 can increase the activities of the enzymes GS, GOGAT, GAD and GDH related to nitrogen metabolism in maize leaves and roots, and can increase the content of pyruvate, so as to promote the synthesis of carbohydrates and the utilization of nitrogen and promote plant growth.

Artificial humic acid promotes growth of maize seedling under alkali conditions

Salinization of cropland is one of the major abiotic stresses affecting global agricultural sustainability, posing a serious threat to agricultural productivity and food security. Application of artificial humic acid (A-HA) as plant biostimulants has been increasingly attracting farmers and researchers. However, its regulation of seed germination and growth under alkali stress has rarely received attention. The purpose of this study was to investigate the response of maize (Zea mays L.) seed germination and seedling growth after the addition of A-HA. The effects of A-HA on seed germination, seedling growth, chlorophyll contents and osmoregulation substance under black and saline soil conditions were studied by soaking maize in solutions with and without various concentrations of A-HA. Artificial humic acid treatments significantly increased the seed germination index and dry weight of seedlings. The effects of maize root in absence and presence of A-HA under alkali stress were also evaluated using transcriptome sequencing. GO and KEGG analyzes were performed on differentially expressed genes, and the reliability of transcriptome data was verified by qPCR analysis. Results showed that A-HA significantly activated phenylpropanoid biosynthesis, oxidative phosphorylation pathways and plant hormone signal transduction. Moreover, Transcription factor analysis revealed that A-HA induced the expression of several transcription factors under alkali stress which had a regulatory effect on the alleviation of alkali damage in the root system. Overall, our results suggested that soaking seeds with A-HA can alleviate alkali accumulation and toxicity in maize, constituting a simple and effective strategy to mitigate saline toxicity. These results will provide new insights for the application of A-HA in management to reduce alkali-caused crop loss.

Immediate effects of atrazine application on soil organic carbon and selected macronutrients and amelioration by sawdust biochar pretreatment

Abstract Increasing use of herbicides has contributed immensely to current soil and water degradation in the tropics. Published works on effects of herbicides on soil organic carbon (SOC) – a major indicator for soil health and macronutrients and their enhancement by biochar are scarce for soils in Africa despite heavy herbicide applications every cropping season. This incubation trial evaluated immediate effects of atrazine application on SOC and selected soil macronutrients. The potential of sawdust (SD) biochar to mitigate associated SOC and macronutrients depletion was also assessed. A total of 950 g soil was placed in each leaching column (20 cm length and 7 cm diameter). The experiment was a factorial combination of four SD biochar types: SD + poultry manure (PM) pyrolyzed at 350 °C, SD-PM at 350 °C, SD + PM at 450 °C and SD-PM at 450 °C applied at two rates of 5 and 10 t/ha equivalent to 2.38 and 4.76 g/950 g soil, respectively. Atrazine alone and absolute control (AC) that received neither biochar nor atrazine were included for comparison. The treatments were replicated thrice in completely randomized design. Appropriate biochar was applied within 5 cm soil depth, moistened to field capacity, and left to equilibrate for 2 weeks. Thereafter, 20 mL atrazine solution was applied at 2.5 kg a.i/ha (achieved through 6.75 g atrazine powder/l of distilled water). Basal NPK 15:15:15 fertilizer mixed with urea at 0.1 and 0.03 g/900 g soil, respectively, was applied to mimic farmers’ practice on atrazine treated fields. Maize seeds were thereafter sown in the treated soils and nurtured for 2 weeks. Data taken on soil pH, SOC, exchangeable bases, available phosphorus, and dry biomass weight (DBW) of maize seedlings at the expiration of the trial were subjected to two-way analysis of variance using Genstat Statistical Package with means separated using LSD at 5% probability level. There were significant reductions in soil pH (5.8%), SOC (31%), and Ex. Ca (27%) in atrazine alone soil compared to AC. Contrarily, similar atrazine treated soil pretreated with SD biochar had increased soil pH, SOC, exchangeable Ca, available P, and DBW by 5.6 (in SD + PM@450 °C), 73.6 (SD-PM@450 °C), 84 (SD + PM@450 °C), 2,338.4 (SD + PM@450 °C), and 154.8% (SD + PM@350 °C), respectively, dominantly at 10 t/ha compared to AC. Sole atrazine treated soil was, however, higher in soil available P (23.8 mg/kg) and TDBW (0.56 g) against 5.42 mg/kg and 0.42 g from AC, respectively. Biochar pH and organic carbon were the most influential biochar properties contributing significantly to SOC sequestration and macronutrient enrichment in the atrazine treated soil. Pretreatment of soils with sawdust biochar prior to atrazine application is, therefore, recommended for mitigating associated organic carbon and macronutrient depletion in the soils for enhanced maize production.

Fungicidal activity nanoemulsions of citronella oils (Cymbopogon nardus L.) against rice seed-borne pathogenic fungi

Rice seed-borne pathogenic fungi are one of the causes of decreased rice productivity. Nanoemulsion of citronella oil is an alternative control for seed-borne pathogenic fungi carried by rice seeds and is effective and environmentally friendly. The research aimed to determine the effective concentration of nanoemulsions of citronella oil in controlling rice seed-borne pathogenic fungi. The study was conducted in two stages: 1. In the laboratory using a completely randomized design (CRD) with seven treatments and four replications. 2. Greenhouse uses the same design and treatment in stage one. The treatments used were control (soaking using sterile distilled water), nanoemulsion of citronella oil concentrations of 0.40%, 0.45%, 0.50%, 0.55%, 0.60%, and synthetic fungicide with propineb active site (70 WP) at a 2 g/l. The data obtained were analyzed using variance with the advanced test of Least Significance Different (LSD) at the 5% level. The parameters observed were the percentage of rice seeds that were attacked by fungi, identification of seed-borne pathogenic fungi, percentage of rice seeds that were attacked by each fungus, percentage of seedlings that appeared in the field, percentage of seedlings attacked by fungi, percentage of dead seedlings, seedling height, fresh and dry weight of seedlings. The result showed that nanoemulsion with a concentration of 0.50% was the most effective in controlling rice seed-borne pathogenic fungi, with the effectiveness of seeds being attacked suppressed by fungus, seedlings appearing in the field, seedlings being attacked by fungus, dead seedlings, seedling height, fresh and dry weight seeds were 75.00%, 60.00%, 100.00%, 100.00%, 60.83%, 141.55%, 366,67% respectively.

Genome-Wide Association Study for Root Morphology and Phosphorus Acquisition Efficiency in Diverse Maize Panels.

Maximizing soil exploration through modifications of the root system is a strategy for plants to overcome phosphorus (P) deficiency. Genome-wide association with 561 tropical maize inbred lines from Embrapa and DTMA panels was undertaken for root morphology and P acquisition traits under low- and high-P concentrations, with 353,540 SNPs. P supply modified root morphology traits, biomass and P content in the global maize panel, but root length and root surface area changed differentially in Embrapa and DTMA panels. This suggests that different root plasticity mechanisms exist for maize adaptation to low-P conditions. A total of 87 SNPs were associated to phenotypic traits in both P conditions at -log10(p-value) ≥ 5, whereas only seven SNPs reached the Bonferroni significance. Among these SNPs, S9_137746077, which is located upstream of the gene GRMZM2G378852 that encodes a MAPKKK protein kinase, was significantly associated with total seedling dry weight, with the same allele increasing root length and root surface area under P deficiency. The C allele of S8_88600375, mapped within GRMZM2G044531 that encodes an AGC kinase, significantly enhanced root length under low P, positively affecting root surface area and seedling weight. The broad genetic diversity evaluated in this panel suggests that candidate genes and favorable alleles could be exploited to improve P efficiency in maize breeding programs of Africa and Latin America.

Effect of Different Sowing Dates and Various Varieties on Seedling Growth of Late Kharif Onion (Allium cepa L.) in Assam

Experiments were conducted on sandy loam soil of Horticulture Experimental Farm, Department of Horticulture, College of Agriculture, Assam Agricultural University, Jorhat, Assam during 2020-21 and 2021-22. The experiment was conducted on “The effect of different sowing dates and various varieties on seedling growth of late kharif onion (Allium cepa L.) in Assam.” Fifteen treatment combinations comprising of five onion varieties viz., Arka Kalyan, Bhima Dark Red, Agrifound Dark Red, Bhima Super and Bhima Red and three dates of sowing viz., 25th August, 5th September and 15th September were tested in Factorial Randomized Block Design (FRBD) with three replications. At the nursery stage, on the basis of pooled data, the relationship of different growth characters with various varieties and different dates of sowing revealed that variety Bhima Super sowing on 25th August (D1V4) was the best in the number of leaves (3.77), fresh weight of seedling (344.16 mg) and dry weight of seedlings (58.85 mg) at 40 days of sowing. Number of leaves per plant 25, 30 and 35 days after sowing were not affected by combination of various varieties and different dates of sowing.

Effects of adding pyrochar and hydrochar to calcareous soil on nutrient uptake by maize

The patterns and mechanisms underlying the effects of different types of biochar on crop dry matter accumulation and uptake of major soil minerals are uncertain. This study demonstrated the positive effects of adding pyrochar (PC) and hydrochar (HC) to calcareous soils on nutrient uptake by maize seedlings and revealed the important role of mycorrhizal colonization. The effects depended on the type of biochar added and the type of nutrient evaluated. The dry weights of maize seedlings were higher in the HC and PC groups than in the control group, and the P accumulation was 17% higher than that of the control. Adding PC significantly increased Zn accumulation and the concentration and accumulation of Cu in maize seedlings, whereas adding HC increased the Fe concentration. Applying PC and HC also promoted mycorrhizal colonization of maize roots, and P, Zn, and Cu accumulations in the plant were positively correlated with the mycorrhizal colonization rate. This study found that applying PC and HC to calcareous soil at the tested application rate promotes the uptake of some mineral nutrients by maize at the seedling stage, and this effect was at least partially influenced by an increased mycorrhizal colonization rate in the plant root system.

Influence of Seasons and Nutrient Invigoration on Seed Quality in Greengram

The influence of seed invigoration on seed yield and quality was studied in two seasons, i.e., summer and kharif. Among the seasons studied, seed quality parameters significantly differed for both seasons. Summer recorded the highest values in growth and yield parameters, viz., field emergence and plant population at harvest (91.75 and 87.75 %, respectively), number of nodules (35.71), seed yield (q/ha) (3.49), and seed quality parameters, viz., seed germination (%) (g) (91.7), and seedling vigour index I and II (3392 and 2252, respectively). But the lowest hard seeds were recorded in kharif (71.71%). Among treatments studied, 1 % ZnSO4 recorded the highest values in growth and yield parameters, viz., field emergence and plant population at harvest (96.50 and 91.17 %, respectively), number of nodules (38.50), pod length (cm), and number of seeds per pod (11.00 and 12.23, respectively). also in seed quality parameters, viz., seed germination (%) and 100 seed weight (g) (94.7 and 3.78, respectively), shoot length and root length (25.93 and 14.51 cm, respectively), mean seedling length (cm) and mean seedling dry weight (mg) (40.44 and 278, respectively), seedling vigour index I and II (3829 and 2636, respectively), and total dehydrogenase activity (A480nm) (1.825).

Drought-induced recruitment of specific root-associated bacteria enhances adaptation of alfalfa to drought stress.

Drought is a major abiotic stress that threatens crop production. Soil microbiomes are thought to play a role in enhancing plant adaptation to various stresses. However, it remains unclear whether soil microbiomes play a key role when plants are challenged by drought and whether different varieties are enriched with specific bacteria at the rhizosphere. In this study, we measured changes in growth phenotypes, physiological and biochemical characteristics of drought-tolerant alfalfa (AH) and drought-sensitive (QS) under sterilized and unsterilized soil conditions with adequate watering and with drought stress, and analyzed the rhizosphere bacterial community composition and changes using 16S rRNA high-throughput sequencing. We observed that the unsterilized treatment significantly improved the growth, and physiological and biochemical characteristics of alfalfa seedlings under drought stress compared to the sterilized treatment. Under drought stress, the fresh and dry weight of seedlings increased by 35.24, 29.04, and 11.64%, 2.74% for unsterilized AH and QS, respectively, compared to sterilized treatments. The improvement was greater for AH than for QS. AH and QS recruited different rhizosphere bacteria when challenged by drought. Interestingly, under well-watered conditions, the AH rhizosphere was already rich in drought-tolerant bacterial communities, mainly Proteobacteria and Bacteroidetes, whereas these bacteria started to increase only when QS was subjected to drought. When drought stress was applied, AH was enriched with more drought-tolerant bacteria, mainly Acidobacteria, while the enrichment was weaker in QS rhizosphere. Therefore, the increase in drought tolerance of the drought-tolerant variety AH was greater than that of the drought-sensitive variety QS. Overall, this study confirmed the key role of drought-induced rhizosphere bacteria in improving the adaptation of alfalfa to drought stress, and clarified that this process is significantly related to the variety (genotype). The results of this study provide a basis for improving drought tolerance in alfalfa by regulating the rhizosphere microbiome.

Enhancement of Seed Germination mediated by OH-functionalised Multiwalled Carbon Nanotubes (OH-MWCNTs) and their effect on morphological Parameters of Pennisetum glaucum (L.) R.Br. Genotypes

With an innovative approach, nanotechnology is proving to be a boon in various multifacet fields by easing the life of mankind. Owing to its changed physical and chemical properties, nanomaterials have exhibited advanced applications in the field of agriculture. Current study is focused to see the effects of OH-functionalised multiwalled carbon nanotubes (OH-MWCNTs) on germination and morphological parameters in seedlings of three different genotypes (HHB-67, RHB-173 and MPMH-17) of Pennisetum glaucum (L.) R.Br. under in vitro conditions. Seeds were primed with various concentrations of OH-MWCNTs (0, 25, 50, 75, 100 and 125 mg L−1) for 12 hours while control was treated with only water. On 14th day of treatment, seed germination and morphological parameters were measured in Pennisetum seedlings. All three selected genotypes of Pennisetum showed the highest final germination percentage (FGP), seed vigour index I (SVI-I), seed vigour index II (SVI-II) along with root-shoot length and fresh and dry weight of seedlings at 100 mg L-1 concentration of OH-MWCNTs. This study indicates clearly that MWCNTs in low doses (25-100 mg L−1) can boost germination attributes in comparison to control, while beyond a threshold dose (125 mg L-1), all parameters of seedling growth showed signs of waning, however, the measurement of growth parameters was still better than control.

Zat12 Gene Ameliorates Temperature Stress in Wheat Transgenics by Modulating the Antioxidant Defense System

The present study was undertaken with the objective to reconnoiter the role of Zat12-related biochemical activities in temperature stress tolerance in wheat transgenic lines Z-8-12 1A, Z-8-12 1B, Z-8-19, and Z-15-10, which were produced by transforming wheat-cultivar PBW 621. Zat12 transgenics (ZT) along with non-transgenic (NT) wheat cultivars (PBW 621, PBW, 550, and HD 3086) were assessed at the three-weeks seedling stage under chilling (−2 °C and −4 °C) and heat (30 °C and 32 °C) stress. Specific activities of superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), glutathione-S-transferase (GST), glutathione reductase (GR), and antioxidants (proline and ascorbate) were profoundly increased under temperature stress in ZT related to NT. However, under −4 °C and 32 °C, a significantly higher increase was reported. In contrast, H2O2 and MDA were found to be much lower in ZT than in NT. Similarly, lesser decreases in length, fresh weight, and dry weight of seedlings were reported in ZT at 30 °C and 32 °C. RT-PCR studies revealed the enhanced expression of Zat12 in the roots of seedlings at the 5, 10, and 14 days after germination (DAG) stages in ZT under the stress conditions. Upregulation of the antioxidant defense system in ZT and their better tolerance depict an alternative for wheat cultivation under temperature stress-prone areas.

Seed Priming Treatments to Improve Heat Stress Tolerance of Garden Pea (Pisum sativum L.)

Heat stress seriously affects the production of cool-season food legume crops such as garden peas. Seed priming is a widely used technique that increases germination and improves plant growth and development, resulting in better field performance and higher yield of crops. In the current study, we investigated three seed priming treatments—hydropriming (dH2O), osmopriming (2.2% w/v CaCl2), and hormopriming (50 mg L−1 salicylic acid—SA)—and their effect on germination, initial seedling development, and physiological traits of two novel garden pea cultivars, under optimal conditions and heat stress. Seed priming with H2O, CaCl2, and SA enhanced garden pea performance under both optimal and stress conditions via significant improvements in germination energy, final germination, mean germination time, mean germination rate, seedling vigor index, shoot length, root length, fresh seedling weight, dry seedling weight, shoot elongation rate, root elongation rate, relative water content, chlorophyll content, and membrane stability index, as compared to control. The highest effect on the examined parameters was achieved by osmopriming and hormopriming in both cultivars, suggesting that these treatments could be used to improve the heat stress tolerance of garden pea, after extensive field trials.

Prediction Model of Pumpkin Rootstock Seedlings Based on Temperature and Light Responses

Temperature and light are the key factors that affect the quality of pumpkin rootstock seedlings’ growth process. Responses to temperature and light are an important basis for optimizing the greenhouse environment. In order to determine the quantitative effects of temperature and light on the growth and development of pumpkin (Cucurbita moschata cv. RTWM6018) rootstock seedlings, relationships between temperature, light, and pumpkin rootstock seedlings growth were established using regression analysis. The results indicated that the daily average temperature had a significant negative correlation with the development time of pumpkin rootstock seedlings, and the shoot dry weight of pumpkin rootstock seedlings increased within a certain range of the daily light integral (DLI). We established a prediction model of pumpkin rootstock seedling quality indicators (hypocotyl length, stem diameter, shoot dry weight, root dry weight, root shoot ratio, and seedling quality index) based on thermal effectiveness and photosynthetic photon flux density (TEP). The coefficient of determinations (R2) of the hypocotyl length and seedling quality index prediction models of pumpkin rootstock seedlings, based on accumulated TEP, were 0.707 and 0.834, respectively. The hypocotyl length and seedling quality index prediction models of pumpkin rootstock seedlings, based on accumulated TEP, were y1 = 0.001 x2 − 0.180 x + 13.057 and y2 = 0.008 x0.722, respectively, which could be used for predicting the growth of pumpkin rootstock seedlings grown under different temperature and light conditions.

Genome-wide association study identifies GhSAL1 affects cold tolerance at the seedling emergence stage in upland cotton (Gossypium hirsutum L.).

Genomic analysis of upland cotton revealed that cold tolerance was associated with ecological distribution. GhSAL1 on chromosome D09 negatively regulated cold tolerance of upland cotton. Cotton can undergo low-temperature stress at the seedling emergence stage, which adversely affects growth and yield; however, the regulatory mechanism underlying cold tolerance remains nebulous. Here, we analyze the phenotypic and physiological parameters in 200 accessions from 5 ecological distributions under constant chilling (CC) and diurnal variation of chilling (DVC) stresses at the seedling emergence stage. All accessions were clustered into four groups, of which Group IV, with most germplasms from the northwest inland region (NIR), had better phenotypes than Groups I-III under the two kinds of chilling stresses. A total of 575 significantly associated single-nucleotide polymorphism (SNP) were identified, and 35 stable genetic quantitative trait loci (QTL) were obtained, of which 5 were associated with traits under CC and DVC stress, respectively, while the remaining 25 were co-associated. The accumulation of dry weight (DW) of seedling was associated with the flavonoid biosynthesis process regulated by Gh_A10G0500. The emergence rate (ER), DW, and total length of seedling (TL) under CC stress were associated with the SNPs variation of Gh_D09G0189 (GhSAL1). GhSAL1HapB was the elite haplotype, which increased ER, DW, and TL by 19.04%, 11.26%, and 7.69%, respectively, compared with that of GhSAL1HapA. The results of virus-induced gene silencing (VIGS) experiment and determination of metabolic substrate content preliminarily illustrated that GhSAL1 negatively regulated cotton cold tolerance through IP3-Ca2+ signaling pathway. The elite haplotypes and candidate genes identified in this study could be used to improve cold tolerance at the seedling emergence stage in future upland cotton breeding.

Influence of Nitric oxide donor nanoencapsulation on Dyckia excelsa Lema (Bromeliaceae) germination

Bromeliads are used in landscaping due to the beauty of their leaves and flowers. The use of plant regulators such as nitric oxide (NO) promotes the stimulus of germination and it has been a way out to enhance production and reduce the search for plants in nature and nanoencapsulation aims to optimize its effect. The objective of this work was to evaluate the effect of using free and nanoencapsulated NO donor on the germination of D. excelsa. The treatments consisted of soaking the seeds for 5 minutes with s-nitrosoglutathione (GSNO), chitosan/sodium tripolyphosphate nanoparticles containing GSNO (NP CS/TPP-GSNO) and empty (NP CS/TPP) at doses: 15 mM and 20 mM. The control consisted of imbibition in distilled water. For each treatment, 4 replications of 50 seeds were used. The following variables were evaluated: percentage of germination (GER), first germination count (FGC), germination speed index (GSI), average germination time (AGT) in addition to the length (SL) and seedling dry weight (SDW). To characterize the seeds, water content and viability were evaluated. D. excelsa seeds had 9.9% water content and 64% viability. For GER, treatments with GSNO ranged from 43 to 60%. The application of GSNO stimulated the germination process of D. excelsa and the nanoencapsulation did not cause any difference in the results compared to the free GSNO. It was concluded that the application of 15 or 20 mM of the GSNO donor is recommended for stored seeds of D. excelsa.

UJI FORMULASI BIOFUNGISIDA GRANULAR BERBAHAN AKTIF Trichoderma virens ENDOFIT DALAM MENGENDALIKAN Ganoderma Boninense Pat. PADA BIBIT KELAPA SAWIT (Elaeis guineensis Jacq.)

The aim of this work is to find out the effect of granular bio fungicide formulations with the active ingredient of T. virens endophytes and to obtain the best biofungicide preparations to control G. boninense and improve the quality of oil palm seeds. The research was conducted at the experimental farm and plant disease laboratories, Faculty of Agriculture, the University of Riau from February 2017 to September 2018. The research was carried out experimentally using a completely randomized design (CRD). The treatment tested was the Trichoderma virens formulation F0 = Control without treatment, F0- = Control negative (Ganoderma inoculant), F0 + = Positive control (15 ml Trichoderma virens inoculant + Ganoderma inoculant), F1 = 15 ml Trichoderma virens inoculant +100 g sago starch + 25 peat peat +25 g tapioca starch, F2 = 15 ml Trichoderma virens inoculant +100 g palm frond flour + 25 sago dregs + 25 g tapioca flour, F3 = 15 ml Trichoderma virens inoculant + 100 g solid +25 g talc + 25 g flour tapioca, F4 = 15 ml Trichoderma virens inoculant + 100 g cocoa shell flour + 25 g zeolite + 25 g tapioca flour. The parameters observed were the intensity of the attack of the disease, seed height, weevil diameter, number of fronds, root volume, seed dry weight, and sprout ratio. uk root. The obtained data were statistically analyzed using variant fingerprints. The average results of the analysis were continued with the BNJ test at the 5% level. F4 treatment showed the best granular formulation for the growth and development of T. virens endophytes, inhibiting the infection of Ganoderma sp. Attack. on seedlings and better seed growth on observations of seed height, root volume, number of midribs, root crown ratio, and dry weight of oil palm seedlings.

Mixed inoculation of dark septate endophytic and ericoid mycorrhizal fungi in different proportions improves the growth and nutrient content of blueberry seedlings

Despite extensive studies on the interaction between dark septate endophytes (DSE) and host plants, little is known about the effects of mixed inoculation of DSE and ericoid mycorrhizal fungi (ERMF) on plants. We assessed the effects of mixed inoculation of five species of ERMF and five species of DSE on soil factors and growth and physiological functions of blueberry (Vaccinium corymbosum L. ‘O’Neal’) seedlings. The strains were isolated from blueberries in several regions of Guizhou Province. The fungi suspension root irrigation method was used to inoculate the seedlings. Six inoculation treatments, i.e. D (Cladosporium cladosporioides), N (Oidiodendron citrinum), D1N1 (D : N, 1:1), D1N2 (D : N, 1:2), D2N1 (D : N, 2:1) and CK (not inoculated) were conducted. Samples were collected two months after inoculation. The mixed inoculation of DSE and ERMF significantly promoted the height, stem diameter, shoot dry weight, total biomass, root activity and total chlorophyll content of the blueberry seedlings and enhanced their absorption capacity to mineral nutrients. The mixed inoculation also improved the activities of soil enzymes such as urease and acid phosphatase. The effect of mixed inoculation was better than that of single inoculation or CK. Combining the analysis results of the membership function, we concluded that D1N2 and D2N1 most significantly promoted the growth of blueberry seedlings. These data provide a basis for the potential application of DSE and ERMF mixed inoculation for promoting the growth of seedlings.

Activated charcoal alleviates fluoride stress by restricting fluoride uptake and counteracting oxidative damages in the rice cultivar MTU1010

This work was aimed to explore the efficacy of activated charcoal (5 mg g-1 soil) in abating fluoride (25 mg L-1 NaF) stress in rice seedlings, since the protective role of charcoal is widely reported against other forms of abiotic stress. Application of NaF solution reduced germination rate, dry and fresh weight, and shoot and root length of seedlings. Extensive fluoride accumulation lowered the chlorophyll level along with higher electrolyte leakage and formation of H2 O2 , malondialdehyde, and methylglyoxal. Administration of activated charcoal lowered the extent of oxidative damages by inhibiting the uptake of fluoride ions. Exogenous application of activated charcoal also restored the activity of Kreb's cycle enzymes, i.e. PDH, IDH, MDH, and SDH, thereby overcoming the burden of carbon utilization and energy depletion occurring during stress. Additionally, the osmolyte (soluble sugar, proline, glycine-betaine, and amino acid) level was further escalated in presence of activated charcoal. The inhibition in catalase activity in fluoride-stressed seedlings was also restored. The activity of a range of enzymatic antioxidants (guaiacol peroxidase, superoxide dismutase, and ascorbate peroxidase) along with the glyoxalase system associated-enzymes (glyoxalase I and II) was further triggered in stressed seedlings treated with activated charcoal. The enhanced level of carotenoids, ascorbic acid, and total phenolics also enabled efficient scavenging of reactive oxygen species, thereby reducing cellular necrosis in the leaves. Based on the current investigation, it can be concluded that activated charcoal application appears a promising strategy to improve growth and mitigate damages in rice plants, growing in fluoride-polluted soil.

DEVELOPMENT OF HIGH-YIELDING SESAME (SESAMUM INDICUM L.) GENOTYPES UNDER DROUGHT STRESS CONDITIONS

Ten drought-tolerant and six sensitive lines with their resultant crosses emerged from crossing in the Line × Tester mating design, then evaluated at the maturity stage in the field. Data recorded for morphological and physiological parameters took place, as well as, for drought tolerance and yieldrelated traits. Recorded data followed analysis to access the variability in germplasm and general and specific combining ability effects. Combining ability analysis exhibited variable direction and magnitude of specific combining ability effects among crosses and general combining effects among line and testers. Results showed the breeding material had genetic variability that can serve in developing drought-tolerant and high-yielding genotypes of Sesamum indicum L. The testers 93004 and 96019 and Lines 90005 and 96006 revealed the best general combiners under normal and drought stress. Results of SCA indicated that 95001 × 97005, 97007 × 97001, 95010 × 93004, TH-6 × 96019, and 90005 × 96014 exhibited to have positive significant specific combining ability effects for most of the traits under control and drought stress conditions that can undergo further evaluation for growing under drought conditions. The fresh and dry weight of seedlings and 1000-seed weight traits proved useful as selection criteria in developing drought-tolerant types in sesame.