ARTICLE | doi:10.20944/preprints202104.0497.v1
Online: 19 April 2021 (14:30:34 CEST)
In recent years cultivated soils have been increasingly supplemented with nutrients that at low doses are necessary for proper plant functioning but become toxic at high doses. New methods are needed to prevent these destructive actions, and for this reason we studied the effects of two elements – Mn treated as a stressor and Se treated as a potential defense in two wheat cultivars. The intensity of stress was manifested in tissue browning and weight reduction and was determined by an increase in lipid peroxidation and quantitative analysis of hydrogen peroxide levels. It was found that the excess of Mn in the substrate caused more intense changes in these indicators in the root system than in the leaves, and that Se presence partly eliminated the stress evoked effects. Moreover, Mn-treatment was accompanied by a greater absorption of this element by the roots, and a reduced uptake of other elements (K, Fe, S, P), with the exception of Ca, an increase in which was observed especially in the additional presence of Se. It was suggested that the rise in Ca level can lead to modification of cell differentiations and may be one of the steps in defense mechanisms. The change in the direction of cell differentiation in the apical part of the root was observed microscopically under Mn stress and was accompanied by a quantitative increase in 5-met C. Based on DNA methylation profiles detected by MSAP we concluded that various types of methylation sites may be activated under Mn treatment in roots.
ARTICLE | doi:10.20944/preprints201809.0298.v1
Subject: Life Sciences, Biotechnology Keywords: Mortierella; phytohormones; winter wheat seedlings; psychrotrophs
Online: 17 September 2018 (10:10:24 CEST)
The endogenous pool of phytoregulators in plant tissues supplied with microbial secondary metabolites may be crucial for the development of winter wheat seedlings during cool springs. Phytohormones may be synthesized by psychrotrophic microorganisms in lower temperatures occurring in temperate climate. Two fungal isolates from the Spitzbergen soils after the microscopic observations and ITS region molecular characterization were identified as Mortierella antarctica (MA DEM 7) and Mortierella verticillata (MV DEM32). To study the synthesis of indoleacetic acid (IAA) and gibberellic acid (GA) Mortierella strains were grown on media supplemented with precursors of phytohormones (tryptophan or methionine) at 9, 15 and 20 °C for 9 days. The highest amount of IAA synthesis was observed in MV DEM 32 9-day culture at 15 °C with 1.5 mM of tryptophan. At the same temperature the significant promoting effect (about 40% root and shoot fresh weight) of this strain on seedlings was observed. However, only MA DEM 7 had the ACC-deaminase activity with the highest efficiency in 9 °C and at this temperature synthesized IAA without tryptophan also at the same conditions the strain confirmed the strong promoting effect (about 40% root and 24% shoot fresh weight) on seedlings. Both strains synthesized GA in all tested terms and temperatures. Tested Mortierella strains had some important traits to consider them as microbial biofertilizers component improving plant growth in difficult temperate climate.
ARTICLE | doi:10.20944/preprints202208.0459.v1
Subject: Biology, Forestry Keywords: growth and yield; Tetrapluera tetraptera; organic fertilizers; seedlings
Online: 26 August 2022 (10:18:12 CEST)
The study was carried out to investigate the growth response of Tetrapluera tetraptera to selected organic fertilizers. Organic fertilizers: poultry manure and cow dung of different concentration and mixture were used to raise seedlings from Germination experiment for a period of 12 weeks. Six treatments were used for this research: T1 (control experiment), T2 (10g of poultry manure), T3 (10g of cow dung), T4 (20g of poultry manure), T5 (20g of cow dung), T6 (15g of poultry manure + 15g of cow dung). Growth parameters such as diameter, plant height and number of leaves were measured weekly over a period of twelve (12) weeks. Data obtained were subjected to Anova and mean separated using Duncan multiple range tests. on the height parameter assessed on Tetrapluera tetraptera, the highest plant height mean of 12.20cm was recorded in treatment 6 (15g of poultry manure + 15g of cow dung) while the lowest mean plant height 7.19cm was recorded in treatment 3 (10g of cow dung) . the highest mean stem diameter was recorded in treatment 4 with a value of 0.43mm from while the least was recorded in Treatment 1 with mean value of 0.21 m. also, highest mean number of leaves was recorded treatment 4 (12.81) while the least was observed in T3 (11.01) . The results showed that organic manure has considerable effect on the growth of Tetrapluera tetraptera seedlings and it use should be encouraged. T3 (10g of poultry Manure + 10g of cow dung) was hereby recommended to be the best of all in the growth of Tetrapluera tetraptera.
ARTICLE | doi:10.20944/preprints202207.0289.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Planting method; Seedlings; Value index; Weed, Tillering; Efficiency
Online: 19 July 2022 (14:17:25 CEST)
A field experiment was conducted at farmer field of Sundarbazar, Lamjung during rainy season of 2020 with an objective to determine the dynamics of weed with respect different planting methods and varieties. The experiment was laid out in split plot design with three replications where five Varieties (KabreKodo 1, KabreKodo 2, Dalle 1, Okhale 1 and local) were used as the main plot factor and three planting methods (Direct sowing;10*10cm, Conventional transplanting;10*10 cm with 15 days old seedlings and System of Crop Intensification;25*25 cm with 30 days old seedlings) as sub plot factor. Result showed that among 5 genotypes of weeds based on Importance value index, Cyperusrotundus was the most dominant during the initial stage but after the first weeding, Aegeratumhaustinianum dominated the field. Weed biomass and density was recorded highest in directly sown field than that in transplanted field. Among the transplanted crop, weed infestation was seen higher in SCI than in conventionally transplanted finger millet due to wider spacing. But after the first hand weeding, due to profuse root growth and tillering in SCI, weeds were suppressed and thus weed biomass was observed higher in CT. After one hand weeding, SCI showed higher weed control index, crop resistance index and planting method efficiency index in terms of yield. Weed infestation was observed higher in Dalle 1 among varieties.
ARTICLE | doi:10.20944/preprints202207.0183.v1
Subject: Biology, Forestry Keywords: growth and yield; Khaya senegalensis; organic fertilizers; seedlings
Online: 12 July 2022 (09:26:44 CEST)
The study investigated the comparative effect organic fertilizers on the growth of Khaya senegalensis (Desr). Four treatments were used for this research: T1 20g of poultry manure, T2 (20g of cow dung), T3 (10g of poultry Manure + 10g of cow dung), T4 (Control experiment). Growth parameters such as diameter, plant height and number of leaves were measured weekly over a period of twelve (12) weeks. Data obtained were subjected to ANOVA and mean separated using Duncan Multiple Range Test. on the height parameter assessed on Khaya Senegalensis, the highest plant height mean of 8.40cm was recorded in treatment 1(20g of poultry Manure) while the lowest mean plant height 7.19cm was recorded in treatment 4 (Control experiment). Also, the highest mean stem diameter was recorded in Treatment 1 with a value of 0.309mm from while the least was recorded in Treatment 4 with mean value of 2.1175mm. However, highest mean number of leaves was recorded treatment 1 (20g of poultry manure) while the least was observed in T3 (10g of poultry Manure + 10g of cow dung). The results showed that organic manure has considerable effect on the growth of Khaya senegalensis seedlings and it use should be encouraged. T3 (10g of poultry Manure + 10g of cow dung) is hereby recommended to be the best of all in the growth of Khaya senegalensis.
ARTICLE | doi:10.20944/preprints201808.0515.v1
Subject: Biology, Forestry Keywords: balsam fir; white spruce; seedlings; partial cut; plantation; naturals stands; light; seed rain
Online: 30 August 2018 (05:36:10 CEST)
This study documents the conditions associated to white spruce and balsam fir regeneration after partial cutting. Measurements were collected 9 to 30 years after partial cutting in 12 natural fir stands and 5 white spruce plantations. We estimated seed input, measured light reaching the undergrowth, recorded seedlings (<150 cm) and their age on 6 different seedling establishment substrates: mineral soil, moss, rotten wood, litterfall, herbaceous and dead wood. Partial cutting generally favours the establishment and growth of seedlings. The number of fir and spruce seedlings is always greater in natural stands than in plantations, a trend likely associated with the reduced abundance of preferential establishment substrate in the latter. White spruce significantly prefers rotten wood while fir settles on all types of substrates that cover at least 10% of the forest floor. There is a strong relationship between light intensity and the median height of spruce seedlings, but this relationship is non-significant for fir. Seedlings of both species can survive at incident light intensities as low as 3%, but an intensity of 15% or more seems to offer the best growth conditions. The conditions for successful forest regeneration proposed in this study should be applied when the goal is to establish a new stand prior to clear cutting or to convert stand structure.