Maximum Root Length Research Articles

Identification of a unique allele in the quantitative trait locus for crown root number in <i>japonica</i> rice from Japan using genome-wide association studies

To explore the genetic resources that could be utilized to help improve root system architecture phenotypes in rice (Oryza sativa), we have conducted genome-wide association studies to investigate maximum root length and crown root number in 135 10-day-old Japanese rice accessions grown hydroponically. We identified a quantitative trait locus for crown root number at approximately 32.7 Mbp on chromosome 4 and designated it qNCR1 (quantitative trait locus for Number of Crown Root 1). A linkage disequilibrium map around qNCR1 suggested that three candidate genes are involved in crown root number: a cullin (LOC_Os04g55030), a gibberellin 20 oxidase 8 (LOC_Os04g55070), and a cyclic nucleotide-gated ion channel (LOC_Os04g55080). The combination of haplotypes for each gene was designated as a haploblock, and haploblocks 1, 2, and 3 were defined. Compared to haploblock 1, the accessions with haploblocks 2 and 3 had fewer crown roots; approximately 5% and 10% reductions in 10-day-old plants and 15% and 25% reductions in 42-day-old plants, respectively. A Japanese leading variety Koshihikari and its progenies harbored haploblock 3. Their crown root number could potentially be improved using haploblocks 1 and 2.

Iron efficiency of rice cultivars as related to iron dynamics in the rhizosphere

The present study aimed at investigating the iron (Fe) efficiency of rice cultivars with respect to Fe dynamics in the rhizosphere. A pot plant experiment was conducted using Fe-deficient (Diethylenetriamine pentaacetate-extractable Fe 2.41 mg/kg) loamy sand soil (pH 7.9, EC 0.24 dS m−1, and SOC 0.5%). Rice cultivars PR 114, PR 121, PR 126, PR 127 and PR 129 were grown in pots containing 5 kg soil. Treatments included foliar sprays of 0, 0.5 and 1.0% FeSO4 7H2O solution in triplicates. In no Fe spray treatment, rice cultivars produced 52–87% of the maximum shoot dry matter (SDM), which was achieved through foliar Fe. Considering the relative SDM as a measure of Fe efficiency, cv. PR 126 was the most efficient, followed by PR 129, PR 127, PR 121 and PR 114. In no-Fe spray treatment, PR 114 produced 60%, while PR 126 produced 55% of the maximum root length. Calculations with steady-state model demonstrated that in the absence of Fe spray application, cv. PR 126 developed 1.6-fold higher concentration gradient than PR 114 due to the depletion of Fe at root surface that derived 1.5-fold higher Fe influx. Cultivar PR 126 had lesser roots and lower root-to-shoot ratio but was more Fe efficient because of highest Fe influx and shoot demand on roots resulting from better Fe uptake mechanism.

Plant growth promoting microbial consortia for enhancing growth and yield attributes of Brinjal (Solanum melongena L.)

Combinations of plant growth promoting microorganisms were evaluated under pot culture to test their ability to enhance growth and yield attributes of Brinjal during rabi 2020 at the Department of Vegetable Science, College of Horticulture, Bagalkot, (UHS, Bagalkot), Karnataka, India. The pot experiment was laid out in a completely randomized design with sixteen treatments and three replications. The experiment results showed that combination of VAM + Azotobacter + Trichoderma harzianum to be the best PGPR consortia for enhancing the growth and yield attributes of brinjal followed by VAM+PSB. The treatment combination containing VAM + Azotobacter + Trichoderma harzianum showed the maximum plant height (22.56, 46.16 and 62.76 cm), highest number of branches per plant (4.00, 10.66 and 13.33), more number of leaves per plant (61.33, 102.33 and 126.33) at 30, 60 and 90 days after transplanting respectively and the treatment also recorded maximum root length (59.86 cm) and fruit yield per plant (615.93 g/plant), shoot fresh and dry weight (268.70 g and 54.20 g respectively), root fresh and dry weight (237.43 g and 55.36 g), nutrients in soil (495.00: 66.73: 402.80 NPK kg/ha.) and nutrient uptake of brinjal plant (461.66: 196.66: 523.33 NPK kg/ha) at 90 days after transplanting.

Nutrient Media Optimization for Date Palm Micropropagation (Phoenix dactylifera L.)

An experimental study was conducted to optimise nutritional media for date palm (Phoenix dactylifera L.) micropropagation by employing a shoot tip as an explant on basic Murashige and Skoog (MS) medium with varied Auxin (IAA, NAA) and Cytokinin (Kinetin and 2ip) concentrations for shoot and root multiplication. The findings of date palm regeneration on basal MS medium (Control) without Kinetin and IAA indicated a decreased survival rate (5.0%) and no root or shoot up to the end of the experiment. When the basal MS medium having different Kinetin and IAA concentrations showed an increased rate of survival, i.e. basal MS +0.5 mg/L of Kinetin and 0.0 IAA (8.0%), MS basal+1.0 mg/L of Kinetin and 0.5 IAA (6.6) and basal MS +2.0 mg/L of Kinetin and 1.5 IAA (7.0) and basal MS contains 1.5 mg/L of Kinetin and 1.0 IAA resulted in highest survival rate (8.8%). However, the highest number of shoots (2.2) and a maximum length of shoots (8.8 cm) were recorded on basal MS medium containing 2.0 mg/L of Kinetin and 1.5 IAA. Moreover, the highest number of roots (3.34) and measured the maximum length of roots (3.56 cm) was achieved on basal MS media containing 1.0 NAA and 1.5 mg/L of 2ip.

Influence of Microbial Priming on Germination and Seedling Growth Traits of Compact Cotton CO17

Cotton, known as “the King of fibers”, is the predominant fiber in the Indian textile industry. Plant growth-promoting rhizobacteria (PGPR) represent a potential sustainable alternative for the enhancement and protection of crops. The germination and seedling growth of cotton can be optimized by inoculating with PGPR. An experiment was conducted to evaluate the effect of different PGPR strains on seed germination and seedling establishment characters on cotton. The highest germination percentage, maximum vigour index and leaf area was obtained with the PPFM TNAU1 strain inoculation. The maximum shoot and root length were observed with seeds treated with Azospirillum strain sp7 with an increase of 24.4 and 42.8% over the control. Underground fresh and dry matter was higher in seedlings treated with Azospirillum sp7 strain compared to control, while the PPFM TNAU1 strain treatment increased the aerial fresh and dry matter content because of its larger leaf area. Seeds inoculated with individual strain of Azospirillum sp7 and PPFM TNAU1 outperformed the combined inoculation of PGPR strains. The increase in germination traits and seedling characters by PGPR strains indicates the positive influence on improving cotton seedling establishment traits associated to higher yield.

Exogenous salicylic acid-induced drought stress tolerance in wheat (Triticum aestivum L.) grown under hydroponic culture.

Wheat is an important cereal crop, which is adversely affected by water deficit stress. The effect of induced stress can be reduced by the application of salicylic acid (SA). With the objective to combat drought stress in wheat, an experiment was conducted in greenhouse under hydroponic conditions. The treatments consisted of (a) no drought (DD0 = 0 MPa), mild drought (DD1 = -0.40 MPa) and severe drought (DD2 = -0.60 MPa) by applying PEG-8000, (b) two contrasting wheat varieties Barani-17 (drought tolerant) and Anaj-17 (drought-sensitive), and (c) foliar treatments of salicylic acid (0, 50 mM, 75 mM, and 100 mM). Evaluation of wheat plants regarding biochemical, physiological, and morphological attributes were rendered after harvesting of plants. Statistically, maximum shoot and root fresh and dry weights (18.77, 11.15 and 1.99, 1.81 g, respectively) were recorded in cultivar Barani-17 under no drought condition with the application of SA (100 mM). While, minimum shoot and root fresh and dry weights (6.65, 3.14 and 0.73, 0.61 g, respectively) were recorded in cultivar Anaj-2017 under mild drought stress without SA application. The maximum shoot length (68.0 cm) was observed in cultivar Barani-2017 under no drought condition with the application of SA (100 mM). While, maximum root length (59.67 cm) was recorded in cultivar Anaj-17 under moderate drought stress without application of SA. Further, minimum shoot length (28.67 cm) was recorded in Anaj-17 under moderate drought stress without SA application. Minimum root length (38.67 cm) was recorded in cultivar Barani-17 under no drought condition without SA application. Furthermore, maximum physio-biochemical traits, including membrane stability index (MSI), chlorophyl content, photosynthetic rates, stomatal conductance, antioxidant enzymatic activities and relative water content (RWC) were found highest in cultivar Barani-17 under no drought stress and SA application at 100 mM. However, minimum values of these traits were recorded in cultivar Anaj-17 under severe drought stress without SA application. Our results also demonstrated that under severe drought, application of SA at 100 mM significantly increased leaf nitrogen (N), phosphrus (P) and potassium (K) contents and cultivar Barani-17 demonstrated significantly higher values than Anaj-17. The obtained results also indicated that the cultivation of wheat under drought stress conditions noticeably declines the morphological, physiological, and biochemical attributes of the plants. However, the exogenous application of SA had a positive impact on wheat crop for enhancing its productivity.

Effects of gibberellic acid on the stem and root growth patterns of Abelmoschus esculentus

The seeds of Abelmoschus esculentus were grown in sandy loam soil of three field plots for the treatment of GA3 hormone concentration such as control plot (A), no treatment was given to this plot. Plot (B) was treated by GA3 (10-2 M) concentration and plot (C) was treated by GA3 (10-3 M) concentration daily and compared to the control field plot. The plants of Abelmoschus esculentus, for the growth analysis were taken regularly and randomly at the 15 days interval from the seedling emergence stage till to maturity. The length of Abelmoschus esculentus stem and root growth pattern (Okra) was observed with two concentrations of these plant hormones such as GA3 (10-2 M) and GA3 (10-3 M)) concentration and to evaluate the best concentration of these growth regulators as (GA3 (10-3 M)) only, which showed the maximum stem and root length of the Abelmoschus esculentus as compared to the control.

Deciphering in vitro mutated sugarcane clones for growth parameters

Callus derived from sugarcane variety CoN – 13073 subjected for mutagenic treatment varying in different concentration as well as time period. Callus culture of 25 - 30 days old white globular form is considered a suitable material to undergo mutagenic treatments. Among the mutagenic treated calli, Maximum shoot length (26.6 cm) was observed in the treatment, EMS 0.2% + 30 min. Maximum root length (12.8 cm) was observed in treatment MMS 0.3% + 30 min. A higher concentration of all mutagenic agents registered higher root length with the maximum of 1.14 g was observed in treatment EMS 0.3% + 60 min. Maximum leaf area (44.7 cm2/plant) was observed in treatment MMS 0.2% + 30 min. Irrespective to concentration SA and EMS found significant for this character. Maximum chlorophyll content index (4.87) was observed in treatment EMS 0.2% + 30 min. In case of this character higher to lower concentration as well as time period influenced in both higher and lower directions. Among the treatments, the maximum multiplication rate (12.45%) was observed in treatment EMS 0.2% + 30 min. Both factors showed different effects on this character. The effect of the mutagenic agent was found to be succeeding to create variability at a lower concentration for lower time intervals for most of the characters under study. In the present study EMS, 0.2% in addition to 0.3%, treatments were most effective. And the effectiveness decreases with the increase in the time interval.

Cattle manure compost and biochar supplementation improve growth of Onobrychis viciifolia in coal-mined spoils under water stress conditions

Surface mining is a critical anthropogenic activity that significantly alters the ecosystem, while the use of appropriate revegetation techniques can be considered an important and feasible strategy in the way to improve the ecosystem services of degraded land. In the present study, we carried out a pot experiment to investigate the effects of three different variables on morpho-physiological and biochemical parameters of Onobrychis viciifolia to assess the capability of this species to be used for restoration purposes. Specifically, the variables studied were: (a) water (W) regime, working at five values as regards field capacity (FC) (i.e., 80% FC = highest, 72% FC = high, 60% FC = moderate, 48% FC = low, and 40% FC = very-low dose); and (b) rates of cattle manure compost (CMC) and wood biochar (BC) (weight/weight ratio), working at five rates (i.e., 4.0% = highest, 3.2% = high, 2.0% = moderate, 0.8% = low, and 0% = either no-CMC or no-BC dose). In addition, soil physical-chemical properties and enzyme activities were also investigated at the end of the experimental period. It was found that morphological growth attributes such as plant height, maximum root length, and dry biomass significantly increased with W, CMC and BC applications. Compared to control, moderate-to-high W, CMC and BC doses (W80CMC2BC2) increased net photosynthesis rate (by 42%), stomatal conductance (by 50%), transpiration rate (by 29%), water use efficiency (by 10%), chlorophyll contents (by 73%), carotenoid content (by 81%), leaf relative water content (by 33%) and leaf membrane stability index (by 30%). Under low-W content, the application of CMC and BC enhanced osmotic adjustments by increasing the content of soluble sugar and the activities of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase, decreasing the oxidative stress, as verified by low levels of hydrogen peroxide, superoxide anion, malondialdehyde and proline contents in leaf tissues. Moreover, application of W, CMC and BC significantly improved soil water holding capacity, available nitrogen, phosphorus and potassium, urease and catalase activities, which facilitate plant growth. These results would aid in designing an appropriate strategy for achieving a successful revegetation of O. viciifolia, providing optimum doses of W (64% field capacity), CMC (2.4%) and BC (1.7%), with the final aim of reaching ecological restoration in arid degraded lands.

Effect of five Bacillus strains on seed germination of Pisum sativum and plant growth of Origanum vulgare subsp. hirtum (oregano)

This study aims to investigate the effect of PGP-strains from genus Bacillus on seed germination of Pisum sativum and plant growth of Origanum vulgare subsp. hirtum in comparison with two growth plant regulators. Bacterial cell free supernatants (CFS) from five Bacillus strains were used in two different concentrations – 100 and 500 fold dilutions. The growth regulators (gibberellic acid and indole acetic acid) were used to determine optimal concentration to Pisum sativum seeds germination and plant growth, and were compared with the bacterial CFS. PGP-activities of CFS and plant regulators were evaluated by morphometric data of sprouted seeds and plants. Bacterial CFS increase the number of lateral root branching and the average number of leaves compared with the tested growth regulators. The growth regulators had positive effect on plant growth, although their accumulation in the soils has been shown to cause soil erosion and pollution. The treatment of Origanum vulgare subsp. hirtum with bacterial CS from B. subtilis 8VR, B. pumilus 9VR and B. thuringiensis 13VR, resulted in significant increase in the root length compared to the control. The maximum length of the main root was measured after treatment with CS from B. thuringiensis 13VR. Bacterial CS from genus Bacillus had no effect of stem length of Origanum vulgare subsp. hirtum, while CS from B. cereus 7VR and B. subtilis 8VR increased the number of leaf trichomes compared to the control.

Phenotypic Diversity of Root Characteristics in Recombinant Inbred Lines of Cross Between Lowland and Highland Rice Varieties for Drought Tolerance Potential.

<b>Background and Objective:</b> Breeding between highland and lowland rice varieties is one of the strategic breeding of lowland rice for enhancing drought-tolerant capacity through root structure improvement. The objective of this study was to evaluate the phenotypic diversity of rice root traits in pot screening compared to the lowland parent. <b>Materials and Methods:</b> The basket method was utilized in pot cultivation to evaluate the 100 of F7 Recombinant Inbred Lines (RILs) derived through single seed descent method from a cross between lowland rice, RD49 variety and upland rice, Payaleumgaeng (PLG) variety. The two parents and F7 progenies were evaluated for the number of shallow roots (SRN) and the number of deep roots (DRN), together with other traits which were the number of total roots (TRN), the Ratio of Deep Rooting (RDR), maximum Root Length (RL), Root Dry Weight (RDW), Shoot Dry Weight (SDW), the ratio of Root to Shoot Weight (RSR) and Plant Height (PH). <b>Results:</b> The result showed that PLG had significantly higher SRN, DRN, TRN and RDR than RD49. The distribution of these traits showed slightly positive skewness in DRN, RDR, RDW, SDW and RSR and negative skewness in SRN, TRN, RL and PH. However, some lines in this RIL population displayed better performance of root traits compared to both parents. Principal Component Analysis (PCA) of DRN, SRN, TRN and RDR in this population showed a distinctly different pattern among both parents. Most of the selected lines had superior RDR over RD49 and had various root characteristics patterns due to the diverse PCA coordinates. The yield trial of some breeding lines in this cross show superior yield over RD49 under drought-prone cultivation area. <b>Conclusion:</b> This study showed broad phenotypic diversity in the population constructed through single seed descent selection for enhancing deep root structure in rice for drought adaptation.

Picloram-induced enhanced callus-mediated regeneration, acclimatization, and genetic clonality assessment of gerbera

BackgroundGerbera jamesonii Bolus ex Hooker f. (African daisy) is listed among the top five most important ornamental plants in the global floricultural industry. To satisfy its demand, the floriculture industry relies on reproducible and effective propagation protocol while retaining the genetic uniformity of G. jamesonii. The present study, for the first time, reports the potential of picloram for enhanced induction of organogenic calli from leaves of G. jamesonii and its high-frequency indirect regeneration. ResultsThe fastest induction of calli with maximum fresh and dry weight was recorded in the Murashige and Skoog (MS) semisolid medium supplemented with 1 mg/l picloram. In addition, callus induction was observed in 2,4-dichlorophenoxy acetic acid- and α-napthaleneaceticacid-supplemented media but with delayed response and reduced fresh and dry weight. The proliferated calli were transferred to shoot induction media containing MS salt and 0.5–1 mg/l N6-benzylaminopurine, kinetin, or thidiazuron. A mean number of ~6 shoots per callus were developed after 5 days of culture in the MS medium supplemented with 1 mg/l kinetin, with a mean length of 5.2 cm. Successful rooting of shoots was achieved in the MS medium fortified with 1.5 mg/l indole-3-acetic acid, wherein the earliest root initiation (~5 days), as well as the maximum number (~9) and length (~4.8 cm) of roots, were recorded. Complete plantlets were primarily acclimatized in sand before being transferred to a mixed substrate (of soil, sand, tea leaf waste, and cow urine) that secured >90% survival and further growth of the plantlets. Eventually, clonal fidelity of the in vitro regenerants assessed via inter-simple sequence repeats (ISSR) primers exhibited a monomorphic banding patterns that suggested genetic integrity within the plantlets as well as with their mother plant. ConclusionsThe results of the present study should be of interest for commercial propagation and mutagenesis- as well as genetic transformation-related research.

Effects of residual film on maize root distribution, yield and water use efficiency in Northwest China

With the extensive use of plastic film, a large number of residual film accumulated in the farmland, bringing a huge negative impact on agricultural production. Studying the effect of residual film on roots is helpful to understand the damage mechanism of residual film on crop growth. Thus, a two-year field experiment was conducted with 0 (M0), 90 (M90), 180 (M180), 360 (M360), and 720 (M720) kg ha−1 residual film, and sine and logistic functions were used to simulate root growth and vertical distribution of maize. Results showed that root length decreased with residual film increasing and was more sensitive to residual film at tasseling, filling and maturity stages than at seedling and jointing stages. The results of the sine function fitting the total root length showed that the potential maximum root length was decreased and the rooting time was delayed, and the root growth time was shortened with the amount of residual film increasing. M90 had no significant effect on root length but residual film equal to or greater than 180 kg ha−1 had significant negative effects on root length. M180, M360 and M720 significantly reduced the actual total root length by 13.7%, 23.8% and 33.3%, and reduced the potential root length by 9.4%, 17.1% and 21.8%. M360 and M720 significantly shortened the growth time by 3.8% and 6.6%. The logistic function fit the vertical root distribution well. Residual film decreased the root length in deep soil and gathered roots in the soil layer near the depth of d50 at which 50% of the root length was accumulated. Residual film decreased the soil depth where 50% and 95% root length were accumulated and increased the proportion of root length in 0–30 cm soil layer. This adverse effect increased with residual film amount increasing. The dry matter of stems, leaves and ears decreased with residual film increasing. M90 reduced the above-ground dry matter insignificantly and the other treatments with residual film had significant effects. At the maturity stage, the above-ground dry matter in M90, M180, M360 and M720 was reduced by 2.4%, 14.2%, 22.2% and 29.4%, compared with M0. Residual film decreased evapotranspiration (ET), grain yield and water use efficiency (WUE) significantly except M90. ET, yield and WUE were reduced by 1.7%, 3.0% and 1.1% in M90, and 2.5%, 17.1% and 16.1% in M180, and 6.2%, 27.1% and 23.4% in M360, and 8.5%, 34.7% and 30.8% in M720, respectively. In summary, the residual film beyond 180 kg ha−1 had a significant negative effect on summer maize. This information will be useful to better understand and respond to residual film pollution and ensure safe agricultural production.

Effect of Exogenous Application of Some Growth Regulators on Growth and Yield of Maize(Zea mays L.) Cultivars

Maize being subtropical crop is sensitive to low temperature at early growth stages. Exogenous application of humic acid (HA), ascorbic acid (AsA), and thiourea (TU) can improve the growth of maize. This experiment was conducted to investigate the effect of different plant growth regulators to as a foliar spray to two (pioneer 1543 and monsanto 8441) maize cultivars. Main objective of this research is exogenous application of plant growth regulators that significantly increase the growth parameters, plant biomass and yield of plant. A total of 3 treatments TO = control, T1 = 20ml/L HA, AsA and TU, T2 = 30ml/L HA, AsA and TU and T3 = 50ml/L HA, AsA and TU were tested in a randomized complete block design with three replications. All the treatments improved the yield, growth and biomass of maize. Although, various treatments, thiourea showed the maximum leaf length, root length and cobe length of the plant. Results declared that foliar spray of plants growth regulators increased the growth parameters viz; plant height, Number of leaves per plant, Leaf area, Number of nodes and Fresh weight of plant.

Influence of Illumination Time and Soil Moisture on Seed Germination and Seedling Establishment of Magnolia sprengeri Pamp.

This study investigated the effects of illumination time and soil moisture on seed germination and seedling establishment of Magnolia sprengeri Pamp. to improve the seed germination percentage and seedling survival percentage of M. sprengeri. It is of great significance for rapid propagation, seedling regeneration, field management, and artificial high-efficiency cultivation of M. sprengeri. In this study, the seeds of natural M. sprengeri populations from original habitat were used as test materials. Seed germination and seedling establishment of M. sprengeri were performed under different illumination time and soil moisture treatments in artificial climate incubator. The study found that there were significant differences among various key parameters related to seed germination and seedling establishment under different treatments (P < 0.05). Germination percentage, germination potential, germination index, vigor index, germination rate, plant height, number of leaves, base diameter, taproot length, number of lateral roots, maximum lateral root length, single plant leaf area, fresh weight, and seedling survival rate reached the maximum at continuous illumination and 13% of soil moisture, respectively. By the integrative evaluation for the influence of these two factors on seed germination and seedling establishment, soil moisture is a dominant factor affecting seed germination and seedling establishment, whereas illumination is an important promoting factor for seedling establishment of M. sprengeri. Continuous illumination and 13% of soil moisture content is suitable for seed germination and seedling establishment of M. sprengeri.

Оценка эффективности укоренения сортов барбариса Тунберга (Berberis thunbergii dc.) методом зеленого черенкования

In this work, the results of evaluating the differences in the variants of the three-factor experiment on rooting of varieties of Barberry Thunberg (Berberis thunbergii DC.) By factors: varietal characteristics, the number of nodes and the use of a root formation regulator are considered. The study involved cuttings of the following varieties: ‘Dart’s Red Lädy’, ‘Kobold’, ‘Golden Ring’, ‘Harlequin’, ‘Rosetta’, ‘Red Chief’ and ‘Aurea’. 4- (indol-3-yl) butyric acid (trademark "Kornevin") was used as a root formation stimulator by the method of dusting. The green cuttings had 2 and 3 knots. The results of analysis of variance on the variability of the average total root length in green cuttings depending on varietal characteristics, dusting with a root formation stimulator and the number of nodes made it possible to establish that the ‘Red Chief’ variety had the maximum average total root length and was significantly different from all other varieties. The average total length of roots when using a root formation stimulator is significantly higher than in the control variant. Cuttings with three nodes reliably had a large average total root length. Based on the results obtained, it is assumed that the use of a root formation stimulator and rooting of cuttings with three nodes has a positive effect on the rooting processes of barberry cuttings. Keywords: BERBERIS THUNBERGII, THUNBERG BARBERRY, GREEN CUTTINGS, 4- (INDOL-3-YL) BUTYRIC ACID, KORNEVIN, KNOTS

Standardization of in vitro micropropagation procedure of Oriental Lilium Hybrid Cv. 'Ravenna'.

Micropropagation protocol of Oriental Hybrid Lilium cv. Ravenna was developed using bulb scale segments (Basal and Tip) as explants. Surface sterilization of healthy bulb scales with carbendazim 200 ppm for 30 min, then 0.1 percent mercuric chloride for 10 min, then 70% ethyl alcohol for 30 s was superior to all other treatments in recording highest culture asepsis (77.08%) and higher explant survival (86.12%). Explant survival was higher in basal segments (88.54%) compared to tip segments (85.52%). Highest culture establishment was recorded in basal scale segments (68.26%) followed by tip scale segments (55.21%). MS medium augmented with 0.50 mgl−1 Naphthalene acetic acid and 2.0 mgl−1. 6-Benzylamino Purine recorded maximum culture establishment (76.17%), highest bulblet number/explant (5.52) with maximum length of shoots (2.20 cm) and number of leaves (3.39). This treatment combination of growth regulators resulted in highest shoot proliferation (83.33%) along with maximum shoot number (2.41explant−1), shoot length (2.35 cm) and leaf number (5.44) of micro shoots during proliferation stage. Rooting of explants was superior with Indole-3-butyric acid compared to Naphthalene acetic acid. Highest rooting of 92.71% along with maximum number of primary roots shoot−1 (12.06), maximum primary root length (3.17 cm) was documented in Murashige and Skoog medium added with Indole-3-butyric acid 1.50 mgl−1 with best ex vitro survival rate (98.96%) of rooted plantlets during primary hardening in perlite + vermiculite (1:1) mixture.

Влияние освещения на ризогенез ягодных растений при клональном микроразмножении

Introduction. Forest berry plants are popular on the food market and in pharmacy for their high nutritional and medicinal value. Plantations of forest berry plants can proliferate on unused lands, including depleted peatlands. Clonal micropropagation is the most effective method for obtaining large quantities of high quality planting material. Light-emitting diodes are highly effective for clonal micropropagation. The research objective was to study the effect of different spectral ranges on the process of root formation of forest berry plants in vitro.
 Study objects and methods. The research featured regenerant plants of half-highbush blueberry, arctic bramble, American cranberry, European cranberry, lingonberry, and Kamchatka bilberry of different cultivars. A set of experiments made it possible to study the effect of lighting type on the growth and development of the root system of forest berry plants in vitro using white fluorescent lamps, white spectrum LED lamps, and LED lamps with a combination of white, red, and blue spectra at the in vitro rooting stage of clonal micropropagation.
 Results and its discussion. The largest number (3.4–14.6 pcs.) and the maximum total length (10.0–156.9 cm) of roots were observed under LED lamps with a combination of white, red, and blue spectra. The effect was by 1.1–2.8 and 2.0–4.5 times higher than in the case of white-spectrum LED lamps, and by 2.3–7.0 and 3.3–14.9 times than in the case of fluorescent lamps. Variety and shape proved to have no significant effect on biometric indicators.
 Conclusion. LED lamps had a positive effect on the process of rhizogenesis of forest berry plants during clonal micropropagation. They appeared to be more effective than fluorescent lamps. The combination of white, blue, and red spectra increased the biometric parameters of plants at the stage of in vitro rooting.

Effect of different doses of vermicompost on growth, yield and quality of radish (Raphanus sativus L. cv. Mino Early)

A field experiment was conducted at Horticulture farm of Nepal Polytechnic Institute (NPI) Bharatpur-11, Chitwan to study the effects of different doses of vermicompost on growth, yield and quality of radish (Raphanus sativus L. cv. Mino Early) from January 2020 to March 2020. Five different doses (0 ton, 5 ton, 10 ton, 15 ton, and 20 ton per hectare) of vermicompost were taken as treatments and the experiment was replicated four times. The experiment was set up in Randomized Complete Block Design (RCBD). The result of the study showed that there was a significant effect of different doses of vermicompost on plant height, the number of leaves per plant, spreading of the plant, root length, root weight per plant, root diameter, and root yield at harvesting. The maximum plant height, the maximum number of leaves per plant and maximum plant spreading in radish plant on vermicompost application was recorded every 30, 45 and 60 days after sowing (DAS). The maximum root length (29.60 cm), maximum root diameter (36.27 mm), maximum root weight (191.8 g), maximum biomass weight (241.6 g/plant), maximum root yield (47.9 ton/ha), were recorded on applying 15 ton/ha vermicompost at 60 DAS. The control treatment showed the minimum vegetative growth and yield. Among the different doses of vermicompost, the overall performance of radish was found better in 15 ton/ha of vermicompost. Statistical analysis showed no differences among (5 ton, 10 ton, 15 ton, 20 ton per hectare of vermicompost) applications. Hence, 5 ton per hectare of vermicompost application will be best for radish production in Chitwan.

Genetics of nitrogen use efficiency and its component traits under nitrogen-rich environment in wheat (Triticum aestivum)

Minimizing the footprints of overuse of nitrogen (N) on the ecosystem is the need of an hour. There is little information on the genetic inheritance of NUE and its component traits. The present study was therefore designed to study the genetic behaviour of NUE traits under abundant N supply. Diallel analysis of 21 F1 along with 7 parents was carried out for NUE traits, viz. shoot dry weight (SDW), root dry weight (RDW), maximum root length (MRL), N% in shoot, gram N in shoot (gN) and nitrogen use efficiency (NUE) under high N in hydroponic condition. Analysis of variance revealed significance for both general combining ability (GCA) and specific combining ability (SCA) for all NUE traits indicating the importance of both additive and non-additive gene action for these traits. Baker's ratio revealed a preponderance of additive genes over non-additive for SDW, RDW and MRLsuggesting thereby effectivity of selection for SDW, RDW, gN, and MRL in the early segregating generation of high GCA lines can improve NUE under high N. Crosses with high SCA effects for SDW, RDW, gN and N% were from the parent combination of high × low GCA effects, whereas for MRL, low × low GCA parents resulted in crosses with high SCA effect indicating the dispersal of favourable alleles in the different parents. Our study indicates the feasibility of improvement of NUE through direct selection for the component traits under N rich environment.