2,610 research outputs found

    An efficient callus initiation and direct regeneration of Stevia rebaudiana

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    The experiment was carried out to establish an efficient callus induction system of Stevia rebaudiana from a variety of explants as well as direct regeneration from nodes. Callus initiation was done to extract secondary metabolites. However direct regeneration is essential for rapid large-scale clonal propagation. Among leaf, node and inter-nodal explants, the best callus initiation performance was observed by nodes. MS medium fortified with α-naphthalene acetic acid (NAA) 2.0 mg/L + 6-benzyladenine (BA) 2.0 mg/L showed the highest (93.33 ± 6.67%) callus induction by nodal explants. Though inter-nodal explants showed a moderate response (73.33 ± 6.67%) for callus induction in MS medium complemented with NAA 3.0 mg/L + BA 1.0 mg/L, nodal explants showed higher response (86.67 ± 13.33%) than inter-nodal explants in that nutritional environment. Leaf explants always showed very poor callus. However, the best direct regenerating medium was MS medium + BA 1.0 mg/L for multiple shoot proliferation and then transferring those shoots to ½ MS medium + NAA 1.0 mg/L for root formation.Key words: In vitro, Stevia rebaudiana, 2,4-D, α-naphthalene acetic acid (NAA), 6-benzyladenine (BA), plant growth regulators

    Study of Shoot Multiplication of Strawberry (Fragaria ananassa)

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    Effects of different hormonal concentration on multiple shoot formation of RABI Strawberry-3 were studied. Where the explants were runner tips that cultured on MS basal medium supplemented with 6-Benzyl Adenine and Kinetin. The maximum percentage 80% of shoot was obtained from Benzyl Adenine concentrations of 0.5 mg/l and 1.0 mg/l whereas Kinetin concentrations were 1.5 mg/l and 2.0 mg/l separately. More promising result was found by combining two impressive concentrations of each hormone. When MS basal media was supplemented with Kinetin 2.0mg/l + Benzyl Adenin A 0.5 mg/l, Kinetin 1.5 mg/l + Benzyl Adenine 0.5 mg/l and Kinetin 1.5 mg/l + Benzyl Adenine 1.0 mg/l respectively then 100% shoots were obtained. DOI: http://dx.doi.org/10.3329/ijarit.v1i1-2.13936 Int. J. Agril. Res. Innov. & Tech. 1 (1&2): 69-72, December, 201

    An Efficient Irrigation System for Plasticulture of Strawberry in Bangladesh

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    Plasticulture technique is a commonly used technique for advanced strawberry production. Due to high cost and tough maintenance, this technique is not practiced commercially in Bangladesh. We have found that, if the irrigation system can be switched to a cheaper one with high efficiency, then the cost can be minimized. We applied Micro-drip mediated irrigation system to minimize the cost. Our proposed modification of plasticulture using micro-drip irrigation system was outstanding in all our concerned horticultural parameters like height of the plants, number of leaves, north-south spreading, and east-west spreading of the plants. Paired Samples analysis between conventional and plasticulture procedure, test of significance for the pairs of mean, analysis of variance and LSD test at 5% level of significance were done for statistical analysis to conclude the  result. The statistical analysis has also shown that the plasticulture method proposed by us was highly significant over the conventional technique and practical for the rural farmer of Bangladesh. It reduces the production costs, improves fruit quality and yield, and reduces the need for chemical pesticides. Keywords: Micro drip irrigation, Soil solarization, Mulching, and Fruit Qualit

    Hybrid technology for the use of solar energy : the challenge towards green energy / S. I. Hossain ... [et al.]

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    Large areas in many countries are populated but have no connection to a national electricity grid. Centralized electricity generating facilities burning fossil fuels have been the normal. Renewable energy resources, especially solar energy is now penetrating this sector. Long-term energy storage is the universal challenge in providing renewables-based electricity with high availability across the seasons. Solar domestic hot water system is widely used and developing fast in recent years. However many problems occur at the same time, for example more energy consumption by circulation pump, water reheating, long investment payback period, and etc. The motivation for the development of a combined hot water and sorption store is to complement the advantages and to reduce the disadvantages of the two particular storage technologies. Hot water stores offer high heat supply rates but are particularly suitable for short term storage due to heat losses whereas for a sorption store the power drain is low but it shows the advantage of a high storage density and long-term heat storage almost without losses. We investigated the demonstration project and discuss the need for authoritative system modelling in order to size the system components for minimum cost at a designated availability of supply

    Development of Efficient Callus Initiation of Malta (Citrus sinensis) Through Tissue Culture

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    The effects of different hormonal concentration on shoot formation and callus induction were studied on BARI Malta-1 (Citrus sinensis). Seeds containing seed coat and without seed coat was treated by Murashige and Skoog (MS) media supplemented with 6-benzyl adenine (BA) and Kinetin (KIN). Removal of seed coat showed an early response for shoot formation. The highest (70%) shoot formation was obtained from seeds without seed coat treated with MS basal media + BA 1.0 mg/l while KIN showed no response for shoot formation in any supplemented concentration. However, in case of callus induction internodes and apical shoot tips were used as explants and 2, 4-dichlorophenoxy acetic acid (2, 4-D) was used as callus inducing hormone. MS basal media supplemented with 2, 4-D, 2.0 mg/l showed highest (68%) callus induction. DOI: http://dx.doi.org/10.3329/ijarit.v1i1-2.13935 Int. J. Agril. Res. Innov. & Tech. 1 (1&2): 64-68, December, 201

    Integrating genetic and oral histories of Southwest Indian populations

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    India is home to thousands of ethno-linguistically distinct groups, many maintaining strong self-identities that derive from oral traditions and histories. However, these traditions and histories are only partially documented and are in danger of being lost over time. More recently, genetic studies have established the existence of ancestry gradients derived from both western and eastern Eurasia as well as evidence of practices such as endogamy and consanguinity, revealing complexity in the regional population structure with consequences for the health landscape of local populations. Despite the increase in genome-wide data from India, there is still sparse sampling across finer-scale geographic regions leading to gaps in our understanding of how and when present-day genetic structure came into existence. To address the gaps in genetic and oral histories, we analyzed whole-genome sequences of 70 individuals from Southwest India identifying as Bunt, Kodava, and Nair—populations that share unique oral histories and origin narratives—and 78 recent immigrants to the United States with Kodava ancestry as part of a community-led initiative. We additionally generated genome-wide data from 10 individuals self-identifying as Kapla, a population from the same region that is socio-culturally different to the other three study populations. We supplemented existing but limited anthropological records on these populations with oral history accounts narrated by community members and non-member contacts during sampling and subsequent community engagement. Overall, we find that components of genetic ancestry are relatively homogeneous among the Bunt, Kodava, and Nair populations and comparable to neighboring populations in India, which motivates further investigation of non-local origin narratives referenced in their oral histories. A notable exception is the Kapla population, with a higher proportion of ancestry represented in the Onge from the Andaman Islands, similar to several South Indian tribal populations. Utilizing haplotype-based methods, we find latent genetic structure across South India, including the sampled populations available under aCC-BY-NC-ND 4.0 International license.was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made bioRxiv preprint doi: https://doi.org/10.1101/2022.07.06.498959; this version posted July 7, 2022. The copyright holder for this preprint (which 2 from Southwest India, suggesting more recent population structure between geographically proximal populations in the region. This study represents an attempt for community-engaged anthropological and genetic investigations in India and presents results from both sources, underscoring the need to recognize that oral and genetic histories should not be expected to overlap. Ultimately, oral traditions and unique self-identities, such as those held close by some of the study populations, warrant more community-driven anthropological investigations to better understand how they originate and their relationship to genetic histories

    Silicon Mie Resonators for Highly Directional Light Emission from monolayer MoS2

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    Controlling light emission from quantum emitters has important applications ranging from solid-state lighting and displays to nanoscale single-photon sources. Optical antennas have emerged as promising tools to achieve such control right at the location of the emitter, without the need for bulky, external optics. Semiconductor nanoantennas are particularly practical for this purpose because simple geometries, such as wires and spheres, support multiple, degenerate optical resonances. Here, we start by modifying Mie scattering theory developed for plane wave illumination to describe scattering of dipole emission. We then use this theory and experiments to demonstrate several pathways to achieve control over the directionality, polarization state, and spectral emission that rely on a coherent coupling of an emitting dipole to optical resonances of a Si nanowire. A forward-to-backward ratio of 20 was demonstrated for the electric dipole emission at 680 nm from a monolayer MoS2 by optically coupling it to a Si nanowire
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