Single crystal diamond nanobeam waveguide optomechanics

Optomechanical devices sensitively transduce and actuate motion of nanomechanical structures using light. Single--crystal diamond promises to improve the performance of optomechanical devices, while also providing opportunities to interface nanomechanics with diamond color center spins and related quantum technologies. Here we demonstrate dissipative waveguide--optomechanical coupling exceeding 35 GHz/nm to diamond nanobeams supporting both optical waveguide modes and mechanical resonances, and use this optomechanical coupling to measure nanobeam displacement with a sensitivity of $9.5$ fm/$\sqrt{\text{Hz}}$ and optical bandwidth $>150$nm. The nanobeams are fabricated from bulk optical grade single--crystal diamond using a scalable undercut etching process, and support mechanical resonances with quality factor $2.5 \times 10^5$ at room temperature, and $7.2 \times 10^5$ in cryogenic conditions (5K). Mechanical self--oscillations, resulting from interplay between photothermal and optomechanical effects, are observed with amplitude exceeding 200 nm for sub-$\mu$W absorbed optical power, demonstrating the potential for optomechanical excitation and manipulation of diamond nanomechanical structures.Comment: Minor changes. Corrected error in units of applied stress in Fig. 1

Design and experimental demonstration of optomechanical paddle nanocavities

We present the design, fabrication and initial characterization of a paddle nanocavity consisting of a suspended sub-picogram nanomechanical resonator optomechanically coupled to a photonic crystal nanocavity. The optical and mechanical properties of the paddle nanocavity can be systematically designed and optimized, and key characteristics including mechanical frequency easily tailored. Measurements under ambient conditions of a silicon paddle nanocavity demonstrate an optical mode with quality factor $Q_o$ ~ 6000 near 1550 nm, and optomechanical coupling to several mechanical resonances with frequencies $\omega_m/2\pi$ ~ 12-64 MHz, effective masses $m_\text{eff}$ ~ 350-650 fg, and mechanical quality factors $Q_m$ ~ 44-327. Paddle nanocavities are promising for optomechanical sensing and nonlinear optomechanics experiments.Comment: 5 pages, 4 figure

Micropropagation of lisianthus (Eustoma grandiflorum), an ornamental plant

Abstract Lisianthus (Eustoma grandiflorum) is an ornamental plant with beautiful flowers. Micropropagation is a powerful tool for large-scale propagation of ornamental plants. The shoot tips explants from Lisianthus were cultured on MS medium supplemented with concentrations of 0, 0.5, 1 and 2 mg/L of NAA and KIN. Here, we present a simple and reliable strategy for micropropagation of Eustoma grandiflorum in presence of the single growth regulator, KIN, which enables the production of stock plants. Multiple shoots containing roots can be obtained simultaneously on MS basal medium only supplemented with 0.5-1 mg/L KIN. Shoot tips media supplemented with 1 mg/L KIN without NAA resulted in the best shoot length per explant (2.058 cm) and shoot number per explant (2.62). Also, the most number of nodes per explant (8.86) was obtained in medium containing 0.5 mg/L KIN without NAA. The highest root number per shoot (2.40) was seen in medium supplemented with 2 mg/L KIN + 0.5 mg/L NAA. Shoot tips grown in medium containing 2 mg/L NAA without KIN showed the most callus formation. The results of this study revealed that the best shoot proliferation was achieved in MS medium supplemented with 0.5 or 1 mg/L KIN without NAA. Regenerated plants were transferred to peat and perlite (1:1) after hardening and they showed 100% survival

COMPARISON OF DIFFERENT MEDIA TO PRODUCE CYMBIDIUM ORCHIDS BY PSEUDOBULBS

Nowadays, Orchids are one of the most commercial products in flower markets. One of the propagation methods for Cymbidium is using old pseudobulbs that are thrown out after flowering period. This research carried out using standard Cymbidium back-bulbs based on randomized complete block design with 5 treatments in 3 replications. The trial traits were leaf length, root length, leaf number and root number that were studied for 180 days. The results show that minimum length of root was significant under different growth beds. The minimum percent of rooting was observed in pure sand treatment. The maximum length was observed in pure perlite. The shortest of leaves were gained in perlite + sand treatment and the maximum leaf length was observed in pure perlite treatment. The maximum average of root percent was seen in pure perlite treatment

Optimization of In Vitro Propagation of Pear (Pyrus communis L.) ‘Pyrodwarf®(S)’ Rootstock

Pears are among the most economically important fruits in the world that are grown in all temperate zones. Pyrus communis L., ‘Pyrodwarf®(S)’ rootstock is one of the gene sources used to improve fruit productivity, rootstock resistance, and tolerance to biotic and abiotic stresses. Traditional propagation of P. communis L. is time-consuming and limited by a short growing season and harsh winter conditions. Therefore, in vitro propagation is a suitable alternative. Murashige and Skoog medium (MS) and woody plant medium (WPM) supplemented with different concentrations of 6-benzyladenine (BA) and kinetin (Kin), individually or in combination, were used for in vitro shoot proliferation. Nodal segments were used as explants. MS medium augmented with indole-3-butyric acid (IBA) or indole-3-acetic acid (IAA) was then used for rooting of microshoots. A combination of 2 mg·L−1 BA and 1 mg·L−1 Kin in MS medium resulted in a significant improvement in shoot proliferation. This combination produced the highest number of shoots (4.352 per explant) and leaves (10.02 per explant). The longest shoots (4.045 cm) were obtained in WPM enriched with 1 mg·L−1 BA. However, these shoots were not suitable for multiplication and rooting steps. The largest number of roots (5.50 per microshoot) was obtained on MS medium augmented with IAA at 1 mg·L−1. The produced plantlets were cultivated in pots filled with perlite and cocopeat (in a ratio of 1:3) and acclimatized gradually in a greenhouse, recording an even 90% survival rate

Cryopreservation of Endangered Ornamental Plants and Fruit Crops from Tropical and Subtropical Regions

Horticultural crops comprise various economic species extending from fruits, nuts, vegetables, spices and condiments, ornamentals, aromatic, and medicinal plants. Ornamental and fruit plants are produced mainly for their nutritional and aesthetic values, respectively. Unfortunately, many tropical and subtropical species are in danger of extinction because of climate change and (a)biotic stresses. It is imperative to preserve the germplasms of these species for the present and future genetic improvement programs. Cryopreservation, i.e., maintenance of tissues at the ultralow temperature of liquid nitrogen, is a promising long-term preservation technique, alternative to seed or in vitro banks, which can be applied for both vegetatively and generatively (through seeds) propagated crops, including those with recalcitrant seeds. It is a technology of choice not only for the preservation of plant biodiversity but also for virus elimination in the proficient administration of large-scale micropropagation. The main advantages of cryopreservation are the lowering of in vitro culture expenditures, needed space, contamination risk, and operator errors. However, tropical species are temperature delicate and one of the foremost challenging issues is preconditioning treatments that stimulate physiological reactions to sufficiently enhance tolerance to dehydration and cryogenic procedures. In recent years, several cryopreservation methods based on encapsulation-vitrification, droplet-vitrification, the use of aluminum cryo-plates, and cryo-mesh have been established. Combined cryo-techniques, gene/DNA conservation, as well as studies on perceiving bio-molecular events and exploring the multistage process from the beginning to end of cryopreservation are receiving more emphasis. The development of cryobiomics delivers a conceptual framework to assess the significance of cell signaling mechanisms on cellular functions, the influence of cryoinjury factors on sample viability, and the implications for genetic stability following cryo-storage. The aim of this mini-review article is to provide a succinct synthesis of the developed cryogenic procedures and their use for the storage and exchange of genetic resources of tropical and subtropical horticultural crops, particularly fruit crops and ornamental plants under the threat of extinction

Cryopreservation of Endangered Ornamental Plants and Fruit Crops from Tropical and Subtropical Regions

Horticultural crops comprise various economic species extending from fruits, nuts, vegetables, spices and condiments, ornamentals, aromatic, and medicinal plants. Ornamental and fruit plants are produced mainly for their nutritional and aesthetic values, respectively. Unfortunately, many tropical and subtropical species are in danger of extinction because of climate change and (a)biotic stresses. It is imperative to preserve the germplasms of these species for the present and future genetic improvement programs. Cryopreservation, i.e., maintenance of tissues at the ultralow temperature of liquid nitrogen, is a promising long-term preservation technique, alternative to seed or in vitro banks, which can be applied for both vegetatively and generatively (through seeds) propagated crops, including those with recalcitrant seeds. It is a technology of choice not only for the preservation of plant biodiversity but also for virus elimination in the proficient administration of large-scale micropropagation. The main advantages of cryopreservation are the lowering of in vitro culture expenditures, needed space, contamination risk, and operator errors. However, tropical species are temperature delicate and one of the foremost challenging issues is preconditioning treatments that stimulate physiological reactions to sufficiently enhance tolerance to dehydration and cryogenic procedures. In recent years, several cryopreservation methods based on encapsulation-vitrification, droplet-vitrification, the use of aluminum cryo-plates, and cryo-mesh have been established. Combined cryo-techniques, gene/DNA conservation, as well as studies on perceiving bio-molecular events and exploring the multistage process from the beginning to end of cryopreservation are receiving more emphasis. The development of cryobiomics delivers a conceptual framework to assess the significance of cell signaling mechanisms on cellular functions, the influence of cryoinjury factors on sample viability, and the implications for genetic stability following cryo-storage. The aim of this mini-review article is to provide a succinct synthesis of the developed cryogenic procedures and their use for the storage and exchange of genetic resources of tropical and subtropical horticultural crops, particularly fruit crops and ornamental plants under the threat of extinction

Somatic embryogenesis, encapsulation, cold storage, and growth of hybrid <em>Citrus</em> [<em>C.</em> <em>paradisi</em> Macf. (‘Duncan’) × <em>C. reticulata</em> Blanco. (‘Dancy’)] shoot tip segments

134-144Artificial seed or encapsulation technology presents an innovative tool in plant biotechnology for an efficient and cost-effective large-scale propagation, breeding, in vitro conservation, non-embryonic synthetic seed production and germplasm exchange and distribution. Somatic embryogenesis is a proper method for micropropagation of fruit crops like Citrus and has the potential of commercial mass propagation. This method offers advantages in improving fruit species over other in vitro propagation methods. The combination of somatic embryogenesis and conservation strategies allows to develop both in vitro propagation and propagated germplasm exchange. In the first study, seeds of Minneola tangelo [C. paradisi Macf. (‘Duncan’) × C. reticulate Blanco. (‘Dancy’)] were placed on MS (Murashige and Skoog) medium supplemented with 500 mg l-1 malt extract. Shoot tips from in vitro grown seedlings were excised and cultured on MS basal medium supplemented with 10 mg l-1 BAP and 1 mg l-1 napthalene acetic acid (NAA) for proliferation. A large number of micro-shoots were obtained when shoot tip explants were cultured on this medium. In vitro derived shoot tips were dipped in 3%, 4% and 5% of Na-alginate dissolved either in liquid MS medium supplemented with 50 g l-1 sucrose + 10 mg l-1 6 benzyl amino purine (BAP) + 1 mg l-1 NAA, liquid MS medium supplemented with 50 g l-1 sucrose and distilled water with 50 g l-1 sucrose as treatments. The suitable artificial or synthetic seeds were formed when the micro-shoots were encapsulated in 4% Na-alginate with 100 mM CaCl2.2H2O. Encapsulated and non-encapsulated shoot tips were stored at 4°C for different storage periods (1-8 weeks). Maximum viability (55% after 3 weeks, 34% after 4 weeks and 12% after 7 weeks) was obtained in shoot tips encapsulated on liquid MS medium supplemented with 50 g l-1 sucrose + 10 mg l-1 BAP + 1 mg l-1 NAA, while non-encapsulated shoot tips and shoot tips encapsulated on distilled water with 50 g l-1 sucrose lost their viability completely after 3 weeks. After the storage time, encapsulated shoot tips were germinated and multiplied on MS medium containing 10 mg l-1 BAP + 1 mg l-1 NAA as regeneration medium. Roots were formed on the basis of shoots when they grew on MS medium enriched with 50 mg l-1 indole-3-butyric acid (IBA). In the second study, the effects of various media on callus induction and direct and indirect somatic embryogenesis of immature seeds of Citrus were examined. Maximum somatic embryogenesis (direct and indirect), induction of embryonic callus and embryo maturation were achieved in MS medium supplemented with 500 mg l-1 malt extract, 50 g l-1 sucrose and 3 mg l-1 BAP