16,526 research outputs found
The Production of Cauliflower Microshoots using Curd Meristematic Tissues and Hypocotyl–derived Callus.
The capacity for microshoot production from cauliflower was investigated applying two different protocols. In the first, cauliflower curd meristematic tissue was used as a source of explants. The meristematic layer was shaved off and the clusters produced were homogenised using a commercial blender. In terms of its effect on the number and viability of microshoots, the use of 30 s blending duration treatment was found to be optimal between several treatments tested in the range 15 to 120 sec. Explants were cultivated in agitated S23 (MS (Murashige and Skoog, 1962) + 3 % sucrose) liquid media supplemented with different combinations of plant growth regulators. The use of 2 mg/L kinetin and 1 mg/L IBA gave the optimal results in terms of the number and viability of microshoots. The second protocol was designed to investigate the regeneration potential of hypocotyl explants of cauliflower via callus culture. The callus tissue was initiated from hypocotyl explants in callus induction medium (CIM), which consisted of S23 supplemented with 2,4-D at 1 mg/L and kinetin at 1.5 mg/L. The highest number of shoots was obtained after 28 days from sub-cultured hypocotyl derived callus on S23 basal media containing 0.5 mg/L of kinetin. This study demonstrated the ability of producing microshoots using various parts of cauliflower through both callus and without callus formation which can be useful in the later applications of cauliflower tissue culture such as the production of artificial seeds
Artificial Seed Production from Encapsulated Microshoots of Cauliflower (Brassica oleraceae var botrytis)
A cost effective protocol for the production of cauliflower microshoots suitable for encapsulation was designed. Microshoots were encapsulated in sodium chloride matrices. The use of 2% of sodium alginate and 15 g/L of dehydrate calcium chloride produced the optimal quality of artificial seeds (rigidity, conversion rate and viability). Of the various plant growth regulator combinations used with the microshoot liquid culture medium, the use of 1 mg/L of IBA (indole butyric acid) and 1 mg/L Kinetin was found to be optimal in terms of the conversion rate and viability of artificial seeds. To standardize a medium composition of artificial endosperm of synthetic seeds, different concentrations and combinations of plant growth regulators with S23 (4.4 MS + 30 g/L sucrose) medium were used in the beads to achieve optimum conversion rate and viability on an in-vitro medium. Whilst several combinations of plant growth regulators gave a conversion rate up to 100% (for example (0.5 mg/L Kinetin + 0.5 mg/L IBA), (1 mg/L Kinetin + 0.5 mg/L NAA (naphthaleneacetic acid)) and (1 mg/L Kinetin + 1 mg/L IAA (indole-3-acetic acid)), no significant effect on the viability of artificial seeds was found when these combinations were used. Artificial seeds were cultivated in a semi-solid medium containing several types and concentrations of auxin, 2 mg/L of IBA gave the best results in terms of artificial seed viability. However, artificial seed conversion rate was not significantly affected by the auxins and full conversion rate was obtained using many different treatments. This research indicated the feasibility of using artificial seeds as a promising alternative to seeds produced by traditional methodology
Germination of primed seed under NaCl stress in wheat.
Copyright © 2012 Michael P. Fuller et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Soil salinity affects a large and increasing amount of arable land worldwide, and genetic and agronomic solutions to increasing salt tolerance are urgently needed. Experiments were conducted to improve wheat seed performance under salinity stress conditions after priming. An experiment was conducted using a completely randomized design of four replications for germination indices in wheat (Triticum aestivum L. cv. Caxton). Normal and primed seed with PEG6000 at −1MPa and five concentrations of NaCl (0, 50, 100, 150, and 200mM) were tested. Results indicate that priming seed significantly (P < 0.05) increased germination percentage at first count and final count, coefficient of velocity of germination, germination rate index, and mean germination time, while increasing of NaCl concentration significantly reduced it. Priming seed improved germination attributes at all NaCl concentration levels. The priming appeared to be able to overcome the effect of salt stress at 50 to 100mMand reduce the effect of NaCl at higher concentrations up to 200 mM. The primed seed gave both faster germination and led to higher germination when under salt stress. We conclude that using priming techniques can effectively enhance the germination seed under saline condition
Frost Hardiness of Iraqi Wheat genotypes
Frost hardiness level in winter cereals is especially temperature dependent. The low temperature which kills 50% of plants (LT50) is considered to be a standard indicator of frost hardiness level of plant. Frost hardiness is considered the most important parameter for the field survival which is the ultimate measure of winter-hardiness of a cultivar. This study aimed to determine the genetic level of frost hardiness of five Middle Eastern varieties (Abu-Ghraib, Fatah, IPA 95, IPA 99, and Sham 6) in comparison to the European cultivar (Claire). All of the Middle Eastern varieties tested showed very similar LT50’s in the nonacclimated state, whilst when of acclimated they responded in different ways to freezing temperatures. Abu-Ghraib and Claire showed more tolerance than the other cultivars
Exogenous application of molybdenum affects the expression of CBF14 and the development of frost tolerance in wheat.
Wheat is able to cold acclimate in response to low temperatures and thereby increase its frost tolerance and the extent of this acclimation is greater in winter genotypes compared to spring genotypes. Such up-regulation of frost tolerance is controlled by Cbf transcription factors. Molybdenum (Mo) application has been shown to enhance frost tolerance of wheat and this study aimed to investigate the effect of Mo on the development of frost tolerance in winter and spring wheat. Results showed that Mo treatment increased the expression of Cbf14 in wheat under non-acclimating condition but did not alter frost tolerance. However, when Mo was applied in conjunction with exposure of plants to low temperature, Mo increased the expression of Cbf14 and enhanced frost tolerance in both spring and winter genotypes but the effect was more pronounced in the winter genotype. It was concluded that the application of Mo could be useful in situations where enhanced frost resistance is required. Further studies are proposed to elucidate the effect of exogenous of applications of Mo on frost resistance in spring and winter wheat at different growth stages
Continuous non-invasive eye tracking in intensive care
Delirium, an acute confusional state, is a common occurrence in Intensive Care Units (ICUs). Patients who develop delirium have globally worse outcomes than those who do not and thus the diagnosis of delirium is of importance. Current diagnostic methods have several limitations leading to the suggestion of eye-tracking for its diagnosis through in-attention. To ascertain the requirements for an eye-tracking system in an adult ICU, measurements were carried out at Chelsea & Westminster Hospital NHS Foundation Trust. Clinical criteria guided empirical requirements of invasiveness and calibration methods while accuracy and precision were measured. A non-invasive system was then developed utilising a patient-facing RGB camera and a scene-facing RGBD camera. The system’s performance was measured in a replicated laboratory environment with healthy volunteers revealing an accuracy and precision that outperforms what is required while simultaneously being non-invasive and calibration-free The system was then deployed as part of CONfuSED, a clinical feasibility study where we report aggregated data from 5 patients as well as the acceptability of the system to bedside nursing staff. To the best of our knowledge, the system is the first eye-tracking systems to be deployed in an ICU for delirium monitoring
What is the patient looking at? Robust gaze-scene intersection under free-viewing conditions
Locating the user’s gaze in the scene, also known as Point of Regard (PoR) estimation, following gaze regression is important for many downstream tasks. Current techniques either require the user to wear and calibrate instruments, require significant pre-processing of the scene information, or place restrictions on user’s head movements.We propose a geometrically inspired algorithm that, despite its simplicity, provides high accuracy and O(J) performance under a variety of challenging situations including sparse depth maps, high noise, and high dynamic parallax between the user and the scene camera. We demonstrate the utility of the proposed algorithm in regressing the PoR from scenes captured in the Intensive Care Unit (ICU) at Chelsea & Westminster Hospital NHS Foundation Trust a
- …