Date palm (Phoenix dactylifera L.) in vitro morphogenesis in response to growth regulators, sucrose and nitrogen

Studies were conducted to test the effect of different growth regulators, sucrose and nitrogen on Phoenix dactylifera L. explants cultured on Eeuwen’s basal medium. Naphthalene acetic acid (NAA) wasvery effective for callus induction. Addition of cytokinins (BAP and Kinetin) to NAA containing media did not enhance actual callus growth. Sucrose influenced callus production. Depending on the auxin concentration of media, callus production could be supported by sucrose within the range 15 - 105 g/l but the optimum sucrose concentration in the medium in all cases, as determined by size of callus was 30 g/l. NAA and sucrose tended to interact at relatively high levels of sucrose (45 – 90 g/l) to produceroots in culture. KNO3 was essential as a source of nitrogen for callogenesis and optimum callus formation was observed at 50 mM (combined nitrogen)

The inevitable youthfulness of known high-redshift radio galaxies

Radio galaxies can be seen out to very high redshifts, where in principle they can serve as probes of the early evolution of the Universe. Here we show that for any model of radio-galaxy evolution in which the luminosity decreases with time after an initial rapid increase (that is, essentially all reasonable models), all observable high-redshift radio-galaxies must be seen when the lobes are less than 10^7 years old. This means that high-redshift radio galaxies can be used as a high-time-resolution probe of evolution in the early Universe. Moreover, this result helps to explain many observed trends of radio-galaxy properties with redshift [(i) the `alignment effect' of optical emission along radio-jet axes, (ii) the increased distortion in radio structure, (iii) the decrease in physical sizes, (iv) the increase in radio depolarisation, and (v) the increase in dust emission] without needing to invoke explanations based on cosmology or strong evolution of the surrounding intergalactic medium with cosmic time, thereby avoiding conflict with current theories of structure formation.Comment: To appear in Nature. 4 pages, 2 colour figures available on request. Also available at http://www-astro.physics.ox.ac.uk/~km

Wetlands for wastewater treatment and subsequent recycling of treated effluent : a review

Due to water scarcity challenges around the world, it is essential to think about non-conventional water resources to address the increased demand in clean freshwater. Environmental and public health problems may result from insufficient provision of sanitation and wastewater disposal facilities. Because of this, wastewater treatment and recycling methods will be vital to provide sufficient freshwater in the coming decades, since water resources are limited and more than 70% of water are consumed for irrigation purposes. Therefore, the application of treated wastewater for agricultural irrigation has much potential, especially when incorporating the reuse of nutrients like nitrogen and phosphorous, which are essential for plant production. Among the current treatment technologies applied in urban wastewater reuse for irrigation, wetlands were concluded to be the one of the most suitable ones in terms of pollutant removal and have advantages due to both low maintenance costs and required energy. Wetland behavior and efficiency concerning wastewater treatment is mainly linked to macrophyte composition, substrate, hydrology, surface loading rate, influent feeding mode, microorganism availability, and temperature. Constructed wetlands are very effective in removing organics and suspended solids, whereas the removal of nitrogen is relatively low, but could be improved by using a combination of various types of constructed wetlands meeting the irrigation reuse standards. The removal of phosphorus is usually low, unless special media with high sorption capacity are used. Pathogen removal from wetland effluent to meet irrigation reuse standards is a challenge unless supplementary lagoons or hybrid wetland systems are used

A Bioinformatics Filtering Strategy for Identifying Radiation Response Biomarker Candidates

The number of biomarker candidates is often much larger than the number of clinical patient data points available, which motivates the use of a rational candidate variable filtering methodology. The goal of this paper is to apply such a bioinformatics filtering process to isolate a modest number (<10) of key interacting genes and their associated single nucleotide polymorphisms involved in radiation response, and to ultimately serve as a basis for using clinical datasets to identify new biomarkers. In step 1, we surveyed the literature on genetic and protein correlates to radiation response, in vivo or in vitro, across cellular, animal, and human studies. In step 2, we analyzed two publicly available microarray datasets and identified genes in which mRNA expression changed in response to radiation. Combining results from Step 1 and Step 2, we identified 20 genes that were common to all three sources. As a final step, a curated database of protein interactions was used to generate the most statistically reliable protein interaction network among any subset of the 20 genes resulting from Steps 1 and 2, resulting in identification of a small, tightly interacting network with 7 out of 20 input genes. We further ranked the genes in terms of likely importance, based on their location within the network using a graph-based scoring function. The resulting core interacting network provides an attractive set of genes likely to be important to radiation response

Assessment of an oil palm population from Nigerian Institute for Oil Palm Research (NIFOR) for simple sequence repeat (SSR) marker application

Oil palm (Elaeis guineensis Jacq.), a monocotyledonous plant belonging to the Arecaceae family, is one of the most important oil crops in the world. In Nigeria, oil palm has benefited immensely from conventional breeding efforts resulting in high yields that have been achieved with this breeding material. However, oil palm breeding is slow and time-consuming due to a breeding cycle of about 10 years. In addition, the process of outcrossing leads to high variation in yield components and vegetative traits. Although DNA marker technologies offer great possibilities for plant breeding through marker-assisted selection, there are so far no reports of its application to oil palm breeding in Nigeria. In this study, 32 SSR markers were used for the assessment of marker application in an oil palm breeding population coming from the extensive breeding program at the Nigerian Institute for Oil Palm Research (NIFOR). Seven SSR markers out of the 32 tested (22%) segregated in the progeny 12 (tenera x Deli dura). SSR markers mEgCIR0059, mEgCIR1917, mEgCIR3260, mEgCIR3275, mEgCIR3533 and mEgCIR3557 proved to be fully informative markers following a segregation ratio of 1:1:1:1, while marker mEgCIR0074 segregated in a 1:1 ratio.Keywords: Oil palm, microsatellite marker, marker-assisted selection, NIFORAfrican Journal of Biotechnology, Vol 13(14), 1529-154