Hybridization of Gossypium species through in ovulo embryo culture

An interspecific hybrid of the sexually incompatible species G. hirsutum cv. Laxmi and G. arboreum cv. Jyoti was obtained through in ovulo embryo culture. Eightto twelve-day-old ovules were excised and cultured on Beasley and Ting's medium supplemented with Indol-3 acetic acid (5×10^-6 to 7×10^-6 M), Kinetin (5×10^-6 to 5×10^-8 M), Gibberellic acid (5×10^-7 to 5×10^-9M), Ammonium chloride (5 to 15mM) and Casein hydrolysate (50 to 200mg/l) added individually and in various combinations along with sucrose. No single medium was adequate to ensure complete development of the fertilized ovules to plantlets, thus necessitating a sequential five step transfer to different media. Cytological studies confirmed the hybrid nature of the plants.Abbreviation IAA Indol-3 acetic acid - Kn Kinetin - GA₃ Gibberellic acid - CH Casein hydrolysate - NAA -Naphthalene-acetic acid - BT Beasley and Ting's basal medium - MS Murashige and Skoog's basal medium - W White's basal medium NCL Communication number 3823.     

Anther culture in Helianthus annuus L., influence of genotype and culture conditions on embryo induction and plant regeneration

Summary Production of microspore-derived embryos from cultured anthers is now a well established technique for the isolation of homozygous lines in many crop plants. We describe here a culture method for embryo induction and plant regeneration from anthers of four sunflower genotypes. For preliminary experiments, anthers of uninucleate microspores were cultured on four types of basal media viz., Murashige and Skoog's MS, Gamborg's B5, Nitsch and Nitsch, and White's W, supplemented with 1.0 mg/l 2,4 dichlorophenoxy acetic acid and 0.5 mg/l 6-benzylaminopurine and 40 g/l sucrose. MS basal medium, being more responsive for embryo induction, was used for further experimentation. To optimise the culture requirement MS basal medium was supplemented with 0.2–2.0 mg/l 2,4 dichlorophenoxy acetic acid and 0.5 and 1.0 mg/l 6-benzylaminopurine. The effect of cold pretreatment, hormone regime and sucrose concentration were tested for embryogenic efficiency. Genotype had a significant effect on the capacity of embryo induction. Addition of silver nitrate (2.5 mg/l), an ethylene inhibitor, stimulated embryo germination. Plantlets were obtained (10–15%) from embryos of only one genotype.Abbreviations 2,4-D 2,4 dichlorophenoxy acetic acid - NAA -naphthalene acetic acid - IAA indole-3-aceticacid - BAP 6-benzylaminopurine - KN Kinetin - ABA abscisic acid - GA₃ gibberellic acid     

Somatic embryogenesis and plant regeneration from immature embryo explant of papaya (Carica papaya L. cv. washington and honey dew)

Immature zygotic embryo explants of Carica papaya were cultured on MS medium supplemented with 2,4-D (2.0 mg/l) and formed globular embryos on explants without callus formation in 4-6 weeks. Maturation and conversion of somatic embryos was also achieved on the same medium. Cotyledonary stage embryos germinated to 63.66 and 68.33% in cv. honey dew and washington respectively in MS basal medium supplemented ABA (0.5 microm/l). Robust development and proliferation of plantlet roots in vitro was obtained on MS basal medium. Hardened plantlets have 60% survival rate.     

Metal accumulation in two contiguous eutrophic peri-urban lakes,Chivero and Manyame,Zimbabwe

Concentrations of aluminium, cadmium, chromium, cobalt, copper, iron, lead, nickel and zinc were determined in surface water, benthic sediments, and the gills, liver and stomach muscle tissues of Oreochromis niloticus and Clarias gariepinus in peri-urban lakes Chivero and Manyame, Zimbabwe. Five sites were sampled in each lake once per month in November 2015, February, May, August and November 2016. Pollution load index detected no metal contamination, whereas the geo-accumulation index reflected heavy to extreme sediment pollution, with Fe, Cd, Zn, Cr, Ni and Cu present in both lakes. Significant spatial temporal variations were detected for Al, Cr, Cu and Pb across sites within and between the two lakes. High Fe, Al and Cr concentrations in water and sediments in lakes Chivero and Manyame derive from geogenic background sources in addition to anthropogenic loads and intensity. Elevated concentrations of Al, Pb, Cu, Cd, Fe and Zn detected in gills, liver and stomach tissue of catfish corroborate concentrations in water and sediments, and pose the highest ecological and health risk for hydrobionts in lakes Chivero and Manyame. Contiguity of peri-urban lakes exposes them to similar threats, necessitating creative water management strategies, which ensure ecological continuity.     

The antidepressant-like effect of Ocimum basilicum in an animal model of depression

We investigated the efficacy of Ocimum basilicum (OB) essential oils for treating depression related behavioral, biochemical and histopathological changes caused by exposure to chronic unpredictable mild stress (CUMS) in mice and to explore the mechanism underlying the pathology. Male albino mice were divided into four groups: controls; CUMS; CUMS plus fluoxetine, the antidepressant administered for pharmacological validation of OB; and CUMS plus OB. Behavioral tests included the forced swim test (FST), elevated plus-maze (EPM) and the open ?eld test (OFT); these tests were performed at the end of the experiment. We assessed serum corticosterone level, protein, gene and immunoexpression of brain-derived neurotropic factor (BDNF) and glucocorticoid receptors (GRs) as well as immunoexpression of glial fibrillary acidic protein (GFAP), Ki67, caspase-3 in the hippocampus. CUMS caused depression in the mice as evidenced by prolonged immobility in the FST, prolonged time spent in the open arms during the EPM test and reduction of open field activity in the OFT. OB ameliorated the CUMS induced depressive status. OB significantly reduced the corticosterone level and up-regulated protein and gene expressions of BDNF and GR. OB reduced CUMS induced hippocampal neuron atrophy and apoptosis, and increased the number of the astrocytes and new nerve cells. OB significantly increased GFAP-positive cells as well as BDNF and GR immunoexpression in the hippocampus.     

Preparation of soybean seed samples for FT-IR microspectroscopy

Typical preparation of seed samples for infrared (IR) microspectroscopy involves imbibition of the seed for varying time periods followed by cryosectioning. Imbibition, however, may initiate germination even at 4° C with associated changes in the chemistry of the sample. We have found that it is possible to section seeds that are sufficiently hard, such as soybeans, on a standard laboratory microtome without imbibition. The use of dry sectioning of unimbibed seeds is reported here, as well as a comparison of different mounting media and modes of analysis. Glycerol, Tissue-Tek, and ethanol were used as mounting media, and the quality of the resulting spectra was assessed. Ethanol was the preferred mountant, because it dried quickly with no residue and thus did not interfere with the spectrum of interest. Analysis in transmission mode using barium fluoride windows to hold the samples was compared with transmission-reflection analysis with sections mounted on special infrared-reflecting slides. The two modes of analysis performed well in different regions of the spectrum. The mode of analysis (transmission vs. transmission-reflection) should be based on the components of greatest interest in the sample.