In vitro mutagenesis in Rosa hybrida using oryzalin as a mutagen and screening of mutants by randomly amplified polymorphic DNA (RAPD) marker

Apical and axillary meristems of Rosa hybrida Cv. First red were pretreated with various concentrations (0, 5.0, 10.0, 15.0, 20.0, 25.0 and 30.0 μM) of oryzalin (C12H18N4O6) to induce variation in vitro. The present results indicate that fifty percent survivability (LD50) was obtained in 20 μm oryzalin. Both the treated and untreated meristems were cultured in Murashige and Skoog (MS) basal medium supplemented with 0.5 mg/l benzylaminopurine (BAP), 0.01 mg/l indole acetic acid (IAA), 25 mg/l adenine sulphate (Ads) and 20 μm oryzalin. The elongated shoots were rooted in the half strength MS basal medium supplemented with 0.25 mg/l indole-3-butyric acid (IBA) and about 60% rooted plants survived in the green house. A total of 28 mutants were obtained and evaluated by randomly amplified polymorphic DNA (RAPD) markers using control as untreated meristems. Out of the twenty-eight mutants, eight mutants, which deviate from the DNA banding pattern when compared with the control plants, were obtained. This result showed the efficiency of oryzalin to induce in vitro variability in hybrid rose and detect variation through molecular markers. This investigation will give a better understanding on the rose breeding program.Key words: Hybrid rose, in vitro, oryzalin, mutation

SHODHANA DECREASES NOOTROPIC ACTIVITY OF SEMECARPUS ANACARDIUM

ABSTRACTObjective: To evaluate the nootropic activity of methanolic extract of pre-shodhit and shodhit Semecarpus anacardium (SA) nuts and to observe theeffect of shodhana on nootropic activity of SA.Methods: Spatial learning and working memory was considered for evaluation. The parameters used were spontaneous alternation behavior(Y-maze), number of correct responses (radial maze), and transfer latency in day 1 (elevated plus maze). Scopolamine, an anticholinergic drug, wasused to induce cognitive deficit. % inhibition of acetylcholine esterase (AChE) was measured in vitro.Results: Both pre-shodhit and shodhit drug reversed the scopolamine-induced a decrease in percentage spontaneous alternation behavior in Y-mazeand number of correct responses in radial maze. Scopolamine-induced increase in transfer latency in elevated plus maze was significantly decreasedby pre-shodhit drug only. Shodhit drug has no significant effect on transfer latency. Both pre-shodhit and shodhit drug showed dose-dependentinhibition of AChE activity in vitro. Pre-shodhit drug showed a more nootropic activity than shodhit drug.Conclusion: Methanolic extract of the nuts of S. anacardium possesses nootropic activity which may be attributed to inhibition of cholinesteraseactivity. Shodhana of the nuts decreases nootropic activity.Keywords: Semecarpus anacardium, Acetylcholine esterase, Shodhana, Nootropic

An assessment of genetic fidelity of in vitro grown plantlets of rose (Rosa hybrida) through molecular markers

A simple and routine method for the analysis of somaclonal variation among tissue culture derived rose plants is a prerequisite for precise monitoring of quality control during rapid mass micropropagation. Random  amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR) molecular marker techniques were employed to validate the genetic fidelity in three varieties of Rosa hybrida [Culture varieties (cvs) First  Red, Cri Cri and Pusa Gaurav] multiplied in vitro by axillary multiplication for up to 26 subcultures. Twelve  RAPD and seventeen ISSR primers generated a total of 119, 104 and 114 amplicons in cvs First Red, Cri Cri  and Pusa Gaurav, respectively. A homogeneous amplification profile was observed between the explant source and all the micropropagated plantlets. The result indicated the clonal fidelity of the tissue culture raised R.  hybrida plantlets and corroborated the assumption that axillary multiplication is the safest mode for  multiplication of true to type plants without any somaclonal variation.Key words: Rosa hybrida, in vitro, genetic fidelity, molecular markers

Biodegradation of the Alkaline Cellulose Degradation Products Generated during Radioactive Waste Disposal.

The anoxic, alkaline hydrolysis of cellulosic materials generates a range of cellulose degradation products (CDP) including α and β forms of isosaccharinic acid (ISA) and is expected to occur in radioactive waste disposal sites receiving intermediate level radioactive wastes. The generation of ISA's is of particular relevance to the disposal of these wastes since they are able to form complexes with radioelements such as Pu enhancing their migration. This study demonstrates that microbial communities present in near-surface anoxic sediments are able to degrade CDP including both forms of ISA via iron reduction, sulphate reduction and methanogenesis, without any prior exposure to these substrates. No significant difference (n = 6, p = 0.118) in α and β ISA degradation rates were seen under either iron reducing, sulphate reducing or methanogenic conditions, giving an overall mean degradation rate of 4.7×10−2 hr−1 (SE±2.9×10−3). These results suggest that a radioactive waste disposal site is likely to be colonised by organisms able to degrade CDP and associated ISA's during the construction and operational phase of the facility

Nucleocytoplasmic transport: a thermodynamic mechanism

The nuclear pore supports molecular communication between cytoplasm and nucleus in eukaryotic cells. Selective transport of proteins is mediated by soluble receptors, whose regulation by the small GTPase Ran leads to cargo accumulation in, or depletion from the nucleus, i.e., nuclear import or nuclear export. We consider the operation of this transport system by a combined analytical and experimental approach. Provocative predictions of a simple model were tested using cell-free nuclei reconstituted in Xenopus egg extract, a system well suited to quantitative studies. We found that accumulation capacity is limited, so that introduction of one import cargo leads to egress of another. Clearly, the pore per se does not determine transport directionality. Moreover, different cargo reach a similar ratio of nuclear to cytoplasmic concentration in steady-state. The model shows that this ratio should in fact be independent of the receptor-cargo affinity, though kinetics may be strongly influenced. Numerical conservation of the system components highlights a conflict between the observations and the popular concept of transport cycles. We suggest that chemical partitioning provides a framework to understand the capacity to generate concentration gradients by equilibration of the receptor-cargo intermediary.Comment: in press at HFSP Journal, vol 3 16 text pages, 1 table, 4 figures, plus Supplementary Material include