Authors:Amol Mhatre, P. Kalsi, Onkar Choudhary, and G. Sachdev
The gamma irradiation effects in the dose range of 2.5–43.0 Mrad on the etching and optical characteristics of CR-39 solid
state nuclear track detector (SSNTD) have been studied by using etching and UV–Visible spectroscopic techniques. From the
measured bulk etch rates at different temperatures, the activation energies for bulk etching at different doses have also
been determined. It is seen that the bulk etch rates increase and the activation energies for bulk etching decrease with the
increase in gamma dose. The optical band gaps of the unirradiated and the gamma -irradiated detectors determined from the
UV–Visible spectra were found to decrease with the increase in gamma dose. These results have been explained on the basis
of scission of the detector due to gamma irradiation. The present studies can be used for the estimation of gamma dose in
the range of 2.5–43.0 Mrad and can also be used for estimating track registration efficiency in the presence of gamma dose.
The CR-39 detector has also been applied for the assay of uranium in some soil samples of Jammu city.
Authors:L.R. Vemireddy, N. Ranjithkumar, A. Vipparla, M. Surapaneni, G. Choudhary, K.V. Sudhakarrao, and E.A. Siddiq
India bred high yielding rice varieties have enriched to a great extent the global rice germplasm since the mid-sixties. Systematic research efforts for development of cultivar-specific DNA fingerprints of major Indian rice cultivars, however, have not received due attention. The present investigation was aimed at development of DNA fingerprints for 90 high yielding rice varieties using hypervariable microsatellite (hvRM) markers. A panel of eight markers, viz. RM11313, RM13584, RM15004, RM5844, RM22250, RM22565, RM24260 and RM8207 was chosen from 52 polymorphic markers based on their highly polymorphic nature, SSR repeat type and number and ability to distinguish genotypes, in order to develop DNA fingerprints of 90 varieties. The remaining high polymorphic hvRM markers could be of immense value in future to distinguish new cultivars, in case they could not be distinguished by the 8 marker panel. Four of the 8 markers, viz. RM22250, RM13584, RM24260 and RM5844 were located in expressed genes and could be of value in DUS (Distinctness, Uniformity and Stability) testing. Thus we suggested, that this set of 8 loci could be used as standard for DNA fingerprinting of Indian rice cultivars.