13 research outputs found
Chickpea
The narrow genetic base of cultivated chickpea warrants systematic collection,
documentation and evaluation of chickpea germplasm and particularly wild
Cicer species for effective and efficient use in chickpea breeding programmes.
Limiting factors to crop production, possible solutions and ways to overcome
them, importance of wild relatives and barriers to alien gene introgression and
strategies to overcome them and traits for base broadening have been discussed.
It has been clearly demonstrated that resistance to major biotic and abiotic
stresses can be successfully introgressed from the primary gene pool
comprising progenitor species. However, many desirable traits including high
degree of resistance to multiple stresses that are present in the species
belonging to secondary and tertiary gene pools can also be introgressed by
using special techniques to overcome pre- and post-fertilization barriers.
Besides resistance to various biotic and abiotic stresses, the yield QTLs have
also been introgressed from wild Cicer species to cultivated varieties. Status
and importance of molecular markers, genome mapping and genomic tools
for chickpea improvement are elaborated. Because of major genes for various
biotic and abiotic stresses, the transfer of agronomically important traits into
elite cultivars has been made easy and practical through marker-assisted
selection and marker-assisted backcross. The usefulness of molecular markers
such as SSR and SNP for the construction of high-density genetic maps of
chickpea and for the identification of genes/QTLs for stress resistance, quality
and yield contributing traits has also been discussed
Pt metal supported and Pt4+ doped La1−xSrxCoO3: non-performance of Pt4+ and reactivity differences with Pt metal
In the present work, we correlate the CO-oxidation activity with the oxidation state of platinum with combined experimental and DFT calculations. XPS reveals that Pt supported La1−xSrxCoO3 (Pt/La1−xSrxCoO3) and Pt doped La1−xSrxCoO3 (La1−xSrxCo1−yPtyO3) consist of Pt in 0 and + 4 oxidation states respectively. Further, catalytic CO oxidation over Pt-doped and Pt-supported La1−xSrxCoO3 in the presence of oxygen demonstrates the lowest activity of the doped compound. Pt supported La1−xSrxCoO3 showed the highest activity with almost 100% conversion at 150 °C. La1−xSrxCo1−yPtyO3 was slightly inferior to the blank La1−xSrxCoO3 suggesting that Pt4+ is an inactive or non-performing entity in the doped compound. Temperature programmed desorption (TPD) demonstrates the low amount of CO desorption from La1−xSrxCoO3 and Pt-doped La1−xSrxCoO3 due to the very weak interaction. On the other hand, Pt-supported La1−xSrxCoO3 shows a substantial amount of CO desorption due to strong interaction and large number of metallic sites available for adsorption. This was supported by density functional theory (DFT) based calculations which showed that Pt-supported La1−xSrxCoO3 surface has higher binding energy of CO than the La1−xSrxCoO3 surface confirming the strong CO interaction. Transient responses using mass spectrometer suggest that the Pt supported perovskite utilizes the lattice oxygen for the reaction and vacancies are formed which gets filled with gaseous oxygen. No such phenomenon is observed in the doped compound demonstrating the mechanistic differences in the two catalysts. Often, during the synthesis of Pt-based compounds, it is common to get mixed phases of platinum including Pt4+. From this study, it can be established that one can discard the contribution from Pt4+ in the calculations of kinetic data such as rate or turnover number because this oxidation state is inactive/nonperforming.by Anuj Bisht, Amita Sihag, Akkireddy Satyaprasad,Sairam S. Mallajosyala and Sudhanshu Sharm