Home > Influence of Salt Stress on Some Physiological and Biochemical Attributes and Oil Composition of a Potential Oilseed Crop Safflower Carthamus Tinctorius L. .
Influence of Salt Stress on Some Physiological and Biochemical Attributes and Oil Composition of a Potential Oilseed Crop Safflower Carthamus Tinctorius L. .
The principal objectives of the present investigation were to assess inter- cultivar variation for salt tolerance in safflower, draw relationships of various physiological and biochemical attributes to salt tolerance of safflower, identify selection criteria for further improvement in salt tolerance of safflower through specific breeding programs and to appraise whether or not salt stress alters the composition and quality of safflower oil. Different experiments were carried out to assess variation in salt tolerance in 10 accessions (Safflower-31, Safflower-32, Safflower-33, Safflower-34, Safflower-35, Safflower-36, Safflower-37, Safflower-38, Safflower-39, Safflower-78) of safflower (Carthamus tinctorius L.) at varying levels of salt (NaCl) at different growth stages, germination, seedling and adult stages. The results of the germination experiment showed that salt stress had an inhibitory effect on germination percentage and seedling biomass of all 10 accessions. A significant variation in the accessions was observed at the two higher salt levels (180 and 240 mM). While ranking the accessions on the basis of their potential for germination and producing seedling biomass at 240 mM NaCl, lines Safflower- 31 and Safflower-35 were found to be tolerant, Safflower-33, Safflower-37, Safflower-38 and Safflower-78 salt sensitive, and Safflower-32, Safflower- 34, Safflower-36 and Safflower-39 moderately tolerant. To further evaluate safflower lines for their performance at later growth stages, an experiment was conducted using two salt levels (0 control, 150 mM NaCl). Salt stress caused a marked reduction in biomass production, photosynthetic pigments, leaf water relations, gas exchange characteristics, proline content, mineral nutrients, activities of some key antioxidant enzymes, different fatty acids, tocopherol contents and yield attributes. A significant inter-cultivar variation was found in the set of 10 diverse safflower accessions at the adult stage. Although variation for salt tolerance was found at all growth stages, that found at the germination and seedling stage was not maintained at the vegetative or adult growth stages. On the basis of shoot biomass production at the vegetative stage, accession Safflower-37 was ranked as tolerant, while Safflower-31, Safflower-32, Safflower-34, Safflower-39, and Safflower-78 as salt sensitive. In contrast, in terms of seed yield, accessions Safflower- 32, Safflower-34, and Safflower-39 were ranked as tolerant, while Safflower-31, Safflower-33, Safflower-35, Safflower-36, and Safflower-38 as salt sensitive. A positiveassociation of net photosynthetic rate (A) with growth and seed yield was observed in the 10 diverse safflower lines under saline conditions, and thus it could be used as an effective selection criterion for salinity 2 tolerance in safflower.
The purpose of this research was to study the persecution of press in Sindh during the currency of Pan-Indian political movements known as Khilafat and Non-Cooperation Movements, during 1920-22. In this regard the case study of two popular newspapers, Al-Waheed and Watan, were conducted to understand the mechanism of monitoring and controlling the newspapers in Sindh by the colonial rulers. The study explores the political landscape of Sindh in particular and India in general during those turbulent times as well as examines the state of journalism in the province at that time. With the help of the case study of two popular newspapers, the study highlights the mechanism adopted by the colonial government for monitoring and controlling the press in Sindh. In this regard the archival official records as well as translations of the critical articles published in those newspapers were accessed at the India Office Records (IOR) section of British Library, London. The methodology adopted for the current study mainly comprised historical, analytical and content analysis. The study concludes that the press in Sindh faced severe hardships at the hands of the British government through a coercive mechanism with active involvement and concurrence of all the capitals of Sindh’s governance, i.e. Karachi, Bombay, Delhi and London. The study is first of its kind that highlights the role played and sacrifices rendered by press in Sindh for the freedom of press during colonial rule in 192022. ______
This thesis presents studies on magnetic and magnetoelectric behavior of composite multiferroics, materials that are strong candidates for next generation multifunctional devices. These investigations have been carried out on matrix based composite magnetoelectric multiferroics consisting of magnetostrictive cobalt ferrite (CoFe2O4) and piezoelectric barium titanate (BaTiO3) or bismuth ferrite (BiFeO3), with the magnetostrictive phase embedded in a three dimensional matrix of the piezoelectric phase. The direct magnetoelectric (ME) effect has been investigated in 0-3 composites of BaTiO3 (BTO) and CoFe2O4 (CFO). The ME response has been found to depend non- linearly on the ratio of the magnetostrictive (CFO) content and it is proportional to the strength of the applied magnetic field. The non-linear behavior is explained in terms of the compound effect of the increasing CFO content and the number density of CFO-BTO interfaces. Epitaxial self-assembled nanocomposite thin films were grown by laser ablating targets of magnetostrictive (CoFe2O4) and piezoelectric (BiFeO3 or BaTiO3) phases, on (001) oriented substrates using a combinatorial approach. The surface morphology of the nanocomposite films reveal CFO nanopillars protruding out of a flat piezoelectric matrix. Structural properties were investigated by a four-circle diffractometer, which revealed the presence of the epitaxially grown phases and was used to find the in-plane and out-of-plane lattice parameters of the constituent phases. The magnetization hysteresis loops were measured by a SQUID magnetometer at room temperature. The highly magnetostrictive CFO phase under epitaxial strain from the piezoelectric matrix, exhibits a strong perpendicular anisotropy in the magnetic properties. Changes in the magnetic anisotropy were investigated under different strain conditions induced by (i) post growth annealing, (ii) exploiting phase transitions in the BaTiO3 substrate, and (iii) applying an electric field to the electromechanical substrates. It has been shown that by exploiting the hysteretic properties of a suitable electromechanical substrate, one can control volatile or non-volatile magnetic states by means of an electric field. These results make an important contribution towards the understanding and potential applications of magnetoelectric multiferroics.