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.
Mankind is scattered across the surface of the earth in the forms of different religious creeds, tribal affiliations, race, colour and nationalities. Yet they share some traits that are similar and universal to all human societies. These traits include love for children and respect for the elders. However, changing times have eroded some of these positive traits. The condition of senior citizens is not enviable in the West and those following in their footsteps. Children are not fulfilling their natural duty to their old parents, and quite often the elderly are forcefully kicked out of their own houses and accommodated in designated places for the old, run by the state welfare organizations.
Conceptual Modeling is one of the most important stages of the database (DB) design methodology. A number of approaches for conceptual modeling have been devised in the literature amongst which the Entity-Relationship (ER) modeling technique is extensively used. Since the quality of a conceptual model impacts the quality of the end product, our research focuses on how the quality of an ER model can be improved. We have identified modeling problems in the existing ER modeling technique and have suggested an approach which solves these problems. The result is an improved ER model which closely represents the real-world problem thereby improving the semantic representation. Our proposed approach incorporates real-world constraints that can be described in the form of functional dependencies. This approach applies schema transformations iteratively for which a new set of rules has also been defined. New constructs namely single-valued relationship attribute and multi-valued relationship attribute have also been proposed for improving semantics of the relationship types in an ER model. The impact of the proposed approach on later stages of the database design methodology has also been studied which shows that the resulting relational database satisfies higher normal forms as compared to the existing technique. Quantitative aspect of measuring improvement in the quality of a conceptual model is also an integral part of the research. For this purpose, we have proposed new metrics called completeness index, normalization index, and overall quality index. Completeness index is further refined by applying fuzzy logic and thus a fuzzy completeness index is proposed. We have also defined quantitative metrics for the structural complexity of an ER model in terms of correctness and modifiability. These metrics help us compare the quality of two ER models quantitatively and objectively. We have shown with several examples the efficacy of our approach and proposed metrics. The ultimate result is a better database design and improved database designers’ productivity.