Dengue Fever: A Continuous Threat

Dengue fever is a vector borne disease and is caused by DEN Virus. This virus has four different serotypes. The vectors are two mosquitoes known as Aedesaegypti (the yellow fever mosquito) and Aedesalbopictus(the Asian tiger mosquito).  First case of dengue fever was reported back in 1994 in Karachi. A complete outbreak of this epidemic shook the whole nation in 2012. Uptill now, Lahore a city full of culture, witnessed about 16,580 confirmed cases and 257 deaths. About 5000 confirmed cases with 60 deaths were reported from the rest of the provinces. Under guidelines of WHO, Government has made efforts to combat this epidemic. Although the overall efforts have minimized the outbreak on controllable levels but dengue fever is a continuous threat. Since no permanent cure is available, the transmission of DEN virus is controlled indirectly. So the prime focus is to control mosquito population and decrease the possible hot spots i.e. Mosquito breeding sites in human habitations. Every year, the country witnesses monsoon season which brings vast areas full of clear standing waters providing breeding sites for mosquitoes which ultimately leads to increased number of patients suffering from dengue fever. Efforts have been made to fight against dengue including formation of dengue wards in hospitals, vector surveillance, community education, reactive vector control etc. A study has shown prevalence of four mosquito genera in Pakistan including Aedes, Culex, Armigeresand Anopheles. All of the above mentioned genera are associated with disease transmissions as they are the vectors of different viruses and parasites. It is the need of hour to do a collaborative effort stressing the community mobilization and management in war against dengue.

Qtl Mapping for Metabolic and Molecular Attributes of Drought Tolerance in Hexaploid Wheat Triticum Aestivum L.

Wheat is the main staple food and largest grain crop of Pakistan. Abiotic stress reduces plant’s growth or development. An extended period of water deficits over months or years is the main cause of the drought. Drought arises in plants when the rate of transpiration is greater than rate of water uptake. QTLs (quantitative trait loci) are detected in mapping populations developed from controlled crosses segregating for the trait of interest and are a correlation of DNA marker data with phenotypic information. The research was conducted at PMAS Arid Agriculture University, Rawalpindi , Wheat Wide Crosses and Cytogenetic (WWC), National Agriculture Research Center, (NARC) Islamabad and Cereal Research institute (CRA-CER), Foggia Italy. The double haploid mapping population 5 (DR.MP. 5), with its individuals having pedigree of (Doy 1 // Ae. Squarrosa (458) / 5 / Opata), was planted under control (Field, fully irrigated) and stress (rain shelter) conditions. The parents of mapping population, i.e., SH349 (D genome grounded drought tolerant synthetic hexaploid wheat) and bread wheat (Opata M-85, drought susceptible) were also grown individually in the field and tunnel. The biochemical analysis included osmolytes determination, i.e. soluble sugar; proline and antioxidant included superoxide dismutase activity, cell membrane stability followed by molecular diagnostics including DNA extraction, polymerase chain reaction and capillary electrophoresis. Yield and Yield Components were included Days to heading, Days to physiological maturity, Plant height (cm), Spike length (cm), Number of grains per spike, 1000 Grain weight (g), pubescence, awn color and prostrate vs. erect habit. In this study, STATISTIX software was used for Two Factors Factorial Analysis of Variance, LSD (Least Significant Difference) did a2 comparison of means, and STATISTICA software was used to find out the correlation among different traits under control and stress conditions. For linkage and QTL analyses, JoinMap4 and MapQTL5 were used. Five Drought tolerant wheat lines were identified (18, 34, 54, 56 and 59). A linkage map was built by using SSR markers. One hundred and seventy four SSRs markers were used to screen the parents, (Opata, drought sensitive, and SH349, drought tolerant). Seventy-nine polymorphic markers were identified and applied to drought mapping populations. Interval mapping (IM) and Multiple QTL mapping (MQM) did detection of QTLs. In IM analysis, fifteen QTLs were found for stress condition and thirty-eight QTLs were found in control conditions. In MQM analysis, twelve QTLs were found to control under field conditions and sixteen QTLs were detected in MQM analysis under stress. Eleven Novel QTLs have been identified for different traits, six by IM and five by MQM. In the end the results of this research presented that there are some drought tolerant or resistant alleles have been identified which can be moved to vulnerable genotypes using MAS (Marker Assisted Selection). In addition, this study provided additional evidence that the QTL strategy is useful and able to enhance performance of existing cultivars. Further QTL studies will assist in the contribution of positive allelic diversity in the future.