Impact of salinity stress on cotton and opportunities for improvement through conventional and biotechnological approaches.

Excess salinity can affect the growth and development of all plants. Salinization jeopardizes agroecosystems, induces oxidative reactions in most cultivated plants and reduces biomass which affects crop yield. Some plants are affected more than others, depending upon their ability to endure the effects of salt stress. Cotton is moderately tolerant to salt stress among cultivated crops. The fundamental tenet of plant breeding is genetic heterogeneity in available germplasm for acquired characteristics. Variation for salinity tolerance enhancing parameters (morphological, physiological and biochemical) is a pre-requisite for the development of salt tolerant cotton germplasm followed by indirect selection or hybridization programs. There has been a limited success in the development of salt tolerant genotypes because this trait depends on several factors, and these factors as well as their interactions are not completely understood. However, advances in biochemical and molecular techniques have made it possible to explore the complexity of salt tolerance through transcriptomic profiling. The focus of this article is to discuss the issue of salt stress in crop plants, how it alters the physiology and morphology of the cotton crop, and breeding strategies for the development of salinity tolerance in cotton germplasm.

Exploitation of various physio-morphological and biochemical traits for the identification of drought tolerant genotypes in cotton.

BACKGROUND: Drought is one of the limiting factors for quality and quantity of cotton lint in tropical and sub-tropical regions. Therefore, development of drought tolerant cotton genotypes have become indispensable. The identification of drought tolerant genotypes is pre-requisite to develop high yielding cultivars suitable for drought affected areas. METHODS: Forty upland cotton accessions were selected on the basis of their adaptability and yield. The collected germplasm accessions were evaluated at seedling stage on the basis of morphological, physiological and biochemical parameters. The experiment was conducted under controlled conditions in greenhouse where these genotypes were sown under different levels of drought stress by following factorial under completely randomized design. The data were collected at seedling stages for root and shoot lengths, relative leaf water content, excised leaf water losses, peroxidase content and hydrogen peroxide concentrations in leaf tissues. RESULTS: The biometrical analysis revealed that germplasm is significantly varied for recorded parameters, likewise interaction of genotypes and water stress was also significantly varied. The cotton germplasm was categorized in eight clusters based on response to water stress. The genotype Cyto-124 exhibited lowest H2O2 content under drought conditions, minimum excised leaf water loss under stress environment was exhibited by genotypes Ali Akber-802 and CEMB-33. Overall, on the basis of morphological and biochemical traits, SL-516 and Cyto-305 were found to be drought tolerant. Genotypes 1852 - 511, Stoneville 15-17 and Delta Pine-55 showed low values for root length, peroxidase activity and higher value for H2O2 contents. On the basis of these finding, these genotypes were declared as drought susceptible. CONCLUSION: The categorization of cotton germplasm indicating the differential response of various parameters under the control and drought stress conditions. The recorded parameters particularly relative leaf water contents and biochemical assays could be utilized to screen large number of germplasm of cotton for water deficit conditions. Besides, the drought tolerant genotypes identified in this research can be utilized in cotton breeding programs for the development of improved cultivars.

Chitosan-coated halloysite nanotube magnetic microspheres for carcinogenic colorectal hemorrhage and liver laceration in albino rats.

Carcinogenic colorectal hemorrhage can cause severe blood loss and longitudinal ulcer, which ultimately become fatal if left untreated. The present study was aimed to formulate targeted release gemcitabine (GC)-containing magnetic microspheres (MM) of halloysite nanotubes (MHMG), chitosan (MCMG), and their combination (MHCMG). The preparation of MM by magnetism was confirmed by vibrating sample magnetometry (VSM), the molecular arrangement of NH2, alumina, and silica groups was studied by X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS), the hollow spherical nature of the proposed MM was observed by scanning electron microscopy (SEM), functional groups were characterized by Fourier transform infrared (FTIR) spectroscopy and thermochemical modification was studied by thermogravimetric analysis (TGA). In vitro thrombus formation showed a decreasing trend of hemostatic time for MMs in the order of MHMG3 < MCMG3 < MHCMG7, which was confirmed by whole blood clotting kinetics. Interestingly, rat tail amputation and liver laceration showed 3 folds increased clotting efficiency of optimized MHCMG7 compared to that of control. In vivo histopathological studies and cell viability assays confirmed the regeneration of epithelial cells. The negligible systemic toxicity of MHCMG7, more than 90% entrapment of GC and high % release in alkaline medium made the proposed MM an excellent candidate for the control of hemorrhage in colorectal cancer. Conclusively, the healing of muscularis and improved recovery of the colon from granulomas ultimately improved the therapeutic effects of GC-containing MMs. The combination of both HNT and CTS microspheres made them more targeted.