Souleymane Bado

Induced protein polymorphisms and nutritional quality of gamma irradiation mutants of sorghum

Physical and biochemical analysis of protein polymorphisms in seed storage proteins of a mutant population of sorghum revealed a mutant with redirected accumulation of kafirin proteins in the germ. The change in storage proteins was accompanied by an unusually high level accumulation of free lysine and other essential amino acids in the endosperm. This mutant further displayed a significant suppression in the synthesis and accumulation of the 27kDa γ-, 24kDa α-A1 and the 22kDa α-A2 kafirins in the endosperm. The suppression of kafirins was counteracted by an upsurge in the synthesis and accumulation of albumins, globulins and other proteins. The data collectively suggest that sorghum has huge genetic potential for nutritional biofortification and that induced mutations can be used as an effective tool in achieving premium nutrition in staple cereals.

Physicochemical Characteristics and Composition of Three Morphotypes of Cyperus esculentus Tubers and Tuber Oils

Tuber characteristics and nutrient composition of three morphotypes of Cyperus esculentus tubers and tuber oils were determined. The mean value for length and width of the tuber and one thousand dried tuber weights ranged from 0.98 to 1.31 cm, 0.90 to 1.19 cm, and 598 to 1044 g, respectively. Tubers displayed high level of starch (30.54–33.21 g 100 g−1), lipid (24.91–28.94 g 100 g−1), and sucrose (17.98–20.39 g 100 g−1). The yellow tubers had significantly higher content in lipid compared to black ones. Levels of ascorbic acid, tocopherol, and β-carotene of the three morphotypes differed significantly. Yellow ones (morphotypes 1 and 2) were the richest in tocopherol and the poorest in β-carotene. Saturated fatty acid content of morphotype 2 was significantly lower than that of morphotypes 1 and 3. Morphotype 3 had the significantly lowest PUFA content compared to morphotypes 1 and 2. Morphotype 1 was found to be richer in Ca, Cu, and Mn contents. Al, Mg, P, S, and Si were most abundant in morphotype 2. Morphotype 3 had the highest content of Cl, K, and Zn.

Uptake of 14C-atropine and/or its transformation products from soil by wheat (Triticum aestivum var Kronjet) and their translocation to shoots

Plant uptake of toxins and their translocation to edible plant parts are important processes in the transfer of contaminants into the food chain. Atropine, a highly toxic muscarine receptor antagonist produced by Solanacea species, is found in all plant tissues and can enter the soil and hence be available for uptake by crops. The absorption of atropine and/or its transformation products from soil by wheat (Triticum aestivum var Kronjet) and its distribution to shoots was investigated by growing wheat in soil spiked with unlabeled or 14C-labeled atropine. Radioactivity attributable to 14C-atropine and its transformation products was measurable in plants sampled at 15 d after sowing (DAS) and thereafter until the end of experiment. The highest accumulation of 14C-atropine and/or its transformation products by plants was detected in leaves (between 73 and 90% of the total accumulated) with lower amounts in stems, roots, and seeds (approximately 14%, 9%, and 3%, respectively). 14C-Atropine and/or its transformation products were detected in soil leachate at 30, 60, and 90 DAS and were strongly adsorbed to soil, with 60% of the applied dose adsorbed at 30 DAS, plateauing at 70% from 60 DAS. Unlabeled atropine was detected in shoots 30 DAS at a concentration of 3.9 ± 0.1 μg kg−1 (mean ± SD). The observed bioconcentration factor was 2.3 ± 0.04. The results suggest a potential risk of atropine toxicity to consumers.

Chemical and Physical Mutagenesis in Jatropha curcas

Mutagenized populations are important resources to generate and identify desirable genetic variation of useful traits for crop improvement. When the lack of genetic variability hampers the breeding progress, mutagenesis can introduce genetic variation, reveal gene function, and aid in the characterization of candidate genes involved in biological functions. Mutagenized populations are useful for screening for altered phenotypes and physiological responses, and as a genomics tool. Jatropha curcas is a semi-wild, economically important shrub useful as a source of biofuel or in soil reclamation, but it requires genetic improvement in order to select the best genotypes for these purposes. Therefore, this chapter describes the general methods for mutation induction (chemical and physical mutagenesis) using ethyl methanesulfonate (EMS) treatment, gamma irradiation, X-rays, and the procedures that can be used to generate large numbers of induced mutants in different tissues of J. curcas under in vitro and in vivo conditions.

Protocols for Pre-Field Screening of Mutants for Salt Tolerance in Rice, Wheat and Barley

Salinity is a major abiotic stress limiting crop yields in many parts of the world. The FAO (Food and Agriculture Organization) Land and Plant Nutrition Management service estimates that over 400 million hectares (6 %) of the Earth’s land is affected by salt. Breeding for salt tolerance is a major goal for cereal researchers for which screens are required to select out tolerant lines. Screening for salt tolerance in the field is difficult as soil salinity is dynamic, the level of salt varies both horizontally and vertically in the soil profile and changes with time. These environmental perturbations can be overcome by testing in hydroponic system where the testing environment is controlled.

Protocol for Screening for Salt Tolerance in Rice

A simple protocol is presented that tests salt tolerance in rice seedlings. The method is based on a glasshouse hydroponics test in which salt is added to the nutrient hydroponic solution in which the seedlings are grown. A list of equipment is provided including hydroponic hardware and stock solutions. Advice is given on seed storage prior to use and pregermination treatments that promote even germination of test samples. Salt treatments commence after seedling establishment in hydroponics, at the 2–3 leaf stage. Information on responses of standard genotypes (tolerant, intermediate and sensitive) is given to which test seedlings are compared. Visual symptoms of salinity stress include reduced leaf area, whitish appearance of lower leaves, leaf tip death, leaf rolling and seedling death. Scoring is carried out according to the standard evaluation system developed by the International Rice Research Institute (IRRI). Recommended test salt concentrations are given along with a method to recover selected seedlings and examples of use.

Protocol for measuring soil salinity

A simple protocol is described that tests soil salinity. Water-soluble salts are extracted from soil samples and salt content measured. Accurate field evaluations require sampling at various field locations and various depths and over time take into account the crop species to be grown. Instruments and reagents are listed in preparing soil–water extracts and for measuring salt content. Two methods are provided in measuring salt content, by weight and by electrical conductivity.

Protocol for Screening for Salt Tolerance in Barley and Wheat

A simple protocol is presented that tests salt tolerance in wheat and barley seedlings. The method is based on a glasshouse, aerated hydroponics test in which salt is added to the nutrient hydroponic solution in which the seedlings are grown. A list of equipment is provided including hydroponic hardware and stock solutions. Advice is given on seed storage prior to use and pregermination treatments that promote even germination of test samples. Salt treatments commence after seedling establishment in hydroponics at the 2–3-leaf stage. Visual symptoms of salinity stress include reduced leaf area, whitish appearance of lower leaves, leaf tip death, leaf rolling and seedling death. Recommended test salt concentrations for testing wheat and barley are given along with a method of recovering selected plants. Examples of protocol used are also given.