Production de génotypes mutants chez le blé dur (Triticum durum)

Abstract

The exploitation of natural and induced genetic diversity is the basic condition for the improvement of the plant in the development of varieties with desired traits. For this purpose the application of physical and chemical mutagenesis has been established. Four experiments were done: The first one for the physical mutation by gamma rays in six varieties, an hydroponic culture study was conducted to determine the effects of Gamma irradiation physiological and morphological parameters of the plant, The germination percentage increases in seedlings irradiated with 25Gy dose and 100Gy compared to non-irradiated control in the middle Knops, these same doses improved the length of the leaves and roots, root volume and the fresh and dry weight. Another test in greenhouse that was the subject of a study of the behavior of durum wheat varieties due to water stress induced in the 4th sheet, allowed us to find some mutants that respond better to stress compared to control, for Waha variety mutated with Gamma radiation dose for 180Gy, variety GGR mutated by 220Gy dose, and variety GTA / dur treated with 50GY dose. These new populations were able to respond well to water stress, their adaptation to this stress was relieved following the study of the rate of chlorophyll, leaf temperature, relative water content and osmotic potential. A third in vitro test was conducted at the end of observing the variations induced by gamma rays on callus of three varieties of durum wheat Waha, Gta / dur and Benimestina. After irradiation, the callus showed browning due to oxidative stress. A second experiment to study the effects of chemical mutation by EMS on three varieties of durum wheat, by studying grain yield and its components. And the collection of the M2 for molecular study. A third experiment was made to determine the total protein levels of leaves for all the irradiated samples M1 and mutated with EMS M1 and M2 by SDS-PAGE . The observed differences revealed protein bands, result in molecular weight and intensity. A fourth to analyze the variations due to the mutations: Molecular analysis by SSR microsatellite made with 12 primers revealed polymorphism by the absence and presence of new bands between treated and control varieties. These 48 DNA samples were amplified by the majority of the primers except for BARC8 and WMC322 where there was no amplification. Regarding Gamma mutants: among the 12 markers, 7 are polymorphic (84%) and for the case of EMS among the 12 primers, 6 are polymorphic (50%). This study showed that random mutagenesis causes changes in the genome that may have an adverse effect, it can also increase plant growth and development, it depends on the variety and dose or concentration.