جستجوی مقالات مرتبط با کلیدواژه « alfalfa » در نشریات گروه « بیوتکنولوژی و ژنتیک گیاهی »

The comet assay is a sensitive test for detecting DNA damages used as an instrument to compare the intensity of the genotoxic effects of colchicine. The Pattern and the index value of three parameters of comet assay (tail length, tail intensity, tail moment) were compared among the autotetraploids produced from three populations of diploid cross pollinated Medicago sativa spp. Caerulea and autotetraploid populations from five diploid self pollinated species by treatment with three concentrations of colchicine (0.1, 0.5, and 1%) and five alfalfa cultivars. Results have shown the same level of increases and pattern in the parameters of comet "among the induced tetraploids from the two categories of medics" in the concentration of 0.1 and 0.5% of colchicine. Also increasing colchicine concentration from 0.1 to 0.5% resulted in a more pronounced augmentation of comet parameters. Induced tetraploids resulted from the two mentioned colchicine concentrations showed increases in the value of the three comet parameters compared to the cultivated alfalfa cultivars and two diploid categories medic species so the pattern of parameters were not similar. At the concentration of 1% of colchicine, only two annual species produced tetraploids showing very pronounced augmentation of comet parameters in comparison with 0.1 and 0.5% colchicine concentrations. Changes in patterns and values of the three parameters in induced tetraploids compared to cultivated alfalfa and diploid medic species demonstrate differential effects of damages of colchicine from one concentration to another, then a new variability in each concentration change will be created.

After the identification of resistant, semi-susceptible, and susceptible genotypes among 42 alfalfa (Medicago sativa L.) genotypes concerning farm traits, nine genotypes were selected. Saponins obtained as a result of homogenous suspension of alfalfa tissue under maximum alfalfa weevil (Hypera postica Gyll.) attack were extracted using methanol and were purified using water-saturated butanol. The resulting solution was immobilized using the active enzyme extracted from the midgut of the pest and the thermally deactivated enzyme. In addition to the isolation of secondary glycosidic metabolites extracted from alfalfa, the enzymatic hydrolysis activity of the pest in the glycosides of genotypes were monitored using thin layer chromatography. The results of the enzymatic digestion test using TLC indicated that other than glycosides1 epigenin, other compounds were digested in the solution. The flavonoidal band of epigenin glycoside1 in all five resistant genotypes, including Tak Buteh and Ranger, was high in density and nearly equal. While maintaining the stability of the molecular structure, this compound was isolated and revealed at Rf=0.45 on a TLC plate. Therefore, midgut enzymes of alfalfa weevil were not able to digest the above compound in alfalfa. In two susceptible genotypes of Poly Cross Shiraz and Mahali Neyshaburi, the saponin band of soysaponin1 at Rf=37 had the highest density. In natural field conditions and at the time of biological stress, the lowest concentrations of saponin, soysaponin 1, and the highest concentration of flavonoids, epigenin glycoside 1, had a significant biological role in resistance to pests, and reduced damage to the cultivars under study.