RESUMO
We attempted to create a new germplasm of cucumber cultivar Chinese long (9930) using different doses of ethyl methyl sulfonate (EMS) to induce variability. We tested EMS concentration (0, 0.5, 1.0, 1.5, 2, 3% v/v) with post-treatment (0.1 M Na2S2O3 and water), EMS concentration (0, 0.5, 1.0, 1.5% v/v) over different treatment times (8, 16, 24 h), and EMS concentration (0, 0.5, 1.0, 1.5% v/v) with different treatment temperatures (20 and 28°C). In all experiments with increasing EMS concentration, germination percent, index, and rate were decreased. After addition of stop solution (0.1 M Na2S2O3), post-treatment mutated seeds showed higher germination (84.44%) and rate (37.5%) than seeds treated with water (80 and 34.07%, respectively), while the germination index was high in seeds treated with water. At 20°C, the germination index (4.13) and rate (56.25%) were affected to a greater extent than at 28°C (7.68 and 91.31%, respectively). Treatment times of 16 and 24 h showed similar results for germination percent and rate, while the germination index was decreased over time. There were significant differences in seedling height, fresh true leaf weight, seedling weight, and plant survival with increasing EMS concentration and time. Higher variations in the form of dwarf seedlings were recorded after treatment with 1.5% EMS for 24 h. Based on germination and morphological data, an EMS concentration of 1.5% for 24 h at 20°C and post-treatment with stop solution (0.1 M Na2S2O3) efficiently caused mutation.
Assuntos
Cucumis sativus/efeitos dos fármacos , Metanossulfonato de Etila/farmacologia , Germinação/efeitos dos fármacos , Plântula/efeitos dos fármacos , Sementes/efeitos dos fármacosRESUMO
Pepper seeds (Capsicum annuum L.) var. B12 were mutagenized by four presoaking treatments in ten concentrations of ethyl methane sulfonate (EMS) to determine the sensitivity of the first generation (M1) to mutagens. The spectrum of mutations and induced variability for various quantitative traits, including germination, percent plant height, injury occurrence, survival ratio, first three fruits weight, and number of seeds per first fruit, were observed in the M1 generation. Our results indicated that all of the test parameters decreased with increasing EMS concentration, except for seedling injury. There were significant differences in germination ratio, LD50, plant height, percent injury, and survival ratio among the tested presoaking treatment. The LD50 was 1% EMS in seeds that were not presoaked (T1) and seeds presoaked for 12 h before treating with EMS (T3). In contrast, the LD50 was 0.5% EMS in seeds presoaked for 6 h (T2) and seeds presoaked in water for 6 h then incubated at 28°C for 12 h before EMS treatment (T4). Five dwarf plants were observed in mutagenized seeds without presoaking as compared to control seeds (at the maturity stage of the control plant).