Effects of Hybrid Drought-resistant Agent on Physiological Characteristics in Millet Seed Germination and Seedling Growth under Drougt Stress
|School||Shanxi Agricultural University|
|Keywords||Millet drought stress drought resistance agent osmoregulation substance membrane lipidperoxidation protective enzyme activity|
In this research, we aimed to find out the response of seed germination and the physiological characteristics of millet by soaking seed with drought resistance agent which was the combination solution of18%PEG using the methods of sand culture for a simulation for agricultural drought. The effects of drought resistance agent on the physiological characteristics of millet were implemented by analysis of millet seed germination rate, germination potential, soluble protein, soluble sugar, proline, starch, amylase activity, membrane lipid peroxidation and protective enzyme activities. This research was made up of two parts, including lab-scale pot experiment and field-scale experiment. The main results were as follows:(1) In marinated experiment with drought resistance agent, the millet seed germination rate and germination potential were increased by factors of25.75%and35.34%with soaking seed by drought resistance agent, compared to the control test (CK). Meanwhile, the length of bud and root were increased by16.61%and11.27%, respectively. The seed moisture content were significantly (p<0.05) increased by11.7%after42h treatment, compared to CK. The amylase activity was also significantly (p<0.01) increased by48.68%at18h, which contributed to the decrease of starch content by a factor of55.34%after48h treatment. Moreover, the soaking seed with drought resistance agent significantly (p<0.01) increased the soluble sugar (22.18%), soluble protein (63.17%), and proline content (70.63%).(2) In pot experiment with arid soil under9%moisture content, the soaking seed by drought resistance agent significantly enhanced the millet seed germination. The millet seed germination rate and germination potential were increased by factors of16.67%and11.22%with the soaking seed. Meanwhile, the length of bud and root were also significantly (p<0.05) increased by27.67%and21.72%. The proline content and soluble protein were improved116.97%and14.19%, respectively. Compared to CK, the Superoxide Dismutase (SOD) was3.87times higher under soaking seed treatment. The Peroxidase (POD) and Catalase (CAT) were improved53%and94.97%, respectively. However, the soaking seed treatment significantly (p<0.05) declined the H2O2, Malondialdehyde (MDA) and O2-by factors of53.5%,26.22%and16.62%, respectively. (3) In pot experiment with the methods of sand culture, using the drought resistance agent spray mitigated the inhibited effect of drought stress on the growth of millet seedling and accelerated the proline content accumulation. The proline content showed the highest value at72h, which was30.91%higher than CK. Moreover, the SOD and POD were also increased at72h, as well as at120h. By contrast, the H2O2and MDA were significantly (p<0.05) decreased24.2%(72h) and31.11%(96h), respectively. The O2and soluble protein also showed the similar trend with4.21%and6.33%increasment at120h (p<0.05).(4) In field experiment, similarly with the pot experiment, the spraying of drought resistance agent mitigated the inhibited effect of drought stress. The spraying of drought resistance agent treatment significantly (p<0.05) contributed the highest values of proline content, soluble protein, SOD, POD, and by factors of96%,17%,52.17%,41.67%at sixth day (6d) and tenth day (10d). However, although the highest values of MDA, O2and H2O2were showed at6d and tenth day10d, the soaking seed treatment significantly (p<0.05) declined the MDA, O2and H2O2by factors of66.34%,44.28%and111.20compared to CK, respectively.