Mechanism Of Drought Resistance Of PGPR And PAA On Seedling Of Millet

Aimed at insufficient rainfall and serious drought in spring along The Great Wall in Inner Mongolia, the influence of PGPR solutions to seed and soil application of PAA in millet were studied, and the plant growth, physiological characters, soil properties and yield were exsamined to reveal the mechanism drought-resistant, seedling and yield of millet in rainfed areas. This study will provide theoretical basis for the application of PGPR and PAA in millet production. The results showed that:1. Seeds soaked with PGPR solutions, can improve millet potential germination to20%,0.5～7.5percent higher than control, germination rate was70%,4～54percent higher than control, seedling rate was78.55%,0.36～18.78percent higher than control, the emergence time shortened3days than control; the plant length, stem diameter and root length increased by0.42%～33.70%,2.47%～22.55%, and0.41%～10.66%respectively; fresh and dry weight of plants above ground increased by15.32%～60.06%and33.33%～97.73%respectively; fresh and dry weight of plants underground increased by9.38%～53.31%and0～116.67%respectively compared with control. Among the soulations, the concentration of10-7mol·l-1had best effect on promoting millet germination. Use of Th-17and LCO solutions to seed combined with water0.2L/hole got highest germination rate in the field, increased by6.67%and10%respectively. Application of PAA combined with water, the emergence rate was70.67%, increased by18.33-52percent, The plant length, stem diameter, root length, the ratio of dry weight and fresh weight, the ratio of root weight and cap weight increased by9.18%～91.19%,41.30%～92.45%,11.11%～38.56%,0.39%～7.02%and0.39%～0.39%respectively compared with control. Applation of PAA without water were lower than control. The order of seedling emergence was P3>P4>P1>P2>CK>PO, In terms of water saving, the best treatment is using water with0.3L/hole.2. Seeds soaked with PGPR. the seedling’s root activity, chlorophyll content, Fv/Fm, Fv/Fo,φPSⅡ and ETR increased by18%～99.64%,9.19%～9.19%,3.34%～19.27%,3.65%～15.59%.21.09%～89.35%and9.08%～63.96%respectively; Pn, SOD activity, POD activity, free proline content and soluble protein content increased by4.64%～4.64%.4.8%-39.08%.12.7%～107.42%,4.08%～55.8%and0.13%～14.78%respectively:the malondialdehyde content reduced of0.91%～15.48%compered with control. LCO had better effect than Th-17on promote root growth and increased root activity, in other aspects the Th-17work best. Among the PGPR solutions,10-7mol·l-1concentration work best.3. Seeds soaked with PGPR could improved the soil moisture content by0.25%～58.25%under seedlings than control, increased soil microbial biomass carbon and nitrogen content by5.06%～14.5%and8.57%～19.61%, increased the soil catalase activity by6.89%-33.87%, sucrose enzyme activity by14.84%-74.38%, urease activity by9.45%～34.52%. Use PGPR with0.2L/hole water had good effects. Application of PAA with water can improve the soil moisture content by0.9%～15.5%, increase soil microbial biomass carbon and nitrogen content by3.37%～39.15%and2.85%-27.63%, increase soil catalase activity by0.9%～21.65%, sucrose enzyme activity by5.49%～24.62%, urease activity by1.78%～10.17%. Above indices increased sharply using PAA with0.3L/hole water.4. PGPR solutions and soil application of PAA combined with water could increase the yield and yield components of millet obviously. Under the condition of0.2L/hole water, the yield of Th-17and LCO treatments were9006.99kg·hm-2and8498.63kg·hm-2, increased by15.75%,9.22%. Application of PAA in combination with0.3L/hole water worked best, and the yield was7103kg·hm-2, increased by35.47%, the next were0.4L/hole,0.1L/hole,0.2L/hole. The treatment that only application of PAA without filling water had lower millet production.Use PGPR to seeds and PAA in soil can promote the germination of millet, shorten the process of emergence, improve the germination rate, promote seedling growth, improve the seedling physiological characters and the rhizosphere environment, and increase yield, ultimately achieve to drought-resistant, survival seedlings and the purpose of increase production of millet in arid and semi-arid region.