Rotation benefit and population changes of soil hydrogen oxidizing bacteria in legume crop fields

豆科作物田土壤氧化细菌轮作效益及种群变化

• 批准号: 218055-2008
• 负责人: Dong, Zhongmin
• 金额: $ 1.83万
• 依托单位: Saint Mary's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=393326
• 关键词: Rotation; benefit; population; changes; soil

Root nodules of legumes have intracellular bacteria that can fix nitrogen gas into a form of nitrogen that the plant can use. Hydrogen gas is a byproduct of the nitrogen reaction, claiming about 33% of the energy that flows to the enzyme. Legume nodules produce a large quantity of hydrogen gas, and release this into soils. For example, in Canadian alfalfa crop alone, we have estimated that there may be as much as 2.4 thousand million liters of hydrogen gas released to Canadian agricultural soils every year. This hydrogen gas production can use up to 6% of the net gain of photosynthetically derived energy of the entire plant. We do not understand why evolutionary processes, plant breeding of agricultural crops, or selection of optimal nitrogen fixing bacteria has not reduced this energy loss in all legumes. Legumes are ideal crops to use in rotation with other crops (especially cereal crops), resulting in a significant increase in the growth and yield of the subsequent crop. Only about 25% of the increase in the growth of the non-legume crop can be attributed to improved nitrogen nutrition. The remaining 75% of the effect have eluded explanation. We are proposing that the hydrogen released by nodules stimulates and support growth of certain soil hydrogen-oxidizing bacteria. These bacteria in return promote plant growth. The purposes of this study are to 1) analyze the soil bacterial community structure changes in these soil communities by T-RFLP, and characterize the "unculturable" nodule/H2-enhanced bacterial populations by screen PCR library according to the T-RFLP results; 2) culture hydrogen oxidizing bacteria from hydrogen-treated soil and the rhizosphere of HUP- nodules; 3) assay these microbes (and previously isolated microbes) for a multitude of growth-promoting traits under controlled greenhouse conditions, and finally 4) inoculate cereal crop seeds with promising bacterial strains, and assay for beneficial effects under field conditions. The long-term goal of my research is to understand the relationship between the plant roots and soil microorganisms, especially the ones promoting the non-legume crop plants, to provide the practical protocols or inoculants for agriculture.

豆类的根结节具有细胞内细菌，可以将氮气固定为植物可以使用的氮形式。氢气是氮反应的副产品，声称大约33％流向酶的能量。豆科植物产生大量的氢气，然后将其释放到土壤中。例如，仅在加拿大苜蓿作物中，我们估计每年可能有多达2400万升向加拿大农业土壤释放的氢气。这种氢气产量最多可消耗整个植物的光合产能的净收益的6％。我们不明白为什么进化过程，农作物的植物育种或选择最佳氮固定细菌并未降低所有豆类的能量损失。豆类是与其他农作物（尤其是谷物作物）旋转的理想作物，从而导致随后作物的生长和产量显着增加。非香肠作物生长增加的25％可以归因于氮营养的改善。其余的75％的效果已经避免了解释。我们提出，结节释放的氢刺激并支持某些土壤氢氧化细菌的生长。这些细菌作为回报促进了植物的生长。这项研究的目的是至1）根据T-RFLP分析这些土壤群落中的土壤细菌群落结构的变化，并根据T-RFLP的结果来表征筛选PCR库的“不可养活”结节/H2增强细菌种群； 2）培养氢处理的土壤和hup-结节的根际的氧化细菌； 3）测定这些微生物（和先前隔离的微生物）在受控温室条件下对多种促进生长的特征，最后4）接种具有有希望的细菌菌株的谷物作物种子，并在田间条件下进行有益作用。我的研究的长期目标是了解植物根和土壤微生物之间的关系，尤其是促进非葡萄植物植物的植物生物，以提供农业的实际方案或接种剂。