接种氨氧化细菌对玉米旱后复水补偿性生长的影响

Effect of inoculation of ammonia oxidizing bacteria on compensatory growth of corn after drought

[目的]本研究旨在探究接种氨氧化细菌(AOB)(Ensifer sesbaniae)能否稳定持续促进玉米旱后复水补偿性生长,为农业节水服务。[方法]以玉米品种‘郑单985’为试验材料,以AOB菌株S2_8_1为试验菌株,采用盆栽试验,试验处理包括:常规湿润即空白对照(WT);湿润时期接种AOB菌株(WI);保持湿润在复水期间接种AOB菌株(WR);旱后复水(DT);出苗后接种AOB菌株然后旱后复水(DI)和旱后复水在复水期接种AOB菌株(DR)。通过测量玉米的生物量、玉米素核苷含量、净光合速率、根际土壤的土壤硝化速率等指标,探究AOB对玉米旱后复水补偿性生长的影响。[结果]出苗后接种S2_8_1(DI)促进旱后复水玉米的生长,复水后10 d, DI处理与空白对照相比,其根际硝化速率提高55.1%,由此引起叶片细胞分裂素浓度增加17.4%,净光合速率增加24.8%,最终引起其总生物量比空白对照提升22.8%,促进其发生补偿性生长,使其水分利用效率增加84.0%。同理,DR处理旱后复水在复水期接种AOB菌株同样促进玉米发生超补偿生长。[结论]出苗后即接种氨氧化细菌能够持续稳定发挥作用,促进旱后复水玉米的补偿性生长,提高水分利用效率,对农业节水生产意义重大。

[Objectives]The purpose of this study was to explore whether ammonia oxidizing bacteria(AOB)could continuously promote the compensatory growth of maize after drought,so as to serve water saving in agriculture.[Methods]Corn variety‘Zhengdan 985’was used as experimental material,and an AOB strain S2_8_1 was used as the test strain.Pot experiments were used.The experimental treatment design included:conventional wetting means blank control(WT),wet with AOB strain inoculation during moist period(WI),wet with AOB strain inoculation during rewatering period(WR),rewatering after drought(DT),inoculated with AOB strain after emergence and rehydrated after drought(DI)and rewatering after drought and inoculating AOB strain during the rewatering period(DR).The biomass,zeatin nucleoside content,net photosynthetic rate,soil nitrification rate of rhizosphere soil and other indicators of corn were measured to explore the influence of AOB on the compensatory growth of corn after rewatering after drought.[Results]Inoculated of S2_8_1 after emergence(DI),the growth of rehydrated corn after drought was promoted.10 days after rehydration,compared with the blank control,the rhizosphere nitrification rate increased by 55.1%,which caused the cytokinin concentration in the leaves increased by 17.4%,resulting in net photosynthetic rate increased by 24.8%,and finally caused the total biomass increased by 22.8%compared with the blank control,which promoted its compensatory growth,and the water use efficiency increased by 84.0%.Similarly,the over-compensatory growth of maize was also promoted by inoculation of AOB strain in the rewatering period after drought treatment with DR.[Conclusions]Inoculation of ammonia-oxidizing bacteria can continue to play a stable role and promote the compensatory growth of rehydrated maize after drought,improve water use efficiency,and have great significance to agricultural water-saving production.