Effects Of Stubble Height Of Hippophae Rhamnoides On Rhizosphere Soil Bacterial Community And Root Physiological Characteristics In Pisha Sandstone Area

The Pisha sandstone in Geqiugou watershed of Zhungeer Banner,Ordos,Inner Mongolia is one of the most serious areas of soil erosion in the world.This area is a typical fengshui compound erosion area in China.The soil erosion is the most serious and the ecological environment is the most fragile.Therefore,Illumina Hiseq high-throughput sequencing method was used to explore the effects of stubble measures(0cm,10 cm,15cm,20cm)on soil bacterial community structure and diversity of Hippophae rhamnoides plantation in Pisha sandstone area.In order to promote soil and water conservation in Pisha sandstone area and sustainable development of ecological environment,it provides a theoretical basis for the renewal and rejuvenation of Hippophae rhamnoides plantation,soil management and increase of species diversity.(1)Stubble height had an effect on the diversity of bacterial communities in the rhizosphere soil of Hippophae rhamnoides in the Pisha sandstone area.The number of unique ASVs in the 15 cm stubble treatment was the highest.The alpha diversity index of bacterial community showed that the soil depth of 0-10 cm was the best,and the 15 cm in the stubble treatment group was the best.(2)Proteobacteria,Actinobacteria,Acidobacteria,Firmicutes and Chloroflexi were the main dominant bacterial phyla in the rhizosphere soil of four stubble heights of Hippophae rhamnoides and non-stubble control group in Pisha sandstone area.The main dominant bacterial classes were γ-Proteobacteria,Actinobacteria,α-Proteobacteria and Bacilli.The main dominant bacterial orders were Burkholderia,Pseudomonas,Rhizobium and Pyranomonadales.The dominant genera were Pseudomonas,Lauerella,RB41 and Sphingomonas.When the stubble height of Hippophae rhamnoides was 15 cm,the relative abundance of phylum,class,order,family and genus was the highest.In May,July and September,the relative abundance of Hippophae rhamnoides was the highest in July,and the relative abundance of soil layer 20-30 cm was the highest in 0-10 cm,10-20 cm and20-30 cm.(3)The effect of stubble height on the root physiology of Hippophae rhamnoides in Pisha sandstone area.The proline,membrane permeability and malondialdehyde of Hippophae rhamnoides roots in the control group > flat stubble 20 cm > flat stubble 0cm >flat stubble 10 cm > flat stubble 15 cm,May is higher than July and September,soil layer20-30 cm is higher than 0-10 cm and 10-20 cm,root activity flat stubble 15 cm > flat stubble10 cm > flat stubble 0cm > flat stubble 20 cm > control group,July is higher than May and September,soil layer 20-30 cm root activity is the smallest.The root soluble sugar of stubble 15 cm > stubble 10 cm > stubble 0 cm > stubble 20 cm > control group.The soluble sugar in May was higher than that in July and September,and the soil layer 20-30 cm was higher than that in 0-10 cm and 10-20 cm.In summary,the Hippophae rhamnoides stubble treatment group in the soft rock area is better than the non-stubble control group;in the flat stubble treatment group,the stubble height of 15 cm had the best treatment effect,which could effectively increase the adaptability of Hippophae rhamnoides to drought stress in Pisha sandstone area.(4)The correlation between rhizosphere bacteria and root physiological properties of Hippophae rhamnoides under different stubble heights.It can be seen from the whole that the proline,membrane permeability and malondialdehyde of Hippophae rhamnoides root system are mainly positively correlated with rhizosphere bacteria,and the root activity and soluble sugar are mainly negatively correlated,indicating that the relationship between rhizosphere bacteria and root physiological properties of Hippophae rhamnoides is the mechanism of interaction.