灌水量对‘赤霞珠’酿酒葡萄根际土壤微生物多样性的影响

Effects of irrigation amount on rhizosphere soil microbial diversity of‘Cabernet Sauvignon’

【目的】为贺兰山东麓地区葡萄园生态系统优化及其影响机制研究提供参考。【方法】以18年生‘赤霞珠’酿酒葡萄为试材,在宁夏农林科学院现代农业综合试验基地,进行了4种灌水量(5250、4500、3750、3000 m^(3)/hm^(2))处理,研究其对距‘赤霞珠’主蔓20 cm、深50 cm处根际土壤的细菌和真菌群落结构、多样性和功能基因的影响。【结果】在门水平上,减少灌水量在一定程度上会降低根际土壤的硝化螺旋菌门的相对丰度,增加绿弯菌门和放线菌门的相对丰度;适度降低灌水量会使变形菌门和酸杆菌门相对丰度减少,使拟杆菌门和硝化螺旋菌门相对丰度增加;根际土壤真菌的优势菌种是子囊菌门,占60%以上,减少灌水量使‘赤霞珠’根际土壤的子囊菌门相对丰度减少,使担子菌门和隐真菌门相对丰度增加;‘赤霞珠’根际土壤真菌对水分含量变化的敏感度高于细菌,适度减少灌水量可增加好氧氨氧化菌和硝化菌的相对丰度,继续重度缺水会直接减少硝化菌的相对丰度;随着控水力度的增加,丛枝菌根菌的相对丰度呈现出先降低、后增加的趋势;4个处理的细菌和真菌在门水平的物种分布之间差异显著,且灌水量与物种分布和相对丰度具有显著的相关性,3000 m^(3)/hm^(2)的灌水量与球囊菌门等的相对丰度具有显著的相关性。【结论】水分含量变化直接影响‘赤霞珠’根际土壤细菌和真菌的多样性,适度减少灌水量有益于增加根际土壤中具有积极作用的细菌和真菌的相对丰度。

【Objective】This study provided a reference for the optimization of vineyard ecosystem and its influencing mechanism in the eastern foothill of Helan Mountain.【Method】Using 18 a‘Cabernet Sauvignon’wine grapes as test materials,in Ningxia Academy of Agricultural Sciences’Modern Agriculture Comprehensive Test Site,four kinds of irrigation water(5250,4500,3750,3000 m3/hm2)were settled to study the rhizosphere bacteria and fungi community structure,diversity,and predict the effects of functional genes in the soil of the‘Cabernet Sauvignon’Lord tendril 20 cm,50 cm deep.【Result】At the phylum level,the relative abundance of Nitrohelicobacteria in the rhizosphere soil decreased to a certain extent by reducing irrigation amount,while the relative abundance of Chlorobacteria and Actinobacteria increased.The relative abundance of Proteobacteria and Acidobacteria decreased,but the relative abundance of Bacteroidetes and Nitrohelicobacteria increased.The advantage of the rhizosphere fungi strains was Ascomycetes,accounted for more than 60%,followed by Mortierellomycota and Basidiomycota,reducing irrigation water reduced‘Cabernet Sauvignon’Ascomycota relative abundance of rhizosphere,increased Basidiomycota and Cryptomycota relative abundance,relative abundance of Mucoromycota and Glomeromycota as irrigation water reducing showed a trend of increase;‘Cabernet sauvignon’rhizosphere fungi of the sensitivity of the moisture changed above mentioned bacteria,appropriate reduction of irrigation amount significantly reduced the rhizosphere soil fungal community diversity and increased the bacterial community diversity of‘Cabernet Sauvignon’.However,with the continuous reduction of irrigation amount,the diversity of fungal community increased significantly,and the diversity of bacterial community decreased significantly.With the increase of deficit degree,the diversity of fungal community increased,but the diversity of bacterial community decreased.Moderate reduction of irrigation amount increased the relative abundance of aerobic ammonia oxidation and nitrification,but continued severe water shortage directly reduced the relative abundance of nitrification,and the reduction of irrigation amount reduced the relative abundance of aerobic nitrite oxidation and chitinolysis in rhizosphere soil to varying degrees.Reducing irrigation amount increased the relative abundance of animal endosymbiont-undefined saprotroph,and the relative abundance of leaf saprophytic fungi gradually decreased with the decrease of irrigation amount,while the relative abundance of arbuscular mycorrhizal decreased sharply with the increase of water control intensity.With the increase of water control intensity,the number of ectopycorrhizal bacteria decreased sharply;there were significant differences in species distribution of bacteria and fungi at phylum level among the four treatments,and there was a strong correlation between treatment and species distribution and relative abundance.There was a significant correlation between T3 treatment and Glomeromycota.【Conclusion】The change of water content directly affects the diversity of bacteria and fungi in the rhizosphere of‘Cabernet Sauvignon’,and a moderate reduction of irrigation amount is beneficial to increase the relative abundance of bacteria and fungi with positive effects in the rhizosphere soil.The results of this study can optimize the irrigation scheme scientifically and effectively,and provide basic scientific reference for improving the water use efficiency of vineyards at the eastern foot of Helan Mountain and improving the soil rhizosphere nutrient absorption environment.