【摘要】 【目的】探讨乳酸菌复合制剂对盐碱地改良、植物生长及土壤微生物群落变化的影响,为利用耐盐碱的乳酸菌研发新型微生物制剂及其大面积应用提供参考依据。【方法】以西红柿为供试作物进行田间试验,设菌剂组(含乳酸菌的菌剂)和对照组(不含乳酸菌的菌剂),两个处理菌剂用量均为15 L/ha,加水稀释10倍,在西红柿种植前1 d喷施于土壤中,并在种植西红柿后每30 d喷施一次;西红柿成熟期测定其农艺性状;种植3个月后采集0～30 cm土样测定土壤的物理性质、养分含量及酸碱度,并对土壤样品进行宏基因组测序,分析土壤微生物的多样性及功能基因的变化。【结果】与对照组相比,菌剂组的土壤p H显著下降0.42(P<0.05,下同),铵态氮、硝态氮及有效磷的含量显著提高,但土壤物理性质无显著变化(P>0.05);供试西红柿的各项农艺性状均有所提高。土壤微生物多样性分析结果表明,在门分类水平上,共检测分类122个菌门,其中变形菌门(Proteobacteria)占有明显优势,相对丰度在50.00%以上,其次为拟杆菌门(Bacteroidetes)和绿弯菌门(Chloroflexi),菌剂组中厚壁菌门(Firmicutes)和放线菌门(Actinobacteria)的相对丰度显著增加;在属分类水平上,菌剂组中乳杆菌属(Lactobacillus)的相对丰度(4.25%)较对照组(0.01%)明显增加。功能基因分析结果表明,菌剂组和对照组的碳水化合物活性酶(CAZy)中,糖苷水解酶(Glycoside hydrolases)的功能基因所占比例最高,分别为35.12%和34.16%,菌剂组6种碳水化合物活性酶基因序列数目均高于对照组;KEGG功能注释结果显示,菌剂组的碳水化合物代谢、氨基酸代谢、能量代谢及辅因子与维他命代谢的基因序列数目均高于对照组;此外,菌剂组土壤中毒素的基因序列数目较对照组明显降低。【结论】乳酸菌复合制剂能有效降低盐碱地的pH并增加养分含量,同时可增加土壤中的放线菌数量,降低病原微生物数量,对盐碱地的改良具有良好效果。更多还原

【Abstract】 【Objective】The effects of lactic acid bacteria compound preparation on the improvement of saline-alkali soil,crop growth and soil microbial community change were explore. It provide theoretical basis for the development of new microbial preparations and its large-area application by using salt-tolerant lactic acid bacteria.【Method】Field experiment was carried out,and the test crops were tomatoes. The tomatoes were divided into treatment group(bacterial agent containing lactic acid bacteria)and control group(bacterial agent without lactic acid bacteria). The dosage of the two treatment agents was 15 L/ha,diluted 10 times with water,sprayed on the soil 1 d before the planting,and sprayed once every30 d after planting tomatoes. The agronomic traits were determined at the maturity stage of the tomatoes. After three months of planting,0-30 cm soil samples were collected to determine the physical properties,nutrient content and pH of the soil,and the soil samples were subjected to metagenomic sequencing to analyze soil microbial diversity and functional gene changes.【Result】Compared to control,in the treatment group,the pH value of the soil decreased significantly by0.42(P<0.05,the same below),and the contents of available phosphorus,ammonium nitrogen and nitrate nitrogen were all increased,and the physical properties of the soil were not significantly changed(P>0.05). The agronomic traits of the tested tomatoes have improved. The soil microbial diversity analysis indicated that,at phylum level,there were 122 bacteria phylum detected and classified,among these,Proteobacteria had a clear superiority with 50.00% relative abundance,and followed by Bacteroidetes and and Chloroflexi. Significant increase in relative abundance of Firmicutes and Actinobacteria in treatment group was observed. At genus level,the relative abundance of Lactobacillus(4.25%)in the treatment group increased significantly compared to control(0.01%). The functional gene analysis showed that,as for carbohydrates active enzyme(CAZy)in treatment group and control group,the proportion of functional genes of glycoside hydrolases were the highest,and were 35.12% and 34.16% in the two groups respectively. The number of six carbohydrate active enzyme gene sequences in the treatment group was higher than the control group. In the KEGG functional annotation results,the number of gene sequences for carbohydrate metabolism,amino acid metabolism,energy metabolism,metabolism of cofactors and vitamins in the treatment group was higher than the control group. In addition,the number of gene sequences of toxin in the soil was significantly reduced in treatment group.【Conclusion】The lactic acid bacteria compound preparation can effectively reduce the pH value of the saline-alkali soil and increase the nutrient content. At the same time,it can increase the number of actinomycetes in the soil,reduce the number of pathogenic microorganisms. It has a good effect on the improvement of saline-alkali soil.更多还原