灵武长枣根蘖繁殖与嫁接繁殖土壤微生物的差异

Differences of soil microorganisms between root tillering and grafting propagation of Ziziphus jujuba cv.Lingwu Changzao

【目的】研究根蘖和嫁接繁殖2种繁殖方式灵武长枣土壤微生物群落结构和多样性的差异,为科学选择灵武长枣繁殖方式提供理论依据。【方法】以根蘖和嫁接繁殖方式下的灵武长枣为研究对象,运用高通量测序技术探究这2种繁殖方式下枣树土壤微生物群落结构和多样性以及微生物生物量的差异。【结果】根蘖和嫁接2种繁殖方式下灵武长枣土壤微生物群落结构组成相似,均以子囊菌门(Ascomycota)为优势菌门,以镰刀菌属(Fusarium)和毛壳菌属(Chaetomium)为优势菌属,其中镰刀菌属均为二者的优势菌属,但其在嫁接繁殖方式下所占比例远高于根蘖繁殖。嫁接繁殖枣树根际土壤微生物生物量碳和磷显著低于根蘖繁殖,而土壤微生物生物量氮显著高于根蘖繁殖。Alpha多样性分析表明,嫁接繁殖土壤微生物Chao 1指数、Observed_species指数高于根蘖繁殖;根蘖繁殖土壤微生物Simpson指数、Shannon指数和Pielou指数高于嫁接繁殖。PICRUSt2功能预测分析表明,灵武长枣根际土壤微生物菌群主要有5大类一级功能层,其中生物合成功能层的菌群相对丰度较高。嫁接繁殖枣树的总根长、根表面积、根体积、根直径和总根尖数显著高于根蘖繁殖。【结论】嫁接繁殖灵武长枣可以提高土壤中微生物数量以及丰富度,有效促进枣树根际微环境中碳和磷的循环,从而提升枣树植株对土壤碳、磷的吸收利用能力,并增大根系与土壤的接触面积,使根系可以更好地吸收土壤中的营养物质,有助于提高灵武长枣产量。

【Objective】This study investigated differences in soil microbial community structure and diversity between two propagation ways of Lingwu Changzao to provide basis for scientific selection of propagation ways.【Method】In this paper,Lingwu Changzao under root tillering and grafting were selected,and high-throughput sequencing technology was used to explore the differences in soil microbial community structure and diversity and microbial biomass.【Result】The soil microbial community structure of Lingwu Changzao was similar under the two propagation modes of root tillering and grafting.Ascomycota were the dominant phyla and the dominant genera were Fusarium and Chaetomium.The proportion of Fusarium in grafting propagation was much higher than that in tillering propagation.The rhizosphere soil microbial biomass carbon and phosphorus of grafted trees were significantly lower than those of root tillering propagation,and soil microbial biomass nitrogen was significantly higher than that of root tillering propagation.Alpha diversity analysis showed that the Chao 1 index and Observed_species index of microorganisms in grafted soil were higher than those in root tillering soil,while the Simpson index,Shannon index and Pielou index of microorganisms in root tillering soil were higher.The PICRUSt2 function prediction analysis showed that there were five main types of primary functional layers in the rhizosphere soil of Lingwu Changzao,and the relative abundance of microbial community in the biosynthetic functional layer was higher.Total root length,root surface area,root volume,root diameter and total root tip number of grafted jujube trees were significantly higher than those of root tiller propagation.【Conclusion】The grafting propagation of Lingwu Changzao increased the quantity and abundance of microorganisms in soil,effectively promoted the circulation of carbon and phosphorus in rhizosphere microenvironment of trees,and thus enhanced the ability of jujube trees to absorb and utilize carbon and phosphorus in the soil.It also increased the contact area between root and soil for better nutrient absorption from soil and improved the yield.