Study On The Mechanism Of Root/Rhizosphere Physiological And Ecological Effects Of Nitrogen Nutrition Regulate The Growth Of Purple Perilla And Common Perilla

Purple perilla and common perilla are important medicinal and edible homologous plants,which play an important role in agricultural production and social and economic life.Nitrogen is called the "life element",and its content,proportion and form in the soil can directly affect the growth of plants.The soil nitrogen absorbed by plants is mainly nitrate nitrogen and ammonium nitrogen,and the response to different nitrogen forms varies greatly between different plant species.The nutrient acquisition,root morphology,biomass accumulation and rhizosphere microbial community structure of purple perilla and common perilla were studied under different nitrogen forms at seedling stage.The aim of this study was to provide a theoretical reference for further study on the growth state and nutrient elements accumulation of purple perilla and common perilla with different nitrogen forms.First,in this experiment,the similarities and differences of purple perilla and common perilla seeds in seed morphology and physiological characteristics were comprehensively evaluated by measuring the diameter,thousand weight,nitrogen content,phosphorus content,potassium content,soluble sugar and amino acid content.Next,this experiment was conducted by pot culture method.There were three nitrogen forms(nitrate nitrogen,ammonium nitrogen and ammonium nitrate nitrogen)and five treatments for soil nitrogen content.In order to explore the interaction of different nitrogen forms and soil nitrogen content on root growth and nutrient uptake of common perilla and purple perilla.Then,high-throughput sequencing method was used to study the effects of different nitrogen forms on the diversity and composition structure of rhizosphere microbial communities of purple perilla and common perilla under optimal nitrogen content conditions.The results can provide theoretical basis for promoting the better growth and development of purple perilla and common perilla by regulating the rhizosphere microbial community structure,which is of great significance for understanding the environmental adaptability of them.The main conclusions are as follows:1.Analysis of the seed morphology of purple perilla and common perilla found that common perilla seeds were brown,near spherical,purple perilla seeds were gray white and elliptical,and the thousand grain weight and size were significantly larger than purple perilla seeds.The nutrients within purple perilla and common perilla seeds were also determined,the results showed that the contents of nitrogen,potassium,and soluble sugar of common perilla seeds were significantly higher than those of purple perilla seeds.common perilla seeds have higher amino acid content,but purple perilla seeds have more abundant amino acid species.In the principal component analysis of amino acids,threonine is heavily weighted in the principal component 1,which indicates that threonine is an important nutrient component in perilla seed,so it should have a good effect on promoting the growth and development of human body.They have quite obvious differences,so it is clear that common perilla seed resources are better nutrition than purple perilla seeds.2.The results of pot experiment showed that nitrogen morphology and nitrogen content supply have a significant interaction on root growth and consumption of nutrient uptake of purple perilla and common perilla.Nitrogen application significantly promoted both purple perilla and common perilla biomass,and the effect of nitrogen morphology is obvious,followed by nitrogen content.At the nitrate-ammonium nitrogen level,purple perilla and common perilla had the best performance under 200 mg/kg soil N content,with maximum dry mass accumulation,nutrient absorption cumulant and root morphological characteristics such as total root length,root surface area and root volume.More conducive to the growth of these two plants.3.The diversity of rhizosphere soil microbial community was higher,and the species of bacteria and fungi in the rhizosphere soil were richer and distributed more evenly under nitrate and ammonium nitrogen levels compared to nitrate and ammonium nitrogen levels.The soil bacterial communities are mainly composed of Proteobacteria,Firmicutes,Actinobacteria,Crenarchaeota and Acidobacteriota under three nitrogen form treatmens,and the highest dominant bacteria is Proteobacteria.The dominant bacteria of soil fungal communities in purple perilla and common perilla rhizosphere with different nitrogen forms are Ascomycota,Chytridiomycota,Mortierellomycota and Basidiomycota,and the highest dominant bacteria is Ascomycota.Soil microbial communities under the three nitrogen form treatments were mostly consistent,but there were different species among the treatments.Bacterial community was less affected by environmental factors,while fungal community was more affected by environmental factors.Soil available nutrients had the greatest influence on rhizosphere bacterial and fungal communities,and soil p H and organic matter also had important effects.Based on the basis of previous studies,this paper systematically explored the effects of nitrogen form on root growth and nutrient absorption of purple perilla and common perilla from the perspective of root / rhizosphere perspective,and the changes of the rhizosphere characteristics of purple perilla and common perilla,which provides theoretical basis for fully tapping the biological potential of purple perilla and common perilla root,efficient utilization of soil nitrogen resources and efficient cultivation of purple perilla and common perilla..