Studies On The Construction And Nutritional Relationship Of Cycas Panzhihuaensis L.Zhou Et S.Y.Yang Mycorrhiza System

Cycas?Cycas?is commonly known as Tieshu,Cycas?Cycas?a beautiful ornamental.Cycas panzhihuaensis L.Zhou et Sutie S.Y.Yang is a national protected plants,is a species endemic to China.Evergreen,because of its beautiful appearance,is widely used city greening construction has attracted much attention.However,Cycas panzhihuaensis pollination rate,seed setting rate and the fertility rate is low,it is very difficult to cycad conservation.The main reason is closely related to Cycas mycorrhiza,mycorrhizal plants provide nutrient elements required by the growth of the construction of Cycas panzhihuaensis mycorrhizal system and trophic relationships,both for the rapid propagation of cycads and growth provide better growth conditions,but also for the establishment of artificial cultivation technology and introducing technology to provide theoretical guidance for population recovery,with It has important practical significance.This study takes Cycas panzhihuaensis as research material,will be screened coralloid mycorrhizal fungi isolated from the field in the endophytic actinobacteria strains were inoculated into sterile cycad roots,the symbiotic culture symbiosis system,microstructure observation of coralloid mycorrhizal fungi by the method of paraffin section and heavy isolation method of plant microbe that symbiotic system form;free culture method and studied the coralloid root endophytic actinobacteria diversity combined with pure culture method for constructing 16S rRNA gene clone library in Cycas panzhihuaensis;Cycas-endophytic actinobacteria symbiosis system construction were studied after coral fungi nutritional components;finally using ¹⁵N markers of cycads-trophic relationships between the lines put bacteria.The main results are as follows:1.The symbiotic relationship was established between the germplasm of Panzhihua cycads and the dominant strains TB-5,TB-6 and TB-14,which were screened out in the field.The formation of symbiotic relationship is the basis for follow-up experiments,follow-up of the experiment are completed at this stage can be implemented.2.The cross section of Panax corniculatum was transected by paraffin section method.Its cross section was elliptical.It was composed of periclium,outer cortex,algal layer,inner cortex and vascular column.Inside and outside the cortex parenchyma cells have been dyed dark red material,presumably for the bacteria group.3.A total of 56 endophytic actinobacteria were isolated from Cycas panzhihuaensis,TWYE and 37 isolates were isolated from TWYE,and glycerol-asparagine.The results showed that the isolation of two endophytic actinobacteria from coralline roots in TWYE medium was higher than that of the medium with asparagine and asparagine 16S rRNA gene sequence analysis found that56 isolates belong to Streptomyces and Nocardia,Streptomyces is the dominant genus.4.Construction of panzhihua cycad coralloid roots endophytic actinobacteria 16s rRNA gene clone library,the results showed that 105 positive clones distribution in actinomycetes of 16 genera respectively:Korean sangon microbes Kribbella,Streptomyces,Actinoplanes,Actinomadura,Micromonospora,mycobacteria Mycobacterium,Phycicoccus,Nonomuraea,Amycolatopsis,Actinomadura,Fodinicol,Janibacter,Nocardioides,Frankia,Actinosynnema,Dactylosporangium,including Frankia frequency of the highest,the second is proposed without branches acid bacteria gener Amycolatopsis and Mycobacterium.5.After symbiosis system was constructed between the Cycas panzhihuaensis and endophytic actinobacteria.Inoculation of cycas and non inoculation?control?coral nutrition research shows that mycorrhizal inoculation with TB-5,TB-6,TB-14 three strains,total nitrogen and control significant difference,inoculation of Actinobacteria was significantly promoted N absorption,but the whole phosphorus and potassium had no significant difference with the control.6.Compare the content of nitrogen absorption of Cycas panzhihuaensis using ¹⁵N isotope tracer method respectively docking bacteria and sterile Cycads in Panzhihua,involving two soil depth:2.5 cm and 7.5 cm,the results showed that in the 2.5 cm soil depth,root absorption of NO₃-sterile cycad mainly,and Jun Gensu iron uptake of NH₄⁺.and mainly isolated from Panzhihua Cycas in mycorrhiza TB-5 mycorrhizal fungi inoculated to Panzhihua cycas,in addition to a significant increase in Cycads in Panzhihua underground biomass,still can increase the uptake of 2.5cm NH₄⁺in Panzhihua Sutie soil depth;in 7.5 cm soil depth,strain TB-6 significantly increased the uptake of glycine nitrogen.The soil depth of Panzhihua cycas,inoculated Panzhihua cycad nitrogen TB-6 and TB-14 strains the absorption of 2.5cm and soil depth are similar.