Effects Of Organic Fertilizers And Soil Microorganisms On Seed Germination And Parasitism Of Cistanche Deserticola

Cistanche deserticola Ma is a root parasitic plant of Orobanchaceae,which has the functions of tonifying liver and kidney,enriching essence and blood,and moistening intestines and laxatives.It is a traditional Chinese herbal medicine.In recent years,the market demand of C.deserticola has increased dramatically,and the wild resources of C.deserticola are on the verge of extinction.Cultivation of C.deserticola is an important way to solve the shortage of wild resources of C.deserticola.However,due to the special growth and development characteristics of C.deserticola and the influence of biological and abiotic factors,the parasitic rate is low,and the seeds needed in the cultivation process are large,resulting in high planting costs.Moreover,crude cultivation management such as lack of experience in water and fertilizer management so it difficult to guarantee the yield of C.deserticola.The analysis of parasitic mechanism of C.deserticola is an important way to improve the yield of medicinal materials,but the current research foundation is weak.In this paper,the effects of organic fertilizer treatment,soil microorganisms and Haloxylon ammodendron root extracts on seed germination and parasitism of C.deserticola were studied.The main research results are as follows:1.Different sources of organic fertilizer and different amounts of fertilizer had certain effects on parasitic and growth of C.deserticola.Fertilizer amount is the main factor of parasitic rate,number of parasitic seeds and stem number of C.deserticola,organic fertilizer source is the main factor of fresh weight.The parasitic rate and fresh weight of C.deserticola were the highest with 30%parasitic rate and 971.78 g fresh weight after using tanjunbao.The number of parasitic seeds of C.deserticola was the most with 4.33 per plant.tanjunbao and farm manure had no difference in stem number,but farm manure had higher proportion of small stem.The parasitic rate of C.deserticola was low under humic acid organic fertilizer and microbial product in agriculture treatment.The parasitism rate,number of seeds parasitism,stem number and fresh weight of C.deserticola were higher with higher fertilization.The results showed that organic fertilizer could effectively promote the parasitism of C.deserticola,and the effect of organic fertilizer from different sources was different.The increase of fertilization amount could significantly improve the growth of parasitic rate of C.deserticola.The application of organic fertilizer can effectively improve the physical and chemical properties of soil.After fertilization,the content of organic matter increased significantly,and the pH decreased significantly.After application of farm manure,the contents of available potassium,organic matter and available phosphorus in soil increased significantly.Soil physical and chemical indexes were significantly correlated with parasitism rate of C.deserticola.Soil available phosphorus content in high parasitism group was significantly higher than that in nonparasitism group.2.The dominant bacteria in the soil of C.deserticola were high in proportion and low in diversity.The dominant bacteria in phylum level were Actinobacteria,Proteobacteria and Chloroflexi etc.,and the dominant bacteria in genus level were Streptomyces,Nocardioides and Pseudonocardia etc..The dominant fungi in phylum level are Ascomycota,Mortierellomycota and Basidiomycota etc.,and the dominant fungi in genus level are Chrysosporium,Mortierella and Pseudogymnoascus etc..The diversity index of soil microorganism population in high parasitic group was the largest,but the parasitic rate of C.deserticola was not significantly correlated with soil bacteria and fungi population.Arbuscular mycorrhizal fungi was only detected in Mucoromycota,which was Glomus,Rhizophagus and Rhizoglomus,and the soil AM fungi abundance of different parasitic groups was significantly different,and the abundance of Rhizophagus in Cistanche parasitism group was high,and only Rhizoglomus existed in the high parasitic group;The abundance of Glomus in the zero parasitism group was high.Therefore,it is suggested that Rhizophagus and Rhizoglomus may promote the parasitism of Cistanche,and the Glomus is not conducive to Cistanche parasitism.3.Root extracts of H.ammodendron and Beta vulgaris had no significant effect on seed germination of C.deserticola.The addition of gibberellin could effectively promote the germination of C.deserticola seeds,but the germinated seeds did not form haustorium.However,the two extracts of host roots added with fluridone could induce the formation of haustorium,and haustorium formation rate of C.deserticola induced by H.ammodendron root extract was high,reaching 16.2%.The effect of ethanol extract is stronger than that of water extract.Fluridone and gibberellin synergistically promoted the germination of C.deserticola seeds,and the germination rate increased to 52.3%,but the formation rate of haustorium did not increase.The shape and position of the haustorium induced by different culture mediums were different.The haustorium induced by the host root extract formed at the top of the bud tube and were multiple papillary bulges.Only low-concentration fluridone treatment produces a haustorium-like structure,but the position is not fixed,which is a single round bulge or bifurcation.The results showed that the key structure of C.deserticola seed was induced by some substances in the host root extract,which could be extracted by ethanol extraction and water extraction,but the ethanol extraction effect was better.Seed germination and parasitism of C.deserticola are affected by various ecological factors such as soil nutrients,microorganisms and signal substances of host roots.In this paper,the effects of different sources of organic fertilizer and fertilization on soil physical and chemical properties were preliminarily clarified,and it was found that the effective phosphorus content was significantly correlated with the parasitic rate of C.deserticola.By analyzing the effect of soil microorganisms on seed germination and parasitism of C.deserticola,it was found that the proportion of dominant bacteria in parasitic soil was high,the diversity of bacterial species was low,and the ecological balance was easy to be destroyed.The species of AM fungi had a certain correlation with the parasitic rate of C.deserticola.At the same time,it was found that the root extract of C.deserticola host contained key substances that induced the formation of haustorium.The results can provide basis for scientific fertilization and soil improvement of C.deserticola,and provide reference for the study of parasitic mechanism of C.deserticola.