Effect Of AM Fungi On The Growth And Quality Of Salvia Miltiorrhiza Bge. Under Different Soil Moisture And Phosphorus Levels

Salvia miltiorrhiza Bge is a medicinal herbaceous plant from Lamiacea, and its dried root and rhizome could remove blood stasis, induce menstruation and relieve menalgia, pure heart and soothe the nerves. It plays an irreplaceable role in the prevention and treatment of several dangerous diseases. The quality of S. miltiorrhiza medicine efficacy has a close relation with its medicinal ingredients. However, due to using of fertilizers improperly, pesticide residues and unstandardized planting during the cultivation process, which resulted in its production and medicinal ingredients decreased and seriously affected the healthy development of Chinese medicine industry. Thus, investigating the correlation analysis between different growing conditions and quality of S. miltiorrhiza is conducive to choose the reasonable cultivation of S. miltiorrhiza, which provide theoretical reference for mycorrhizal biotechnology improving the yield and the clinical curative effect of S. miltiorrhiza. Pot experiments were conducted to study the effects of AM fungi on growth and effective ingredients of S. miltiorrhiza under different soil moisture and phosphorus application rates. The content of mineral elements of S. miltiorrhiza were determine by FAAS. The content of medicinal ingredients of S. miltiorrhiza were determine by HPLC. Orthogonal experiments were conducted to optimize the extraction conditions of polysaccharide, and determine the content of polysaccharides of S. miltiorrhiza. The results obtained were as follows:1. AM fungi could form good symbiotic relationship with S. miltiorrhiza. AM fungi could infect the root of S. miltiorrhiza very well. Soil moisture and phosphorus application rates could affect the infection rate of AM fungi. When at 70% WHC and phosphorus application rate was 0.15 g·kg-1, the AM fungi infection rate was highest.2. Inoculation of AM fungi could increased plant height, root length, root shoot ration, dry weight of overground and underground parts. The contents of chlorophyll, soluble sugar, protein and net photosynthetic rate in inoculated plants were significantly higher than non inoculated plant. However, the contents of MDA and proline in inoculated plants were significantly lower than non inoculated plant. It can be seen AM fungi could promote the growth of S. miltiorrhiza and enhance its stress resistance. Inoculation with AM fungi significantly improved the absorption of N, P, K, Mg, Ca, Fe, Zn, and Cu. The contents of polysaccharide, tanshinone IIA and salvianolic acid B in inoculated plants were significantly higher than non inoculated plant.3. The plant height, root length, root shoot ration, dry weight of overground and underground parts, chlorophyll, soluble sugar, protein, net photosynthetic rate, mineral elements and the content of polysaccharide, tanshinone IIA and salvianolic acid B increased firstly and then decreased with increasing phosphorus application rate, and when at 70% WHC and phosphorus application rate was 0.15 g·kg-1 they reached the maximum. The maximum content of polysaccharides, tanshinone IIA and salvianolic acid B respectively was 6.166%±0.152%, 0.252%±0.004% and 3.352%±0.007%. In contrast, content of MDA and proline decreased firstly and then increased with increasing phosphorus application rate, and when at 70% WHC and phosphorus application rate was 0.15 g·kg-1 they reached the minimum, that were 1.418±0.034 mmol·g-1 and 6.067±0.055 μ g·g-1. It can be seen its stress resistance was highest when at 70% WHC and phosphorus application rate was 0.15 g·kg-1.4. On the same phosphorus level and different soil moisture, compared with 35% WHC, the growth of each part,mineral elements and the content of medicinal ingredients of S. miltiorrhiza were significantly increased at 70% WHC. However, compared with 35% WHC, content of MDA and proline of S. miltiorrhiza were significantly increased at 70% WHC. Water stress decreased the absorption of mineral elements and content of polysaccharides, tanshinone IIA and salvianolic acid B. Inoculation of AM fungi could reduce the inhibitory effect of growth of S. miltiorrhiza.Overall, When at 70% WHC and phosphorus application rate was 0.15 g·kg-1 inoculation of AM fungi in S. miltiorrhiza had the highest medicinal value.