真菌诱导子对铁皮石斛原球茎多糖含量的影响

目的：研究MF24真菌诱导子对铁皮石斛原球茎多糖含量的影响。方法用不同方法制备的MF24真菌诱导子，以不同的剂量，在铁皮石斛原球茎生长的不同时间加入，并继续培养不同时间，观察诱导子对原球茎多糖含量的影响。结果将MF24液体发酵的菌丝体作为诱导子（方法4），以250mL·L^-1（诱导子·培养基。）的剂量（高剂量）加入培养基时，铁皮石斛原球茎多糖含量最高（5．63％），与对照（3．16％）相比提高了78．2％。在原球茎培养的第14d，以高剂量加入方法4制备的诱导子，继续培养2d，获得的多糖含量最高（5．92％），与平均值（4．59％）相比提高了29．0％。结论：在铁皮石斛原球茎培养的后期加入MF24液体发酵菌丝体制备的诱导子，有利于提高原球茎的多糖含量。

Effects of the Fungal Elicitor on the Polysaccharide Content of Dendrobium candidum Protocorms

The effects of MF24 fungal elicitor on the polysaccharide content of Dendrobium candidum protocorms were studied in this work. MF24 fungal elicitor was prepared in 4 ways and added at 3 dosages. Distilled water was used as the control. The elicitor was added at different time points and then co-cultured with protocorms for different time. The polysaccharide content of protocorms rose to 5.63%, as the mycelium of MF24 was used as the elicitor （elicitor T4） and added at 250 mL·L^-1 culture medium （high dosage）, increasing by 78.2% compared with the control （3.16%）. When elicitor T4 was added at a high dosage at the 14th week and then cultured for 2 more weeks, the polysaccharide con- tent reached the highest value of 5.92%, increasing by 29.0% compared with the average value of 4.59%. The results showed that the polysaccharide content of protocorms may be improved when the mycelium of MF24 is used as the elicitor and added at the later stage of the culture.