灰树花是一种珍稀的食药两用蕈菌，由于富含多种有效药用成分和营养成分，而受到国际、国内菌物学家的关注。
　　灰树花多糖具有抗肿瘤、抗高血压、降低血糖、抗肥胖、抗肝炎的药效。据美国一些癌症专门治疗医院临场实验表明，在化学治疗癌症的同时，用灰树花多糖抑制癌细胞比单纯化疗更见效果。日本医学专家用灰树花多糖进行抗肿瘤体内试验，结果表明，灰树花多糖抑制率可达86.5%，比国际认证的抗癌新药香菇多糖抑制率高出32%。
　　由于灰树花目前人工栽培量较少，而且品种来源多限于野生菌株分离，品质较差，子实体萃取物多糖含量较低，因此，近年来，我院致力于灰树花液体深层发酵优良菌株的筛选及各品种子实体提取物含量的研究。进而确定了灰树花多糖提取含量高的优良菌株和多糖提取新工艺，灰树花多糖提取率可达10-15%左右。
　　Elite Strains of Cloud Mushroom(G.frondosa) and Extraction of Their Polysaccharides Cloud Mushroom,or Maitake(G.frondosa) is a rare kind of mushroom for food and medical use.It abounds in efficacious medicative and nutritious ingredients.As a result much attention has been paid to it by mycologists both at home and abroad. The mushroom is versatile in fighting against tumors,high blood pressure,high blood sugar,obesity and hepatitis.Based on clinical studies by U.S. Special cancer therapy hospitals,Chemical treatment of cancers in company with polysaccharides extracted from the maitake had a greater suppression effect on the cancers than it alone.Experiments by Japanese medical experts showed that the suppression rate was 86.5% for the polysaccharides from G.frondosa,which was 32% higher than for polysaccharides extracted from shiang-gu or Shii-mushroom(Lentinula edodes). Currently Cloud mushroom(G.frondosa) has not been widely cultivated,its cultivated strains are mainly derived from the wild ones with poor quality,hence the extractions from the fruitbodies contain less polysaccharides.In recent years great pains have been taken in screening elite strains suited for deep liquid fermentation and investi-gating extraction of various fruitbodies from different strains of maitake in our laboratory.Elite strains of the cloud mushroom and new extraction procedures have been developed with extraction rate of polysaccharides as high as 10-15%.