【摘要】 澳洲坚果(Macadamia integrifolia)根系甲醇溶提物影响离体培养条件下丛枝菌根真菌孢子生长发育的试验结果表明,澳洲坚果根系甲醇溶提物对离体条件下丛枝菌根真菌(Glomus mosseae和Gigaspora margarita)孢子生长发育有明显的促进作用,能显著提高孢子萌发率,增加菌丝长度。浓度为20%~100%的甲醇溶提物均可显著促进丛枝菌根真菌孢子的生长发育,其孢子萌发率和菌丝长度均显著高于对照,60%的甲醇溶提物效果最明显。Glomus mosseae和Gigaspora margarita孢子萌发率随着甲醇溶提物浓度的升高而增加,60%甲醇溶提物孢子萌发率达到最高,分别为81.7%和76.0%。Glomus mosseae和Gigaspora margarita孢子菌丝长度也表现为随洗脱剂浓度的升高,菌丝生长呈先增强后减弱趋势,洗脱剂浓度为60%时菌丝长度达最长,分别为31.2和28.0mm。澳洲坚果根系甲醇溶提物中含丰富的黄酮类物质,其含量与甲醇洗脱剂的浓度有关,当浓度为60%时,黄酮类物质含量最高。通过对澳洲坚果根系甲醇溶提物中黄酮类物质含量与丛枝菌根真菌孢子生长发育的相关性分析发现,甲醇溶提物中黄酮类物质含量与离体条件下丛枝菌根真菌孢子的生长发育表现为极显著的正相关。甲醇溶提物中黄酮类物质含量越高,其对丛枝菌根真菌孢子的生长发育促进作用越大。更多还原

【Abstract】 Macadamia integrifolia originated from Australia where it grows in the rainforests of the eastern coastal areas of the Northern Rivers district of New South Wales and South-East Queensland. The Macadamia tree belongs to Proteaceae. The Macadamia was in fact the only native Australian plant ever developed to a commercial food crop. Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with the roots of approximately 90% of terrestrial plant species. These fungi are an important component of ecosystems, and the diversity of the AMF could largely influence plant biodiversity, ecosystem variability and productivity. We examined the role of M. integrifolia root exudates in stimulating the germination and growth of AMF. In September 2003, 100 g of M. integrifolia roots were sampled, dried and crushed. The roots were then extracted for two hours in a 70% methanol solution, stirred in 80 ℃ water and filtered. The extract was diluted to 20%, 40%, 60%, 80% and 100% with methanol. The AMF cultures were sterilized, and the spores of Gornas mosseae and Gigaspora margarita were inoculated and cultured at 25 ℃ in the dark for 20 days. The number of spores that germinated was counted and the length of the mycelium measured. When the concentration of the extract was diluted by 60% methanol, spore germination of Gornas mosseae and Gigaspora margarita reached maximum levels of 81.7% and 76.0%, respectively. At higher extract dilution levels, spore germination decreased, and at 100% dilution, spore germination was lower than 65%. The mycelium reached maximum lengths when the extract was diluted by 60%. The length of Gornas mosseae was 31.2 mm and Gigaspora margarita was 28.0 mm. Mycelium growth declined when the extract dilution increased, especially at 100% dilution. At lower dilutions of 20%, the growth of Gornas mosseae appeared to be stimulated but no effect on Gigaspora margarita growth was observed. At the zero percent dilution, the promotion of mycelium growth was not observed. The concentration of flavones in the extract was the greatest in the 60% methanol dilution (19.26%) but was lower at lower dilutions and only 2.56% in the zero percent dilution. Flavone concentrations also decreased at higher dilutions and the content of flavones was lower than 80% at 100% dilution. There were significant positive correlations (correlation coefficient > 0.95) between the concentration of flavones in the extract and spore germination and mycelium growth of AMF.更多还原