【作者】 孔苗；

【导师】 蒋士君； 冯晓元；

【作者基本信息】 河南农业大学 ， 植物病理学， 2005， 硕士

【摘要】 本研究在已筛选出4种植物提取物单剂对采后油桃果实3种致腐真菌——褐腐病菌(Monilinia fructicola)、青霉菌(Penicillium expansum)、软腐菌(Rhizopus stolonifer)具有抑制作用的基础上,将这4种植物提取物进行复配,通过定性定量分析筛选具有增效作用的植物提取物复配组合。离体(In vitro)试验测定筛选的复配植物提取物对油桃软腐、褐腐、青霉病菌菌丝生长、孢子形成和萌发的抑制作用及菌体形态变化,初步明确了所筛选的复配植物提取物在油桃防腐中的应用可能性和抑菌机理;活体(In vivo)试验验证了筛选的复配植物提取物在采后油桃果实上对3种病原菌所引起病害的防治效果。所得结果如下: 1.采用滤纸交叉法定性筛选具有增效作用的组合,从抑菌带图形可知3号/5号组合对褐腐病菌(Monilinia fructicola)有增效作用;2号/5号、2号/12号以及5号/12号组合都对根霉菌(Rhizopus stolonifer)有增效作用;3号/5号组合对青霉菌(Penicillium expansum)有增效作用。然后,采用共毒因子法判断复配增效组合的最佳配比。 2.离体(In vitro)抑菌试验,采用生长速率法和孢子萌发法测定复配植物提取物对油桃软腐、褐腐、青霉病菌菌丝生长和孢子萌发的抑制作用。结果表明:复配植物提取物对油桃软腐、褐腐、青霉病菌菌丝生长和孢子萌发有明显的抑制作用,3号/5号(5:1)复配浓度为1.56mg/ml以上时,则能完全抑制M. fructicola菌丝生长和孢子萌发,MIC为0.78mg/ml,MFC为1.56mg/ml;2号/5号/12号(1:1:1)复配浓度为1.56mg/ml以上时,则能完全抑制R. stolonifer菌丝生长和孢子萌发,MIC为3.13mg/ml,MFC为6.25mg/ml;3号/5号(1:1)复配浓度为12.5mg/ml以上时,则能完全抑制P. expansum菌丝生长和孢子萌发,MIC为12.5mg/ml,MFC为25mg/ml。试验还发现复配植物提取物能诱导三种病菌的形态变化,表现为菌丝过度分枝、肿胀,菌体细胞变短,分隔增多。 3.活体(In vivo)试验,采用针刺法在常温下观察复配植物提取物在油桃果实上对3种病原菌所引起病害的防治效果。结果表明,在96h内3号/5号(5:1)复配浓度为3.13mg/ml可以完全防治M. fructicola所引起的褐腐病;2号/5号/12号(1:1:1)复配浓度为100mg/ml时在48h内完全防治R. stolonifer所引起的软腐病;3号/5号(1:1)复配抑制作用有限,浓度为100mg/ml也不能完全防治P. expansum引起的青霉病的发生。 桃的防腐保鲜一直是国内外的一项难题,以上关于植物提取物复配对采后油桃果实常见腐烂病防治效果的研究旨在为桃的天然复配型防腐保鲜剂的开发与应用提供理论基础。更多还原

【Abstract】 On the base of inhibition on Moniliniafructicola, Rhizopus stolonifer, Penicillium expansum rots of postharvest nectarine fruits, four kinds of plant extracts were combined to screen preservatives with synergistic action. In vitro inhibition of preservative candidates on mycelial growth and spore germination of three kinds of pathogens and morphological changes were analyzed in order to evaluate then-application probability in postharvest nectarine fruits and explore the anti-fungal mechnisms. Their control effects in vivo was measured as well.Firstly, according to the results of inhibition experiment by a cross-paper disc method , combinations of Chemical No.3/No.5 showed synergistic action against Monilinia fructicola, and so did No.2/No.5,No.2/No.12 against Rhizopus stolonifer, No.3/No.5 against Penicillium expansum, respectively. Thus, the co-toxicity factor could be used to optimize their combinations .Secondly, in another experiment, these preservative candidates showed significant inhibition on mycelial growth and spore germination in vitro of all the three pathogens. Combinations of No.3/No.5 at a concentration more than 1.56mg/ml completely inhibited mycelial growth and spore germination of Monilinia fructicola, its MIC and MFC were 0.78mg/ml,1.56mg/ml, respectively. Combinations of No.2/No.5 and No.2/No.12 at a concentration more than 1.56mg/ml completely inhibited that of Rhizopus stolonifer, its MIC and MFC were 3.13mg/ml,6.25mg/ml,respectivery. Combinations of No.3/No.5 at a concentration more than 12.5mg/ml completely inhibited that of Penicillium expansum, its MIC and MFC were 12.5mg/ml, 25.0mg/ml, respectively. Furthermore, tested preservatives could cause morphological changes of target pathogen, such as excessive branch , swelling hyphal, shorter and thicker hyphal cell,and more septa.Thirdly, at a concentration of 3.13mg/ml,combinations of No.3/No.5 could absolutely control "Monilinia rot" in vivo,100mg/ml of No.2/No.5 or No.2/No.12 could absolutely control "Rhizopus soft rot",but 100mg/ml of No.3/No.5 could not absolutely control Penicillium mold due to limited inhibition.更多还原