闽楠主要病害病原鉴定及其生物学特性测定和防治药剂筛选

发布时间：2018-05-02 01:20

  本文选题：闽楠 + 病原菌　； 参考：《福建农林大学》2017年硕士论文

【摘要】：闽楠(Phoebe bournei),俗称楠木,木材芳香,材质致密坚韧,是上等家具用材,被列为国家珍稀濒危树种。楠木在福建等地栽有大面积人工林,但因生物多样性匮乏,林分结构稳定性差,造成林分抗逆性差,病害频繁暴发。因此,本文以楠木叶斑病和溃疡病为研究对象,对两种病害的病原进行分离鉴定,并对病原进行生物学特性测定、化学杀菌剂和植物源提取物室内筛选,结果如下:1.病原菌鉴定及生物学测定楠木叶斑病:应用柯赫法则进行病原分离,通过形态学观测结合rDNA-ITS序列比对,确定该病原为小孢拟盘多毛孢(Pestalotiopsis microspora)。生物学特性测定结果表明,病原菌菌丝以查彼培养基(pH5.0)在28℃黑暗条件下生长最好,最适碳源为葡萄糖,最适氮源为蛋白胨;最适产孢量以PDA培养基(pH8.0)在28℃黑暗条件下生长最好;菌丝致死温度为50℃,分生孢子致死温度为60℃。楠木溃疡病:通过形态学测定结合rDNA-ITS序列比对,确定该病原为淡色生赤壳菌(Bionectria ochroleuca)。菌丝以PDA+楠木煎汁培养基(pH6.0)在25℃黑暗条件下生长最好,全光照下整个菌株变色为橘黄色,最适碳源为麦芽糖,最适氮源为硝酸钾;最适产孢量以PDA培养基(pH7.0)在25℃全黑暗条件下生长最好;菌丝致死温度为55℃,分生孢子致死温度为65℃。2.室内毒力测定小孢拟盘多毛孢菌:杀菌剂室内筛选结果表明,曹氏甲托(70%甲基硫菌灵)、多锰锌(16%多菌灵和34%代森锰锌)和恶霉灵对该病原菌丝的抑制效果显著,EC50值分别为0.12μg·mL-1、0.68μg·mL-1和27.1 μg.L-1,其中,多锰锌和曹氏甲拖对分生孢子萌发抑制效果良好,建议采用多锰锌和曹氏甲托作为该病害田间防治试验药剂进一步筛选。淡色生赤壳菌:室内筛选结果表明,世高(10%苯醚甲环硅)和曹氏甲托(70%甲基硫菌灵)对该病原菌抑制效果显著,EC50值分别为0.32μg·mL-1和1.16μg·mL-1,其中世高对该致病菌分生孢子抑制效果良好,建议使用世高作为该病害田间防治试验药剂进一步筛选。3.植物提取物抑菌性测定小孢拟盘多毛孢菌:测定结果表明,黄柏、黄连、知母和远志对菌丝具有较好的抑菌性,抑制率分别为84.13%、68.65%、63.48%和52.58%。其中,黄连和黄柏对孢子抑制效果相对较好。淡色生赤壳菌:测定结果表明,黄连、黄柏和知母对菌丝具有较好的抑菌性,其抑制率分别为80.73%、54.55%和50.10%。其中,知母对孢子抑制效果相对较好。
[Abstract]:Phoebe bourneig, commonly known as nanmu, wood fragrance, dense and tough material, is the best furniture wood, is listed as a rare and endangered national tree species. Nanmu planted in Fujian and other places has a large area of artificial forest, but because of the lack of biodiversity, the stability of stand structure is poor, resulting in poor stand resistance, frequent outbreaks of disease. Therefore, the pathogen of leaf spot and canker of Nanmu was isolated and identified, the biological characteristics of the pathogen were determined, and the chemical fungicides and plant extracts were screened in laboratory. The results were as follows: 1. Identification of pathogenic bacteria and biological determination of leaf spot of Nanmu: the pathogen was isolated by Koch's rule. The pathogen was identified as Pestalotiopsis microspora by morphological observation combined with rDNA-ITS sequence alignment. The results showed that the pathogen mycelium grew best under dark conditions at 28 鈩，

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