华重楼内生真菌聚多曲霉的促生与拮抗作用

Growth promoting and antagonistic effects of endophytic fungus Aspergillus sydowii from Paris polyphylla var. chinensis

摘要:

[背景] 华重楼（Paris polyphylla var. chinensis）是我国一种名贵稀缺中药材，有多种药效，由于过度采挖等原因，其野生资源现已极度匮乏。华重楼的人工栽培技术尚未成熟，生长缓慢、病害频繁发生是主要的制约因素。[目的] 植物益生菌的开发是一种环保且有效的解决途径，符合生态种植的要求。[方法] 通过常规方法分离鉴定内生菌，选取已报道具有促生抗病作用的菌株进行玉米种子发芽试验，无氮培养基定性检测固氮活性，平板拮抗试验检测抗菌性；高效液相色谱-质谱联用技术（Liquid Chromatography-Mass Spectrometry，LC-MS）检测其菌液的代谢成分；分光光度法检测华重楼幼苗丙二醛和叶绿素含量，LC-MS检测叶片水杨酸、茉莉酸、脱落酸、赤霉素、细胞分裂素、生长素的含量，测量华重楼地下部分生物量指标。[结果] 分离得到一株菌jdqmzz-1，经rDNA ITS序列扩增比对、形态学观察、生理生化鉴定，确定为聚多曲霉（Aspergillus sydowii）；其可以促进玉米种子发芽和华重楼生长，具有固氮、拮抗病原真菌尖孢镰刀菌（Fusarium oxysporum GSICC 60612）、病原细菌胡萝卜软腐果胶杆菌胡萝卜亚种（Pectobacterium carotovorum subsp. carotovorum，Pcc ATCC 15713）的作用，真菌拮抗指数为42.50%，其菌液含有种类较多的促生和抑菌杀虫物质，菌液处理过的华重楼幼苗，叶片内源赤霉素和生长素含量较对照分别提高了54.1倍和2.3倍，叶绿素含量达到209.88 mg/g鲜重，较对照增加了48.80%，丙二醛含量较对照降低了15.20%；平均根数、平均根长、平均百株重较对照也有显著性（P<0.01）提高。[结论] 分离出的内生真菌聚多曲霉jdqmzz-1能够有效地促进华重楼的生长。

Abstract:

[Background] Paris polyphylla var. chinensis is a kind of precious chinese medicine materials. Over-exploitation leads to the lack of wild resources. The artificial cultivation is restricted by the poor growth and frequent occurrence of diseases. [Objective] Exploring of plant probiotics is an effective and environment friendly solution, according to the requirements of ecological planting. [Methods] Endophytic fungus was isolated by conventional methods and identified by comprehensive methods. The germination test of maize seeds was carried out for screening the isolated fungus which had been reported to promote growth and resist disease. The nitrogen fixation activity of microorganism was tested qualitatively by nitrogen-free ager. Antimicrobial activity was detected by plate antagonism test. High performance liquid chromatography-mass spectrometry (LC-MS) were used to detected the metabolic components of microorganism and the contents of salicylic acid, jasmonic acid, abscisic acid, gibberellins, cytokinins, auxins in leaves. The underground biomass indexes were also measured. [Results] One of fungi was identified as Aspergillus sydowii by rDNA ITS sequencing, morphological observation, physiological and biochemistry identification, named jdqmzz-1. The strain jdqmzz-1 which contains kinds of stimulative, antibacterial, and insecticidal substances can promote the growth of Paris polyphylla var. chinensis, fix nitrogen, and antagonize pathogenic microorganism. The antagonistic index was 42.50%. The Paris polyphylla var. chinensis seedlings endogenous gibberellins and auxins in leaves were increased by 54.1 and 2.3 times, chlorophyll contents were increased by 48.80%, malondialdehyde contents were decreased by 15.20%, respectively, while treating with the strain. Average root numbers, root lengths and hundred plant weights of seedlings were also significantly increased. [Conclusion] The isolated endophytic fungus Aspergillus sydowii strain jdqmzz-1 can effectively promote the growth of Paris polyphylla var. chinensis.