‘红香酥’梨致腐性真菌的鉴定及其孢子萌发特性

Identifying and determining the spore germination characteristics of decay-causing fungi in’Hongxiangsu’pear

[目的]‘红香酥’梨是近年来发展起来的新品种,具有较高的营养和商业价值,但对其采后病害情况却知之甚少。本研究旨在明确‘红香酥’梨贮藏期间致腐性病原真菌的种类,通过研究其孢子的萌发特性为‘红香酥’梨的采后防病贮藏条件提供参考。[方法]在收集贮藏期间‘红香酥’腐烂果实的基础上,采用组织分离法对病原菌进行分离和致病性鉴定,结合形态学和分子学方法确定了病原菌的分类地位,通过测定不同环境条件对孢子萌发的影响明确了病原菌的最适发病条件。[结果]共分离鉴定出4种典型腐烂病斑的病原菌株,包括2株Alternaria alternate,1株Fusarium proliferatum和1株Penicillium expansum。通过超景深显微镜观察孢子在果实体内的萌发动态,发现分生孢子在48 h内即可萌发出大量的菌丝。进一步体外试验发现温度和湿度对4株菌的孢子萌发有显著影响,而光照条件只对菌株Y003有一定的影响。[结论]本研究明确了‘红香酥’梨采后果实病原菌的分类学地位,测定了不同环境条件下对病原菌孢子萌发的影响,掌握了病原菌的生物学特性,为防治‘红香酥’梨果实腐烂提供参考。

[Objective]‘Hongxiangsu’pear is a new variety developed in recent years with high nutritional and commercial value,but little is known about its postharvest diseases.The purpose of this study was to identify the species of rot-causing pathogenic fungi during storage of’Hongxiangsu’pear,and to provide reference for postharvest storage conditions of‘Hongxiangsu’pear by studying its spore germination characteristics.[Methods]We collected the rotten fruit of‘Hongxiangsu’pear during cold storage,and used tissue isolation method to isolate and identify the pathogenic fungi.The taxonomic statuses of pathogenic fungi were determined by combining morphological and molecular methods.The optimal pathogenic conditions were determined by measuring the influence of different environmental conditions on spore germination.[Results]A total of four pathogenic strains were isolated and identified from typical rot lesions,including two Alternaria alternate,one Fusarium proliferatum and one Penicillium expansum.The germination dynamics of spore in the fruit were observed by ultra-dept-of-field microscope,and it was found that the conidia could germinate a large number of hyphae within 48 h in vivo.Further in vitro experiments showed that temperature and humidity had significant effects on the spore germination of the four strains,while the light condition only had certain effect on strain Y003.[Conclusions]This study has identified the pathogens causing fruit decay during the postharvest storage of‘Hongxiangsu’pear,determined the spore germination responding to different environmental conditions,clarified the biological characteristics of pathogen,for the prevention and control of red crisp pear fruit rot,and provided references for prevention and control of fruit decay in‘Hongxiangsu’pear.