Morphological Characterization and rDNA ITS Sequence Analysis of Five Pathogenic Fungi Isolated from Infected Jujube Fruit(5株枣果实采后病原真菌分离鉴定及rDNA ITS区序列分析)

Jujube fruit is thin-skinned, thick flesh, tender and juicy. During post-harvest transportation, jujube fruit is vulnerable to be damaged and infected by microorganism. In this study, pathogenic fungi that caused postharvest rot and deterioration of jujube were isolated from the infected jujube fruit. Based on morphological observations, fungal rDNA internal transcribed spacer (ITS) sequence analysis, the phylogenetic tree was constructed. Meanwhile healthy jujube fruit was re-inoculated with all of the purified isolates and symptom of lesion was verified. Three filamentous fungi (221^# , 227^# and 232^# ) were isolated from natural infected winter jujube during post-harvest storage and two filamentous fungi (229^# and 230^# ) from jun jujube fruit. According to the morphological observation, the genus of the five fungi strains belong to Fusarium (221^# and 227^# ), Stemphylium (229^# and 232^# ) and Aureobasidium (230^# ). The results obtained by the analysis of rDNA ITS sequence of five strains were identified as 221^# (Fusarium equiseti), 227^# (Fusarium incarnatum), 229^# (Stemphylium lycopersici), 230^# (Aureobasidium proteae) and 232^# (Stemphylium armeriae) respectively. None of these five pathogenic fungi strains had been reported to cause postharvest diseases of jujube, among which S. armeriae was not reported to cause plant diseases. The study aimed to discover more pathogenic fungi species causing jujube diseases, and hoped to provide a theoretical basis for biocontrol measures for jujube fruit diseases.(枣果实皮薄肉厚、细嫩多汁,不仅在采后运输中易损坏,也极易受微生物侵染而腐烂变质。对造成枣果实采后腐烂变质的病原真菌进行分离筛选,结合形态学观察、真菌rDNA内转录间隔区(internal transcribed spacer,ITS)的序列分析构建进化树,同时进行菌株的回接及病斑病症的验证,最终从采后贮藏过程中自然发病的冬枣和骏枣果实上分别分离到3株(221^# 、227^# 、232^# )和2株(229^# 和230^# )丝状病原真菌。经形态学初步鉴定菌株221^# 和227^# 为镰孢菌,229^# 和232^# 为葡柄霉,230^# 为短柄霉属真菌,通过rDNA ITS区序列分析,鉴定221^# 为木贼镰孢菌(Fusarium equiseti),227^# 为变红镰孢菌(Fusarium incarnatum),229^# 为番茄匍柄霉(Stemphylium lycopersici),230^# 为产酶短梗霉(Aureobasidium proteae),232^# 为葡柄霉(Stemphylium armeriae)。目前这5种病原真菌均未发现可导致枣果实采后病害发生的报道,其中Stemphylium armeriae未见引起植物病害的报道。通过挖掘出更多的引起枣果实病害的病原真菌种类,希望为枣果实病害生物防治措施的研究提供参考依据。)