Diversity and Nematocidal Activity of Endophytic Fungi Isolated from Rangoon Creeper (Quisqualis indica)
Fungal endophytes were isolated from the leaves, steins and roots of Rangoon creeper (Quisqualis indica), a Chinese traditional herb that is used for treatment of parasitic nematode in children, collected from four different areas of Guangzhou by using PDA, PCA, PSM, Czapek and an agar medium supplemented with extract of Rangoon creeper. Of 249 isolated fungal endophytes, 222 species identified were involved in 23 genera, based on their morphology and ITS sequencing, which are classified into 15 families, 7 orders and 4 classes of Ascomycota and incertae sedis, respectively. Those 23 genera were as followed: Alternaria (3 isolates), Aspergillus (2 isolates), Botryosphaeria (3 isolates), Chaetomella (1 isolate), Chaetomium (11 isolates), Colletotrichum (109 isolates), Coniella (3 isolates), Eutypella (5 isolates), Fusarium (5 isolates), Glomerella (3 isolates), Guignardia (30 isolates), Nemania (1 isolate), Nodulisporium (1 isolate), Paecilomyces (2 isolates), Paraphaeosphaeria (2 isolates), Penicillium (2 isolates), Pestalotiopsis (2 isolates), Phoma (6 isolates), Phomopsis (21 isolates), Pyrenochaeta (1 isolate), Trichoderma (3 isolates), Xylaria (3 isolates) and Zopfiella (3 isolates). Among them, the genera Colletrichum, Guignardia and Phomopsis were dominant, and occupied as much as 44％, 12％ and 8％of total isolates, respectively. We also found that the quantity and population composition of the endophytic fungi of Rangoon creeper were varied at the different areas of Guangzhou but the dominant genera still kept the same. Moreover, quantity and population composition of fungal endophytes were significantly varied in different tissues of the plant. Isolates from the leaves were up to 69％, higher than the total number from the stems and roots. Botryosphaeria, Guignardia, Nemania, Nodulisporium, Paecilomyces, Paraphaeosphaeria, Pestalotiopsis, Xylaria and Zopfiella were the special populations for the leaves, while Coniella, Eutypella, Chaetomella and Penicillium were special for the stems and Pyrenochaeta for the roots. The isolated fungal endophytes were also different on different culture media. Nemania and Pyrenochaeta were only the populations on PCA, Paecilomyces only on PSM, Zopfiella only on Czapek, and Nodulisporium and Penicillium only on the medium with extract of Rangoon creeper. Toxicity of the isolated fungal endophytes to a nematode (Bursaphelenchus xylophilus) was evaluated by using their culture filtrates. We found that l0 of 249 isolates had toxicity to the nematode. One of them, FDYS-1, exhibited a mortality of 99％, and could be a powerful potential bio-control agent for nematodes. It was observed that the bio-activity of FDYS-1 was hereditarily stable after six successive transfers, and its active substance was heat-stable, at least resistant to 121oC for 20 min. Single factor and orthogonal experiments showed that l00 ml of potato dextrose (PD, pH5-8) and 7 pieces of mycelium mats in diameter 5 mm in a 250ml conical flask were optimal forFDYS-1 growth if incubated at 26℃ with vibration of l50 rpm for 3 days, and its culture filtrate exhibited the strongest nematocidal activity, yielding a mortality of 96％ to nematodes even when it was double-diluted. Furthermore, the time period of culture was found to be crucial to its nematocidal activity.
Rangoon creeper Quisqualis indica fungal endophytes endophytic fungal diversity Bursaphelenchus xylophilus Fungal active substance
Yuan Yongping Xiang Meimei Xi Pinggen Jiang Zide
College of Natural Resources and Environment, South China Agricultural University, Wushan, Guangzhou Institute of Plant Pathology, Zhongkai University of Agriculture and Technology, Dongsha Street, Fan
国际会议
第八届中韩菌物学研讨会(The Eighth China-Korea Joint Symposium for Mycology)
陕西杨凌
英文
14-15
2007-11-18（万方平台首次上网日期，不代表论文的发表时间）