Zi Xiao-Meng, Sheng Chun-Ling, Goodale Uromi Manage, Shao Shi-Cheng, Gao Jiang-Yun
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China.
Mycorrhiza. 2014 Oct;24(7):487-99. doi: 10.1007/s00572-014-0565-8. Epub 2014 Feb 23.
Orchid conservation efforts, using seeds and species-specific fungi that support seed germination, require the isolation, identification, and germination enhancement testing of symbiotic fungi. However, few studies have focused on developing such techniques for the epiphytes that constitute the majority of orchids. In this study, conducted in Xishuangbanna Tropical Botanical Garden, Yunnan, China, we used seeds of Dendrobium aphyllum, a locally endangered and medicinally valuable epiphytic orchid, to attract germination promoting fungi. Of the two fungi isolated from seed baiting, Tulasnella spp. and Trichoderma spp., Tulasnella, enhanced seed germination by 13.6 %, protocorm formation by 85.7 %, and seedling development by 45.2 % (all P < 0.0001). Epulorhiza, another seed germination promoting fungi isolated from Cymbidium mannii, also enhanced seed germination (6.5 %; P < 0.05) and protocorm formation (20.3 %; P < 0.0001), but Trichoderma suppressed seed germination by 26.4 % (P < 0.0001). Tulasnella was the only treatment that produced seedlings. Light increased seed imbibition, protocorm formation, and two-leaved seed development of Tulasnella inoculated seeds (P < 0.0001). Because the germination stage success was not dependent on fungi, we recommend that Tulasnella be introduced for facilitating D. aphyllum seed germination at the protocorm formation stage and that light be provided for increasing germination as well as further seedling development. Our findings suggest that in situ seed baiting can be used to isolate seed germination-enhancing fungi for the development of seedling production for conservation and reintroduction efforts of epiphytic orchids such as D. aphyllum.
利用种子和支持种子萌发的特定物种真菌进行兰花保护工作,需要对共生真菌进行分离、鉴定和萌发增强测试。然而,很少有研究专注于为构成大多数兰花的附生植物开发此类技术。在中国云南西双版纳热带植物园进行的这项研究中,我们使用了本地濒危且具有药用价值的附生兰花石仙桃的种子来吸引促进萌发的真菌。从种子诱捕中分离出的两种真菌中突脐蠕孢属和木霉属,突脐蠕孢属使种子萌发提高了13.6%,原球茎形成提高了85.7%,幼苗发育提高了45.2%(所有P<0.0001)。从滇南虎头兰分离出的另一种促进种子萌发的真菌埃氏菌属,也提高了种子萌发率(6.5%;P<0.05)和原球茎形成率(20.3%;P<0.0001),但木霉属使种子萌发率降低了26.4%(P<0.0001)。突脐蠕孢属是唯一产生幼苗的处理。光照增加了接种突脐蠕孢属种子的吸水量、原球茎形成和两叶期种子发育(P<0.0001)。由于萌发阶段的成功不依赖于真菌,我们建议引入突脐蠕孢属以促进石仙桃种子在原球茎形成阶段的萌发,并提供光照以提高萌发率以及促进进一步的幼苗发育。我们的研究结果表明,原位种子诱捕可用于分离增强种子萌发的真菌,以开发用于保护和重新引入石仙桃等附生兰花的幼苗生产技术。