Enhanced symbiotic seed germination of Cypripedium macranthos var. rebunense following inoculation after cold treatment
Enhanced symbiotic seed germination of Cypripedium macranthos var. rebunense following inoculation after cold treatment
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DOI：
10.1111/j.1399-3054.2005.00462.x
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发表时间：
2005-03
影响因子：
6.4
通讯作者：
H. Shimura;Y. Koda
中科院分区：
文献类型：
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作者：
H. Shimura;Y. Koda
杓兰（Cypripedium macranthos）是日本著名的野生兰花，被认为是珍稀植物保护的象征。一种从大石斛根中分离的真菌在离体条件下诱导了该物种的共生萌发。共生萌发需要在接种真菌前对种子进行4°C的冷处理。改变真菌对种子的接种时间，大大提高了萌发率。冷处理12周后接种种子，萌发率达到最高，约20%的种子发育成长度超过1mm的原球茎。这些结果表明，真菌接种发生在自然界的初春，坚韧的不透水种皮可以在秋冬季节保护种子免受感染。与真菌在同一培养基上20℃培养16周以上，原球茎逐渐褐变和腐烂。通过用杀菌剂消灭真菌并将其转移到营养丰富的培养基中，大约20%的原球茎发育成健康的植株。本文所获得的方法似乎适用于许多其他受威胁的杓兰属植物的共生萌发。
Cypripedium macranthos var. rebunense is a well-known wild orchid in Japan, and is considered to be a symbol for rare plant conservation. A fungus isolated from roots of C. macranthos var. rebunense induced symbiotic germination of the species in vitro. Cold treatment of the seeds at 4°C prior to fungal inoculation was required for the symbiotic germination. Changing the timing of inoculation of the fungus to the seeds greatly improved germination frequency. Maximum germination was attained after seeds were inoculated just after the cold treatment for 12 weeks, and approximately 20% of the seeds developed into protocorms more than 1 mm long. These results suggest that fungal inoculation takes place at the beginning of spring in nature, and the tough impervious seed coat may preserve the seed from the infection during autumn and winter seasons. The lengthy culture period of more than 16 weeks at 20°C on the same medium with the fungus caused gradual browning and rot of the protocorms. By elimination of the fungus with a fungicide and by transfer to a nutrient rich medium, approximately 20% of the protocorms developed into healthy plantlets. The methods obtained here appear to be applicable to symbiotic germination of many other threatened Cypripedium spp.