Preliminary Study of the Symbiosis Bletilla formosana in Taiwan

• Main Authors: Su,Ming-Chih, 蘇明志
• Other Authors: Ying,Shao-Shun;Chen,Zuei-Ching
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/30559060189176863374

碩士 === 國立臺灣大學 === 森林學系 === 84 === The objectives of this thesis are in the investigation of sy- mbiotic fungi in Bletilla formosana (Hayata) Schltr.in Taiwan and their effects on the germination and growth of host plants. The effect of nutrition on seed germination and seedling growth were tested with seven different synthetic culture media at 25℃.16hr- s.illumination with 2,000 lux/8 hrs.dark/day incubation. After 60 days, the results showed that all media tested could provid seed germination of B. formosana . The blank agar medium showed the best result with 69 % of germination and the Ichihashi medium showed the poorest result of 41.2 % germination. In contrast,the Ichihashi medium showed the best effect on the seedling growth with the average seedling height of 7.18 cm at 169 days after sowing and the sucrose agar medium showed the poorest effect with the average seedling height of 0.08 cm. The seeds of B. formosana also can germinate on the sterilized soils of their natural habi -tat in Taiwan but survived only a short time after germination. The isolation of fungi inhabiting in/on the roots of B. formo- sana obtained 154 isolates in 14 taxa and three unidentified fun- gi. The symbiotic association of these isolated fungi with the s- eeds of B. formosana in the OMA medium resulted that only R. rep- ens showed high affinity of symbiosis with the host orchid and o- thers showed parasitism. The different isolates of R. repens sho- wed the variation in the degree of symbiotic effects on seed ger- mination as well as on seedling growth of B. formosana in Taiwan. The best symbiotic strains of R. repens were T1F004,T2F011,T2F012 ,T2F020-2,T3F057 and T3F058. Followed the strains T3F014,T3F055 and T3F056 showed better effect of symbiosis. The mapping of dis- tribution of R. repens in the host roots showed that R. repens t- hough was a dominat colonizer of host roots but its mycelial dis- tribution in host roots were rather sporadic and not systemic.