臺灣的鐘萼木族群遺傳結構研究

Genetic Structure of Bretschneidera sinensis Hemsl. of Taiwan

黄生(Huang, Shong)

《臺灣省立博物館年刊》 37卷 (1994/12) Pp. 49-67

https://doi.org/10.6548/ATMB.199412_37.0004

摘要

台灣的鐘萼木只分佈在北部受東北季風吹襲的面北溼冷山坡上。本研究應用同功酶技術檢測五個鐘萼木亞族群的遺傳變異度和遺傳結構，就整體而言，鐘萼木全族群的變異度爲H_(EP) = 0.082；各亞族群變異度平均值爲H_(EXP) = 0.062，介於特有物種與狹域分佈物種之間。就遺傳結構而言，各亞族群間存有高度的遺傳分化（F_(ST) = 0.256），顯示每個亞族群都有其特殊地位。分析比較各亞族群的遺傳歧異度後，發現侯硐和陽明的鐘萼木族群基因庫各有地區特色，必須加以保護以維持這個物種基因庫的完整性。

關鍵字

族群遺傳 ； 同功酶 ； 自花不親和 ； 華倫得效應 ； 鐘萼木

並列摘要

Among Taiwanese endangered woody species, populations of Bretschneidera sinensis have distributed around the widest natural geographic area in northern Taiwan. However, they occupy as small patches with isolated tuft tree stands in the fragmented forests. In this study, genetic structure of B. sinensis from five subpopulations are examined using isozyme techniques. The results indicated that the degree of among population differentiation was high (F_(ST) = 0.256). This value reveals that nearly 75 % of the detected genetic variation resides within populations. Selection imposed by habitat variation and the effect of restricted gene flow (Nm = 0.727) to be the causes of high F_(ST). Excessive homozygote deviated from Hardy-Weinberg expectation (F_(IS) = 0.226) may be referred to Wahlund effect. Results of pollination experiment show that B. sinensis is a insect-pollinated outcrossing species. The potential influences of mating type, natural selection, gene flow, genetic drift and the Wahlund effect on genetic differentiation within and among populations of B. sinensis are discussed. Management practices and genetic conservation of this species are proposed.

並列關鍵字

population genetics ； isozyme ； Wahlund effect ； self incompatible ； Bretschneidera sinensis