Abstract
The distribution area of Cycas taitungensis was confined only at Tai-tung Costal Range of Hong-Yeh village, and considered as endangered species. Thirteen sets of SSR and 8 sets of ISSR were used in the study to determine the population genetic diversity of Cycas taitungensis. The results indicated the ratio of homozygous was much higher than that of heterogeneity in Cycas taitugensis populations. Coastal Range population had dispersed distribution pattern based on PcoA. Isolation of Cycas taitungensis family was found, according to population structure analysis. The origin of seedlings grown in nursery could be identified by the same method, i.e. all the seedlings were proved to be Lu-ye River compartment source. It’s suggested all populations of the species in both in-situ and ex-situ conservation should be reserved to maintain enough gene pool.
Germination of seeds in Cycas taitungensis from 5 individual plants from the Nature Reserve incubated at 30/20℃ was 6.8-38.8%. However, germination of seeds from the plantation incubated at 25℃ was 80% and incubated at 30/20℃ was 73.3%. Seeds mixed with and without moist sphagnum stored at 5℃ for 12 months germinated to 52% and 64%, respectively, and germination decreased about 10-20% compared fresh seeds. The potted seedlings were shipped to Heng-chun Research Station for further growth.
Embryo cultivation buds of seedlings or mature tree suckers of Cycas taitungensis in Reserve Area were used for micropropagation, and proliferation in vitro to produce multiple buds. Multiple buds were then elongated in medium without growth hormone. Eighty percent cut of the full development of leaf buds with root induction were observed to develop complete root seedlings. Five out of 16 seeds collected on May of 2010 were found with no embryo, which was used for embryo culture to produce new seedlings.