| Summary: | 碩士 === 國立臺灣師範大學 === 生命科學研究所 === 96 === Viola adenothrix complex contains two morphologically similar forms which were usually treated as two varieties, namely V. adenothrix var. adenothrix and V. adenothrix var. tsugitakaensis. Both of them are endemic in Taiwan and are distributed in medium (1000~2500m, V. adenothrix var. adenothrix ) and high elevation (2500-3900 m, V. adenothrix var. tsugitakaensis. ) respectively. The present study investigates the phylogenetic and taxonomic relationship of them by using morphological and molecular data.
In morphometric analysis, a total of 87 samples and 19 characters were measured. The results of ANOVA show that six (width of basal petal, width of sepal, length of floral axis, number of beard in the lateral sepal, thickness of leaves, and ratio of length to width of the leaves) out of 19 measured characters are significantly different between the two taxa. Discriminate analysis and cluster analysis also show that they trend to separate into two groups in spite of some morphologically intermediate individuals.
Two chloroplast DNA regions (trnV-trnM and trnG-trnS) were used in molecular analysis. 21 variable sites and 21 haplotypes were obtained from a total of 226 samples. Based on the AMOVA result, only 2.58% variation (P=0.17) between V. adenothrix var. adenothrix and V. adenothrix var. tsugitakaensis. Based on minimum spaning network, the samples shared the haplotypes of two taxa are up to 73.45% of all. Both the patterns from morphological and molecular data suggest that the two taxa might differentiated recently and are in the stage of incomplete lineage sorting.
Beside, the result of minimum spanning network show that the haplotype of V. adenothrix var. tsugitakaensis was derivated from V. adenothrix. Based on Tajima’s D test, dismatch distribution and the star-like phylogeny result, the species complex might undergo population expansion recently.
In conclusion, the present study support to Wang’s treatment (1988) in which V. adenothrix var. tsugitakaensis was treated as a variety of V. adenothrix.
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