|Joung, Young Hee|
|Lee, Nam Sook|
Submitted to: Chinese Journal of Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/26/2006
Publication Date: 4/17/2007
Citation: Roh, M. S., De Benedetti, L., Joung, Y.H. and Lee, N.S. 2007. Identification of Tsuga germplasm by morphological characters and RAPD markers. Chin. J. Appl. Environ. Biol. 13:145-151 Interpretive Summary: Among 5 Asian Tsuga (hemlock) species that include T. dumosa, T. chinensis var. chinensis, and T. chinensis var. forrestii, T. chinensis var. chinensis is currently cultivated in the United States. Tsuga is usually identified based on the shape and size of cone and seed scales. The shape of the needle apex and leaf margins could be valuable tool to identify young plants. The apices of T. dumosa needles can be acute, obtuse, or intermediate and the needles are rarely notched at the apical half of the leaves. For T. chinensis var. forrestii, leaves are emarginate with an obtuse apex and entire or rarely serrulate in the middle. Because needle characters have been used in some references but not others, it seems appropriate to investigate the usefulness of the needle characters to identify Tsuga taxa from mature plants and young plants. The objective of this study was to identify Tsuga germplasm from Yunnan Province of China, based on the morphological characters and to compare the results with those obtained by RAPD markers. Our results indicate that the shape of the apex and margins of needles could not be used solely to separate T. dumosa and T. chinensis var. forrestii, particularly young plant populations, from Yunnan Province, China.
Technical Abstract: Germplasm collection is important to preserve and maximize genetic diversity for germplasm conservation. Tsuga chinensis (Franchet) Pritzel , T. dumosa (D. Don) Eichler in Engler & Prantl and T. chinensis var. forrestii (Downie) Silba germplasm was collected from three localities in the Peoples Republic of China: Mt. Yulong, Wenfeng temple, and Mt. Dishiergu, Yunnan Province. Identification of the accessions was based on morphological characters and molecular markers. The morphological characters examined were the shapes of the apices and margin of needles, and the length and width of needles, cones, and seeds. Molecular markers generated by randomly amplified polymorphic DNA (RAPD) were also analyzed to characterize the taxa. Although the clustering based on genetic markers was inconsistent with morphological characters of the needles, based on the overall morphological characters of cones and seeds, and on RAPD markers, accessions from Mt. Yulong and Wenfeng Temple were identified as T. chinensis var. forrestii, and accessions from Mt. Dishiergu were identified as T. dumosa. Taxonomic identification of accessions based on morphology and by RAPD markers concurred. However, our results indicate that the shape of the apex and margins of needles, which previously were one of several taxonomic characters to identify mature plants, could not be used solely to separate T. dumosa and T. chinensis var. forrestii, particularly young plant populations, from Yunnan Province, China.