HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Gustine, D. L. Articles by Papadopoulos, Y. A. Search for Related Content PubMed Articles by Gustine, D. L. Articles by Papadopoulos, Y. A. Agricola Articles by Gustine, D. L. Articles by Papadopoulos, Y. A. Related Collections Crop Genetics Other Forage Crops Plant Genetic Resources

CROP BREEDING, GENETICS & CYTOLOGY

Genetic Variation of RAPD Markers for North American White Clover Collections and Cultivars

^a USDA-ARS, Pasture Systems and Watershed Management Research Unit, Curtin Road, Building 3702, University Park, PA 16802-3702
^b USDA-ARS, Appalachian Farming Systems Research Center, 1224 Airport Road, Beaver, WV 25813-9423
^c Dep. of Agronomy, Iowa State Univ., Ames, IA 50011
^d Agriculture & Agri-Food Canada Crops and Livestock Research Centre, P.O. Box 1210, 440 University Ave., Charlottetown, PE, C1A 7M8 Canada

* Corresponding author (d3g{at}psu.edu)

New white clover (Trifolium repens L.) cultivars with improved winter hardiness and persistence are needed for pasture-based cropping systems in temperate regions of North America. This study evaluated, quantified, and compared genetic variation of populations developed from five recently collected germplasms from Georgia (GA), Iowa (IA), Pennsylvania (PA), West Virginia (WV), and Prince Edward Island (PEI), Canada, and three improved cultivars (‘Regal’, ‘Sacramento’, and ‘Will’). ‘Aurora’ alsike clover (T. hybridum L.) was included for comparison. Random amplified polymorphic DNA (RAPD) profiles of these populations were compared. Euclidean metric distance matrices were calculated for all possible pairwise combinations and were evaluated by analysis of molecular variance (AMOVA). An interpopulation distance matrix [_st, an analog of F as described by Excoffier et al. (1992)] for the nine populations was used to calculate a dendrogram based on the unweighted paired group method of arithmetic averages. As anticipated, alsike clover was separated from white clover. At a higher level of similarity, the white clovers were separated into only two groups. One group consisted of GA, IA, PA, and PEI germplasms collected from long-established pastures. The second group included Regal, Sacramento, and Will cultivars and the WV collection. Although Will was originally derived from pasture collections, it has a larger leaf size than any of the five white clover collections. The surprising genetic similarities of eight populations derived from different climates and geographic regions of the continent may indicate a common European origin for much of the naturalized white clover in North American pastures.

Abbreviations: _st, an analog of F as described by Excoffier et al. (1992) • AMOVA, analysis of molecular variance • IA, germplasms from Iowa • GA, germplasms from Georgia • PA, germplasms from Pennsylvania • PCR, polymerase chain reaction • PEI, germplasms from Prince Edward Island, Canada • RAPD, random amplified polymorphic DNA • SAHN, sequential, agglomerative, hierarchical, and nested clustering method • UPGMA, unweighted paired group method of arithmetic averages • WV, germplasms from West Virginia