Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2008
Publication Date: 7/8/2009
Citation: Yue, B., Cai, X., Vick, B.A., Hu, J. 2009. Genetic diversity and relationships among 177 public sunflower inbred lines assessed by TRAP markers. Crop Science, 49:1242-1249 (2009).
Interpretive Summary: About 200 sunflower inbred lines have been released by the Fargo, ND-based USDA-ARS Sunflower Research Unit over the past thirty years. These inbred lines were used by researchers and breeders in the US and abroad as donors of desirable traits in their breeding program and contributed substantially to the US sunflower industry as well as world sunflower production. In this study, we assessed the genetic variability among 177 public sunflower lines released from the 1970s to 2005 with the aid of the target region amplification polymorphism (TRAP) marker technique. Our results revealed that the 177 lines represent a relatively diverse sunflower inbred collection because the pairwise genetic similarity coefficients (simple matching) ranged from 30% to 97%, with a mean of 58% based on 230 TRAP markers. Cluster analysis grouped these lines into two classes, oil type and confectionery type, with a few exceptions. Both oil type and confectionery type classes were further categorized into two groups, i.e. fertility maintainer and fertility restorer groups, as expected. These results are useful to sunflower breeders and will promote the utilization of these public inbred lines.
Technical Abstract: One hundred and seventy-seven public sunflower inbred lines released by the U.S. Department of Agriculture (USDA)-Agricultural Research Services (ARS) from the 1970s to 2005, were investigated for genetic diversity using the target region amplification polymorphism (TRAP) marker technique. A total of 230 polymorphic DNA markers were generated using12 TRAP primer combinations. The pairwise genetic similarity coefficients (simple matching) based on the TRAP markers ranged from 0.30 to 0.97 with a mean of 0.58. The average similarity coefficient of 41 confection inbred lines was significantly higher than that of 136 oilseed inbred lines. Cluster analysis grouped the 177 lines into two classes, oilseed type (O) class and confection type (C) class with only two exceptions. The O and C classes were further categorized into two groups, i.e. fertility maintainer groups (OB and CB) and fertility restorer groups (OR and CR). Moreover, inbred lines in the OB, OR, CR, and CB groups were placed into four, three, two, and two clusters, respectively. The present study demonstrated the utility of TRAP markers in assessing genetic diversity of sunflower inbred lines. Assessment of the genetic diversity for the fertility maintainer and restorer lines will facilitate the development of superior hybrid sunflower cultivars.