Submitted to: International Safflower Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 23, 2001
Publication Date: July 23, 2001
Citation: Johnson, R.C., P.B. Ghorpade, and V.L. Bradley. 2001. Evaluation of the USDA core safflower collection for seven quantitative traits. Proceedings of the Vth International Safflower Conference, Williston, North Dakota, Sidney, Montana, USA. 2001. p. 149-152. Interpretive Summary: Safflower (Carthamus tinctorius L.) is one of our oldest domesticated crops. Historically its flowers were used to prepare fabric dyes, food coloring, and for medicinal purposes. Most production today is for seeds used to extract its high quality edible oil, but there is also a market for seeds as bird feed. Germplasm collections will continue to play a vital role in providing the genetic resources needed for improving safflower. The USDA-ARS maintains a collection of safflower germplasm consisting of about 2300 accessions. To enhance utilization of the whole collection, a safflower core collection representing about 10% of the total accessions was developed from the entire collection based on country of origin and morphological data. The objective of the current work was to evaluate the diversity of USDA safflower core collection for numerous agronomic descriptors and determine if regional differences in agronomic factors could be distinguished. Accessions were highly variable for all factors measured indicating considerable diversity within the core collection. Among the regions, accessions from SW Asia were the most distant from other regions, but S. Central Asia and E. Africa grouped closely together. The results showed that the core collection was a highly diverse germplasm source, and that agronomic attributes could often distinguish regional differences.
Technical Abstract: The United States Department of Agriculture maintains a safflower (Carthamus tinctorius L.) germplasm collection of more than 2,300 accessions from which a core collection of 207 accessions was developed. To enhance characterization and determine diversity, the core collection was evaluated for numerous crop descriptors at the Western Regional Plant Introduction Station in Pullman, Washington USA. This paper reports evaluation results for seven quantitative factors: outer involucral bract (OIB) width, OIB length, primary head diameter, date of 50% flowering, plant height, weight per seed, and yield per plant. Accessions were highly variable for all factors measured indicating considerable diversity within the core collection. Correlation analysis showed the strongest associations were between plant height and flowering (r = 0.62), and between OIB width and OIB length (r = 0.54) (P<0.05). To test regional differences, accessions in the core collection were partitioned into ten major regions (the Americas, Australia, China, E. Africa, Europe, Japan, the Mediterranean, S. Central Asia, and S. West Asia, and Thailand). Significant differences were found among regions for all factors except OIB length and yield per plant. Canonical discriminant functions showed that the first and second functions explained 83% of the total variation. Among the regions, accessions from SW Asia were the most distant from other regions, but S. Central Asia and E. Africa grouped closely together. The results showed that the core collection was a highly diverse germplasm source, and that agronomic attributes could often distinguish regional differences.