Title: Enhanced growth and seed properties in introduced vs. native populations of yellow starthistle (Centaurea solstitialis)
Widmer, Timothy - USDA-ARS-EBCL
Guermache, Fatiha - USDA-ARS-EBCL
Dolgovskaia, Margarita Yu - RUSSIAN ACADEMY SCI
Reznik, Sergey Ya - RUSSIAN ACADEMY SCI
Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 24, 2007
Publication Date: September 1, 2007
Citation: Widmer, T., Guermache, F., Dolgovskaia, M., Reznik, S. 2007. Enhanced growth and seed properties in introduced vs. native populations of yellow starthistle (Centaurea solstitialis). Weed Science. 55:465-473.
Interpretive Summary: Yellow starthistle is considered a noxious weed in the United States, originating from the Mediterranean region. Observations were made that seedlings grown from seed originating from the U.S. were larger than seedlings whose seeds originated from other geographical locations. We wanted to prove that this was true and examine if starch contained within the seeds, which is used as an energy reserve for seed germination, and chromosome numbers of the plants had an effect on this growth. After 2 weeks of growth, seedlings grown from the U.S. seed weighed more than those seedlings grown from France, Italy, Greece, Sicily, Sardinia, and Turkey seed. Chromosome numbers were 16 for all locations except Sicily and Sardinia, which had 18 chromosomes. The amount of starch in the seed from the U.S. was higher than the starch content from any of the other locations. Statistical analysis showed a relationship between the amount of starch in the seed and the seedling growth. The number of chromosomes does not appear to affect growth in a positive manner. This work is important to help understand why yellow starthistle is so invasive in the U.S.
1 We investigated whether Centaurea solstitialis originating from a native or invasive habitat would have similar plant characteristics if grown under the same environmental conditions.
2 Seedlings grown from seed originating from the U.S. (invasive habitat) were larger than seedlings originating from Europe (native habitat) under laboratory conditions.
3 In two field plots in two different years, the U.S. plants were larger in canopy size and height than the other plants originating from native habitats.
4 F1 progeny of original U.S. plants grown and pollinated in France displayed similar growth characteristics to the U.S. plants when grown in France and Russia, suggesting genetic control of growth characteristics.
5 The percentage of seed that was starch and seed weight showed a correlation with seedling weight.
6 Chromosome number was not different in regards with geographical location except from Sicily and Sardenia. Plants from these two island locations are most likely a different subspecies reported from these areas.
7 This information is useful in understanding that plants can undergo genetic changes over time in a new habitat that assists in their invasive ability.