In this study the in vitro cytotoxic properties of ethanol extracts from the herbs, inflorescents and roots of selected Asteraceae species: Arctium lappa, Artemisia absinthium, Calendula officinalis, Centaurea cyanus, Tanacetum vulgare and Tragopogon pratensis on J-45.01 human acute T leukemia cell line was examined. All tested samples possess antileukemic properties and induce cells death via ...

Hexane, chloroform, ethyl acetate and ethanolic extracts of the aerial parts of Centaurea austro-anatolica Hub.-Mor. (Asteraceae) were evaluated against microorganisms, including multiresistant bacteria, using a paper disc diffusion method. The chloroform extract exhibited significant antibacterial activity toward all bacteria tested. The chemical composition of the chloroform extract was deter...

A Russian knapweed (Acroptilon repens) shoot culture system, initiated from shoot tip culture, was used to generate a source of host plant tissue for the rearing of the nematode Subanguina picridis, a biocontrol agent for Russian knapweed. Young shoots growing on solid B5G medium in petri dishes developed galls on leaves, petioles, and shoot tips 7 days after release of 50 nematodes onto the su...

Russian knapweed (Rhaponticum repens) is a rangeland weed pest in the western United States. One candidate fungus for biological control of R. repens is Puccinia acroptili, which causes a rust disease. Understanding the life cycle of candidate rust fungi for weed biological control is an essential component in risk assessments and evaluations, and for P. acroptili such was unknown. For this rea...

Short-fringed or tyrol knapweed, Centaurea dubia (Asteraceae) is an invasive plant of fields and roadsides in the eastern United States. Insects from the plant’s native Eurasian range have been introduced into North America in an attempt to control the spread of related Centaurea species. One of these biological control agents, Urophora quadrifasciata (Diptera: Tephritidae), a picture-winged se...

The influence of temperature, shoot age, and medium on gall induction by Subanguina picridis on Russian knapweed (Acroptilon repens) was examined in vitro. The optimal temperature for gall formation was 20 C. Gall induction was delayed as the temperature decreased, and decreased as shoot age increased. Bud primordia (0-day-old shoots and 5-day-old shoots) with an average length of 4.2 mm and 7....