ARS | Publication request: Differential Susceptibility of Salsola Tragus to Colletotrichum Gloeosporides and Uromyces Salsolae

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 24, 2003
Publication Date: December 30, 2003
Citation: BRUCKART, W.L., CAVIN, C.A., SOBHIAN, R., VAJNA, L., SCHWARCZINGER, I., RYAN, F.J., HASAN, S. DIFFERENTIAL SUSCEPTIBILITY OF SALSOLA TRAGUS TO COLLETOTRICHUM GLOEOSPORIDES AND UROMYCES SALSOLAE. BIOLOGICAL CONTROL. 2003.

Interpretive Summary: Even though the plants look the same, there are now two different kinds (called "Types" A and B) of Russian thistle in the United States. This is important, because they may also differ biologically. If so, then different ways might be needed to control them. In this study, we learned that the two Types are different, and that one is infected and damaged by two different disease agents (pathogens) and the other isn't. If these pathogens were to be used for biological control, then not all of the Russian thistles in the United States would get sick. The others would stay alive and continue to be pests. We now know that it will be necessary to get something else to kill or damage the other Type.

Technical Abstract: One isolate each of Colletotrichum gloeosporioides and Uromyces salsolae, acquired in Hungary and Turkey, respectively, from Russian thistle, were tested for their ability to infect and damage two Types (A and B) of Salsola tragus. Each Type has been shown to differ on the basis of molecular features. Optimal dew period and temperature requirements for C. gloeosporioides were determined to be 12 hr and 25 C. Inoculations of each type of S. tragus with either pathogen indicated that Type A was very susceptible and that Type B was not damaged and showed very little, if any, macroscopic symptoms. Results illustrate the importance of understanding target plant taxonomy in biological control evaluations.