Department of Soil and Crop SciencesDepartment of Soil and Crop Sciences

Sarah Ward Homepage


Current Research Projects

Students

Hybridization Between Invasive Toadflax Species

We are investigating hybridization between yellow toadflax (Linaria vulgaris) and Dalmatian toadflax (Linaria genistifolia subsp. dalmatica), two introduced species now invasive throughout the Intermountain West. Although the native European ranges of these two toadflaxes do not overlap, invasive populations of yellow and Dalmatian toadflax co-occur in many areas of the Rocky Mountains, and our research has confirmed that spontaneous hybridization is taking place between them. We are now investigating whether hybrid populations represent a greater invasive threat than the parent species. 


Toadflax hybrids growing with the parent species in a common
garden experiment at Colorado State University, early July 2009.

In an ongoing collaboration with Dr. Sharlene Sing at Montana State University, we are also examining the feeding behavior on hybrid plants of two biocontrol agents (Brachypterolus pulicarius and Mecinus janthinus) that are currently released on yellow and Dalmatian toadflax. As each of these insects has a distinct preference for one or the other parent toadflax species, our goal is to find out whether both (or neither) of them will be effective on hybrid toadflax plants.

Inheritance of Glyphosate Resistance in Palmer Amaranth
 

Resistance to the herbicide glyphosate has developed in populations of the weed Palmer amaranth (Amaranthus palmeri) in cotton fields in the southeastern U.S.  This resistance appears to be due to amplification of the EPSPS gene, a previously unknown mechanism. We are investigating how this form of glyphosate resistance is inherited in Palmer amaranth, including the role of apomixis in transmitting the gene duplication from resistant female Palmer amaranth plants to genetically identical progeny.
Glyphosate Resistant Palmer
Amaranth
Cross-pollinating Palmer Amaranth
in the Greenhouse

 

Department Main Office:     Plant Sciences C127    Colorado State University     Fort Collins, CO 80523     Voice: 970-491-6517     Fax: 970-491-0564     CAS_SCS@mail.colostate.edu