Identification of Unwanted Plant Species (Weeds)


Available for Licensing
TRL: 7

IP Status

US Patent: US 9963750


Todd Gaines
Eric L. Patterson
Kallie Kessler
Margaret Flemming

Reference No: 17-051
Licensing Manager

Jillian Lang

At a Glance

Researchers at Colorado State University have developed novel assays to determine the genotype of a population of Myriophyllum and Amaranthus plants utilizing Kompetitive Allele Specific PCR, also known as a KASP™ assay.  The assay is based on competitive allele-specific PCR and allows scoring of single nucleotide polymorphisms (SNPs), as well as deletions and insertions at specific loci. Here, the developed KASP™ assays are employed for genotyping a large population of plants, such as a population of weedy or invasive plants, plants growing where they are undesired, or plants that need to be eradicated as a group. By using the assay, it is possible to obtain a DNA sample for a large number of plants in a population, determine which species they are, and if they are hybrid, and adjust eradication methods for optimum use with the plant population.


Specifically, Palmer amaranth has been listed as a prohibited noxious weed species in some US states, whereas species of the genus Myriophyllum, are invasive aquatic plant, that damage aquatic environments.


Identification of both species is crucial for environmental management.


In any particular geographic area, whether aquatic or land, it is often desirable to determine in a population of plants the genotype of those plants. A particular challenge is when within a population of plants there exists more than one species of a genus of the plant, where one or more species has a characteristic distinct from the other, yet is morphologically indistinct. An example of such a situation is where within a population of plants, the wild type species is inter-planted with another species that is more aggressive, more resistant to herbicide application, or has other undesirable characteristics. This is complicated further when the species interbreed, producing a hybrid.


Watermilfoil plants of the genus Myriophyllum 

The invasive aquatic plant Eurasian watermilfoil (Myriophyllum spicatum L.) readily hybridizes with the related North American native species northern watermilfoil (M. sibiricum Kom.). Hybrid watermilfoil (M. spicatum×M. sibiricum) populations have higher fitness and reduced sensitivity to some commonly used herbicides, making management more difficult. There is growing concern that management practices using herbicides with mixed populations such as watermilfoil species may further select for hybrid individuals due to the difference in herbicide sensitivity. Accurate and cost-effective identification of hybrid individuals within populations is therefore critical for management decisions


Land plants of the genus Amaranthus

Palmer amaranth (Amaranthus palmeri) and waterhemp (Amaranthus tuberculatus) are important weed species that can contaminate seeds for sale (e.g., wildflowers, native grasses). Palmer amaranth has been listed as a prohibited noxious weed species in some US states, meaning that a seed lot containing Palmer amaranth may not legally be sold. Waterhemp is prohibited from seeds for sale in Canada and China. Waterhemp and Palmer amaranth seeds cannot be distinguished visually from other, non-noxious Amaranthus species, such as redroot pigweed (Amaranthus retroflexus), smooth pigweed (Amaranthus hybridus), and spiny amaranth (Amaranthus spinosus). There is no fast and inexpensive method for the seed testing industry to reliably assess bulked amaranth seed samples as containing Palmer amaranth or not. Therefore, the seed production and analysis industry has considerable interest in a DNA-based test to identify the presence of any Palmer amaranth and waterhemp seeds.

  • Identification of Palmer amaranth at a 1 in 50 seed ratio (or better)
  • Distinguishing between the Eurasian watermilfoil (Myriophyllum spicatum), Northern watermilfoil (Myriophyllum sibiricum) and hybrids of the two
  • Uses reliable, robust industry standard genotyping methodology
  • Assay validated using blind samples
  • Provides for fast identification of a large number of samples
  • Hundreds and thousands of plants may be screened in a day and at a cost that is 1/10 the cost of present processes
  • Can develop proper control measures for populations of unwanted plants based on accurate results
  • Identification of plants within the genus Amaranthus
  • Identification of plants within the genus Myriophyllum

Last updated: September 2020