Developing a quick test to distinguish fine fescue species in mixtures

October 10, 2018

by Yinjie Qiu

The fine fescue species, which include Chewings fescue, hard fescue, sheep fescue, strong creeping red fescue, and slender creeping red fescue, have been shown to perform well as turfgrasses in low-input environments in temperate climates such as in Minnesota.  Fine fescues grow well in the shade or sun, have reduced mowing requirements, and possess good drought tolerance.

Fine fescues are often planted in mixtures, rather than as a single species, because the different species have complementary characteristics that work together to form a good quality turf stand. There are often, however, differences in performance among these species for traits such as disease resistance and tolerance to traffic. Yet when fine fescues are planted in mixtures, it is difficult to establish final community composition because the species are so similar morphologically (Figure 1).  This presents a challenge for turfgrass researchers because it is difficult to determine which species in a mixture is performing better or worse for a given trait.

fine fescue mixtures in research plots
Figure 1.  Mixtures of fine fescue species in research plots.

At the University of Minnesota, we are working on a technique to quickly determine fine fescue mixture species composition, which will benefit turfgrass researchers across the country. To do this, we are utilizing the chloroplast genome. Unlike the nuclear genome, which is influenced by contributions of genes from both parents, the smaller chloroplast genome is only inherited maternally and the makeup of the genome evolves very slowly. For these reasons, chloroplast genes have been widely used as a sort of DNA barcode to identify the origin of plants because they are highly conserved within a single plant species. We are using sequencing technology to capture the chloroplast genes of the fine fescue species. By comparing differences between fine fescue species’ chloroplast genes, we are able to develop genetic markers that can provide us a fast and easy way for fine fescue species identification. Species identification, and potentially quantification of each species, using genetic markers will be done through the Polymerase Chain Reaction (PCR), which is a fast and accurate molecular biology method used to amplify a targeted DNA region. The reaction usually takes around 90 minutes and is followed by gel electrophoresis, which helps to visualize the DNA fingerprints of each species (Figure 2).

fine fescue markers
Figure 2.  Here are examples of two DNA markers we developed based on the chloroplast sequence of each fine fescue. As is shown by the different patterns, fine fescue species show species-specific DNA fingerprints. The DNA ladder is used to measure the size of the DNA fragment.

With this powerful tool in hand, we can study the dynamics of fine fescue mixtures under different environmental conditions. This knowledge could potentially help us design fine fescue mixtures that perform well under different environment conditions.