Schrotenboer, A.C. and C.M. Malmstrom
Presented at the All Scientist and GLBRC Sustainability Meeting (2009-05-05 to 2009-05-07 )
Native prairie grasses have the potential to be harvested for biofuel feedstocks while also providing ecosystem services and conservation benefits. However, many different seed sources are available for establishing prairie grasses, which may differ in productivity, stress, tolerance, and plant-pathogen interactions. To understand the differences among seed sources, we have assessed field performance and tested for susceptibility to a common group of pathogens, the Barley yellow dwarf viruses (BYDVs). We established a multi-population field experiment of both cultivated and wild-collected populations of big bluestem and little bluestem. Plants were grown in both sandy and loamy soils to compare their productivity and their response to a low resource environment. Among big bluestem plants, cultivated varieties grew larger and produced more inflorescences than wild-collected populations when grown on the loamy soils, but not on the sandy soils. Among little bluestem plants, populations varied in growth, but the effect of cultivation was less evident. In order to assess susceptibility to BYDVs, we assessed the incidence of virus in field-grown plants and conducted greenhouse inoculations of different switchgrass seed sources. We found that BYDVs are present in field-grown switchgrass at significant levels. In the greenhouse experiment, we were able to infect a portion of plants from each of four seed sources with BYDV-PAV, but populations differed in their infection rate. The least susceptible population was a Michigan genotype produced without any selective breeding. The most susceptible population was the cultivar ‘Trailblazer,’ which is recognized for high digestibility as a forage grass, indicating the possibility that selection for digestibility has reduced defensive traits. Further work will assess whether there is a correlation between susceptibility and measures of digestibility and will include other prairie grasses. Our findings indicate that seed sources do vary in productivity, the ability to use soil resources, and pathogen susceptibility. Switchgrass could act as a reservoir for BYDVs and suggests that selection of biofuel cultivars for digestibility could inadvertently increase cultivar susceptibility to virus infection.
Back to meeting | Show |