Huebner, Cynthia .
Seed Germination and Viability of Microstegium vimineum: A Comparison of Flower Type, Habitat, and Seed Age.
Microstegium vimineum (Japanese stiltgrass) is an annual invasive grass of Eastern forests that has both chasmogamous and cleistogamous flowers with a seedbank of 3-7 years. It also produces larger plants with more seed in high-light environments, such as roadsides, compared to forest interiors. Seed were collected from chasmogamous and cleistogamous inflorescences from roadside populations; all seed from forest interior plants were collected, resulting in three different seed types: roadside chasmogamous, roadside cleistogamous, and interior. These collections were made from three West Virginia habitats, including sites that were mesic with high plant diversity, mesic with relatively low diversity, and more xeric with relatively low diversity. Seed from each seed type were collected from three replicate populations from each habitat in both 2005 (three-years old) and 2008 (one-year old). From these collections, 100 seed from each replicate population, seed type, and habitat were germinated in a growth chamber. Another 100 seed from each replicate population, seed type, and habitat were tested for viability using tetrazolium. Results for the 2005 seed showed significant differences in germination rates for seed type, with roadside cleistogamous seed showing significantly lower germination rates than roadside chasmogamous seed and marginally lower germination rates than interior seed. The tetrazolium test results showed that the roadside cleistogamous seed in 2005 was significantly less viable than both roadside chasmogamous and interior seed, and roadside chasmogamous seed were significantly more viable than interior seed. Preliminary results of 2008 seed reveal much higher seed viability than the 2005 seed, with no significant differences between the seed types or habitats. While the seed types begin as equally viable, a seedbank composed of more cleistogamous and interior seed should be less long-lived than a seedbank dominated by chasmogamous seed.
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1 - Northern Research Station, USDA Forest Service, 180 Canfield St., Morgantown, WV, 26505, USA
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Wasatch B/Cliff Lodge - Level C
Date: Monday, July 27th, 2009
Time: 8:00 AM