TY - JOUR
AU - Paschke, Mark W.
AB -  Invasions of North American grasslands by Spotted knapweed (Centaurea maculosa Lam.) are mediated in part by Spotted knapweed root exudation of (±)‐catechin, a potent phytotoxin. Residual soil (±)‐catechin may interfere with reestablishment of native grassland species even after Spotted knapweed populations are controlled. Grassland species that are resistant to (±)‐catechin may be more successful for restoration of areas infested by Spotted knapweed. We evaluated the (±)‐catechin resistance of 23 grassland species by measuring the effects of seven (±)‐catechin concentrations (0–4.0 mg/mL) on seed germination, seedling root and shoot elongation, and seedling mortality. (±)‐Catechin treatments were chosen to reflect the range of observed Spotted knapweed field soil (±)‐catechin concentrations. Inhibition of root elongation was the strongest and most common effect of (±)‐catechin treatment. High (±)‐catechin concentrations reduced mean root lengths of 5 of the species by more than 75% and another 10 species by more than 55%. Experimentally derived concentrations needed to reduce root length by 50% (EC50), an indicator of (±)‐catechin resistance, ranged from 0.43 mg/mL ± 0.30 SE to greater than 4.0 mg/mL among species. Eight species with EC50s greater than 3.0 mg/mL were identified as resistant to (±)‐catechin and are likely suitable for revegetation of Spotted knapweed–infested areas. (±)‐Catechin resistance was positively correlated with mean seed mass, suggesting that seed carbohydrate reserves may allow seedlings to detoxify (±)‐catechin, develop barriers to (±)‐catechin exposure, or sustain a positive growth rate, despite (±)‐catechin‐induced cell death. Future efforts to identify allelochemical‐resistant grassland species should focus on large‐seeded species. 
TI - Screening of Grassland Plants for Restoration after Spotted Knapweed Invasion
JF - Restoration Ecology
DO - 10.1111/j.1526-100X.2005.00092.x
DA - 2005-12-01
UR - https://www.deepdyve.com/lp/wiley/screening-of-grassland-plants-for-restoration-after-spotted-knapweed-GCn0UtDddX
SP - 725
EP - 735
VL - 13
IS - 4
DP - DeepDyve
ER -