Outcrossing in Annual Canarygrass
- M. A. Matus-Cádiz and
- P. Hucl *
Currently recommended minimum isolation distances of 3 and 10 m for pedigreed seed production of annual canarygrass (Phalaris canariensis L.; 2n = 2x = 12) may not be sufficient to maintain the purity of seed lots. The objective of this study was to estimate outcrossing (OC) rates of annual canarygrass over various distances and directions, using the pubescent-hulled trait as a dominant detectable marker. In 2001 and 2002, 5- × 5-m pubescent-hulled pollinator blocks (‘Cantate’) were sown and surrounded by recipient rows of glabrous-hulled annual canarygrass (‘CDC Maria’) at Saskatoon, SK. At maturity, 0.5- × 5-m strips were harvested at 0, 0.5, 1, 2, 3, 6, 9, 12, 15, 18, 21, 24, 27, and 30 m along four transects (N, S, E, W) radiating out from the central pollinator block. Outcrossing from Cantate to recipient plants was identified by the expression of trichomes on the hulls of F1 derived seed. In both years, OC rates adjacent to the pollinator did not exceed ≤2.2%, while OC rates declined rapidly to 0% (2001) or trace levels (0.05%, 2002) at 30 m. Elevated OC to the N of the pollinator was associated with prevailing winds in both years. Maximum OC rates of ≤2.2% support the suggestion that annual canarygrass is predominantly self-fertilizing. In both years, low OC rates of ≤0.07% were observed at 24 m, suggesting that currently recommended minimum isolation distances may be inadequate to reduce outcrossed derived off-types to acceptable levels in pedigreed annual canarygrass seed.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2006.