Characterizing metribuzin herbicide tolerance in lentil
Meier, Kendra Susanne 1987-
Worldwide, lentil (Lens culinaris Medik.) is an important pulse crop. Canada is the world-leading producer and exporter of lentils, with Saskatchewan alone exporting more than 2.0 Mt annually. Lentil is a poor competitor with both grasses and broad-leaved weeds, and chemical methods are the main form of control in mechanized broad acre production systems. Imidazolinone (Group 2) tolerance has been developed in lentil, but due to new resistance to this herbicide in weed populations, the use of metribuzin (MB) (Group 5, approved at 206 g a.i. ha-1) has recently increased in western Canada. However, metribuzin can cause extensive damage to lentil crops under certain environmental conditions. The purpose of these studies was to develop strategies to improve tolerance to metribuzin in lentil through identifying potential genetic sources of improved tolerance and understanding the mode of inheritance of tolerance. Potential metribuzin tolerant F2 populations were screened at 3x (618 g a.i ha-1) rate of metribuzin application for improved resistance. Commercial lentil varieties were screened at 0x, 0.5x, 2x and 4x rates to evaluate tolerance to metribuzin to determine if natural variability occurs among genotypes and market classes. A mutagenized population of CDC Redberry was also screened at 10x (2060 g a.i ha-1) and three putative tolerant selections were identified. Initial F2 populations did not show improved metribuzin tolerance. There were significant differences of metribuzin tolerance between market classes, as well as between rates (P<0.0001). Mutant and commercial genotype tolerance were quantified with dose response studies, indicating that PMBR-1 and 7529s had the largest ED50. Lastly, a genetic study indicated that there was not the 3:1 susceptible to tolerant F2 phenotypic ratio as hypothesized (X2 (1, N=96) = 0.19, p<0.05), but rather a 15:1 F2 phenotypic ratio of susceptible to tolerant.
DegreeMaster of Science (M.Sc.)
SupervisorVandenberg, Dr. Albert
CommitteeWillenborg, Dr. Chris; Ta'ran, Dr. Bunyamin; Neeser, Dr. Chris; Warkentin, Tom
Copyright DateDecember 2016