Selection response for molecular markers associated with anthocyanin coloration and low-temperature growth traits in crested wheatgrasses

Hycrest is an outcrossing tetraploid cultivar of crested wheatgrass developed from a hybrid between an induced tetraploid form of Fairway (Agropyron cristatum) and natural tetraploid Standard (A. desertorum). The CD-II cultivar was selected from cv. Hycrest on the basis of vigorous vegetative growth and green leaf coloration during early spring. This study examines the selection response of molecular markers associated with anthocyanin coloration (AC), growth habit (GH) and other traits in Hycrest, CD-II, and two second-generation polycross (PX 2 ) populations derived from three purple-leaf selections and three green-leaf selections of Hycrest. AC was positively correlated with prostrate GH and inversely correlated with plant height and leaf width in the experimental PX 2 populations. Of the 578 AFLP markers surveyed, 13 showed pleiotropic effects on GH and AC in the PX 2 populations. In all cases, marker alleles associated with prostrate GH also enhanced AC. Four of these 13 markers also showed large selection responses in CD-II (i.e. 80th percentile or higher) relative to Hycrest, always favouring upright GH and low AC alleles.However, the upright GH in CD-II was not explainable solely by molecular marker alleles near the vernalization gene. Key words: Anthocyanin, crested wheatgrass, molecular marker, selection, vernalization