ABSTRACT
An attempt is being made to incorporate pre-harvest dormancy from RL4137 (Triticum aestivum L. em. Thell) into durum wheat (T. turgidum L. var. durum) germplasm. An experiment was conducted to determine if random intermating could be utilized to reduce the genetic associations between kernel colour and pre-harvest dormancy in populations derived from the hybridization of 'Vic' durum and PD#44, a red-seeded tetraploid experimental line possessing preharvest dormancy derived from RL4137. Results indicated that one cycle of random intermating did not reduce the genetic associations between kernel colour and dormancy (visual sprouting scored using intact spikes in a rain simulation chamber) ranged from -0,46 to -0.59. Following random intermating, the genotypic variance for sprouting was significantly higher, and small changes in the population means were detected for sprouting and kernel colour. Fortunately, significant variation exists among amber-seeded lines derived from the experimental populations. Several lines appear to have dormancy levels similar to PD#44, In a backcrossing program using RL4137 and Kenya 321 sib as dormant parents, and Vic as the recurrent parent, we have obtained BC3F2 progeny which appear to have good levels of dormancy. Further research is being conducted to evaluate the alpha-amylase activity of experimental lines using a gel-diffusion technique (amylopectin azure blue). Preliminary results indicate that relative alpha-amylase activity, as determined by the area of gel clearance zones, is moderately correlated with sprouting and kernel colour.
