THE EFFECT OF CHROMOSOME 1AL 1RS TRANSLOCATION ON AGRONOMIC PERFORMANCE OF 85 F-2-DERIVED F-6 LINES FROM 3 TRITICUM-AESTIVUM L CROSSES/

The effect of the 1AL/1RS chromosome translocation on grain yield and other agronomic characteristics of 85 random F-2-derived F-6 bulks fro m three 1AL 1RS x 1A bread wheat crosses was determined under optimum and reduced irrigation conditions at CIANO, Yaqui Valley, Sonora, Mexi co, during the 1991-1992 and 1992-1993 crop production cycles. Harvest plots of 5.0 m(2) were arranged in an alpha lattice design with three replications. The 1AL/1RS translocation increased grain yield, above- ground biomass, spikes/m(2), and test weight under both irrigated and dryland conditions. Homozygous chromosome 1A lines, on the other hand, possessed longer spikes with more grains. The 1AL/1RS cultivars had a n advantage in 1000-grain weight, which was detected only under optimu m irrigation. The translocation lines showed later maturity and longer grainfilling period than the 1A genotypes under one irrigation treatm ent. A significant relationship between grain yield and test weight wa s detected only among the 1AL/1RS genotypes, indicating that they poss ess heavier and plumper grains than the 1A genotypes. These results en courage the continued use of the 1AL/1RS translocation in wheat improv ement.