ASSOCIATED EFFECTS OF CHROMOSOME 1B 1R TRANSLOCATION ON AGRONOMIC TRAITS IN HEXAPLOID WHEAT/

Two trials were conducted to determine the effect of 1B/1R chromosome translocation on selected agronomic characteristics of spring bread wh eats (Triticum aestivum L.) developed at the International Maize and W heat Improvement Center (CIMMYT). Five bread wheat genotypes with a ch romosome 1B/1R translocation and five without representing a sample of high yielding germplasm were identified for the experiment. Non-limit ing levels of fertility and moisture with a preventive pest and diseas e program were used. Plant height, days to heading, grain yield, above -ground biomass at maturity, harvest index, yield components and test weights were determined. Genotypes with the 1B/1R chromosome transloca tion had 2.2% higher above-ground biomass yield, 2.1% more spikes m-2, 1.12 g higher 1,000-grain weight and 0.8 kg/ha-1 higher test weight. The non-1B/1R genotypes had 0.8% higher harvest index and 0.6 cm longe r spikes. Cultivar comparisons indicated that the 1B/1R group headed 2 .5 days later than the 1B group.