DETECTION OF QUANTITATIVE TRAIT LOCI FOR AGRONOMIC, YIELD, GRAIN AND DISEASE CHARACTERS IN SPRING BARLEY (HORDEUM-VULGARE L)

Quantitative trait loci (QTLs) have been revealed for characters in a segregating population from a spring barley cross between genotypes ad apted to North-West Europe. Transgressive segregation was found for al l the characters, which was confirmed by the regular detection of posi tive and negative QTLs from both parents. A QTL for all the agronomic, yield and grain characters measured except thousand grain weight was found in the region of the dense dwarfing gene locus. There were consi derable differences between the location of QTLs found in the present study and those found in previous studies of North American germ plasm , revealing the diversity between the two gene pools. Thirty-one QTLs were detected in more than one environment for the 13 characters studi ed, although many more were detected in just one environment. Whilst b iometrical analyses suggested the presence of epistasis in the genetic control of some characters, there was little evidence of interactions between the QTLs apart from those associated with yield. QTLs of larg e effect sometimes masked the presence of QTLs of smaller effect.