Genetic analysis on the competitive ability of barley (Hordeum vulgare L.) recombinant inbred lines intercropped with oat (Avena sativa L.) weeds

Ninety-eight barley recombinant inbred lines (RILs) were studied to determine oat weed competitive ability at Wageningen Agricultural University farm in 1997/98 summer season. The major objectives of the study were to determine: the influence of oat weed competition on the phenotype of barley lines, competitive ability with oat weeds, Quantitative Trait Loci (QTL) responsible for weed competition, and to study the correlation of competitive ability with yield and other agronomic characters. The most important characters determining competitive ability of barley lines were found to be plant height, droopy leaf type, thousand kernel-weight and grain yield (kg/ha). The QTLs identified for these characters revealed the molecular marker ‘erect gene' as an aid to select lines that are competitive with oat weeds. The QTLs identified are stable for these characters and are located on chromosome VII at position of 62.6 and 67.6 cM. Correlation analysis also showed that plant height and thousand-kernel weight were positively and moderately correlated with grain yield (kg/ha) in the intercrop environments. Selecting barley lines consisting of traits like droopy leaf type, taller, more number of seeds per ear, with better thousand kernel weight and grain yield (kg/ha) would enable one to determine environmentally friendly way of barley lines to withstand oat weed infestation which could easily be used in local communities. Furthermore, the commonly used herbicide price is soaring from time to time and out of the reach of the poor farmers in the developing countries. Therefore, this method is an alternative which uses a low input and environmentally friendly approach to withstand the oat-weed infestation problem. Keywords: barley lines, competitive ability, intercropping, oat-weed, quantitative trait loci SINET: Ethiopian Journal of Science Vol. 29(1) 2006: 27–4