PURE LINE SELECTION FROM BREAD WHEAT FOR SOME FIELD TRAITS UNDER DIFFERENT SEEDING RATES

Abstract

Field experiments were conducted over three growing seasons , during 2009-2012, at the experimental farm of Field Crop Sciences - College of Agriculture - University of Baghdad. This study aimed to application pure line selection in fifteen F4 segregating populations of bread wheat produced from half diallel crossing among 6 parents.The selection was applied in the first season by using 10% selection intensity, further screening was conducted and selected 12 plants from each population.The grains of individual selected plants were planted in the following year in plant to row method and the best 15 progeny lines were selected depending on yield performance. Varietal trail was conducted in the third season as RCBD with four replications using a split plot arrangement, where three seed rates (120, 160, and 200 kg.ha-1) randomized in the main plots and 21 genotypes in the sub-plots. The genotypes included fifteen F6 progeny lines plus six parents: Al-fatah, A3103, M2.0, IPA99, A4.10, and Abu-Ghraib3. The results showed significant differences among progenies for all the studied traits . The pure line S83 produced highest flag leaf area 30.81. Also, the seeding rate 120 kg.ha-1 produced higher flag leaf area 25.98. Plants of the pure line S130 had highest spad reading for chlorophyll content. Plants of the pure line S94 produced maximum plant height 103.9 cm. While, the plants of the pure line S83 take highest number of days from planting to physiological maturity. significant differences were found among the genotypes under the three seeding rates for some traits, indicating relatively high magnitude of genetic variability in these genotypes.