Evaluation of Relative Efficiency of Several Selection Indices for Prediction of Expected Genetic Advance in Bread Wheat Grain Yield (Triticum aestivum L)

This experiment was conducted with fifteen genotypes of bread wheat introduced from ICARDA and two local varieties (Sham6 and Abu-Graib3), using three rows spacing (15, 25 and 35 cm). All genotypes were grown in 7 December, 2017 at Field Crops farm (inside Mosul University) under rain fed conditions with complementary irrigation, using split plots in randomized complete block design with three replications, for evaluation through constructing several selection indices and calculation of the expected gains of grain yield. The analysis of variance results for studied traits (grain yield, plant height, number spikes, biological yield, number of grains per spike, 1000-grain weight and harvest index) showed that mean square of genotypes were highly significant for plant height, number of grains per spike and 1000 grain weight. The selection index constructed from number of grains per spike and harvest index had high increase in the efficiency as compared with direct selection for yield. This indicate of the importance of a selection index based on combination of characters. This index in the present study considered the superior due to its highest efficiency. Using this index for genotypes evaluation revealed that the higher mean of selection index was 109.961 for genotype REYNA-12 with significant difference over Abu-Graib3 and is not with others, followed in importance by Sham6, ATTILA-7, PASTOR-2/BOCRO-2 and HUBARA-5/3/SHA3/SERI//SHA4LLIRA. The local varieties of bread wheat included in this study, (Sham6 and Abu-Graib3) locates at the sequences 2 and 17 respectively.