Analysis of Genetic Divergence for Grain Yield and Grain Quality Traits in Bread Wheat (Triticum aestivum L.) Genotypes at Axum, Northern Ethiopia

Abstract

This study was intended to assess genetic diversity for yield and grain quality traits at Axum Agricultural Research Center in 2016. Forty-nine wheat genotypes were tested using 7 x 7 triple- lattice design in which data were collected for 17 agronomic and grain quality traits. The near infrared transmittance (NIT Infratec 1241 Grain analyzer, Sweden) was used to analyze wheat samples for their protein, wet gluten, zeleny sedimentation and starch content on dry weight basis. The data were subjected to analysis of variance and exhibited significant difference among genotypes. New entries viz .ETBW8486, ETBW8480 and ETBW9016 produced grain yield ranged from 4.52 to 5.44 t ha-1 and protein content 13.1 to 14.67%, which are higher than the check variety (King bird= 4.38 t ha-1 with protein content=11.93% ). These genotypes were also early maturing than the check varieties, thus they might serve as good candidates for variety development. Genetic divergence estimated by squared distance (D2) and clustering conducted using Ward's method grouped the 49 bread wheat genotypes in to five clusters. Cluster mean values and squared distance showed that there is negative association between grain yield and grain quality traits. Hence, for the improvement of grain yield with grain quality, genotypes from cluster V and I might be crossed. PCA analysis also showed that the first five PC’s accounted for 80.12% of total variation and suggested these traits could be used as useful sources of genetic variation for future improvement. Generally, the information obtained from this study can be used to plan hybridization among potential genotypes to maximize genetic diversity and expression of heterosis for feature wheat improvement.