Genetic variability and character associations in some triticale genotypes at Kulumsa and Assasa, Arsi

Forty-nine triticale (X triticosecale Wittmak) genotypes were evaluated for 13 traits in simple lattice design at two locations, Kulumsa and Assasa. The overall objective was to study the extent of genetic variation and association among grain yield and 12 yield-related traits. The genotypes differ significantly for most of the traits and the relatively wide range of the mean values for most of the characters indicated the existence of variations among the tested genotypes. Estimates of phenotypic (PCV) and genotypic (GCV) coefficients of variations were generally low. The PCV values were slightly greater than the GCV values. Relatively higher PCV values were exhibited by number of kernel/spike at Kulumsa and number of tillers, grain yield, biological yield, and number of kernels at Assasa. Days to heading showed the highest heritability at both locations. Moderate to high heritability was observed for days to maturity, plant height, spike length, number of spikelet, number of kernel/spike and thousand kernel weight at Kulumsa, and days to maturity, spikelete/spike and hectoliter weight at Assasa. Estimated genetic advance as percent of the mean was generally low for the 13 characters. Among the characters, number of kernel/spike had higher value at both locations followed by thousand kernel weight. The square D analysis showed the 49 genotypes grouped into five clusters. This makes the genotypes to become moderately divergent. Grain yield showed positive and significant phenotypic correlation with biological yield, harvest index, and hectoliter weight at both locations. Path coefficient analysis showed that biological yield, thousand kernel weight and number of kernel/spike exerted positive direct effect at both locations and the two combined at both levels. Exception was genotypic path at Kulumsa were only biological yield showed positive direct effect. Among these characters biological yield showed the highest direct effect except for the combined genotypic path where thousand kernel weight gave the highest direct effect. While these two characters can be considered for selection, widening the genetic base of the triticale germplasm in Ethiopia is a pre-requisite for a successful breeding program.