GENETIC VARIABILITY AND CHARACTERS ASSOCIATION IN HARARGHE SORGHUM [Sorghum bicolor (L.) Moench] GENOTYPES FOR YIELD, YIELD COMPONENTS, AND QUALITY TRAITS AT HARAMAYA, ETHIOPIA

Abstract

Sorghum is the fifth most important cereal crop in the world. It serves as a staple food for millions in Africa and Asia. Ethiopia is the centre of origin and diversity for this crop. Ethiopia is endowed with diverse genetic resources for sorghum. Many studies were done elsewhere on Ethiopian sorghum genotypes; none of them provides the nutritional profile of rich Ethiopian sorghum germplasm. The aims of this study were to estimate the genetic variability of sorghum genotypes for yield, yield related traits, grain quality and nutritional content; to estimate the magnitude of correlation among grain yield, yield related traits, grain quality, and nutritional content; and to identify the direct and indirect effects of yield related traits, grain physical quality, and nutritional contents on grain yield. Hararghe landraces (186) and recently released sorghum varieties (10) were tested in 2016 growing season at Haramaya University research station (Raare) by 14*14 simple lattice design. In addition to fieldwork, nutritional profiling were also done after harvest. All traits showed significantly high variation between the materials. The genotypes showed considerable amount of variation in mean performances with respect to the characters studied, indicating the scope for further selection thereby breeding superior and desirable genotypes. The average mean for genotypes was 111 days (days to flowering), 177 days (days to maturity), 67 days (grain filling period), 350.2cm (plant height), 104.11g (panicle weight), 73.6g (yield per panicle), 21.91g (thousand kernels weight), 4.23mm (seed length), 3.64mm (seed width), 2.45mm (seed thickness), 20.15mm3 (seed volume), 11.84% (crude protein), 21.29ppm (Zn), 53.93ppm (Fe), 63.14% (starch) and 4.23% ash content. Yield per panicle(29.02) had high Genotypic Coefficient of Variation (GCV), followed by panicle weight (26.36), thousand kernels weight (22.79), and seed volume (22.36). Heritability in broad sense ranged from 35.31(Fe content) to 91.76(days to flowering).High Genetic Advance as Percent of Mean (GAM) was observed for grain yield per panicle (50.27) coupled with high heritability and high GCV, which is more important for effective selection. Panicle weight and thousand kernels weight had strong and positive correlation with yield per panicle. Days to maturity, plant height, panicle weight, thousand kernels weight, seed length, seed thickness, starch and ash content had positive direct effect on grain yield. For the variation seen among the genotypes, the first four principal components (PC) accounted up to 69.88% of variation. Based on the genetic distance in between, genotypes were grouped in to four major clusters. In general, from the genotypes tested11 genotypes were identified as better by yield per panicle while 12 genotypes were high in their protein content. The variation seen between genotypes showed the ample genetic resource for further improvement. For future, incorporating genotypes with good agronomic traits and good by their nutritional profile especially protein content in breeding programs have to be done.