| dc.description.abstract | Sorghum is one of the world’s major tropical cereal crops, ranking fifth after wheat, rice, maize and barley in terms of production and acreage. In Uganda, sorghum yield productivity is still low due to production constraints which include pests and diseases, low seed quality, poor soil fertility, poor agronomic management practices and low yielding varieties currently available to farmers. The main aim of this study was to contribute towards identification of superior genotypes that can be incorporated into Uganda’s sorghum breeding program by, determining the performance and trait interrelations and mode of inheritance for grain yield and its components of the genotypes in MAGIC sorghum population. Experiments were conducted at Makerere University Agricultural Research Institute Kabanyolo (MUARIK) and National Semi-Arid Resource Research Institute- Serere (NaSARRI) during two growing seasons of 2017A and 2018A. A total of 300 genetic materials including 96 inbred lines from Purdue University, 192 hybrids, 2 female sterile lines, 4 elite lines as checks from Purdue University and 6 improved local varieties also used as checks. Field trials were laid out as Alpha lattice design with 2 replications. Results showed that, there were significant differences (P ≤ 0.001) among genotypes for grain and its components. Mean yield performance results revealed superior performance of hybrids compared to the parents and checks. Hybrid genotypes T1/L-64, T1/L-412, T1/L-235, T1/L-214, and T1/L-153 (1367, 1319, 1231, 1224, and 1146g/plot respectively) displayed better yield performance compared to the best checks NAROSorg 2, NAROSorg 1, and Seso 3 (996, 947and 927g/plot respectively) and the best parental genotypes L-489, L-107, and L-470 (903, 900 and 867g/plot respectively) performed lower than the best checks. There were significant positive correlations of grain yield with panicle weight (r = 0.76, P ≤ 0.001), panicle length (r = 0.56, P ≤ 0.001) and plant height (r = 0.55, P ≤ 0.001), panicle length with panicle weight (r = 0.68, P ≤ 0.001) and days to 95% physiological maturity with days to 50% flowering (r = 0.88, P ≤ 0.001) suggesting that indirect selection for grain yield and its components could be employed among MAGIC genotypes. The effects due to GCALines were highly significant (P ≤ 0.001) for grain yield, 100 seed weight, panicle weight, panicle length, plant height, days to 50% flowering studied and days to 95% physiological maturity indicating the influence of additive gene effects. The effects due to GCATesters were non-significant for all traits except for grain yield (P ≤ 0.001), days to 50% flowering (P ≤ 0.05). SCA effects were non-significant for yield and its components. The GCA: SCA values for all traits studied were far greater than unity for grain yield, 100 seed weight, panicle weight, panicle length, plant height, days to 50% flowering and days to 95% physiological maturity suggesting that plant breeders could carry out genetic improvement through crosses and selection. Parents L-64, L-171, L-214, L-122 L-184, L-236, L-153, L-412, L-551 and T1 showed positive significant (P ≤ 0.001, P ≤ 0.01, and P ≤ 0.05) GCA effects while L-493, L-281, L-642 and T2 displayed negative significant (P ≤ 0.05, P ≤ 0.01, and P ≤ 0.001) GCA effects for grain yield indicating the presence of good general combiners that could be used as parents for introgression of genes for grain yield into local cultivars or developing hybrid varieties.. This study revealed marked differences in performance of MAGIC genotypes for grain yield and its component with several hybrid genotypes performing better than their parents and current varieties (checks). | en_US |
