Culinary cassava (Manihot esculenta L.) qualities that make a variety popular are a function of starch physicochemical properties. Hence, in response to inferior root qualities in some released cassava varieties in Uganda compared to the local germplasm, a study was undertaken to examine: (i) starch physicochemical characteristics in both introduced and local varieties; and (ii) the variation in the starch properties of their F 1 progenies. The local varieties included Bao, Nyaraboke, Kakwale, and Bamunanika; and the introduced genotypes SE/95/00036, NASE 10, NASE 12, TME 5, and TME 14. Of the generated 7000 F 1 seedlings, 1077 seedlings were selected, cloned (6-8 plants per genotype) and established in a single-row trial. Root samples were collected per clone and examined for starch physicochemical properties. Considerable variations were observed in the F 1 families compared to the parental lines with weak correlations in most starch properties (r < 0.25). Amylose content ranged from 10 to 25%, with the amylose: amylopectin ratio between 1:3 and 1:9. Among the F 1 families, solubility and swelling power ranged from 1-15g100g -1 and 40-140g100 g -1 starch at 60 o C, respectively. In the parents, it ranged between 1.3-8.6 and 50-67g100g -1 starch at 60 o C, respectively. Fresh root starch yield ranged from 18 to 34%, with dry matter content varying from 19-47% in both the F 1 families and the parents. Ash and lipid content varied among the F 1 families and parents with ranges 0.05-0.29% for ash and 0.1-0.32% for lipids. In both the parents and the F 1 families, the reducing sugar and protein content ranged between 0.7-1.7 and 0.23-0.43%, respectively. These findings demonstrate: (i) existence of considerable genetic variations in starch physicochemical properties in both local and introduced cassava genotypes and their progenies, and (ii) potential utilisation of cassava starches for various applications based on the inherent differences in physicochemical characteristics.Key Words: Amylose, cassava starch, Manihot esculenta, protein, reducing sugar RÉSUMÉLes qualités qui rendent le manioc culinaire (Manihot esculenta L.) une variété populaire sont fonction des propriétés physico-chimiques de l'amidon. Ainsi, en réponse aux qualités inférieures des racines dans certaines variétés de manioc diffusées en Ouganda en comparaison avec les matériels génétiques locaux, une étude avait était menée dans le but d'examiner: (i) les caractéristiques physico-chimiques de l'amidon aussi bien dans les variétés locales que dans les variétés exotiques introduites; en plus (ii) la variation dans les propriétés de l'amidon des progenies F 1 . Les variétés locales sont Bao, Nyaraboke, Kakwale, Bamunanika et les génotypes exotiques SE/95/ 00036, NASE 10, NASE 12, TME 5 et TME 14. De 7000 F 1 plantules générées, 1077 plantules ont été sélectionnées, clonées (6-8 plants par génotype) et établies dans un essai en ligne unique. Les échantillons des racines avaient été collectées par clone et examinées pour les propriétés physico...

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Soybean (Glycine max (L.) Merrill) is among the major food and industrial crops grown globally for its high protein and oil content. Lately, in Uganda, soybean reportedly faces challenges with a storage pest, Callosobruchus chinensis. This study was carried out to quantify the damage caused by the pest and identify the sources of resistance in the germplasm in Uganda. The study was conducted at Makerere University Agricultural Research Institute, Kabanyolo (MUARIK) in Uganda, during 2015 and 2016. Callosobruchus chinensis was used to challenge 498 soybean lines under no choice condition, in the laboratory. Results showed no significant differences in eggs laid amongst the different genotypes; however the genotypes performed significantly different (P< 0.05) for adult insect emergence, median development period (MDP), Dobie susceptibility index (DSI), growth index (GI), insect percent emergence (% IE) and seed weight loss (%WL). Genotype AVRDC G8527 had the lowest % IE (6.31), DSI (0.7), % WL (0.02) and GI (0.07), suggesting high resistance. Weight loss of up to 27% was recorded in genotype USA 7. There was a strong positive correlation between number of adults that emerged with DSI (r=0.87), eggs (r=0.88), % weight loss (r=0.73), and growth index (r=0.996). Cluster analysis revealed that AVRDC G8527, a resistant genotype was closely related to S-line 13.2A, a moderate resistant genotype. Regression analysis, revealed that adult bruchid emergence explain seed weight loss with 62% coefficient of determination; while seed colour could be used to determine genotype DSI with up to 74% coefficient of determination. Genotypes AVRDC G8527 and G89 were identified as the most resistant genotypes based on levels of DSI.

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Aims: To study the phenotypic diversity of 25 forage and 45 grain sorghum genotypes for dual purpose as food and feed and to identify traits that might contribute to genetic improvement. Study Design: A 7 × 10 alpha lattice design was used with two replications at two sites.