I. TABU, K. LUBOBO, K. MBUYA, and N. KIMUNI Citation: Tabu I, Lubobo K, Mbuya K, Kimuni N (2023). Heterosis and line-by-tester combining ability analysis for grain yield and provitamin A in maize. SABRAO J. Breed. Genet. 55(3): 697-707. http://doi.org/10.54910/sabrao2023.55.3.8. Summary Developing a high-yielding and provitamin A-rich maize variety is

This study was implemented to evaluate the performance of biofortified bean under different integrated soil fertility management (ISFM) options and agro-ecological conditions in Democratic Republic of Congo (DRC). A Split-plot design with eight genotypes as main factors and four ISFM options as secondary factors was carried out in eight production zones distributed across South-Kivu, North-Kivu, and Katanga provinces. The application of lime + manure + NPK increased the bean yield by 173% in Lohutu. Compared to local variety in Lohutu, the CODMLB001 variety under the same option increased the yield by 252%. The same ISFM option allowed best response in terms of micronutrient content of bean in Rutshuru, inducing up to 80.3 mg.kg-1 Fe, representing increase 41%. For Zn, the best response was obtained with lime + NPK applied in Kipopo that induced up to 32.2 mg.kg-1 Zn. Lime + manure + NPK fertilizer option reduced root rot severity by 17.8% compared to the control. This study confirmed the potential of increasing bean productivity, micronutrient and reducing the severity of major diseases through application of soil fertility management options, which will vary with the bean genotype and the environment under which bean is cultivated. Key words: Integrated soil fertility management, bean yield, micronutrient content, disease control, Phaseolus vulgaris L. This study was implemented to evaluate the performance of biofortified bean under different integrated soil fertility management (ISFM) options and agro-ecological conditions in Democratic Republic of Congo (DRC). A Split-plot design with eight genotypes as main factors and four ISFM options as secondary factors was carried out in eight production zones distributed across South-Kivu, North-Kivu, and Katanga provinces. The application of lime + manure + NPK increased the bean yield by 173% in Lohutu. Compared to local variety in Lohutu, the CODMLB001 variety under the same option increased the yield by 252%. The same ISFM option allowed best response in terms of micronutrient content of bean in Rutshuru, inducing up to 80.3 mg.kg-1 Fe, representing increase 41%. For Zn, the best response was obtained with lime + NPK applied in Kipopo that induced up to 32.2 mg.kg-1 Zn. Lime + manure + NPK fertilizer option reduced root rot severity by 17.8% compared to the control. This study confirmed the potential of increasing bean productivity, micronutrient and reducing the severity of major diseases through application of soil fertility management options, which will vary with the bean genotype and the environment under which bean is cultivated. Key words: Integrated soil fertility management, bean yield, micronutrient content, disease control, Phaseolus vulgaris L.

Bananas and plantains are edible and vegetatively propagated parthenocarpic species of the genus Musa. They are used as staple food, dessert and cash crop by more than hundred millions of people throughout the world. However, the crop is threatened by several pests and diseases in central and eastern Africa. One way of partly solving this problem is to have diploids which have desirable traits currently lacking in the AAA-Lujugira-Mutika subgroup. The study assessed through 21 microsatellite markers pairs the cladistic closeness of the diploid AA-Mshale accessions with AAA-Lujugira-Mutika with the purpose of inclusion in breeding programmes. Results showed that the eight studied accessions of AA-Mshale were different from each other. AA-Mshale malembo was fairly well established to be among the ancestor of Lujugira-Mutika, suggesting the determinism of its pollen viability and the level of resistance to pests for including in breeding programmes. The use of two pairs of microsatellites per chromosomes linkage group established the existence of alleles’ deletion, recombination or non-annealing. The closeness among AA-Mshale and AAA-subgroups (Ibota, Gros Michel and Green Red) so far established through other techniques was confirmed. The results recommend the use of microsatellite markers, covering 11 linkage groups for cultivar identification and diversity study.