Table of Content, July 2015 | AJAR

Title Conventional Breeding For Improving Micronutritient Density (iron And Zinc) Into Seed Of Common Bean (phaseolus Vulgaris, L.)
Ambit Journal of Agricultural Research (Ajar). July Vol. 1(2)
Authors 1Butare,L., 1Mukamuhirwa, F., 2Anderson M, 1Murwanashyaka, E., 1Ndayizere, V., 1Mukankubana, D., and A. Musoni1
Published on 10 July 2015     Pages: 57 - 67     Article Id : AJAR-004    
Abstract | PDFCited By

Food fortification and supplementation rarely benefit poor households. Since daily consumption of beans in Rwanda is one of the highest in the world, biofortified beans offer a unique opportunity for alleviating the prevalent micronutrient malnutrition. The objective of this research was to improve the micronutrient content of common beans consumed by most people in Rwanda using conventional plant breeding techniques. Biofortification breeding of Andean beans at RAB was done through single cross. Populations were developed in 2002 and advanced from F1 to F 7 following Pedigree advancement method. From the four successful crosses (CAB 2 X LAS 400, CAB 2 X BUBERUKA, NGWINURARE X CAB 2 and ANDx X UMWIZARAHENDA), promising lines were tested for different traits including seed iron (Fe) and zinc (Zn) content. XRF mineral analysis was used to select the most promising advanced lines for Fe and Zn content. From this breeding program, five resulting varieties (RWV 2361, RWV 2887, RWV 3006, RWV 3316 and RWV 3317) were released and are being produced and consumed across Rwanda and has been shared with some counties in the network as biofortified bean varieties. RWV 3317 and RWV3316 have had high Fe of 95 and 92 ppm respectively.

Title Effects Of Soil Fertility And Cropping Patterns On Soil Minerals (fe/zn) Partitioning Into Bean Seeds And Their Distribution Within Plant Canopy
Ambit Journal of Agricultural Research (Ajar). July Vol. 1(2)
Authors 1Butare, L., 1Mukamuhirwa, F., 2Anderson, M., 1Kabeja A., Ndayizere, V., 1Murwanashyaka, E., 1Mukankubana, D., and 1A. Musoni
Published on 10 July 2015     Pages: 40 - 57     Article Id : AJAR-003    
Abstract | PDFCited By

In Rwanda, Common beans are grown under quite diverse conditions including soil fertility, rain fall, and cropping system. The objective of this study was to assess partitioning of soil minerals (Fe/Zn) into seeds and distribution of minerals within plant, effects of foliar Fe [Ferrous sulphate (2%)] application on seed iron and zinc content. Mineral concentrations in seeds were assessed at harvest using X-Ray Fluorescence Spectrometer (XRF). Genotypes were significantly different in their iron and zinc content with the means ranging between 51 – 126 ppm for iron and 28-45 ppm for zinc. Foliar iron application showed significant effect on some of the varieties in Rubona 2012A and Akanyirandoli 2012B and no significant effects on other varieties (bush and climbing) grown in Rubona and Akanyirandoli 2012A. Plant height has no significant effect on seed iron and zinc accumulation. Genetic and environmental interactions for bean seed concentration in iron and zinc was observed across sites at p<0.001.

Title Genotype X Environment Interactions For Higher Iron And Zinc In Selected Bean Varieties
Ambit Journal of Agricultural Research (Ajar). July Vol. 1(2)
Authors Mukamuhirwa, F.1, Tusiime,G1 and Mukankusi M.C2
Published on 10 July 2015     Pages: 16-39     Article Id : AJAR-002    
Abstract | PDFCited By

Common bean is the most consumed pulse globally and a very important crop in tropical Africa, especially in the Central, East and southern Africa, both for its nutritional value and its market potential. Unfortunately, genotype by environment interactions has an important effect on the breeding of better varieties for beans nutritional traits especially iron and zinc. These therefore suggest the need to understand and estimate the magnitude of Genotype and environment interactions for high iron and zinc content in beans and to identify and select genotypes which are widely adapted and can withstand unpredictable environmental fluctuations. This study was carried out to determine the magnitude of G X E for high iron and zinc in sixteen selected varieties, identify and select among them which are consistent for high iron and zinc across environments to be recommended to farmers and for breeding purpose. The experiment was set in Kachwekano and Kawanda Agricultural Research Institutes in a lattice design with 2 replications in plot of 2 x 2m during the second season of 2011 and the first season of 2012. Seed iron and zinc content were analysed using X-Ray Fluorescence (XFR) at Rwanda agriculture Board. However, the results of this study revealed a strong genotype by environment effects on iron and zinc content at 0.001 probabilities. Despite these effects, random error effects contributed more on iron content followed by G X E effects and lastly by genotype effects at 38%, 32 % and 30 % respectively. In contrast the largest contribution on zinc content is due to genotype effects followed by random error effects and G X E effects at 54%, 24 and 22 % respectively. This study suggest that in the selection for stability, zinc content should come first then the iron content next since it is proved that in addition to large random error effects , the large variability of iron content make it unstable when compared to zinc content.