Browsing by Author "Meliyo, Joel"

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Breeding rice for salinity tolerance and salt-affected soils in Africa
(UK Limited, trading as Taylor & Francis Group, 2024) Mheni, Nafeti Titusi; Kilasi, Newton; Quiloy, Fergie Ann; Heredia, Maria Cristina; Bilaro, Atugonza; Meliyo, Joel; Dixit, Shalabh; Msolla, Susan Nchimbi
Salinity is one of the main factors that limit rice production globally. In Sub Saharan Africa, soil salinity has affected many countries. Understanding the available screening techniques and the mechanisms of salinity tolerance in rice is very important for dealing with soil salinity problem. This review summarizes the extent of soil salinity problems in some of the affected African countries and the available salt stress-tolerant rice genotypes. The problems, challenges and opportunities of salt-affected soils in Sub Saharan Africa are thoroughly described in this review, which also looks at breeding techniques which have been used for developing rice cultivars adapted to salt stress. Among the best option to deal with salinity-related problems is through the use of tolerant rice varieties, as many other available management approaches are not economically feasible for small-scale farmers. Also, the review discusses different approaches, both conventional and molecular breeding approaches that have greatly enhanced the current rice breeders’ toolboxes for developing salt-tolerant rice varieties. The review suggests that more efforts are required to leverage conventional breeding with molecular techniques for speedy identification of tolerant cultivars, useful markers and quantitative trait loci (Qt Ls). It is recommended that it is crucial to reinforce collaborative efforts and continuous investment in research, capacity building, and knowledge sharing for developing improved rice tolerant cultivars in order to fully address salinity problems in African.
Integrating land cover and terrain characteristics to explain plague risks in Western Usambara Mountains, Tanzania: a geospatial approach
(Tanzania Journal of Health Research, 2014-07) Hieronimo, Proches; Meliyo, Joel; Gulinck, Hubert; Kimaro, D. N.; Mulungu, Loth S.; Kihupi, Nganga I.; Msanya, B. M.; Leirs, Herwing; Deckers, J.
Literature suggests that higher resolution remote sensing data integrated in Geographic Information System (GIS) can provide greater possibility to refine the analysis of land cover and terrain characteristics for explanation of abundance and distribution of plague hosts and vectors and hence of health risk hazards to humans. These technologies are not widely used in East Africa for studies on diseases including plague. The objective of this study was to refine the analysis of single and combined land cover and terrain characteristics in order to gain an insight into localized plague infection risks in the West Usambara Mountains in north-eastern Tanzania. The study used a geospatial approach to assess the influence of land cover and terrain factors on the abundance and spatial distribution of plague hosts (small mammals) and plague vectors (fleas). It considered different levels of scale and resolution. Boosted Regression Tree (BRT) statistical method was used to clarify the relationships between land cover and terrain variables with small mammals and fleas. Results indicate that elevation positively influenced the presence of small mammals. The presence of fleas was clearly influenced by land management features such as miraba. Medium to high resolution remotely sensed data integrated in a GIS have been found to be quite useful in this type of analysis. These findings contribute to efforts on plague surveillance and awareness creation among communities on the probable risks associated with various landscape factors during epidemics.