Browsing by Author "Priver Namanya"

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A high throughput phenotyping technique for banana cultivar Sukali Ndizi based on internal fruit quality attributes
(International Journal of Science and Technology Research Archive, 2022-12-30) Henry Buregyeya; Steven Kashub. Tumwesigye; Ephraim Nuwamanya; Moses Matovu; Priver Namanya; Kephas Nowankunda; Wilberforce K Tushemereirwe; Patrick Rubaihayo
Background: Sukali Ndizi quality traits such as Total soluble solid (TSS) content, pulp texture and sugar/acid (S/A) ratio are critical in quality assessment. Screening very large numbers of fruit genotypes has prompted the development of a high throughput method using Near Infrared spectrometry (NIRS). Results: The calibration procedure for the attributes of TSS, pulp texture and S/A ratio was optimized with respect to a reference sampling technique, scan averaging, spectral window, data pre-treatment and regression procedure. Calibration equations for all analytical characteristics were computed by NIR Software ISI Present WINISI using Modified Partial Least Squares (MPLS) and Partial Least Squares. The quality of calibration models were evaluated by Standard Error of Calibration and coefficient of determination parameters between the measured and the predicted values. The results obtained with FOSS NIR systems 2500 spectrometer (model DS 2500) using the 350-2500 nm range, showed good prediction of the quality traits TSS content, pulp texture and S/A ratio. The MPLS method produced satisfactory Calibration model performance for TSS, texture and S/A ratio, with typical Rc2 of 0.73%Brix, 0.69kgf and 0.7; and root mean squared standard error of calibration of 0.73%Brix, 0.25kgf and 5.36 respectively. This is a good set of quality traits predicting Sukali Ndizi quality with NIRS with robustness, as it was obtained by using diverse Ndizi populations. Conclusions: This can be a useful tool to phenotype large numbers of Ndizi hybrids per day, making it possible to reduce on the resources spent when utilizing organoleptic evaluation selection technique.
Allometric relationships and carbon content for biomass-carbon estimation of East African Highland Bananas (Musa spp. AAA-EAHB) cv. Kibuzi, Nakitembe, Enyeru and Nakinyika
(Afr. J. Agric. Res., 2017-05-03) Daphine Kamusingize; Jackson Mwanjalolo Majaliwa; Everline Komutunga; Susan Tumwebaze; Kephas Nowakunda; Priver Namanya; Jerome Kubiriba
Globally, interests to increase carbon stocks have gained momentum in both woody and non-woody ecosystems. Despite efforts made to generate appropriate methods to estimate these stocks, most equations developed do not cater for intraspecific variabilities across e.g. species, regions or growth stages; especially in the case of bananas. Therefore, there is need to develop more robust equations to improve on the precision of biomass-carbon prediction especially at local scales to facilitate estimation of specific carbon stocks often lost in global assessments. This study aimed at developing cultivar- specific biomass estimation relationships and determining carbon content of EAHB cultivars at two growth stages. Plant data were collected purposively using destructive sampling techniques on farmers’ plots for 4 cultivars (Kibuzi, Nakitembe, Enyeru and Nakinyika) in two agro-ecological zones: the L. Victoria crescent and the South-western farmlands in the districts of Lwengo and Mbarara respectively. Results show that biomass differed across cultivars (P<0.001); hence four equations (Enyeru, Nakinyika, Kibuzi_Nakitembe and Generic) were developed following an exponential function, y=Aexp(ax), using diameter at breast height (DBH) as the predictor variable with an R2 range of 82-94%. EAHB mean carbon content varied significantly with growth stage (P<0.05) (47.6% for maiden plants before flowering and 48.8% for mature plants with a developed bunch). This study concludes that it is important to develop cultivar-specific equations for biomass-carbon estimation of EAHB cultivars to help assess their contribution to the carbon cycle especially in future studies.
Banana for food and fibre: The position of Uganda’s banana smallholder farmers
(Wageningen University & Research, 2023-03-06) Daphine Kamusingize; Esther Ronner; Godfrey Taulya; Priver Namanya; Jerome Kubiriba; Katrien Descheemaeker
• Growing global interest in utilization of agricultural residues for bio- based industries (e.g., Sarangi et al., 2023). • Uganda, with over 80% of farmers producing bananas, is scaling up its level of banana fibre production. • But, due to potential risks such as food insecurity and barriers like insufficient information, not all farmers may be positioned to benefit or actively engage in fibre production.
Developing a cell suspension system for Musa-AAA-EA cv. ‘Nakyetengu’: a critical step for genetic improvement of Matooke East African Highland bananas
(In Vitro Cellular & Developmental Biology - Plant, 2014-04-26) Priver Namanya; G. Mutumba; S. M. Magambo; W. Tushemereirwe
Embryogenic cell suspensions of triploid East African Highland bananas (Musa AAA-EA) were initiated and generated using cooking cultivar ‘Nakyetengu’ belonging to the Nakabululu clone set. Immature male flowers produced embryogenic calli consisting of embryos and friable tissue after 4 mo culture on a modified MA1 callus induction medium. Friable calli were initiated and maintained in liquid MA2 medium. A cell growth rate of 1.5–2.0 sedimented cell volume (SCV) per month was observed. Embryo development was observed at 2.18 × 103 embryos per mL SCV. Germination of these embryos was observed at 2.8% and 6.2% for two cell suspension lines. Plant regeneration efficiency was 60–100%, all producing normal plants with a shoot and roots at weaning. In the field, somatic cell-derived plants were all normal morphology and comparable to control plants during vegetative and reproductive stages. This study is a breakthrough for recalcitrant East African Highland banana and offers a system that can provide essential raw materials for associated germ- plasm improvement through genetic engineering approaches.
Developing A Cell Suspension System For Musa-Aaa-Ea Cv. ‘Nakyetengu’: A Critical Step For Genetic Improvement Of Matooke East African Highland Bananas
(Vitro Cellular & Developmental Biology - Plant, 2014-04-18) Priver Namanya; G. Mutumba; S. M. Magambo; W. Tushemereirwe
Embryogenic cell suspensions of triploid East African Highland bananas (Musa AAA-EA) were initiated and generated using cooking cultivar ‘Nakyetengu’ belonging to the Nakabululu clone set. Immature male flowers produced embryogenic calli consisting of embryos and friable tissue after 4 mo culture on a modified MA1 callus induction medium. Friable calli were initiated and maintained in liquid MA2 medium. A cell growth rate of 1.5–2.0 sedimented cell volume (SCV) per month was observed. Embryo development was observed at 2.18 × 103 embryos per mL SCV. Germination of these embryos was observed at 2.8% and 6.2% for two cell suspension lines. Plant regeneration efficiency was 60–100%, all producing normal plants with a shoot and roots at weaning. In the field, somatic cell-derived plants were all normal morphology and comparable to control plants during vegetative and reproductive stages. This study is a breakthrough for recalcitrant East African Highland banana and offers a system that can provide essential raw materials for associated germ- plasm improvement through genetic engineering approaches.
Golden Bananas In The Field: Elevated Fruit Pro-Vitamin A From The Expression Of A Single Banana Transgene
(Plant Biotechnology Journal, 1016-12-15) Jean-Yves Paul; Harjeet Khanna; Jennifer Kleidon; Phuong Hoang; Jason Geijskes; Jeff Daniells; Ella Zaplin; Yvonne Rosenberg; Anthony James; Bulukani Mlalazi; Pradeep Deo; Geofrey Arinaitwe; Priver Namanya; Douglas Becker; James Tindamanyire; Wilberforce Tushemereirwe; Robert Harding; James Dale
Vitamin A deficiency remains one of the world’s major public health problems despite food fortification and supplements strategies. Biofortification of staple crops with enhanced levels of pro-vitamin A (PVA) offers a sustainable alternative strategy to both food fortification and supplementation. As a proof of concept, PVA-biofortified transgenic Cavendish bananas were generated and field trialed in Australia with the aim of achieving a target level of 20 lg/g of dry weight (dw) b-carotene equivalent (b-CE) in the fruit. Expression of a Fe’i banana-derived phytoene synthase 2a (MtPsy2a) gene resulted in the generation of lines with PVA levels exceeding the target level with one line reaching 55 lg/g dw b-CE. Expression of the maize phytoene synthase 1 (ZmPsy1) gene, used to develop ‘Golden Rice 2’, also resulted in increased fruit PVA levels although many lines displayed undesirable phenotypes. Constitutive expression of either transgene with the maize polyubiquitin promoter increased PVA accumulation from the earliest stage of fruit development. In contrast, PVA accumulation was restricted to the late stages of fruit development when either the banana 1-aminocyclopropane-1-carboxylate oxidase or the expansin 1 promoters were used to drive the same transgenes. Wild-type plants with the longest fruit development time had also the highest fruit PVA concentrations. The results from this study suggest that early activation of the rate-limiting enzyme in the carotenoid biosynthetic pathway and extended fruit maturation time are essential factors to achieve optimal PVA concentrations in banana fruit.
Ploidy level of the banana (Musa spp.) accessions at the germplasm collection centre for the East and Central Africa
(Afr. J. Biotechnol., 2016-08-21) Deborah Karamura; Robooni Tumuhimbise; Sedrach Muhangi; Moses Nyine; Micheal Pillay; Reuben Ssali Tendo; David Talengera; Priver Namanya; Jerome Kubiriba; Eldad Karamura
Banana Germplasm Collection serves as a source of useful genes for banana breeding. However, insufficient and/or inaccurate information on the ploidy level of the germplasm renders its utilization in breeding difficult. The objective of this study was to determine and validate the ploidy level of 120 banana accessions in the ex situ germplasm collection centre for the East and Central Africa, located in Mbarara, Uganda. Flow cytometric analysis of the nuclear DNA content was used to determine the ploidy level of the accessions. Results indicate that accessions: Bura, Diana, Kambani-Rungwe, Paji and Pagatau, and Rungwe that were previously classified as diploids are actually triploids, whereas Selangor previously known to be a diploid is a tetraploid. Accessions such as Galeo, Mwitupemba and Ntindi 1 that were previously classified as triploids were found diploids. GT, FHIA 25 and Muzungu Mwekundu that were considered as tetraploids, were found triploids. The information generated will guide correct placement of these accessions in the regional germplasm collection centre for the East and Central Africa and their utilization in banana breeding.
TARIBAN1, TARIBAN2, TARIBAN3, and TARIBAN4 ‘Matooke’ Cooking Banana Cultivars for the Great Lakes Region of Africa
(HortScience, 2022-11-23) Noel A. Madalla; Cornel Massawe; Mpoki Shimwela; Daud Mbongo; Grace Kindimba; Jerome Kubiriba; Ivan Arinaitwe; Kephas Nowakunda; Priver Namanya; Robooni Tumuhimbise; Asher W. Okurut; Adolf Saria; Munguatosha Ngomuo; Rony Swennen; Allan F. Brown; Michael Batte; Sebastien Carpentier; Inge Van den Bergh; Rhiannon Crichton; Pricilla Marimo; Eva Weltzien; Rodomiro Ortiz
Bananas and plantains (Musa sp.) are important staple and income-generating fruit crops for millions of people worldwide (Robinson and Sauco 2010; Ssebuliba et al. 2005). They are edible and vegetatively propagated parthenocarpic species (Ortiz 1997; Simmonds 1962). East African highland bananas (EAHBs) are a dis- tinct group of cultivars found only in the highland of African Great Lakes region, where the “greatest mass of bananas in the world” are found (Simmonds 1966). Bananas are important in the food economy of millions of people in this region, with annual per capita consumption estimated to be between 250 and 600 kg (Karamura et al. 2012). These triploid (2n 5 3x 5 33 chromosomes) cultivars are known locally as Matooke. When fully ripe, they can be eaten raw like dessert bananas; however, be- cause their pulp is insipid, they are mostly eaten after cooking. Shepherd (1957) referred to them as the ‘Lujugira-Mutika’ subgroup of the AAA genome group. They are also known by its acronym (EAHBs) because they thrive on the East African plateau at altitudes ranging from 900 to 1800 m above sea level (Davies 1995). A small group of these EAHBs are processed into a beverage, and called beer or ‘Mbidde’ bananas.