Browsing by Author "Karamura, Deborah"
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Item Assessing New Banana Genotypes for Relevant Traits: Implication for Variety Selection(Agricultural Sciences, 2020) Tumuhimbise, Robooni; Barekye, Alex; Talengera, David; Akankwasa, Kenneth; Nowakunda, Kephas; Asasira, Moreen; Karamura, Deborah; Karamura, EldadUnderstanding the performance of new crop genotypes for traits of relevance is important in selecting potential cultivars to satisfy end-users. The objective of this study was to determine the performance of new banana genotypes for bunch mass (BMS) and BMS-related traits, resistance to black Sigatoka and sensory attributes. Eight cooking banana genotypes consisting of six new hybrid genotypes selected from advanced breeding trials and two control cultivars were evaluated in a randomized complete block design for three crop cycles at three locations in Uganda. Genotype, location, crop cycle and their interaction effects were significantly different for most traits assessed. The overall top two genotypes (“9058K-2” and “8099K-16”) combining high BMS, resistance to black Sigatoka and acceptable sensory attributes were identified. These genotypes are suggested as potential commercial cultivars for release to farmers in Uganda and/or other East African countries with similar environmental conditions to those where the genotypes were tested. It should be noted that high BMS/yield and resistance to diseases are not the only factors to consider when selecting banana genotypes that meet end-user needs. A combination of high BMS/yield, acceptable sensory attributes and resistance to diseases essentially influence the selection process of banana cultivars.Item Bananas and Plantains (Musa spp.)(Springer, Cham, 2017) Brown, Allan; Tumuhimbise, Robooni; Amah, Delphine; Uwimana, Brigitte; Nyine, Moses; Mduma, Hassan; Talengera, David; Karamura, Deborah; Kuriba, Jerome; Swennen, RonyWith a production of 145 million metric tons worldwide (worth 26.5 billion Euro), banana (Musa spp.) is one of the world’s most important staple food crops and arguably the world’s most popular fruit in terms of international trade (FAO 2014). Banana and plantains (Musa spp.), collectively referred to here as bananas, are grown in more than 135 countries and found in most tropical and subtropical regions around the world. While industrialized nations view banana primarily as a dessert item, many regions of the developing world consider cooking bananas and plantains as essential staples that contribute significantly to the caloric intake of low-income subsistence farmers. Although sensitivity to photoperiod has been noted in certain cultivars (Fortescue et al. 2011), banana is an almost nonseasonal crop that reliably provides a carbohydrate source year-round which makes it vitally important to both nutrition and food security.Item Breeding banana (Musa spp.) for drought tolerance: A review(Plant Breeding, 2020) Nansamba, Moureen; Sibiya, Julia; Tumuhimbise, Robooni; Karamura, Deborah; Kubiriba, Jerome; Karamura, EldadDrought is a major abiotic stress affecting banana production worldwide, leading to yield losses of up to 65%. Consequently, numerous efforts to understand and mitigate drought effects that include developing tolerant crop varieties are ongoing in several banana breeding programmes. The breeding efforts, however, have been greatly slowed down by inherent banana problems (polyploidy and male or female sterility) and complexity of drought tolerance (reportedly controlled by several genes). This review summarizes the pertinent research findings on water requirements of banana for its proper growth and productivity, symptoms of drought-sensitive varieties and field management strategies to cope with drought stress. The coping strategies deployed by resistant cultivars include high assimilation rates and water retention capacity as well as minor losses in leaf area and gaseous exchange. Reduced bunch weight, leaf chlorosis, wilting and strangled birth are underlined to be directly associated with drought susceptibility. Integration of conventional, molecular breeding and biotechnological tools as well as exploitation of the existing banana genetic diversity presents a huge opportunity for successful banana improvement.Item Development of two high-yielding, consumeracceptable apple banana hybrids (Musa species, AAB genome group) with resistance to Fusarium oxysporum f. sp. cubense race 1(Journal of Plant Breeding and Crop Science, 2018) Buregyeya, Henry; Tumuhimbise, Robooni; Kubiriba, Jerome; Talengera, David; Nowankunda, Kephas; Arinaitwe, Geofrey; Tushemereirwe, Wilberforce K.; Karamura, Deborah; Karamura, Eldad; Rubaihayo, PatrickFusarium wilt of bananas (Musa species) is caused by Fusarium oxysporum f. sp. cubense (Foc). Foc race 1 in particular affects dessert bananas in Uganda, causing >60% yield loss. This study was conducted to assess the performance of two new apple banana genotypes for bunch yield, resistance to Foc race 1 and consumer acceptability. The new apple banana genotypes (NAMU1 and NAMU2), along with two check cultivars, one susceptible but preferred by consumers (Sukali ndiizi) and the other resistant (Yangambi-KM5), were evaluated at the National Agricultural Research Laboratories in Uganda. Bunch yields of the two new apple bananas were higher than those of check cultivars by >50%. NAMU1 and Yangambi-KM5 showed no symptoms of Foc race 1, whereas NAMU2 showed mild symptoms on its corms. Sukali ndiizi showed severe pseudostem splitting and corm discoloration as the key symptoms of Foc race 1. The consumer acceptability of NAMU1 and NAMU2 was as high as that of Sukali ndiizi, implying that they can be perfect substitutes for the Foc race 1 susceptible Sukali ndiizi.Item Fusarium oxysporum Race 1 resistance and quality traits variations in apple banana germplasm(Journal of Plant Breeding and Crop Science, 2020) Buregyeya, Henry; Tumuhimbise, Robooni; Matovu, Moses; Tumwesigye, Kashub S.; Kubiriba, Jerome; Nowankunda, Kephas; Tushemereirwe, Wilberforce K.; Karamura, Deborah; Karamura, Eldad; Kityo, Robert M.; Rubaihayo, PatrickMusa species, AAB genome group, commonly known as Sukali Ndizi (SND) in Uganda, has attained a substantial commercial value in the recent past owing to its superior fruit quality attributes and better prices. However, its sustainable production and productivity are highly threatened by Fusarium wilt. To facilitate large scale area expansion of this important dessert banana, the present study was carried out to identify the near-ideotypic lines of best quality fruit traits that are also resistant to Fusarium wilt. Nineteen SND ecotypes were subsequently collected from nine key SND growing districts of Uganda and evaluated in the field and laboratory for different fruit quality attributes and response to Fusarium wilt. Results showed a wide diversity among SND ecotypes for fruit-quality traits (fruit pulp texture, flavor and taste). The ecotypes were, however, not significantly different (p > 0.05) for susceptibility to FOC race 1. Cluster analysis based on organoleptic and physio-chemical properties grouped the 19 ecotypes into two major-clusters, each of which was also split into two sub-clusters. Individual subclusters summarize levels of similarity amongst the different ecotypes. The study confirmed the presence of diversity in SND germplasm that could be exploited for SND genetic improvement of the crop through hybridization and selection.Item ‘NABIO808’ (Syn. ‘NAROBAN5’): A tasty cooking banana cultivar with resistance to pests and diseases(Crop Breeding and Applied Biotechnology, 2019) Tumuhimbise, Robooni; Buregyeya, Henry; Kubiriba, Jerome; Tushemereirwe, Wilberforce K.; Barekye, Alex; Tendo, Reuben S.; Namagembe, Betty; Muhangi, Sedrach; Kazigye, Francis; Talengera, David; Tindamanyire, Jimmy; Akankwasa, Kenneth; Nabulya, Gertrude; Namaganda, Josephine; Waswa, William; Kushaba, Abias; Namuddu, Mary; Oyesigye, Naboth; Namanya, Priver; Arinaitwe, Ivan K.; Waniale, Allan; Karamura, Deborah; Karamura, Eldad‘NABIO808’ is a newly released, conventionally-bred triploid cooking banana cultivar in Uganda. It produces an average bunch yield of 54.5 t ha-1 yr-1 and is resistant to weevils, nematodes, and black Sigatoka. Additionally, its food is yellow, soft, and tasty, like that of most preferred landrace cultivars, making it more acceptable to end-users.Item Ploidy level of the banana (Musa spp.) accessions at the germplasm collection centre for the East and Central Africa(African Journal of Biotechnology, 2016) Karamura, Deborah; Tumuhimbise, Robooni; Muhangi, Sedrach; Nyine, Moses; Pillay, Micheal; Ssali Tendo, Reuben; Talengera, David; Namanya, Priver; Kubiriba, Jerome; Karamura, EldadBanana 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.Item Selection of cooking banana genotypes for yield and black Sigatoka resistance in different locations in Uganda(Journal of Plant Breeding and Crop Science, 2016) Tumuhimbise, Robooni; Buregyeya, Henry; Barekye, Alex; Ssali, Reuben T.; Talengera, David; Kubiriba, Jerome; Muhangi, Sedrach; Namagembe, Betty; Namanya, Priver; Arinaitwe, Geofrey; Tushemereirwe, Wilberforce K.; Karamura, Deborah; Karamura, EldadIt is imperative to systematically evaluate new banana genotypes in different locations before national release. This enables selection and recommendation of superior genotypes as new varieties for a wider range of environments. The objective of the present study was to select banana genotypes with stable and high performance for bunch yield and leaf black Sigatoka resistance. Eleven cooking banana genotypes developed by the Uganda National Agricultural Research Organization in collaboration with Bioversity International, and two check varieties were evaluated in multi-location preliminary yield trials in Uganda. Data collected were analyzed using Additive Main Effects and Multiplicative Interaction (AMMI) model, AMMI Stability Value, and Genotype Selection Index (GSI). Genotype × location interaction was significant for all the traits assessed. Most of the new genotypes had low interaction effects with locations for bunch yield (69.2%) and black Sigatoka (92.3%). The most stable genotypes for bunch yield were NABIO815, NABIO1117, NABIO216 and NABIO306 whereas for black Sigatoka resistance, were NABIO1011, NABIO815, NABIO1009 and NABIO216. Using the GSI that defines the most desirable genotypes as those that combine high agronomic performance and stability across environments, four genotypes (NABIO306, NABIO1011, NABIO808 and NABIO1009) were selected. These genotypes, in addition to their high performance for agronomic traits and stability, had soft and yellow fruit pulp on cooking, and will be advanced on farm for further evaluation.