NRU :: Browsing by Author "Tushemereirwe, Wilberforce K."

Browsing by Author "Tushemereirwe, Wilberforce K."

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Application of Pollen Germination Media on Stigmas during Pollination Increases Seed Set in East African Highland Cooking Bananas (Musa spp.)
(Agronomy, 2021) Waniale, Allan; Swennen, Rony; Settumba, B. Mukasa; Tugume, Arthur K.; Kubiriba, Jerome; Tushemereirwe, Wilberforce K.; Amah, Delphine; Tumuhimbise, Robooni
Seed set in East African Highland Cooking bananas (EAHBs) is extremely low and therefore hampers breeding. Pollen–pistil interaction is a key contributing factor. We assessed the effect of pollen germination media (PGM) on seed set in EAHBs. Five EAHB cultivars were pollinated with pollen from the wild banana ‘Calcutta 4’. Glucose-based PGM sprayed on freshly emerged stigmas significantly increased seed set per 100 fruits per bunch. Increases were 73.5% in ‘Enzirabahima’, 39.9% in ‘Mshale’, and 302.4% in ‘Nshonowa’. However, PGM did not increase seed set in the female sterile ‘Mlelembo’ and ‘Nakitembe’. As larger bunches were more fertile, good field management practices are also recommended to get more seed to improve breeding efficiency.
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, Patrick
Fusarium 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.
Early Withering of Enlarged Ovules in Pollinated Fruits of Bananas (Musa spp.) Suggest Abortion after Fertilization
(Horticulturae, 2022) Waniale, Allan; Mukasa, Settumba B.; Tugume, Arthur K.; Kubiriba, Jerome; Tushemereirwe, Wilberforce K.; Tumuhimbise, Robooni
Sterility in edible bananas is as a result of a long history of anthropogenic-driven selection for sterile genotypes, since seed is not desirable in fruit pulp for human consumption. However, this poses a challenge to conventional genetic improvement by slowing breeding pipelines. In this study, we investigated whether pollen tubes reach all parts of the ovary, the position of fertilized ovule development in fruits, and potential seed set in selected banana genotypes. We selected four cultivars of East African Highland Cooking bananas (EAHBs), a Matooke hybrid ‘222K-1’, improved diploid ‘2905’, and wild bananas ‘Zebrina (G.F.)’ and ‘Calcutta 4’. There was evidence of pollen tubes in the distal, mid and proximal sections of the fruit, irrespective of hand position and genotype. Fertilization, as indicated by an increase in ovule size, happened along the entire length of the fruit but complete development was biased at the distal end in some genotypes. There were some differences in ovule fertilization rates between hands, with distal hands having more ovules and higher ovule fertilization rates. Ovule fertilization happens in bananas but the vast majority aborts, especially at the proximal end of the ovary. Ovule fertilization rates are generally much lower than available ovules.
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, Patrick
Musa 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.
Isolation and characterisation of a banana CYCD2;1 gene and its over-expression enhances root growth
(African Journal of Biotechnology, 2012) Talengera, David; Beemster, Gerrit T.S.; Tushemereirwe, Wilberforce K.; Kunert, Karl
Stimulation of the cell cycle by over-expression of Arabidopsis CyclinD2;1 enhanced growth in tobacco and rice, but not Arabidopsis. To broaden the range of species and to improve an important crop species for developing countries, a CyclinD2;1 homologue was isolated from an East African highland banana cultivar ‘Nakasabira’ (Musa spp., AAA group) and designated Musac;CYCD2;1 (Genebank accession no HQ839770). Musac;CYCD2;1 amino-acid sequence exhibited 40, 54, 57 and 57% identity with CYCD2;1 sequences of Arabidopsis, rice, maize and wheat, respectively. Over-expression of Musac;CYCD2;1 driven by the CaMV 35S promoter in cultivar ‘Sukali ndizi’ (AAB) resulted in transformed plants with no significant increase in total banana CYCD2;1 transcripts in the shoot, but up to 66-fold increase of total banana CYCD2;1 transcripts in roots. Correspondingly, transformed plants had no change in above-ground growth but produced longer main roots and more lateral roots under in vitro conditions. A deeper root system was observed in one transgenic line relative to non-transformed plants when grown in soil. Results demonstrate that a banana homologue of Arabidopsis CYCD2;1 can also enhance growth in a homologous background and the potential of enhancing banana root growth.
‘Kiwangaazi’ (syn ‘KABANA 6H’) Black Sigatoka Nematode and Banana Weevil Tolerant ‘Matooke’ Hybrid Banana Released in Uganda
(HortScience, 2015) Nowakunda, Kephas; Barekye, Alex; Ssali, Reuben T.; Namaganda, Josephine; Tushemereirwe, Wilberforce K.; Nabulya, Gertrude; Erima, Rockefeller; Akankwasa, Kenneth; Hilman, Edison
This article presents the attributes of the first East African highland banana hybrid, ‘Kiwangaazi’ (Fig. 1), which was recently selected, released, and added to the national cultivar list in Uganda. The ‘matooke’ hybrid ‘Kiwangaazi’ was conventionally bred at Kawanda by crossing the tetraploid hybrid ‘1201k-1’ (‘Nakawere’ AAA · ‘Calcutta4’ AA) with the improved diploid ‘SH3217’ AA. The main target was black Sigatoka resistance, a disease caused by the fungal pathogen Mycosphaerella fijiensis, ranked as the most important constraint to the production of the East African highland bananas, especially in the low lands (covering most of central and eastern Uganda). ‘Kiwangaazi’, together with other hybrids was evaluated for black Sigatoka response, nematode andweevil damage, yield, and consumer acceptability.
Mode of inheritance for resistance to FOC Race 1 and fruit quality traits in Sukali Ndizi cultivar of Banana
(Journal of Plant Breeding and Crop Science, 2021) Buregyeya, Henry; Tumwesigye, Kashub S.; Matovu, Moses; Nowakunda, Kephas; Namanya, Priver; Tushemereirwe, Wilberforce K.; Karamura, Eldad; Rubaihayo, Patrick
Information on the genetic control of resistance to Fusarium oxysporum f.sp.cubense (FOC) race (1) and fruit quality traits in Sukali Ndizi cultivar of banana is key to its genetic improvement. The mode of resistance to Fusarium wilt in Sukali Ndizi was analyzed in 536 hybrids and 5 parental lines and quality attributes in 137 hybrids and two parental lines, grown in same environment. Fruit quality was assessed by physical measurements and fruit composition whereas resistance to Fusarium wilt was assessed by corm discoloration symptoms. All the assessed traits were quantitatively inherited. Flavor attributes, and pulp texture showed a predominance of additive inheritance with complementary gene action whereas total soluble solutes showed non-additive gene with dominant gene action. Fruit acidity had incomplete dominancy with the genetic model explained by both single gene and certain multiple genes. Resistance to Fusarium wilt showed dominant gene action and polygenic effects. Involvement of a few genes governing wilt resistance suggested the ease of breeding for this trait. Pedigree breeding method could be recommended for incorporating various traits in (cv. Sukali Ndizi) of banana.
‘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.
Seed Set Patterns in East African Cooking Bananas (Musa spp.) are Dependent on Weather Before, During, and After Pollination
(Research Square, 2020) Waniale, Allan; Mukasa, Settumba B.; Tugume, Arthur K.; Tumuhimbise, Robooni; Kubiriba, Jerome; Tushemereirwe, Wilberforce K.; Batte, Michael; Brown, Allan; Swennen, Rony
Seed set in banana (Musa spp.) is influenced by weather but the most critical weather attribute(s) and the critical period are unknown. Such information is of paramount importance to increase seed set for banana breeding programs. Three female fertile East African cooking bananas (EACBs), ‘Enzirabahima’ (AAA), ‘Mshale’ (AA), and ‘Nshonowa’ (AA) were pollinated with the highly male fertile wild banana ‘Calcutta 4’ (AA). At full maturity, bunches were harvested and ripened and seeds extracted from ripe fruit pulp. Seed set was then correlated with weather before, during, and after pollination. Results: Seed set was positively correlated with high temperatures (r=0.172 – 0.488), solar radiation (r=0.181 – 0.282) and negatively correlated with rainfall (r=-0.214 – -0.238) and relative humidity (RH) (r=-0.158 – -0.438) between 75 and 15 days before pollination (DBP). The pattern of weather association was cultivar-dependent with ‘Nshonowa’ having the strongest significant associations. At the time of pollination, high average temperatures were critical for seed set in ‘Enzirabahima’ (r=0.214, P<0.01) while high morning RH was critical for ‘Mshale’ (r=0.299, P<0.01). After pollination, high morning temperatures were associated with seed set (r=0.150 – 0.429) between 15 days to 90 days after pollination (DAP). High average temperatures were negatively correlated with seed set in ‘Mshale’ and ‘Nshonowa’ from 45 DAP to time of harvest (r=-0.208 – -0.344). Coefficients of correlation were generally highest 15 DBP especially for ‘Mshale’ and ‘Nshonowa.’ Principle component analysis showed that average and maximum temperature are the most important variables in the entire data set. Conclusion: Coefficients of correlation were generally less than 0.5 partly as a result of weather involvement in seed set at several floral development stages; before, during, and after pollination. The most critical developmental stage is 15 DBP especially for ‘Mshale’ and ‘Nshonowa’ as they had the high correlation coefficients. Average temperature should be the main focus for seed set increase in banana.
Seed Set Patterns in East African Cooking Bananas are Asymmetric in Bunches and Fruits
(Research Square, 2020) Waniale, Allan; Mukasa, Settumba B.; Tugume, Arthur K.; Tumuhimbise, Robooni; Kubiriba, Jerome; Tushemereirwe, Wilberforce K.; Batte, Michael; Brown, Allan; Swennen, Rony
Low female fertility in bananas is the biggest hurdle for banana breeding. The aim of this study was to determine seed set patterns in East African cooking bananas EACBs to inform future decisions on a more targeted approach of increasing seed set and subsequently banana breeding efficiency. Matooke (AAA) and Mchare (AA) bananas are genetically distinct but belong to the same genetic complex, they referred to as EACBs. Seed set patterns in ‘Enzirabahima’ (AAA), ‘Mshale’ (AA) and ‘Nshonowa’ (AA) all with residual fertility were examined after hand pollination with a highly male fertile wild banana ‘Calcutta 4’ (AA). Results: Seed set in ‘Enzirabahima’ is predominant in distal hands. Mchare cultivars have a slightly more even distribution of seeds in their hands compared to ‘Enzirabahima.’ There is a gradual increase in seed set from proximal to distal hands with a slight drop in the last hand. This pattern is more definite in ‘Enzirabahima’ and ‘Mshale’ while ‘Nshonowa’ has a somewhat inconsistent pattern. There is also a drop in seed set per 100 fruits per hand from small to larger bunches. However, larger bunches have a higher pollination success compared to smaller bunches. They therefor set more seed on 100 fruits per hand and per bunch basis if bunches without seed are accounted for. Pollination success rate increases from smaller to larger bunches of EACBs. Seed set is biased toward the distal third part of fruits of examined EACBs as well tetraploid Matooke hybrid ‘401K-1’ (AAAA) and improved diploid ‘Zebrina’ GF (AA) that were used for comparison. In comparison, in the highly female fertile ‘Calcutta 4,’ seed set is along the entire length of the fruit. Conclusion: Seed set bias in the distal hands and distal end of fruits suggests a systematic mechanism rather than a random occurrence. It is expected that this information will provide a foundation for increased crossbreeding efficiency in bananas.
Seed Set Patterns in East African Highland Cooking Bananas Are Dependent on Weather before, during and after Pollination
(Horticulturae, 2021) Waniale, Allan; Swennen, Rony; Mukasa, Settumba B.; Tugume, Arthur K.; Kubiriba, Jerome; Tushemereirwe, Wilberforce K.; Batte, Michael; Brown, Allan; Tumuhimbise, Robooni
Seed set in banana is influenced by weather, yet the key weather attributes and the critical period of influence are unknown. We therefore investigated the influence of weather during floral development for a better perspective of seed set increase. Three East African highland cooking bananas (EAHBs) were pollinated with pollen fertile wild banana ‘Calcutta 40 . At full maturity, bunches were harvested, ripened, and seeds extracted from fruit pulp. Pearson’s correlation analysis was then conducted between seed set per 100 fruits per bunch and weather attributes at 15-day intervals from 105 days before pollination (DBP) to 120 days after pollination (DAP). Seed set was positively correlated with average temperature (P < 0.05–P < 0.001, r = 0.196–0.487) and negatively correlated with relative humidity (RH) (P < 0.05–P < 0.001, r = 􀀀0.158–􀀀0.438) between 75 DBP and the time of pollination. After pollination, average temperature was negatively correlated with seed set in ‘Mshale’ and ‘Nshonowa’ from 45 to 120 DAP (P < 0.05–P < 0.001, r = 􀀀0.213–􀀀0.340). Correlation coefficients were highest at 15 DBP for ‘Mshale’ and ‘Nshonowa’, whereas for ‘Enzirabahima’, the highest were at the time of pollination. Maximum temperature as revealed by principal component analysis at the time of pollination should be the main focus for seed set increase.
Seed Set Patterns in East African Highland Cooking Bananas Show Asymmetric Distribution in Bunches and Fruits
(Agronomy, 2021) Waniale, Allan; Swennen, Rony; Mukasa, Settumba B.; Tugume, Arthur K.; Kubiriba, Jerome; Tushemereirwe, Wilberforce K.; Batte, Michael; Brown, Allan; Tumuhimbise, Robooni
Low female fertility in bananas is the biggest hurdle for banana breeding. The aim of this study was to determine seed set patterns in East African Highland Cooking bananas (EAHBs) to inform future decisions on a more targeted approach of increasing seed set and subsequently banana-breeding efficiency. Matooke (AAA) and Mchare (AA) bananas are genetically distinct but belong to the same genetic complex, referred to as EAHBs. Seed set patterns in “Enzirabahima” (AAA), “Mshale” (AA), and “Nshonowa” (AA), all with residual fertility, were examined after hand pollination with a highly male fertile wild banana “Calcutta 4” (AA). Seed set in “Enzirabahima” is predominant in distal hands. Mchare cultivars have a slightly more even distribution of seeds in their hands compared to “Enzirabahima”. There is a gradual increase in seed set from proximal to distal hands with a slight drop in the last hand. This pattern is more definite in “Enzirabahima” and “Mshale”, while “Nshonowa” has a somewhat inconsistent pattern. There is also a drop in seed set per 100 fruits per hand from small to larger bunches. However, larger bunches have a higher pollination success compared to smaller bunches. They therefore set more seed on 100 fruits per hand and per bunch basis, if bunches without seed are accounted for. Pollination success rate increases from smaller to larger bunches of EAHBs. Seed set is biased toward the distal third part of fruits of examined EAHBs, as well as tetraploid Matooke hybrid “401K-1” (AAAA), and improved diploid “Zebrina” GF (AA) that were used for comparison. In comparison, in the highly female fertile “Calcutta 4”, seed set is along the entire length of the fruit. Seed set bias in the distal hands and distal end of fruits suggests a systematic mechanism rather than a random occurrence. It is expected that this information will provide a foundation for increased crossbreeding efficiency in bananas.
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, Eldad
It 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.
Use of timelapse photography to determine flower opening time and pattern in banana (Musa spp.) for efficient hand pollination
(Scientific Reports, 2021) Waniale, Allan; Swennen, Rony; Mukasa, Settumba B.; Tugume, Arthur K.; Kubiriba, Jerome; Tushemereirwe, Wilberforce K.; Uwimana, Brigitte; Gram, Gil; Amah, Delphine; Tumuhimbise, Robooni
Sterility and low seed set in bananas is the main challenge to their conventional genetic improvement. The first step to seed set in a banana breeding program depends on pollination at the right time to ensure effective fertilization. This study aimed at determining bract opening time (BOT) to enhance efficient pollination and seed set in bananas. A Nikon D810 digital camera was set-up to take pictures of growing banana inflorescences at five-minute intervals and time-lapse movies were developed at a speed of 30 frames per second to allow real-time monitoring of BOT. Genotypes studied included wild banana (1), Mchare (2), Matooke (4), Matooke hybrid (1), and plantain (1). Events of bract opening initiated by bract lift for female flowers (P < 0.01) started at 16:32 h and at 18:54 h for male flowers. Start of bract rolling was at 18:51 h among female flowers (P < 0.001) and 20:48 h for male flowers. Bracts ended rolling at 02:33 h and 01:16 h for female and flowers respectively (P < 0.05). Total time of bract opening (from lift to end of rolling) for female flowers was significantly longer than that of male flowers (P < 0.001). On average, the number of bracts subtending female flowers opening increased from one on the first day, to between one and four on the fourth day. The number regressed to one bract on day eight before start of opening of bracts subtending male flowers. There was a longer opening interval between bracts subtending female and male flowers constituting spatial and temporal separation. Bract rolling increased from partial to complete rolling from proximal to the distal end of the inflorescence among female flower. On the other hand, bracts subtending male flowers completely rolled. Differences in BOT of genotypes with the same reference time of assessment may be partly responsible for variable fertility. Hand pollination time between 07:00 and 10:00 h is slightly late thus an early feasible time should be tried.

Browsing by Author "Tushemereirwe, Wilberforce K."

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