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Baguma JK, Mukasa SB, Nuwamanya E, Alicai T, Omongo C, Hyde PT, Setter TL, Ochwo-Ssemakula M, Esuma W, Kanaabi M, Iragaba P, Baguma Y, Kawuki RS. Flowering and fruit-set in cassava under extended red-light photoperiod supplemented with plant-growth regulators and pruning. BMC Plant Biol 2023; 23:335. [PMID: 37353746 DOI: 10.1186/s12870-023-04349-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 06/15/2023] [Indexed: 06/25/2023]
Abstract
BACKGROUND Cassava (Manihot esculenta Crantz) is staple food and major source of calories for over 500 million people in sub-Saharan Africa. The crop is also a source of income for smallholder farmers, and has increasing potential for industrial utilization. However, breeding efforts to match the increasing demand of cassava are impeded by its inability to flower, delayed or unsynchronized flowering, low proportion of female flowers and high fruit abortions. To overcome these sexual reproductive bottlenecks, this study investigated the effectiveness of using red lights to extend the photoperiod (RLE), as a gateway to enhancing flowering and fruit set under field conditions. MATERIALS AND METHODS Panels of cassava genotypes, with non- or late and early flowering response, 10 in each case, were subjected to RLE from dusk to dawn. RLE was further evaluated at low (LL), medium (ML) and high (HL) red light intensities, at ~ ≤ 0.5; 1.0 and 1.5PFD (Photon Flux Density) in µmol m-2 s-1 respectively. Additionally, the effect of a cytokinin and anti-ethylene as plant growth regulators (PGR) and pruning under RLE treatment were examined. RESULTS RLE stimulated earlier flower initiation in all genotypes, by up to 2 months in the late-flowering genotypes. Height and number of nodes at first branching, particularly in the late-flowering genotypes were also reduced, by over 50%. Number and proportion of pistillate flowers more than doubled, while number of fruits and seeds also increased. Number of branching levels during the crop season also increased by about three. Earlier flowering in many genotypes was most elicited at LL to ML intensities. Additive effects on flower numbers were detected between RLE, PGR and pruning applications. PGR and pruning treatments further increased number and proportion of pistillate flowers and fruits. Plants subjected to PGR and pruning, developed bisexual flowers and exhibited feminization of staminate flowers. Pruning at first branching resulted in higher pistillate flower induction than at second branching. CONCLUSIONS These results indicate that RLE improves flowering in cassava, and its effectiveness is enhanced when PGR and pruning are applied. Thus, deployment of these technologies in breeding programs could significantly enhance cassava hybridizations and thus cassava breeding efficiency and impact.
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Affiliation(s)
- Julius K Baguma
- School of Agricultural Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda.
- National Crops Resources Research Institute (NaCRRI), Namulonge, P. O. Box 7084, Kampala, Uganda.
| | - Settumba B Mukasa
- School of Agricultural Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda
| | - Ephraim Nuwamanya
- School of Agricultural Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda
- National Crops Resources Research Institute (NaCRRI), Namulonge, P. O. Box 7084, Kampala, Uganda
| | - Titus Alicai
- National Crops Resources Research Institute (NaCRRI), Namulonge, P. O. Box 7084, Kampala, Uganda
| | - Christopher Omongo
- National Crops Resources Research Institute (NaCRRI), Namulonge, P. O. Box 7084, Kampala, Uganda
| | - Peter T Hyde
- Soil and Crop Sciences, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Tim L Setter
- Soil and Crop Sciences, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | | | - William Esuma
- National Crops Resources Research Institute (NaCRRI), Namulonge, P. O. Box 7084, Kampala, Uganda
| | - Michael Kanaabi
- National Crops Resources Research Institute (NaCRRI), Namulonge, P. O. Box 7084, Kampala, Uganda
| | - Paula Iragaba
- National Crops Resources Research Institute (NaCRRI), Namulonge, P. O. Box 7084, Kampala, Uganda
| | - Yona Baguma
- National Agricultural Research Organisation (NARO) Secretariat, P. O. Box 295, Entebbe, Uganda
| | - Robert S Kawuki
- National Crops Resources Research Institute (NaCRRI), Namulonge, P. O. Box 7084, Kampala, Uganda
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Wagaba H, Kuria P, Wangari P, Aleu J, Obiero H, Beyene G, Alicai T, Bua A, Esuma W, Nuwamanya E, Gichuki S, Miano D, Raymond P, Kiggundu A, Taylor N, Zawedde BM, Taracha C, MacKenzie DJ. Comparative compositional analysis of cassava brown streak disease resistant 4046 cassava and its non-transgenic parental cultivar. GM Crops Food 2021; 12:158-169. [PMID: 33147421 PMCID: PMC7657582 DOI: 10.1080/21645698.2020.1836924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Compositional analysis is an important component of an integrated comparative approach to assessing the food and feed safety of new crops developed using biotechnology. As part of the safety assessment of cassava brown streak disease resistant 4046 cassava, a comprehensive assessment of proximates, minerals, amino acids, fatty acids, vitamins, anti-nutrients, and secondary metabolites was performed on leaf and storage root samples of 4046 cassava and its non-transgenic parental control, TME 204, collected from confined field trials in Kenya and Uganda over two successive cropping cycles. Among the 100 compositional components that were assessed in samples of 4046 and control TME 204 cassava roots (47 components) and leaves (53 components), there were no nutritionally relevant differences noted. Although there were statistically significant differences between the transgenic and control samples for some parameters, in most cases the magnitudes of these differences were small (<20%), and in every case where comparative literature data were available, the mean values for 4046 and control cassava samples were within the range of normal variation reported for the compositional component in question. Overall, no consistent patterns emerged to suggest that biologically meaningful adverse changes in the composition or nutritive value of the leaves or storage roots occurred as an unintended or unexpected consequence of the genetic modification resulting in 4046 cassava. The data presented here provide convincing evidence of the safety of 4046 cassava with respect to its biochemical composition for food and feed, and it could be considered as safe as its non-transgenic control.
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Affiliation(s)
- H Wagaba
- National Crops Resources Research Institute , Kampala, Uganda
| | - P Kuria
- Kenya Agricultural and Livestock Research Organization , Nairobi, Kenya
| | - P Wangari
- Kenya Agricultural and Livestock Research Organization , Nairobi, Kenya
| | - J Aleu
- National Crops Resources Research Institute , Kampala, Uganda
| | - H Obiero
- Institute for International Crop Improvement , Kakamega, Kenya
| | - G Beyene
- Donald Danforth Plant Science Center , St. Louis, MO, USA
| | - T Alicai
- National Crops Resources Research Institute , Kampala, Uganda
| | - A Bua
- National Crops Resources Research Institute , Kampala, Uganda
| | - W Esuma
- National Crops Resources Research Institute , Kampala, Uganda
| | - E Nuwamanya
- National Crops Resources Research Institute , Kampala, Uganda
| | - S Gichuki
- Kenya Agricultural and Livestock Research Organization , Nairobi, Kenya
| | - D Miano
- Department of Plant Science and Crop Protection, University of Nairobi , Nairobi, Kenya
| | - P Raymond
- AG SCI Consulting, LLC ., Cottageville, SC, USA
| | - A Kiggundu
- Donald Danforth Plant Science Center , St. Louis, MO, USA
| | - N Taylor
- Donald Danforth Plant Science Center , St. Louis, MO, USA
| | - B M Zawedde
- National Crops Resources Research Institute , Kampala, Uganda
| | - C Taracha
- Kenya Agricultural and Livestock Research Organization , Nairobi, Kenya
| | - D J MacKenzie
- Donald Danforth Plant Science Center , St. Louis, MO, USA
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