In vitro propagation of three mosaic disease resistant cassava cultivars

Abstract

Background Cassava is a staple food for over 800 million people globally providing a cheap source of carbohydrate. However, the cultivation of cassava in the country is facing to viral diseases, particularly cassava mosaic disease (CMD) which can cause up to 95% yield losses. With aim to supply farmers demand for clean planting materials, there is need to accelerate the production of the elite cultivars by use of tissue culture in order to cope with the demand. Methods Nodal explants harvested from the greenhouse grown plants were sterilised using different concentrations of a commercial bleach JIK (3.85% NaOCl) and varying time intervals. Microshoots induction was evaluated using thidiazuron (TDZ), benzyl amino purine (BAP), and kinetin. Rooting was evaluated using different auxins (Naphthalene acetic acid NAA and Indole-3-butyricacid IBA). PCR-based SSR and SCAR markers were used to verify the presence of CMD2 gene in the regenerated plantlets. Results The highest level of sterility in explants (90%) was obtained when 20% Jik was used for 15 min. The best cytokinin for microshoots regeneration was found to be kinetin with optimum concentrations of 5, 10 and 20 μM for Agric-rouge, Atinwewe, and Agblehoundo respectively. Medium without growth regulators was the best for rooting the three cultivars. A survival rate of 100, 98, and 98% was recorded in the greenhouse for Agric-rouge, Atinwewe, and Agblehoundo respectively and the plantlets appeared to be morphologically normal. The SSR and SCAR analysis of micropropagated plants showed a profile similar to that of the mother plants indicating that the regenerated plantlets retained the CMD2 gene after passing through in vitro culture, as expected with micropropagation. Conclusion The nodal explants was established to be 20% of Jik (3.85% NaOCl) with an exposure time of 15 min. Kinetin was proved to be the best cytokinins for microshoot formation with the optimum concentration of 5, 10 and 20 μM for Agric-rouge, Atinwewe, and Agblehoundo respectively. The protocol developed during this study will be useful for mass propagation of the elite cassava cultivars.

Application of NAA and BA to Calotropis gigantea (L.) W.T. Aiton in vitro

“…High concentrations of NAA can disrupt the delicate balance of hormonal signaling involved in root formation, leading to a delay or inhibition of root emergence in crown flower. This follows the opinion of Sessou et al (2020), stating that increasing the concentration of NAA can inhibit root formation. In addition, according to Adugna et al (2020), different genotypes of each explant also influence the root formation process.…”

Influence of Explants Type, Nodal Positions and Two Cytokinins on Cassava (Manihot esculenta, Crantz) In vitro Organogenesis

“…Regarding plantlets rhizogenesis, a highly significant effect was observed on MS supplemented with NAA (0.5 mg/l) + ZEAT (0.5 mg/l) and NAA (0.5 mg/l) + BAP (0.5 mg/l) that highlighted the role of NAA in roots formation [15]. These results therefore indicated that each variety may require a particular combination of growth regulators.…”

“…Few years ago, cassava breeding research in Benin has leaded in the clearance of some local cultivars with important economic value [9,10]. Since the multiplication of cassava cultivars in field by cutting was limited in the numbers of planting materials, bulky, and chore intensive, research works have been started for in vitro culture of cassava [11][12][13][14][15]. Therefore, the improvement strategies for producing planting material through in vitro tissue culture remained an alternative and fast propagation method [16].…”

“…The combined effect of BAP and Zeatin, and their combination with NAA effects are not clearly established on cassava buds' organogenesis especially in the local cultivars of Benin. In some cultivars, Sessou et al [15] have established to regeneration methods based on TDZ, kinetin, and BAP for microshoots induction and on NAA, and IBA concentrations for microshoots rooting which did not well respond for overall cultivars. Understanding the influence of types and nodes explants in positions 4, 5, 6, and 7 on the plantlet's regeneration with antagonism effects of Zeatin, BAP, and NAA in the local cassava cultivars will accelerate cassava planting materials production and generate new knowledge for future research.…”

Integrated Analysis of Morphological, Physiological, Anatomical and Molecular Responses of Cassava Seedlings to Different Light Qualities

“…For now, the most common method of cassava propagation is taking stem cuttings. However, this approach is somewhat prone to introducing diseases that threaten cassava production [ 3 , 4 ]. Tissue culture technology is, therefore, increasingly seen as an effective alternative method by which to rapidly obtain a large number of virus-free plantlets [ 5 ].…”