Najda cv. is an important date palm cultivar due to its high fruit quality and resistance to bayo... more Najda cv. is an important date palm cultivar due to its high fruit quality and resistance to bayoud, a disease that killed million plants of date palm. The in vitro propagation of cv. Najda through organogenesis is hampered by some physiological disorders, namely hyperhydricity, tissue browning and precocious rooting. In order to achieve efficient and large-scale propagation of true-to-type plantlets of cv. Najda, we evaluated the effect of different cytokinin types and concentrations (6-benzylaminopurine (BAP), 6-(dimethylallylamino) purine (2iP) and thidiazuron (TDZ), at 0.1, 0.2, 0.3, 0.4 or 0.5 mg/L), as well as that of medium texture (semi-solid and liquid) on adventitious shoot bud multiplication, hyperhydricity, tissue browning and precocious rooting. The optimal culture conditions for shoot bud proliferation and subsequent development were observed on semi-solid half-strength Murashige and Skoog (MS/2) medium supplemented with 0.5 mg/L 1-naphthaleneacetic acid (NAA) and 0.4 mg/L BAP, where an average of 23.8 shoot buds per explant, low rate of hyperhydricity (22.5%), moderate tissue browning (55.0%) and low percentage of precocious rooting (20.0%) were observed. Shoot elongation and rooting were performed on semi-solid and liquid plant growth regulator (PGR)-free MS/2 medium. Shoots were then transferred to the glasshouse, where the survival rate reached 95 %. The findings of the present study will be highly beneficial to rehabilitate the Moroccan palm groves infested by bayoud.
Najda cv. is an important date palm cultivar due to its high fruit quality and resistance to bayo... more Najda cv. is an important date palm cultivar due to its high fruit quality and resistance to bayoud, a disease that killed million plants of date palm. The in vitro propagation of cv. Najda through organogenesis is hampered by some physiological disorders, namely hyperhydricity, tissue browning and precocious rooting. In order to achieve efficient and large-scale propagation of true-to-type plantlets of cv. Najda, we evaluated the effect of different cytokinin types and concentrations (6-benzylaminopurine (BAP), 6-(dimethylallylamino) purine (2iP) and thidiazuron (TDZ), at 0.1, 0.2, 0.3, 0.4 or 0.5 mg/L), as well as that of medium texture (semi-solid and liquid) on adventitious shoot bud multiplication, hyperhydricity, tissue browning and precocious rooting. The optimal culture conditions for shoot bud proliferation and subsequent development were observed on semi-solid half-strength Murashige and Skoog (MS/2) medium supplemented with 0.5 mg/L 1-naphthaleneacetic acid (NAA) and 0.4 ...
In vitro multiplication of date palm is a very promising way for the rehabilitation of Moroccan p... more In vitro multiplication of date palm is a very promising way for the rehabilitation of Moroccan palm devastated. The objective of this work was to study the development of vitroplants introduced into traditional and modern palm of the Errachidia region. The procedure followed is to make descriptive diagnoses in different sites where the palm was introduced and to evaluate the mortality of plants and cultural practices. The mortality rates varied from 78% to 19% in new plantation depending on the cultivation technique used. At the traditional palm, the rate of recovery of plantlets was zero. The mortality is higher in Nejda cultivar compared to Boufegouss. This variety also presented a better adaptation in terms of shoot height in comparison with the development of Nejda and Mejhoul varieties. The production of offshoots as well as inflorescences takes place three years after plantation. The importance of improving cultivation techniques in date palm for the development of this secto...
Maturation and germination of somatic embryos are two crucial steps in the somatic embryogenesis ... more Maturation and germination of somatic embryos are two crucial steps in the somatic embryogenesis process. Herein, we evaluated the effects of several factors on the maturation and germination of date palm somatic embryos. Globular somatic embryos of cv. ‘Najda’ were cultured on Murashige and Skoog medium at full strength (MS), half strength (1/2MS), and one-third strength (1/3MS), with or without agar, and supplemented with various concentrations of mannitol, sorbitol, polyethylene glycol (PEG, MW 8000) and abscisic acid (ABA). Our results showed that culture medium strength and texture (liquid or semi-solid), osmotic agents, and the concentration and time of exposure to ABA influence somatic embryo maturation. The highest mean number of mature somatic embryos (106.4 per 100 mg fresh weight callus) was obtained after 3 weeks of culture on full-strength liquid MS medium supplemented with 30 g L-1 PEG and 40 µM ABA, followed by 9 weeks of culture on the same medium but without ABA. So...
Thidiazuron: From Urea Derivative to Plant Growth Regulator, 2018
Plant tissue culture is now a widely used technology for many applications. Plant growth regulato... more Plant tissue culture is now a widely used technology for many applications. Plant growth regulators (PGRs) play an important role in this technology. Auxins and cytokinins are by far the most commonly used PGR classes in plant tissue culture. N-Phenyl-N′-1,2,3-thiadiazol-5-ylurea, also known as thidiazuron or TDZ, is a synthetic PGR and a phenylurea derivative with a strong cytokinin-like activity. TDZ has been successfully used for the micropropagation of several plant species and sometimes was reported to be more effective than adenine-based cytokinins or to fulfil both the auxin and the cytokinin requirement for in vitro growth and differentiation. In this chapter, we will focus on the use of TDZ for the micropropagation of six Mediterranean crop species. Thus, we will report some findings from past and recent studies in which TDZ was employed for in vitro culture and regeneration of Olea europaea L., Citrus spp., Ceratonia siliqua L., Punica granatum L., Ficus carica L., and Prunus dulcis Mill. We will also highlight the specific action of TDZ depending on its concentration as well as the species, the genotype, the explant, and the concentration of the associated PGRs.
Date palm (Phoenix dactylifera L.) inflorescence rot caused by Mauginiella scaettae poses a serio... more Date palm (Phoenix dactylifera L.) inflorescence rot caused by Mauginiella scaettae poses a serious threat to date palm in Morocco. The present study aims to determine the antifungal activity of five plant extracts against M. scaettae, including Acacia cyanophylla, Cupressus atlantica, Eucalyptus torquata, Nerium oleander, and Schinus molle and link this effect to their content in phenolics and flavonoids, as well as their antioxidant properties. Plant extracts exhibited significant discrepancies regarding their antifungal activity ( p < 0.05 ). The extracts of E. torquata and C. atlantica had the strongest and dose-dependent manner inhibitory effect against mycelial growth and spore germination. E. torquata and S. molle caused the greatest sporulation reductions of about 88.05% and 36.11%, respectively. In addition, there were significant differences among the examined plant extracts with respect to their total polyphenols (14.52–76.68 mg GAE/g DW), flavonoids (8.75–57.78 g RE/1...
Najda cv. is an important date palm cultivar due to its high fruit quality and resistance to bayo... more Najda cv. is an important date palm cultivar due to its high fruit quality and resistance to bayoud, a disease that killed million plants of date palm. The in vitro propagation of cv. Najda through organogenesis is hampered by some physiological disorders, namely hyperhydricity, tissue browning and precocious rooting. In order to achieve efficient and large-scale propagation of true-to-type plantlets of cv. Najda, we evaluated the effect of different cytokinin types and concentrations (6-benzylaminopurine (BAP), 6-(dimethylallylamino) purine (2iP) and thidiazuron (TDZ), at 0.1, 0.2, 0.3, 0.4 or 0.5 mg/L), as well as that of medium texture (semi-solid and liquid) on adventitious shoot bud multiplication, hyperhydricity, tissue browning and precocious rooting. The optimal culture conditions for shoot bud proliferation and subsequent development were observed on semi-solid half-strength Murashige and Skoog (MS/2) medium supplemented with 0.5 mg/L 1-naphthaleneacetic acid (NAA) and 0.4 mg/L BAP, where an average of 23.8 shoot buds per explant, low rate of hyperhydricity (22.5%), moderate tissue browning (55.0%) and low percentage of precocious rooting (20.0%) were observed. Shoot elongation and rooting were performed on semi-solid and liquid plant growth regulator (PGR)-free MS/2 medium. Shoots were then transferred to the glasshouse, where the survival rate reached 95 %. The findings of the present study will be highly beneficial to rehabilitate the Moroccan palm groves infested by bayoud.
Najda cv. is an important date palm cultivar due to its high fruit quality and resistance to bayo... more Najda cv. is an important date palm cultivar due to its high fruit quality and resistance to bayoud, a disease that killed million plants of date palm. The in vitro propagation of cv. Najda through organogenesis is hampered by some physiological disorders, namely hyperhydricity, tissue browning and precocious rooting. In order to achieve efficient and large-scale propagation of true-to-type plantlets of cv. Najda, we evaluated the effect of different cytokinin types and concentrations (6-benzylaminopurine (BAP), 6-(dimethylallylamino) purine (2iP) and thidiazuron (TDZ), at 0.1, 0.2, 0.3, 0.4 or 0.5 mg/L), as well as that of medium texture (semi-solid and liquid) on adventitious shoot bud multiplication, hyperhydricity, tissue browning and precocious rooting. The optimal culture conditions for shoot bud proliferation and subsequent development were observed on semi-solid half-strength Murashige and Skoog (MS/2) medium supplemented with 0.5 mg/L 1-naphthaleneacetic acid (NAA) and 0.4 ...
In vitro multiplication of date palm is a very promising way for the rehabilitation of Moroccan p... more In vitro multiplication of date palm is a very promising way for the rehabilitation of Moroccan palm devastated. The objective of this work was to study the development of vitroplants introduced into traditional and modern palm of the Errachidia region. The procedure followed is to make descriptive diagnoses in different sites where the palm was introduced and to evaluate the mortality of plants and cultural practices. The mortality rates varied from 78% to 19% in new plantation depending on the cultivation technique used. At the traditional palm, the rate of recovery of plantlets was zero. The mortality is higher in Nejda cultivar compared to Boufegouss. This variety also presented a better adaptation in terms of shoot height in comparison with the development of Nejda and Mejhoul varieties. The production of offshoots as well as inflorescences takes place three years after plantation. The importance of improving cultivation techniques in date palm for the development of this secto...
Maturation and germination of somatic embryos are two crucial steps in the somatic embryogenesis ... more Maturation and germination of somatic embryos are two crucial steps in the somatic embryogenesis process. Herein, we evaluated the effects of several factors on the maturation and germination of date palm somatic embryos. Globular somatic embryos of cv. ‘Najda’ were cultured on Murashige and Skoog medium at full strength (MS), half strength (1/2MS), and one-third strength (1/3MS), with or without agar, and supplemented with various concentrations of mannitol, sorbitol, polyethylene glycol (PEG, MW 8000) and abscisic acid (ABA). Our results showed that culture medium strength and texture (liquid or semi-solid), osmotic agents, and the concentration and time of exposure to ABA influence somatic embryo maturation. The highest mean number of mature somatic embryos (106.4 per 100 mg fresh weight callus) was obtained after 3 weeks of culture on full-strength liquid MS medium supplemented with 30 g L-1 PEG and 40 µM ABA, followed by 9 weeks of culture on the same medium but without ABA. So...
Thidiazuron: From Urea Derivative to Plant Growth Regulator, 2018
Plant tissue culture is now a widely used technology for many applications. Plant growth regulato... more Plant tissue culture is now a widely used technology for many applications. Plant growth regulators (PGRs) play an important role in this technology. Auxins and cytokinins are by far the most commonly used PGR classes in plant tissue culture. N-Phenyl-N′-1,2,3-thiadiazol-5-ylurea, also known as thidiazuron or TDZ, is a synthetic PGR and a phenylurea derivative with a strong cytokinin-like activity. TDZ has been successfully used for the micropropagation of several plant species and sometimes was reported to be more effective than adenine-based cytokinins or to fulfil both the auxin and the cytokinin requirement for in vitro growth and differentiation. In this chapter, we will focus on the use of TDZ for the micropropagation of six Mediterranean crop species. Thus, we will report some findings from past and recent studies in which TDZ was employed for in vitro culture and regeneration of Olea europaea L., Citrus spp., Ceratonia siliqua L., Punica granatum L., Ficus carica L., and Prunus dulcis Mill. We will also highlight the specific action of TDZ depending on its concentration as well as the species, the genotype, the explant, and the concentration of the associated PGRs.
Date palm (Phoenix dactylifera L.) inflorescence rot caused by Mauginiella scaettae poses a serio... more Date palm (Phoenix dactylifera L.) inflorescence rot caused by Mauginiella scaettae poses a serious threat to date palm in Morocco. The present study aims to determine the antifungal activity of five plant extracts against M. scaettae, including Acacia cyanophylla, Cupressus atlantica, Eucalyptus torquata, Nerium oleander, and Schinus molle and link this effect to their content in phenolics and flavonoids, as well as their antioxidant properties. Plant extracts exhibited significant discrepancies regarding their antifungal activity ( p < 0.05 ). The extracts of E. torquata and C. atlantica had the strongest and dose-dependent manner inhibitory effect against mycelial growth and spore germination. E. torquata and S. molle caused the greatest sporulation reductions of about 88.05% and 36.11%, respectively. In addition, there were significant differences among the examined plant extracts with respect to their total polyphenols (14.52–76.68 mg GAE/g DW), flavonoids (8.75–57.78 g RE/1...
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