Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 – 5902]
Volume 73: 5959 – 5965 Published January 31, 2014.
Influence of growth regulators on callus induction from embryos of five citrus rootstocks
1Ramdan R1, Handaji N2, Beyahia H2 and Ibriz M1.
1 L.G.B., University Ibn Tofail, Faculty of Science, Kénitra, Morocco;
2 P O Box 257, National Institute of Agricultural research, Kénitra, Morocco;
(*) Corresponding author: Mobile + 212 6 61 54 10 57; E-mail: rajaeramdan@gmail.com
Original submitted in on 2nd May 2013 Published online at www.m.elewa.org on 31st January 2014.
ABSTRACT
Objective: The aim of this work is to develop a protocol for callus induction of Moroccan Citrus rootstocks.
Methodology and results: Callus cultures were initiated from embryos explants of five Citrus rootstocks (Cleopatra mandarin, Rangpur lime, Citrus volkameriana, Trifoliate orange, Citrus aurantium) on Murashige and Tucker (MT) and Tucker (MT) basal media. Different concentrations of growth regulators were tested in order to obtain the best callus formation: 2, 4-dichloro-phenoxyacetic acid (2, 4-D) in combination with benzylaminopurine (BAP) at five levels (0, 0.5, 1, 2 and 3mgL-1) were used in this study. It was found that growth regulator concentration had a significant effect on the callus induction, the callus growth and callus physical appearance. The highest frequency of the callus induction rate (100% and 83%) was observed with two combinations of 2, 4-D/BAP: 1 / 0, 5 and 2/1 (mgl-1). Medium containing only BAP (1mgl-1) resulted in the formation of large numbers of roots. Also, the callus induced on MT medium containing only 2, 4-D (1mgl-1) was brown in color and of low quality compared to that produced on MT media containing 2, 4-D/BAP. There was no callus formation on MT basal medium without growth regulators.
Also, the callogenesis depended on the genotype. It was maximal for Cleopatra mandarin followed by Rangpur lime and Citrus volkameriana, and then Citrus aurantium and trifoliate orange.
Conclusion and application: Passing through callus is paramount in vitro selection that plant tissue is an important source of genetic variability. The explants and exogenous phytohormones proved of paramount importance for the success of the callus and the formation of somatic embryos and their development.
Key words: Callus induction, Citrus rootstocks, 2, 4-D, BAP.
Methodology and results: Callus cultures were initiated from embryos explants of five Citrus rootstocks (Cleopatra mandarin, Rangpur lime, Citrus volkameriana, Trifoliate orange, Citrus aurantium) on Murashige and Tucker (MT) and Tucker (MT) basal media. Different concentrations of growth regulators were tested in order to obtain the best callus formation: 2, 4-dichloro-phenoxyacetic acid (2, 4-D) in combination with benzylaminopurine (BAP) at five levels (0, 0.5, 1, 2 and 3mgL-1) were used in this study. It was found that growth regulator concentration had a significant effect on the callus induction, the callus growth and callus physical appearance. The highest frequency of the callus induction rate (100% and 83%) was observed with two combinations of 2, 4-D/BAP: 1 / 0, 5 and 2/1 (mgl-1). Medium containing only BAP (1mgl-1) resulted in the formation of large numbers of roots. Also, the callus induced on MT medium containing only 2, 4-D (1mgl-1) was brown in color and of low quality compared to that produced on MT media containing 2, 4-D/BAP. There was no callus formation on MT basal medium without growth regulators.
Also, the callogenesis depended on the genotype. It was maximal for Cleopatra mandarin followed by Rangpur lime and Citrus volkameriana, and then Citrus aurantium and trifoliate orange.
Conclusion and application: Passing through callus is paramount in vitro selection that plant tissue is an important source of genetic variability. The explants and exogenous phytohormones proved of paramount importance for the success of the callus and the formation of somatic embryos and their development.
Key words: Callus induction, Citrus rootstocks, 2, 4-D, BAP.
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