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Tissue culture in Pinus caribaea Mor. var. Hondurensis barr. and golf. II: Effects of two auxins and two cytokinins on callus growth habits and subsequent organogenesis
FI Akaneme, EE Eneobong
African Journal of Biotechnology , 2008,
Abstract: The growth habits of calluses of Pinus caribaea Mor. were investigated to determine their correlation with organogenesis for micropropagation purposes. Two forms of callus growth habits were observed; friable and compact calluses. Their development occurred over a range of auxin-cytokinin combinations. In naphthalene acetic acid (NAA) x 6-furfuryl amino purine (kinetin) cultures, 100% friable calluses were obtained while in NAA x 6-benzyl aminopurine (BAP) cultures, 100% friable callus was formed only with 1:2 NAA/BAP ratio. Many compact calluses were also formed by the various combinations of NAA and BAP. Friability of calluses was further promoted by the interaction of indole butyric acid (IBA) and BAP, but organogenesis was not achieved. However, different degrees of greening were observed in some of the cultures (both compact and friable type). Thus, greening was not associated with a particular type of callus growth habit. Anatomical studies indicated that the differences between the compact and friable calluses were in the distribution of the meristematic cells. The histological studies also revealed some important and unexpected features. These were the presence of embryo-like structures, tracheary elements, lignification and starch-grain like structures. These results have further demonstrated the potential totipotency of callus cells of P. caribaea.
In Vitro Callus Induction and Embryogenesis of Oil Palm (Elaeis guineensis Jacq.) from Leaf Explants  [cached]
HAYATI Journal of Biosciences , 2011,
Abstract: This research was to study in vitro callus induction and somatic embryogenesis in oil palm from leaf explants. Young leaf segments from mature oil palm were cultured on MS medium supplemented with different concentrations of 2,4-D with or without addition of 2 g/l activated charcoal (AC) or 2,4-D and picloram. Embryogenesis induction was done using MS medium containing 2,4-D 450 M and benziladenine 4.4 M with 3g/l activated charcoal. The treatment of 2,4-D 15 M resulted in the highest percentage of callus induction. The treatment of 2,4-D and AC showed that 2,4-D 450 M and AC led to higher percentage of callus induction than that of 2,4-D 400 M and 2 g/l AC. Embryogenesis occured in 27 out of 250 clumps of primary callus was occurred after 2-3 times subcultures. Somatic embryo development occurred when the embryogenic callus was transferred on the same basal medium supplemented with casein hydrolysate with 1 M BA or growth regulator free basal medium with 2 g/l activated charcoal.
Wheat Immature Embryo Culture for Embryogenic Callus Induction
Kamil Haliloglu
Journal of Biological Sciences , 2002,
Abstract: Four 2,4-D concentrations along with three embryo developmental stages were tested to determine the optimum morphogenesis of wheat immature embryo culture. Concentration of 2 mg L -1 2,4-D was found to be optimum level for morphogenesis which was a good indicator of embryogenesis. Compact and nodular calli were observed in first and second developmental stages of 2 mg L 1 2,4-D concentration. In addition, five callus initiation media were tested to determine effects of medium constituents on somatic embryogenesis of wheat (Triticum aestivum L.). The highest embryogenic callus formation was observed on MS+B5 medium (98.3%). Therefore, first and second developmental stages of 2 mg L -1 2,4-D concentration along with MS+B5 medium is suitable for embryogenic callus production in wheat.
Callus Induced Organogenesis in Okra (Abelmoschus esculents L. Moench.)  [PDF]
M. Anisuzzaman,S. Jarin,K. Naher,M.M. Akhtar
Asian Journal of Plant Sciences , 2008,
Abstract: A viable protocol has been developed for indirect shoot organogenesis of okra. To establish a stable and high-frequency plant regeneration system, leaf disc and hypocotyl explants were tested with different combinations of α-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA),iIndole-3-butyric acid (IBA), thidiazuron (TDZ) and 6-benzylaminopurine (BAP). Morphogenic callus induction was observed in highest frequency from hypocotyl explant by culturing in MS medium supplemented with 2.0 mg L-1 NAA plus 0.5 mg L-1 TDZ. The highest percentage of shoot regeneration and highest mean number of shoot per callus mass was obtained with 2.0 mg L-1 BAP plus 0.1 mg L-1 IBA. Root formation was observed from callus induced in medium containing 1.5 mg L-1 NAA. Morphogenic difference due to explant type is clear for the studied in vitro traits. About 80% of regenerated plantlets were survived and showed new leaves development under ex vitro condition. This protocol would be useful to create somaclonal variation and to utilize transgenic approach for varietal improvement of okra.
Callus Induction from Mature Embryo of Winter Wheat (Triticum aestivum L.)  [PDF]
Hakan Turhan,Ismet Baser
Asian Journal of Plant Sciences , 2004,
Abstract: Five media supplemented with different concentrations of NAA and 2,4-D growth regulators and two different mature embryo sources were tested in order to obtain the best wheat callus formation. One of these mature embryo sources is whole seed with moved embryo and the other was embryo set free from seeds. The highest callus formation rate was observed in embryo set free cultured on MS supplemented with 4 mg l-1 2,4-D and 1 mg l-1 NAA. There was no callus formation on basal medium MS. In overall, percentage of embryogenic callus formation in free embryo procedure was higher than in endosperm supported embryo procedure. In embryogenic wheat callus formation, 2,4-D seemed an effective growth regulator as all 2,4-D supplemented media showed higher callus formation than alone NAA. On the other hand, NAA (1 mg l-1) in the 2,4-D supplemented MS medium enhanced wheat callus induction.
Induction of embryogenic callus and plantlet regeneration from young leaves of high yielding mature oil palm
Te-chato, S.,Hilae, A.,Yeedum, I.
Songklanakarin Journal of Science and Technology , 2004,
Abstract: Callus induction and plantlet regeneration from young leaves of high-yielding mature oil palm were carried out using 10-year and 20-year-old trees from Thepa Research Station, Faculty of Natural Resources,Prince of Songkla University, Hat Yai, and Trang Agricultural College, respectively. Culture media used in this experiment were Murashige and Skoog (1962) and Oil Palm supplemented with various concentrations of α-naphthaleneacetic acid (NAA) or 2,4- dichlorophenoxy acetic acid (2,4-D) or dicamba (Di) and antioxidants.Young leaves from 6th to 11st frond were excised, sterilized, cut into 5x5 mm pieces and cultured in the dark at 26±4oC or 28±0.5oC for 3 months. The results revealed that MS medium with 200 mg/l ascorbic acid (As) and 1 mg/l Di (MS-AsDi) gave the highest callus induction percentage (7.93) after culture for 3 months at 28±0.5oC. Leaf segments from 6th - 8th frond yielded callus forming percentage at 10% (averaged from 1, 2.5 and 5 mg/l Di containing MS medium). Ascorbic acid as an antioxidant at concentration of 200 mg/l supplemented in MS medium in the presence of 2.5 mg/l Di produced the highest callus induction percentage (11.2) and number of nodules (7.06). A high percentage of embryogenic callus formation (66.67) was obtained when the calli were transferred to the same medium component supplemented with 0.5 mg/l Di and 1,000 mg/l casein hydrolysate (CH) (MS-AsDiCH). Haustorial-staged embryos were observed to be isolated as an individual embryo and germinated on MS medium without plant growth regulator (MS-free). Development of root could be classified into two distinct types, fibrous and tap root.
Effect of Abscisic Acid and Polyethylene Glycol on the Synchronization of Somatic Embryo Development in Date Palm (Phoenix dactylifera L.)  [PDF]
Jameel M. Al-Khayri,Abdulaziz M. Al-Bahrany
Biotechnology , 2012,
Abstract: Somatic embryogenesis provides the best method for commercial micropropagation of date palm (Phoenix dactylifera L.); however, a current limitation is the lack of synchronization of developing somatic embryos. The objective of this study was to evaluate the effect of Abscisic Acid (ABA) and polyethylene glycol (PEG) combinations on the synchronization of embryo development in date palm cell suspension. Callus maintained on MS medium containing 54 μM Naphthalene Acetic Acid (NAA) and 7 μM 2-isopentenyladenine (2iP) was transferred to regeneration liquid medium supplemented with ABA at 0-100 μM and PEG at 0-15%. Maximum fresh culture weight was obtained with 10% PEG in the absence of ABA. The addition of as low as 1 μM ABA to the suspensions inhibited growth. In the absence of ABA, increasing PEG concentration increased total somatic embryo numbers reaching a maximum number at 10% PEG. Various embryo sizes differing in abundance were associated with different treatments. The highest percentage of medium size embryos, 52%, was obtained at 10 μM ABA; whereas, the highest percentage of small embryos was obtained at 50-100 μM ABA. The small embryos exhibited a state of synchronization. Although, treating suspensions with ABA and PEG affected embryo size distribution, germination was influenced by embryo developmental phase, expressed in size. Germination of 43, 63, 52 and 23% was obtained from the small, medium, large and very large embryos, respectively. Retardation of somatic embryo development caused by ABA can be further exploited to optimize culture synchronization.
Expression of Cadherin-11 during Organogenesis in the Chick Embryo  [cached]
Kacie D. Flaherty,Alicia F. Paulson,Ashley L. Adamson,Darrell J. Wiens
International Journal of Biology , 2011, DOI: 10.5539/ijb.v4n1p36
Abstract: Cadherin-11 (cad-11) is primarily a mesenchymal cadherin that appears in delaminating neural crest cells. Its expression correlates with morphogenetic events and the pattern has been studied in mouse, rat and Xenopus embryos, but not during avian organogenesis. Our purpose was to investigate this pattern in the chick embryo during organogenesis using immunolocalization and in situ hybridization. Cad-11 was expressed in mesenchyme around the pharynx and aortic arches, eyes, auditory vesicles, lung buds, stomach, and nasal placodes. Neural expression included some cranial ganglia and also new neuroepithelium within the tail bud region undergoing secondary neurulation. We also found expression in epithelia of the developing circulatory and digestive organs. The limb buds, pineal rudiment and mesonephros were also positive. Cad-11 expression became more widespread with development. Our findings support the role of cad-11 as a mesenchymal cadherin, but provide evidence for a wider role that includes epithelial morphogenesis and secondary neurulation.
Scientific Annals of Alexandru Ioan Cuza University of Iasi. New Series, Section 2. Vegetal Biology , 2006,
Abstract: The plants of Chrysanthemum morifolium Ramat. (cultivar Romica) have been regenerated from callus cultures, established from stem and leaves explants. Callus cultures induced from stems had a greater shoot differentiation than those obtained from leaves. Despite the great opportunity of genetic variation in callus cultures , the regenerated plants differ not in their externel appearance from the normal plants.
Irradiation effect on in vitro organogenesis, callus growth and plantlet development of Gerbera jamesonii
Hasbullah, Nor A;Taha, Rosna M;Saleh, Azani;Mahmad, Noraini;
Horticultura Brasileira , 2012, DOI: 10.1590/S0102-05362012000200012
Abstract: the present work was carried out to study the effects of gamma irradiation on in vitro growth of explants, callus and the formation of shoots and plantlets. irradiation is known to exhibit or inhibit the differentiation of cells and growth of plants in vitro, which helps in producing new plant varieties. gamma irradiation is one of the physical mutagens that are widely used for mutation breeding. a gradual decline was observed in the number of shoots regenerated from irradiated petiole explants compared to control. numbers of shoots regenerated from irradiated petiole explant cultured on murashige & skoog medium supplemented with 2.0 mg l-1 bap and 0.5 mg l-1 naa was reduced to 6.6±0.9 from 7.5±0.4 (control) when explants were exposed to 20 gray of irradiation dose. similar observation was reported on effects of gamma irradiation on in vitro propagated plantlets. gradual decline was observed based on plant height as the dose of gamma irradiation increased. a significant decline was observed in the fresh weight of irradiated callus compared to control. in this case, growth responses of callus were strongly influenced by the radiation dose. the fresh weight of callus was reduced to 76.4±2.2% compared to 89.7±0.5% of control when callus tissues were exposed to 20 gy.
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