An Adventitious Shoot Formation from a White Spruce Root

Ecology ◽  
1962 ◽  
Vol 43 (1) ◽  
pp. 142-144
Author(s):  
Gordon F. Weetman
1986 ◽  
Vol 64 (5) ◽  
pp. 997-1002 ◽  
Author(s):  
Colin Rumary ◽  
Kamlesh R. Patel ◽  
Trevor A. Thorpe

Histological analysis of developmental events during adventitious shoot formation in cultured epicotyl explants of black and white spruce was carried out. Cells towards the periphery of the expiants and between the bases of the cotyledons responded to cytokinin and became meristematic. Cell division in these regions led to the formation of meristemoids and ultimately intercotyledonary adventitious shoots. These shoots developed a vascular system, which became connected to the main vascular system of the expiant. After about a month of culture, the entire expiant became meristematic and showed evidence of additional de novo shoot development. Several rings of bud primordia were found at the periphery of the expiant after about 40 days of culture. These primordia that developed in the subepidermal layers could easily be distinguished from the surrounding cells by their distinct boundaries and intense staining for nucleic acids and proteins. After 2 months of culture, the entire expiant was covered with well-developed shoots having organized apical meristems, needle primordia, and vascular systems.


1970 ◽  
Vol 18 (2) ◽  
pp. 173-179 ◽  
Author(s):  
T. Mallikadevi ◽  
P. Senthilkumar ◽  
S. Paulsamy

The in vitro regeneration of Plubago zeylanica exhibited that the callus was initiated in the basal medium containing BAP, NAA, 2, 4-D, and IBA.  The high amount (90%) of organic calli was induced in the basal medium supplemented with 2, 4-D, alone at 2.0 mg/l. In the subculture the adventitious shoot formation was prominently higher (83%) in the basal medium containing BAP, and NAA at 3.5 and 0.3 mg/l, respectively. IAA (1.0 mg/l)effectively produced higher percen-tage (90) of roots and root growth. After sequential hardening, survivability rate was observed to be significantly higher (80%) in the hardening medium containing garden soil, sand and vermicompost in the ratio of 1 : 1 : 1 by volume under greenhouse condition.  Key words: Plumbago zeylanica, In vitro regeneration, Medicinal plant D.O.I. 10.3329/ptcb.v18i2.3648 Plant Tissue Cult. & Biotech. 18(2): 173-179, 2008 (December)


1993 ◽  
Vol 118 (1) ◽  
pp. 151-157 ◽  
Author(s):  
Michael E. Compton ◽  
D.J. Gray

Adventitious shoots were obtained from watermelon [Citrullus lanatus (Thunb.) Matsun. & Nakai] cotyledons incubated on a modified Murashige and Skoog medium containing BA. Initial experiments comparing the effects of BA (0, 5, 10, or 20 μm) and IA4 (0, 0.5, or 5 μm) demonstrated that BA was required for adventitious shoot formation but its concentration in the medium was not critical. The addition of IAA to medium with BA increased callus production and inhibited shoot formation. However, the percentage of responding explants in the best treatment was <30%. Therefore, the manner in which cotyledon explants were prepared and seedling age at the time of explantation was examined to improve the organogenic response. The percentage of explants with shoots was improved by using explants that consisted of cotyledon bases (43%) or cotyledons cut in half longitudinally (39%). A lower percentage (16%) of cotyledons cut longitudinally into four pieces produced shoots. Explants taken from the apical half of cotyledons failed to regenerate shoots. Shoot formation was improved further by using explants from young seedlings. The percentage of explants with shoots was >90% for `Minilee', 64% for S86NE, and 50% for `Jubilee II' when explants were prepared from 5-day-old seedlings. Explants from nongerminated embryos or seedlings germinated for 10, 15, or 20 days produced fewer shoots. The effect of several cytokinins on shoot organogenesis was then examined using the optimized protocol. The percentage of explants with shoots and the number of shoots per explant were about two to four times higher when 5 to 10 μm BA was used compared to the most effective kinetin (20 μm) or thidiazuron (0.1 μm) concentration. The percentage of explants with shoots and the number of shoots per explant were greater for diploid (57% and 2.2, respectively) than for triploid (22% and 0.6, respectively) or tetraploid (20% and 0.8, respectively) lines. Chemical names used: N -(phenylmethyl)-1 H -purin-6-amine (BA); 6-furfurylaminopurine (kinetin); N -phenyl-N' -1,2,3-thiadiazol-5-ylurea (thidiazuron); 1 H -indole3-acetic acid (IAA).


1992 ◽  
Vol 30 (3) ◽  
pp. 237-241 ◽  
Author(s):  
Giovanni Iapichino ◽  
Steve MeCullech ◽  
Tony H. H. Chen

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