Cultural manipulations affecting callus formation from seedling explants of the pearl lupin (Lupinus mutabilis Sweet)

1993 ◽  
Vol 123 (2) ◽  
pp. 419-432 ◽  
Author(s):  
MUSHTAQ A PHOPLONKER ◽  
P D S CALIGARI
HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 528a-528
Author(s):  
Sharon A. Bates ◽  
John E. Preece ◽  
John H. Yopp

Both greenhouse-grown white ash plants derived from tissue culture and rooted microshoots in high humidity trays were inoculated with 11 tumor-inducing Agrobacterium strains. Eight strains stimulated mutative gall formation. Plants inoculated with strain A281 exhibited a higher frequency of callus formation (greenhouse-22.2%; microshoots-18.8%) than other strains at the site of the wound. Therefore, strain A281 was used to inoculate seed and seedling explants in vitro. Explants were placed on MS medium containiner no plant growth regulators and inoculated at 0, 3, 5, 7, or 10 days after initiation. Plants inoculated at 10 days showed a higher frequency of callus formation (16.4%) than with earlier inoculations. Also, rewounding of the explant at inoculation resulted in a higher frequency of callus formation (11.3%) compared to not rewounding the explant (3.9%).


1994 ◽  
Vol 35 (5) ◽  
pp. 426-428
Author(s):  
A. -J. Burchardt ◽  
AA. Wagner ◽  
P. Basse

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1120G-1120
Author(s):  
J. L. Jacobs ◽  
C. T. Stephens

Several growth hormone combinations and silver nitrate concentrations were examined for their effect on regeneration of different pepper genotypes. Primary leaf explants from in vitro seedlings were cultured on a revised Murashige and Skoog medium supplemented with auxin, cytokinin and 1.6% glucose. Combinations of different concentrations of indole-3-acetic acid (IAA), 0-5 mg/l, and 6-benzylaminopurine (BAP), 0-5 mg/l, were tested to determine the most effective medium for shoot primordium formation. Experiments with IAA and BAP did not result in a specific growth hormone combination appropriate for regeneration of all genotypes tested. Of the silver nitrate concentrations tested, 10 mg/l resulted in the best shoot and leaf differentiation and reduced callus formation. Differences in organogenic response of individual genotypes were evaluated on a single regeneration medium. Whole plants were regenerated from 11 of 63 genotypes examined. Based on these experiments, a reproducible regeneration system for pepper was developed with a total of 500 plants regenerated to date.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 478e-479
Author(s):  
M.M. Jenderek ◽  
A.J. Olney

Hibiscus syriacus is a difficult species in micropropagation due to its endogenous contamination and recalcitrant shoot formation; therefore, studies on using explants other than shoot tip or axillary buds of growing shrubs were initiated. Three different seedling fragments (root, hypocotyl, and leaf petiole) from aseptically germinated seedlings of hibiscus (var. Aphrodite) were evaluated for adventitious bud formation, shoot and leaf development. The explants were cultured on McCown's woody plant basal salt medium supplemented with KNO3 (800 mg/L), adenine sulfate (80 mg/L) and MS vitamins containing BA or 2iP or TDZ at 0.5, 1.0, 2.2, 4.4 and 10 mM. Adventitious buds were present on all of the three different explants grown on medium containing TDZ; however, the most abundant bud formation, with many small leaves originating from callus was observed on hypocotyl explants cultured on medium with 1 mM of TDZ. Petiole explants were the most frequent to develop short shoots (≈15 mm) and one to nine leaves without callus formation, where 70% of hypocotyl and the root explants formed leaves originating from callus. Callus was induced on all explant types regardless of the level or type of cytokinin used. However, the number of shoots produced by any explant type was low, petioles cultured on 0.5 and 1mM of TDZ were the most suitable material for non-callus shoot development in H. syriacus. Hypocotyl explants proved to be an excellent source for adventitious bud formation but their ability to develop shoots needs to be investigated.


Author(s):  
Samuel Crompton ◽  
Fabrizio Messina ◽  
Gillian Klafkowski ◽  
Christine Hall ◽  
Amaka C. Offiah

Abstract Background Recent studies have analysed birth-related clavicular fractures to propose time frames for healing that could be applied to dating of all fractures in cases of suspected child abuse. Objective To assess differences in healing rates between femoral fractures and birth-related clavicular fractures in infants and young children. Materials and methods A retrospective 5-year pilot study of femoral fractures in children younger than 3 years of age was performed. Anonymised radiographs were independently scored by two radiologists for stages of fracture healing. In cases of reader disagreement, radiographs were independently scored by a third radiologist. Results In total, 74 radiographs (30 children) met the inclusion criteria. Fracture healing evolved over time with subperiosteal new bone formation (SPNBF) appearing first, followed by callus then remodelling. A power calculation for a single proportion, with a level of confidence of 95% and a margin of error of 5%, showed that in a definitive study, 359 radiographs would be required. Conclusion Although the overall pattern of healing is similar, in this small pilot study, the earliest times for SPNBF and callus formation in femoral fractures appeared to lag behind healing of birth-related clavicular fractures. Remodelling appeared earlier than remodelling of clavicular fractures. A power calculation has determined numbers of femoral radiographs (359) required for a definitive study.


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