Thidiazuron stimulates shoot regeneration of sugarcane embryogenic callus

Summary Efficient shoot regeneration of sugarcane (Saccharum spp. hybrid cv. CP84-1198) from embryogenic callus cultures has been obtained using thidiazuron (TDZ). Callus was placed on modified Murashige and Skoog (MS) medium containing 2.3 μM 2,4-dichlorophenoxyacetic acid (2,4-D), or 9.3 μM kinetin and 22.3 μM naphthaleneacetic acid (NAA) and compared with the same MS medium supplemented with 0.5, 1.0, 2.5, 5.0 or 10.0 μMTDZ, A11 TDZ treatments resulted in faster shoot regeneration than the kinetin/NAA treatment, and more shoot production than either the 2,4-D or kinetin/NAA treatments. Maximum response, as determined by total number of shoots (26 per explant) and number of shoots greater than 1 cm (4 per explant) 4 wk after initiation, was obtained with 1.0 μM TDZ. The shoots rooted efficiently on MS medium supplemented with 19.7 μM indole-3-butyric acid (IBA). These results indicate that TDZ effectively stimulates sugarcane plant regeneration from embryogenic callus, and may be suitable to use in genetic transformation studies to enhance regeneration of transgenic plants.     

Plant regeneration from shoot tips and callus of papaya

Summary Two methods of in vitro culture were employed to regenerate papaya plants. One involved regeneration of plants from callus and the other, production of multiple plants from single shoot-tip explants. Callus was induced from stem sections of papaya seedlings in a medium containing 1 mg per 1 NAA and 0.1 mg per 1 kinetin. The callus regenerated shoots and/or embryoids when transferred to a medium of lower auxin, 0 to 0.05 mg per 1 IAA, and higher cytokinin, 1 to 2 mg per 1 kinetin Multiple shoots were produced when the excised shoot-tip explants were cultured in a medium supplemented with 0.05 mg per 1 IAA and either 5 mg per 1 kinetin or 0.5 to 1.0 mg per 1 benzyladenine. Root formation of the shoots or embryoids that derived from callus or shoot tips occurred in a medium containing 5 mg per 1 IAA and in a light intensity of 3000 to 4000 Ix. The rooted plants could be established in soil and under standard greenhouse conditions after they had been acclimated by initially growing them in moist vermiculite contained in polyethylene-covered pots. This research was supported by the National Science Council, Republic of China.     

In vitro plant regeneration from callus of shoot apices in apple shoot culture

A new reliable protocol for the induction of adventitious shoot formation and plant regeneration from apple callus has been developed. High regeneration frequency was obtained with this method in four different genotypes (Jork9, M26, Gala and McIntosh) and callus maintained regeneration ability for several months. The procedure consists of inducing vegetative shoot apices, excised from in vitro shoots, for 20 days in darkness on an MS medium without glycine, supplied with 17.8 μM BA, 2.7 μM NAA and 250 mg l⁻¹ cefotaxime. The explants are then transferred to a fresh auxin-free medium and given light. Histological studies revealed that all the regenerated shoots originated from callus. Regenerated shoots were multiplied, rooted and successfully established in soil. Received: 2 April 1999 / Revision received: 10 November 1999 / Accepted: 15 November 1999     

Changes in isoperoxidases during shoot formation in tobacco callus

Summary Shoot formation in tobacco (Nicotiana tabacum L.) callus is accompanied by an increase in peroxidase activity which takes a form similar to a sigmoid curve. The “stationary” phase coincide with the period of organ formation. Characteristic changes in isoperoxidase pattern are found in the shoot-forming part of the callus. These changes are different from those in the nonshoot-forming part or in gibberellin-treated tissue, which does not form shoots.     

Changes in isoperoxidases during shoot formation in tobacco callus

Shoot formation in tobacco (Nicotiana tabacum L.) callus is accompanied by an increase in peroxidase activity which takes a form similar to a sigmoid curve. The "stationary" phase coincides with the period of organ formation. Characteristic changes in isoperoxidase pattern are found in the shoot-forming part of the callus. These changes are different from those in the nonshoot-forming part or in gibberellin-treated tissue, which does not form shoots.     

Physiological gradients and shoot initiation in tobacco callus cultures

Support for the idea that physiological gradients of substancesinto the tissue may be the operative factors promoting organinitiation in vitro is presented. Evidence for this conceptwas obtained through measurement of the starch content and respiratoryactivity of upper and lower segments of tobacco (Nicotiana tabacumL. cv. Wisconsin 38) callus and inversion of the tissue duringculture. ¹This investigation was supported by NRC of Canada grant A-6467to T.A.T. (Received October 16, 1972; )     

Improvement of embryogenic callus induction and shoot regeneration of buffalograss by silver nitrate

Addition of the ethylene antagonist, silver nitrate (AgNO₃), into callus induction medium significantly enhanced embryogenic callus production (both induction frequency and callus growth) of field-collected male immature inflorescence cultures of buffalograss NE84-45-3 and 'Texoka'. No stimulatory effect of AgNO₃ was observed on embryogenic callus induction for female immature inflorescence culture of a female genotype `609' and `Texoka'. Calli initiated on AgNO₃-containing media had more shoot-regenerating calli than those initiated on AgNO₃-free media, when they were transferred to the regeneration media. Benzyladenine at 2.2 μM gave the best response for regeneration, regardless of the callus source. Although average number of shoots regenerated per callus was lower for calli initiated on AgNO₃-containing media, total number of shoots regenerated was higher. The stimulatory effect, however, was environment and genotype dependent. While the addition of AgNO₃ significantly stimulated embryogenic callus induction of NE84-45-3 immature inflorescences collected in Fall 1995 and May 1997, it only slightly increased the embryogenic callus induction frequencies in May 1996 when rainy conditions occurred. For male inflorescences of `Texoka' collected in early May, AgNO₃ significantly enhanced embryogenic callus production consistently over the two-year period (1996, 1997). Published as Journal Series No. 1351, Agricultural Research Division, University of Nebraska. This revised version was published online in June 2006 with corrections to the Cover Date.     

Mitochondrial activity during shoot formation and growth in tobacco callus

Mitochondria isolated from tobacco ( Nicotiana tabacum L. cv. Wisconsin 38) callus growing on either shoot-forming or non-shoot forming medium show an increase in state 3 and state 4 respiration and a drop in respiratory control and ADP/O ratios after subculture. the protein content of the mitochondria fraction and the activity of succinate dehydrogenase, malate dehydrogenase, cytochrome c oxidase and catalase also increase after subculture but there is no apparent difference between shoot-forming and non-shoot-forming tissue. For mitochondria assayed at their native osmolarities, a trend of higher respiration rates and respiratory control as well as lower levels of cyanide-resistant respiration was observed for shoot-forming tissue. Generally, differences were greatest after day 9 in culture, the time during which primordia formation occurred in the shoot-forming callus. These patterns are in concert with the view that the shoot-forming process has a high energy requirement which must be realized during the time of primordia formation.     

The effect of barban on shoot formation in tobacco callus cultures

Shoot formation in tobacco callus was completely inhibited bythe presence of barban in the media during the first 2 daysof culture. Callus transferred to media containing barban from4th to the 12th day showed progressively less inhibition. Similarresults were obtained with GA₃. ¹Present address: Biology Department, Chung Chi College, TheChinese Univ. of Hong Kong, Shatin, N.T., Hong Kong ²Present address: Plant Hormone & Regulator Pioneering ResearchLab., U.S. Dept. Agric, Crops Res. Div., Beltsville, Md., U.S.A. (Received April 21, 1970; )     

Physiological effects of Na2SO4 and NaCl on callus cultures of Brassica campestris (Chinese cabbage)

Hypocotyl-derived callus cultures of Brassica campestris L. ssp. pekinensis cv. Kim-jung (Chinese cabbage) were grown on Murashige and Skoog medium containing no additional salt, NaCl or Na₂SO₄. Na₂SO₄ was more than twice as inhibitory in comparison to the same concentration of NaCl when growth and fresh:dry weight ratios of established callus were measured. Levels of protein, starch, sucrose and α-amino nitrogen were not significantly altered in salt-grown callus. Concentrations of reducing sugars and chlorophyll were 2–3 times greater in callus grown on either salt. Proline concentration increased 15–20 fold on the highest levels of salt. Final concentrations (reached in 20–24 days) were closely correlated to the initial Na⁺ concentration of the medium, regardless of salt type. The osmotic potential in callus transferred to NaCl or Na₂SO₄ reached a maximum negative value after 16 days. For both salts, subsequent increases were correlated to increases in fresh:dry weight and growth. On both salts, turgor remained relatively constant (0. 6–0.75 MPa). Changes in Na⁺, K⁺, Mg²⁺ and Ca²⁺ content were correlated to initial Na⁺ concentration in the medium, not salt type. Accumulation of Na⁺ was accompanied by loss of K⁺ and Mg²⁺. Six to seven times less sulfate was measured in callus grown on Na₂SO₄ than chloride in callus grown on similar concentrations of NaCl.     

Morphactin-kinetin interaction on growth and shoot formation in tobacco callus cultures

Pith-derived calluses of Nicotiana tabacum L. cv. Wisconsinno. 38 were inoculated on an RM-1964 medium containing variousconcentrations of a morphactin, chlorflurenol (CFl) and kinetin(KIN). An addition of KIN (0.1–2 mg/liter) alone was effectivefor shoot formation from the calluses, but a high dose (10 mg/liter)resulted in the inhibition of growth and in no differentiation.The inhibitory effect of a high dose of KIN was counteractedwith CFl. Three combinations of KIN and CFl; CFl (0.1 mg/liter)$KIN(2.0 mg/liter); CFl (0.1 mg/liter)$KIN (10.0 mg/liter) and CFl(1.0 mg/liter) $KIN (2.0 mg/liter), were successful for 100%shoot redifferentiation in inoculated calluses. An appropriatebalance between CFl and KIN seems to be involved in shoot formation.The present results can best be interpreted by assuming thatCFl acts as an auxin in cultured tissues. (Received January 16, 1975; )     

Plant regeneration from cocoyam callus derived from shoot tips and petioles

The effects of various growth regulators on morphogenesis from cocoyam tissues (Xanthosoma sagittifolium) were investigated. Calluses were initiated from shoot tip and petiole explants and proliferated on medium containing 1.36 μM dicamba. Callus production was significantly greater from petioles than from shoot tips. Thidiazuron (0.045 μM) enhanced callus production when dicamba (13.5 μM) was used, and was more favorable to petioles than shoot tips. Friable shoot tip callus was subcultured into liquid media containing either 1.36 μM dicamba alone, 1.35 μM 2,4-D + 0.46 μM kinetin or 1.36 μM dicamba + 0.46 μM kinetin to induce adventive regeneration. Tissues producing single or aggregated shoot buds were subcultured into media containing 0, 0.049 and 0.49 μM 2-isopentenyladenine where bud multiplication and shoot regeneration were observed. Bud aggregates were formed from callus in liquid cultures containing 1.36 μM dicamba, 1.36 μM dicamba + 0.46 μM kinetin or 1.35 μM 2,4-D + 0.46 μM kinetin. Shoot bud clumps which remained green produced shoots, daughter buds, and plantlets in stationary and agitated liquid media containing 0, 0.049 and 0.49 μM 2iP. This revised version was published online in June 2006 with corrections to the Cover Date.     

Plant regeneration through shoot formation from callus of Areca catechu L.

In order to establish and optimize an in vitro micropropagation protocol of Venus fly trap (Dionaea muscipula Ellis), a carnivorous plant, the effects of medium type, MS medium concentration, pH, and cytokinin and auxin types on shoot proliferation and root formation were investigated using 3-month-old shoots. The shoot proliferation was most effective in 2.3 M kinetin-supplemented 1/3MS medium at pH 5.5. The best conditions for rooting were 1/3MS medium supplemented with 0.5 M IBA. All subcultured shoots produced extensive root systems after 5–6 weeks culture. When plantlets after rooting were planted in plastic pots filled with 1:1 peat moss and sand, the survival rate of plantlets was almost 100%, exhibiting normal development. With subculture every 8 weeks, hundreds of the plants were propagated from a single plant within a year.     

Plant regeneration from shoot callus of rosewood (Dalbergia latifolia Roxb.)

In vitro propagation of trees using cell, tissue and organ culture is a fast emerging area. We report here the clonal propagation of Indian rosewood (Dalbergia latifolia Roxb.) from shoot callus cultures of 5 year old trees. Bud regeneration was obtained on MS media supplemented with BA and NAA. About 35% of the cultures showed organogenesis. Shoots measuring about 3–5 cm can be excised and rooted in White's medium supplemented with 1–2 mg/L IAA. Rooted plants were successfully established in soil.Abbreviations BA Benzyladenine - CM Coconut milk - 2,4-D 2,4 dichlorophenoxyacetic acid - IAA Indoleacetic acid - IBA Indolebutyric acid - K Kinetin - NAA Naphthaleneacetic acid - PVP-360 Polyvinyl pyrrolidone     

Modulation of shoot formation in tobacco callus by tissue transfer between permissive and inhibitory media

Summary In an attempt to understand events involved in the cellular regulation of in vitro plant organogenesis, experiments were performed in which tobacco (Nicotiana tabacum L.) callus was transferred at different days in culture from a shoot-forming medium to a non-shoot-forming medium and vice versa. The transfers were made at key histologic stages of the shoot-forming process and known biochemical and biophysical correlates were examined. The changes in starch accumulation and disappearance supported the previously assigned functions, and could be correlated with the histologic changes that occurred in the callus after transfer at the different culture times. In contrast, the changes in respiration could not be correlated with these events. The changes in osmotic and turgor potentials after transfer showed that osmotic adjustment preceded both shoot initiation and development. This suggests that osmotic adjustment might play an important role in in vitro organogenesis. This research was supported by the Natural Sciences and Engineering Research Council of Canada grant A-6467 to T. A. T.     

In vitro selection and characterization of a callus line ofVigna radiata resistant to NaCl,KCl and Na2SO4

A salt mixture resistant (SMR) cell line ofVigna radiata (L.) Wilczek was isolated by selection on agar solidified PC-L2 medium supplemented with NaCl, KCl and Na₂SO₄ (8∶1∶1) equimolar to 300 mol m^?3 NaCl, a concentration inhibitory to the wild-type non-selected cells (salt mixture sensitive, SMS). This line retained its resistance after subculture for 3 passages (3 months) on normal medium. The SMR line grew significantly better than SMS line at all the levels of salts, though less in saline medium than the SMR on normal medium. The growth of SMR line was significantly higher than that of SMS line under KCl stress. However, both the lines responded similarly to Na₂SO₄ at a concentration higher than 100 mol m^?3. The SMR line was found to be more sensitive to NaCl than SMS line. The SMR line under salt mixture stress maintained lower levels of Na⁺ and higher levels of K⁺ than SMS line. The SMR line failed to regenerate shoots, although rhizogenesis was observed on PC-L2 medium containing salt mixture (300 mol m^?3).     

The role of cellulase in hormonal regulation of shoot morphogenesis in tobacco callus

A polyclonal antibody raised against cellulase (EC 3.2.1.4.) from callus ofNicotiana tabacum L. cv. Petit Havana SR1 reduced cellulase activity and induced shoot formation in tobacco callus in the presence of callus maintaining concentrations of auxin and cytokinin. Shoot induction as well as reduction of the cellulase activity was also obtained by withdrawing auxin from the callus medium. The effect of the two hormones on cellulase activity in the tobacco tissue was examined by varying the concentration of one of the hormones -naphthylacetic acid (NAA) or benzylaminopurine (BAP) at a time while the other was kept at a level sufficient for either callus growth or shoot induction. While NAA stimulated the enzyme activity increasingly with concentration in the range 5 × 10^–7 M to 5 × 10^–5 M at both levels of BAP, BAP only stimulated the cellulase activity at an optimum concentration of 5 × 10^–6 M when NAA was present at a level sufficient to induce callus growth. The results point to a pivotal role of the downward regulation of cellulase in the initiation of shoot induction. A series of events leading to oriented cell divisions as a result of the lowered cellulase level during the initial phase of the morphogenetic process is discussed.Abbreviations Ab Purified cellulase antibody - BAP benzylaminopurine - MS Murashige and Skoog medium - NAA -naphthylacetic acid - PS Purified preimmune serum We thank Mr. Poul Fabech for constructing the automatic viscosimetric equipment and Mr. Hans Hjorth for making the computer programme. This work was supported by The Danish Veterinary and Agricultural Research Council.     

In vitro regeneration of plantlets from shoot callus of mature trees ofDalbergia latifolia

A successful procedure was established for in vitro mass multiplication of Indian rosewood (Dalbergia latifolia Roxb.). In vitro regeneration of plantlets was achieved from callus of shoot tips and shoot segments of over 50-year-old elite trees on Murashige & Skoog's medium containing naphthaleneacetic acid (NAA) and benzylaminopurine (BAP). For rooting, regenerated shoots from the calli were excised and first treated with White's liquid medium or half-strength Murashige & Skoog's medium, supplemented with indole-3-acetic acid, indole-3-butyric acid and naphthaleneacetic acid for 48 h to 72 h. Following this treatment, plantlets were transferred to hormone-free half-strength MS medium. Rooted plantlets were then transferred to pots and grown in the greenhouse.Abbreviations BAP 6-benzylamino pruine - CH casein hydrolysate - CM coconut milk - 2, 4-D dichlorophenoxyacetic acid - GA gibberellic acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid - NAA naphthaleneacetic acid - PVP-10 polyvinyl pyrrolidone - YE yeast extract     

用电渗析法分离牛磺酸与硫酸钠混合水溶液

利用电渗析技术 ,分离化学合成牛磺酸所生成的牛磺酸与硫酸钠混合水溶液 ,可以回收所生成牛磺酸的 78.1 % ,理论产量的 6 4 .7% ,与传统化学分离法相比有很多优点