‘章姬'草莓茎段愈伤组织诱导及高频植株再生体系的建立北大核心CSCD

In order to cultivate an improved variety with higher potential yield and establish an efficient in vitro regeneration system of strawberry ‘Akihim'(Fragaria × ananassa), callus induction and plant regeneration protocol was designed for solve browning problem. A formal L9(34)orthogonal experiment was designed to investigate the browning research in primary culture using explants of creeping stems excised from aseptic seedlings. Based on the improved medium above, single-factor experiments were conducted to select effective plant growth regulators and appropriate concentrations on blank MS medium. A L9(34)orthogonal experiment was designed to study effects of types and concentrations of plant growth regulators on callus induction, adventitious shoot formation, and plant regeneration. The results indicated that MS medium was inferior to B5 and 1/2MS in inhibiting browning condition. The browning rate was dramatically reduced while the callus still survived on the medium with the addition of 20 g·L-1 Na2S2O3. The callus induction and shoot formation of the explants were observed on MS + 0.1 mg· L-1 6-BA + 0.05 mg·L-1 2, 4-D + 0.1 mg·L-1 NAA with effective inhibiting browning. The optimal medium protocol for multiple shoots proliferation was MS + 0.1 mg·L-1 6-BA + 0.1 mg·L-1 NAA where the proliferation coefficient was 12.86 after 30 d. Healthily regenerated plants were yielded on culture medium 1/2MS + 1.0 g·L-1 AC after 35 d, with a rooting rate of 92.50%. More than 95% of plantlets survived after transplanting into field. The rapid propagation system is helpful to provide homogeneous progeny and high quality seedlings for cultivation of strawberry ‘Akihime' as well as a technical reference for other strawberry species in vitro regeneration. [ABSTRACT FROM AUTHOR]     

'红香芋'茎尖玻璃化法保存条件的筛选

In order to screen suitable vitrification conservation conditions for shoot tip of Colocasia esculenta'Hongxiangyu', pre?culture, vitrification protection and thawing conditions were compared. The results show that with increasing of sucrose concentration in the medium and extending of pre?culture time, survival rate of shoot tip increases gradually. After different loaded and dehydrated measures, water content in shoot tip is lower than that of the control, while survival rate of shoot tip increases significantly than that of the control. Thawing for 1-2 min at 40℃-60℃ generally has no significant effect on survival rate of shoot tip. Suitable cryopreservation steps of vitrification as follows: shoot tip pre?cultured for 3 d in medium with 06 mol·L-1 sucrose firstly, then loaded for 30 min in 60% PVS2, dehydrated for 15 min in PVS2, put in PVS2 and conserved in liquid nitrogen, and shoot tip thawed for 1-2 min in 40 ℃.     

外植体类型和培养基中激素浓度对香茶菜愈伤组织诱导的影响

Effects of explant type ( leaf and stem segment) and hormone concentration ( 01, 02 and 03 mg·L-16?BA;10, 15 and 20 mg·L-12,4?D) in medium on callus induction of Isodon amethystoides (Benth.) H. Hara were studied by using single?factor and L9 ( 32 ) orthogonal experiments. The results show that compared with callus induction from leaves, calli can be induced from stem segments within a short time, which are loose and large in quantity. The results of orthogonal experiment show that the callus induction rate of stem segments of I. amethystoides varies from 72% to 93% in different media, in which, mass concentration of 2,4?D has a significant ( P<005) effect on callus induction rate, while that of 6?BA has no significant effect. According to the results, MS medium ( containing 30 g·L-1 sucrose and 7 g·L-1 agar, pH 58) with 01 mg·L-16?BA and 15 mg·L-12,4?D is considered as an optimum medium for callus induction from stem segments of I. amethystoides.     

Thidiazuron-induced highly morphogenic callus and high frequency regeneration of fertile peanut (Arachis hypogaea L.) plants

Summary An efficient regeneration system was developed by culturing immature cotyledons and embryo axes of Arachis hypogaea L. cv. Georgia Green on Murashige and Skoog basal medium (MS) supplemented with various concentrations of thidiazuron (TDZ; 1, 5, 10, and 15 μM). Highly morphogenic callus was produced from 100% of the explants comprising the cotyledon with attached embryo axis when cultured in the dark on 10 μM TDZ. Upon excision and continued culture in the dark on 10 μM TDZ, morphogenic callus grew repetitively during monthly subcultures and retained its regeneration potential. For organogenesis, a gradual reduction in TDZ concentration and exposure to light were necessary before transfer to MS basal medium. Inclusion of indole-3-butyric acid in liquid MS medium favored rooting of recovered shoots. A distinct feature of this investigation is the induction of highly morphogenic callus by TDZ and regeneration of morphologically normal, fertile peanut plants after 8 months of callus subculture.     

NaCl and TDZ are Two Key Factors for the Improvement of In Vitro Regeneration Rate of Salicornia europaea L.

The present study aimed to find out suitable conditions for the In vitro culture of Sallcornla europaea L. and to develop an efficient regeneration system. S. europaea plants were regenerated successfully In vitro from callus derived from mature embryos. Via the method of 2,4-dlchlorophenoxyacetlc acid （2,4-D）-short-treatment on mature seeds, callus was Induced from hypocotyls on the MS medium with 4.55 μmol/L N-phenyl-N＇-1, 2, 3-thladlazol-5-yl urea （TDZ） 3-4 weeks after the seeds germinated. The callus differentiated Into shoots at a rate of 27.6% after subculture for one time on the same medium. When NaCl was Included In the medium, shoots were formed In cluster and the shoot differentiation frequency was Increased to 55.2%. The shoots were rooted when cultured on 1/2 MS medium supplemented with Indole-3-butyric acid （IBA）, kinetin （KN） end activated charcoal （AC）. The results Indicated that NeCl and TDZ played an Important role In the Improvement of the regeneration rate of the halophyte, S. europaea.     

Rapid micropropagation of <Emphasis Type="Italic">Ocimum basilicum</Emphasis> using shoot tip explants pre-cultured in thidiazuron supplemented liquid medium

An efficient protocol has been developed for rapid micropropagation of Ocimum basilicum. Multiple shoots were induced by culturing shoot tip explants excised from mature plants on a liquid Murashige and Skoog (MS) medium supplemented with 5–100 μM of thidiazuron (TDZ) for different treatment duration (4, 8, 12 and 16 d). The optimal level of TDZ supplementation to the culture medium was 50 μM for 8 d induction period followed by subculturing in MS medium devoid of TDZ as it produced maximum regeneration frequency (78 %), mean number of shoots (11.6 ± 1.16) and shoot length (4.8 ± 0.43 cm) per explant. A culture period longer than 8 d with TDZ resulted in the formation of fasciated or distorted shoots. The regenerated shoots rooted best on MS medium containing 1.0 μM indole-3-butyric acid (IBA). The micropropagated shoots with well developed roots were successfully established in pots containing garden soil and grown in greenhouse with 95 % survival rate. The regenerated plants were morphologically uniform and exhibited similar growth characteristics and vegetative morphology to the donor plants.     

Effect of Agar, MS Medium Strength, Sucrose and Polyamines on in vitro Rooting of Syzygium Alternifolium

This paper describes the effect of agar, MS basal medium strength, sucrose and polyamines on the in vitro rooting of Syzygium alternifolium realized by a two step procedure involving root initiation (RI) and root elongation (RE). RI was carried out on solidified MS medium supplemented with 1.0 mg dm⁻³ indole-3-butyric acid (IBA) for 3 weeks, and RE following transfer to half-strength MS medium devoid of growth regulators for another 3 weeks. Agar and MS basal medium concentrations played important role on rooting response as well as on health of rooted shoots. Sucrose concentration was positively correlated with the rooting percentage, root number per shoot and root length. The combination of polyamines and 1.0 mg dm⁻³ IBA increases rooting percentage compared to media containing only 1.0 mg dm⁻³ IBA. Optimum rooting was attained with half-strength MS medium containing 1.0 mg dm⁻³ IBA, 2 % sucrose, 10 μM spermine and 0.8 % agar. This revised version was published online in June 2006 with corrections to the Cover Date.     

Embryogenic callus formation,growth and regeneration in callus and suspension cultures of Miscanthus x ogiformis Honda Giganteus' as affected by proline

The effects of proline additions to culture systems of Miscanthus x ogiformis Honda Giganteus' were investigated. Proline was added in concentrations of 0, 12.5, 25, 50, 100 or 300 mM to the callus induction and suspension culture media containing either Murashige and Skoog or N6 basal salts and 22.6 μM 2,4-dichlorophenoxyacetic acid. Shoot apices and leaves from in vitro-propagated shoots, and immature inflorescences from greenhouse-grown plants were used as explants for callus induction and formation. Suspension cultures initiated from embryogenic callus of immature inflorescences were used to test the effect of proline in suspension cultures. The proline additions affected the formation of embryogenic callus and the growth of suspension cultures. Improvements depended on the proline concentration and the basal salts of the medium. Addition of 12.5 to 50 mM proline to callus induction medium with Murashige and Skoog salts increased embryogenic callus formation on shoot apices and leaf explants while proline had no effect on embryogenic callus formation in medium with N6 salts. Increased growth with increasing proline concentration was obtained in suspension aggregates grown in medium with N6 salts, whereas proline only increased growth of suspension aggregates grown in medium with Murashige and Skoog salts at concentrations of 12.5 or 25 mM. A stimulating effect of proline on plant regeneration was observed in short-term cultures of callus as well as in long-term cultures of suspension aggregates. An optimum proline concentration for plant regeneration was found at 12.5 mM. This revised version was published online in June 2006 with corrections to the Cover Date.     

TDZ induces shoot regeneration in various Kalanchoë blossfeldiana Poelln. cultivars in the absence of auxin

In order to optimize shoot regeneration in Kalancho? blossfeldiana, leaf and internode explants of seven cultivars including one inter-specific were studied. The effects of various combinations of α-naphthalene acetic acid (NAA) (0, 0.57 M) and thidiazuron (TDZ) (0, 0.45, 4.5, 22.5, 67.5 μM) on MS medium were examined. In all cultivars shoot regeneration frequency and number of shoots per explant were enhanced by increasing TDZ concentration. Supplementing the media with NAA did not improve shoot regeneration. Maximum regeneration frequency and optimum concentration of TDZ for shoot regeneration depended significantly on the cultivar. Internode explants, but not leaf explants, of some cultivars, were able to produce adventitious shoots without treatment with growth regulator.     

Somatic embryogenesis and shoot proliferation of Mussaenda cultivars

Midrib sections of Mussaenda 'Queen Sirikit', 'Do?a Luz', and 'Do?a Hilaria' were cultured on Murashige and Skoog medium (MS) supplemented with 87.7 mM sucrose, 5 g agar l⁻¹, 0, 5, 10 or 20 μM indole-3-acetic acid (IAA) and 0, 0.5, 1, 2.5, 5, 10, 25 or 50 μM 6-benzyladenine (BA). In addition, aseptic 5 mm shoot tips from 'Do?a Luz' cultures were excised and cultured on MS basal salts, 0.6 mM myo-inositol, 1.2 μM thiamine-HCl, 87.7 mM sucrose, 7 g agar l⁻¹, 0, 2.5, 5, 10, 20, or 40 μM BA, 0 or 1 μM α-naphthaleneacetic acid (NAA) and 0 or 217 μM adenine sulfate at pH 5.8. Calluses began to develop after two weeks at the cut ends of midribs when cultured on a medium containing IAA. Somatic embryos first appeared at eight weeks but only on 'Queen Sirikit' callus. After 15 weeks, the average number of somatic embryos produced per tube decreased as the IAA concentration increased from 0 to 20 μM. BA concentrations between 5.0 and 10.0 μM resulted in the largest number of somatic embryos per tube. After six weeks, the total, axillary and adventitious number of 'Do?a Luz' shoots increased as the BA concentration in the culture medium increased from 0 to 20 μM. Average shoot length and fresh weight decreased from 0 to 40 μM BA. The addition of NAA to the culture medium reduced shoot number. Adenine sulfate in the presence of BA reduced the total number of shoots. An ideal medium for proliferating the largest number of 'Do?a Luz' shoots would be a MS medium supplemented with 10–20 μM BA. This revised version was published online in June 2006 with corrections to the Cover Date.     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism