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1.
In vitro propagation of northern red oak (Quercus rubra) shoots was successful from cotyledonary node explants excised from 8-wk-old in vitro grown seedlings. Initially, four shoots per explant were obtained on Murashige and Skoog (MS) medium supplemented with 4.4 μM
6-benzylaminopurine (BA), 0.45 μM thidiazuron (TDZ), and 500 mg l−1 casein hydrolysate (CH) with a regeneration frequency of 64.7% after 3 wk. Subculturing explants (after harvesting shoots)
to fresh treatment medium significantly increased shoot bud regeneration (16.6 buds per explant), but the buds failed to develop
into shoots. A higher percentage (73.3%) of the explants regenerated four shoots per explant on woody plant medium (WPM) supplemented
with 4.4 μM BA, 0.29 μM gibberellic acid (GA3), and 500 mg l−1 CH after 3 wk. Explants subcultured to fresh treatment medium after harvesting shoots significantly increased shoot regeneration
(16 shoots per explant). Shoot elongation was achieved (4 cm) when shoots were excised and cultured on WPM supplemented with
0.44 μM BA and 0.29 μM GA3. In vitro regenerated shoots were rooted on WPM supplemented with 4.9 μM indole-3-butyric acid. A higher percentage regeneration response
and shoot numbers per explant were recorded on WPM supplemented with BA and GA3, than on MS medium containing BA and TDZ. Lower concentrations of BA and GA3 were required for shoot elongation and prevention of shoot tip necrosis. Each cotyledonary node yielded approximately 20
shoots within 12 wk. Rooted plantlets were successfully acclimatized. 相似文献
2.
Kaitlin J. Palla Paula M. Pijut 《In vitro cellular & developmental biology. Plant》2011,47(2):250-256
A plant regeneration protocol was developed for white ash (Fraxinus americana L.). Hypocotyls and cotyledons excised from embryos were cultured on Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine
(BA) plus thidiazuron (TDZ), and compared for organogenic potential. Sixty-six percent of hypocotyl segments and 10.4% of
cotyledon segments produced adventitious shoots, with a mean number of adventitious shoots per explant of 3.5 ± 0.9 and 2.5 ± 1.5,
respectively. The best regeneration medium (52% shoot formation; 47% shoot elongation) for hypocotyls was MS basal medium
containing 22.2 μM BA plus 0.5 μM TDZ, producing a mean of 3.9 ± 0.4 adventitious shoots. Adventitious shoots were established
as proliferating shoot cultures following transfer to MS medium with Gamborg B5 vitamins supplemented with 10 μM BA plus 10 μM
TDZ. For in vitro rooting, woody plant medium with indole-3-acetic acid (IAA) at 0, 2.9, 5.7, or 8.6 μM in combination with 4.9 μM indole-3-butyric
acid (IBA) was tested for a 5- or 10-d dark culture period, followed by culture under a 16-h photoperiod. The best rooting
(78% to 81%) of in vitro shoots was obtained with a 5 d dark culture treatment on medium containing 2.9 or 5.7 μM IAA plus 4.9 μM IBA, with an average
of 2.6 ± 0.4 roots per shoot. Rooted plants were successfully acclimatized to the greenhouse. This adventitious shoot regeneration
and rooting protocol will be used as the basis for experimental studies to produce transgenic white ash with resistance to
the emerald ash borer. 相似文献
3.
Plantlet regeneration through shoot formation from young leaf explant-derived callus of Camptotheca acuminata is described. Calli were obtained by placing leaf explants on Woody plant medium (WPM) supplemented with various concentrations
of 6-benzyladenine (BA) and naphthaleneacetic acid (NAA) or 2,4-dichlorophenoxyacetic acid (2,4-D). Callus induction was observed
in all media evaluated. On the shoot induction medium, the callus induced on the WPM medium containing 19.8 μM BA and 5.8
μM NAA was the most effective, providing high shoot regeneration frequency (70.3 %) as well as the highest number of shoots
(11.2 shoots explant−1). The good rooting percentage and root quality (98 %, 5.9 roots shoot−1) were achieved on WPM medium supplemented with 9.6 μM indole-3-butyric acid (IBA). 96 % of the in vitro rooted plantlets with well developed shoots and roots survived transfer to soil. 相似文献
4.
L. Buendía-González J. Orozco-Villafuerte F. Cruz-Sosa V. M. Chávez-Ávila E. J. Vernon-Carter 《In vitro cellular & developmental biology. Plant》2007,43(3):260-266
Plantlet regeneration in Prosopis laevigata (Humb. & Bonpl. ex Willd.) Johnston (Fabaceae), a multipurpose tree, has been achieved from cotyledonary nodes excised from
in vitro grown seedlings. The explants were cultured on MS media containing different concentrations of N-6 benzyladenine (BA) and
2,4-dichlorophenoxyacetic acid (2,4-d) and a mixture of organic components. The highest number (3.37 + 0.51) of multiple shoots was observed in MS media containing
2,4-d (9.05 μM) + BA (6.62 μM). The regenerated shoots were then transferred onto half-strength MS medium containing a plant growth
regulator that was either: indole-3-butyric acid, 1-naphthaleneacetic, indole-3-acetic acid, or 2,4-d as well as phytagel or vermiculite for adventitious root initiation. Best rooting efficiency of 44.0% was obtained when NAA
(16.11 μM) and vermiculite were used. After rooting, the cloned plantlets were successfully hardened to ex vitro conditions. This work may help to reduce the devastation caused by the overexploitation of this species. 相似文献
5.
María del Socorro Santos Díaz Candy Carranza Álvarez 《In vitro cellular & developmental biology. Plant》2009,45(2):162-170
Two procedures for the in vitro propagation of Encyclia mariae, a threatened Mexican orchid, were developed. In the first procedure, leaves from in vitro germinated seedlings were cultured on Murashige and Skoog medium (MS) supplemented with the range of 2.21–4.4 μM 6-benzylaminopurine
(BA) in combination with 2.69–10.74 μM naphthalene acetic (NAA), 2.07–8.29 μM indole-3-butyric (IBA), or 2.85–11.42 μM indole-3-acetic
acid (IAA) to determine the best medium for the induction of shooting. Maximum direct shoot formation from leaves was observed
on MS containing 22.21 μM BA and 10.74 μM NAA (25 shoots/explant). The second procedure began with the culture of protocorms
on media containing NAA, IBA, or IAA, which induced callus formation with high regenerative potential in the form of protocorm-like-bodies
(PLBs) that eventually differentiated into shoots. The optimal response was attained when these structures were cultured on
medium with 4.14 μM IBA (30 shoots/PLB). To promote the elongation of shoots derived from PLBs, the material was subcultured
onto MS medium containing 22.21 μM BA and 5.37 μM NAA. Through the exploration of the effects of auxins and matrix on the
rooting of shoots, it was determined that the optimal rooting occurred on media supplemented either with 5.71 μM IAA or 4.14 μM
IBA either on agar-gelled medium or in liquid media with coir as the matrix. Rooting was found to be 20% higher in liquid
media than in agar-gelled medium. 相似文献
6.
Seabuckthorn (Hippophae rhamnoides) is a multipurpose small tree with unique berries of high nutritional and pharmaceutical values. A clonally propagated plant
originating from a 20-year-old tree of H. r. rhamnoides × mongolica hybrid cultivar Julia and seedling offspring of this cultivar were investigated regarding induction of shoot organogenesis
in leaf explants and in roots of intact seedlings, and induction of direct somatic embryogenesis in explants from shoot tissue.
The highest percentage of leaf explants showing shoot organogenesis was achieved (juvenile explants, 65%; adult explants,
75%) when incubated in Murashige and Skoog (MS) medium supplemented with either 4.5 μM of the phenylurea cytokinin thidiazuron
(TDZ) or 2.25 μM TDZ plus 2.2 μM 6-benzyladenine (BA), for juvenile and adult explants, respectively, both supplemented with
0.53 μM α-naphthaleneacetic acid (NAA). Juvenile explants developed on average 18 shoots per explant in the MS medium supplemented
with 4.5 μM TDZ, a four fold increase over those incubated on the medium supplemented with 2.25 μM TDZ and 2.2 μM BA. Adult
leaf explants grown on medium containing 2.25 μM TDZ and 2.2 μM BA medium produced 12 shoots per explant, while those grown
on medium containing 4.5 μM TDZ produced 5 shoots per explant. Shoot organogenesis was observed in roots of intact seedlings
pre-cultured on plain medium lacking nutrients (PM) or woody plant medium (WPM) salts and then grown on WPM salts supplemented
with 4.4 μM BA, 0.29 μM gibberrelic acid (GA3), and 57.0 μM indoleacetic acid (IAA). The number of shoots formed on each seedling
root system was ten fold higher when the pre-culture was in WPM medium indicating a promoting effect of mineral nutrients
in the pre-culture medium. Somatic embryogenesis was induced in both juvenile and adult leaf explants in 65 and 78% of the
explants, respectively, in MS-based medium supplemented with 2.0 μM N-(2-Chloro-4-pyridyl)-N
1-phenylurea (CPPU), 0.53 μM NAA and varying concentrations of BA. There was an interaction effect between MS salt strength
and BA concentration. The most effective medium for inducing somatic embryogenesis in juvenile explants contained half strength
MS salts and 2.2 μM BA and full strength MS salts and 13.2 μM BA for adult explants. 相似文献
7.
When cotyledonary explants, excised from in vitro germinated seedlings, of pomegranate (Punica granatum L.) were incubated on solid Murashige and Skoog (1962) medium supplemented with 21 μM naptheleneacetic acid (NAA) and 9 μM 6-benzyladenine (BA), 80% of explants developed callus.
A high frequency of shoot organogensis was obtained when explants were incubated on MS medium supplemented with 8 μM BA, 6 μM
NAA, and 6 μM giberrellic acid (GA3). However, adding 24 μM silver nitrate (AgNO3) to this medium markedly enhanced shoot regeneration frequency (63%) and mean number of shoots per explant (11.26) and length
of shoots (2.22 cm). Highest frequency of in vitro rooting, mean number of roots/shoot (4.32), and mean root length (2.71 cm)
were obtained when regenerated shoots were transferred to half-strength MS medium supplemented with 0.02% activated charcoal.
Well-rooted plantlets were acclimatized, and then transferred to soil medium. Moreover, when zygotic embryos of P. granatum, excised from seeds collected at 16 weeks following full bloom, were incubated on MS medium containing 30 g l−1 sucrose, 15% coconut water, 21 μM NAA, and 9 μM BA, they developed the highest frequency of embryogenic callus, clumps with
globular embryos, and mean number of both globular and heart-shaped embryos per callus clump. Subjecting zygotic embryo explants
to six-week dark incubation period was essential for embryogenic callus induction, and these were subsequently transferred
to 16 h photoperiod for further growth and development of somatic embryos. Germination of somatic embryos was observed when
these were transferred to MS medium was supplemented with 60 g l−1 sucrose. 相似文献
8.
Nodular callus was induced at a high frequency on young purple red, 5–15 mm long laminae taken from in vitro grown plants of mangosteen. The optimal medium was composed of Murashige and Skoog (MS) nutrients supplemented with 2.22
μM benzyladenine (BA), 2.25 μM thidiazuron (TDZ), 500 mg l-1 polyvinylpyrrolidone (PVP 360 000) and 3% sucrose. A multiplication rate of two–three was obtained by subculture of the nodular
callus at 3–4-week intervals. Plantlet regeneration from the nodules was achieved by transfer to woody plant medium (WPM)
with 500 mg l-1 PVP, 0.4 μM BA and 3% sucrose and overlaying with half strength liquid MS containing 0.32 μM naphthaleneacetic acid (NAA),
0.13 μM BA and 3% sucrose. Elongated shoots were rooted to 100% when wounded at the base of shoot, dipped in 4.4 mM indolebutyric
acid (IBA) solution in the dark for 15 min and cultured on WPM supplemented with 1.11 μM BA, 0.25% activated charcoal, 34.5
μM phloroglucinol (PG) and 3% sucrose.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
9.
A. V. Raghu S. P. Geetha Gerald Martin Indira Balachandran P. N. Ravindran 《In vitro cellular & developmental biology. Plant》2006,42(6):584-588
Summary A protocol was developed for rapid clonal propagation of the important medicinal climber, Tinospora cordifolia, through in vitro culture of mature nodal explants. Shoots were initiated on both Murashige and Skoog (MS) medium and woody plant medium (WPM)
supplemented with 2.32 μM kinetin (KIN). Of the two basal media tested, WPM was found to be superior to MS medium for the induction of multiple shoots.
Among the cytokinins tested, N6-benzyladenine (BA) was more effective than KIN for axillary shoot proliferation. KIN was superior to BA in terms of shoot
elongation. An average multiplication rate of 6.3 shoots per explant was obtained with WPM supplemented with 8.87 μM BA. Shoot clumps harvested from this medium were transferred to WPM supplemented with 2.22 μM BA and 4.65 μM KIN for shoot elongation. Elongated shoots were rooted in half-strength MS medium supplemented with 2.85 μM indole-3-acetic acid (IAA). Rooted plantlets were successfully transferred to sand and established with 80% survival. 相似文献
10.
Sclerocarya birrea (marula) is an indigenous South African tree with highly valued medicinal and nutritional properties. Induction of nodular
meristemoids from leaf explants was achieved on Murashige and Skoog (MS) and woody plant medium (WPM) supplemented with 6-benzyladenine
(BA) in combination with naphthalene acetic acid (NAA), indole-3-butryric acid (IBA) and indole-3-acetic acid (IAA). Induction
of nodular meristemoids from 86% of the leaf cultures was achieved on MS medium with 4.0 μM BA and 1.0 μM NAA. High levels
(78–100%) of induction were also achieved on WPM with different concentrations of BA (1.0–4.0 μM) and IBA (1.0–4.0 μM). The
highest conversion of meristemoids into shoots was only 22% for 4.0 μM BA and 1.0 μM NAA on MS initiation medium. This was
improved to 62% when nodular clusters were cultured in a MS liquid medium. Histological studies revealed the globular stage
of the nodular meristemoids. This protocol has potential for application in mass micropropagation and plant breeding of S. birrea. 相似文献
11.
Mehmet Nuri Nas Leyla Gokbunar Nevzat Sevgin Murat Aydemir Merve Dagli Zahide Susluoglu 《Plant Growth Regulation》2012,67(1):57-63
The effects of culture media and cytokinin types on micropropagation of mature Crataegus aronia L. were investigated. Using single-axillary bud explants, the growth of cultures on MS, WPM, DKW and NRM containing 4.44 μM
benzyladenine (BA) plus 0.05 μM indole-3-butyric acid (IBA), and on NRM containing thidiazuron, meta-Topolin (mT) or BA at
1.25, 2.5, 5.0 or 7.5 μM plus 0.05 μM IBA were compared. The culture medium had significant effects on shoot number and length.
In comparison with MS, DKW and WPM, shoot production was greater on NRM (5.7 shoots per explant). Shoot production on MS,
DKW and WPM (4.2, 4.2 and 4.1, respectively) were statistically similar to each other. Thidiazuron was detrimental to shoot
formation and caused formation of rosette shoots and/or large callus to form on explants. In the presence of mT, only some
of the explants developed into shoots. Benzyladenine was the only cytokinin that promoted both shoot proliferation and shoot
elongation. Higher shoot numbers were obtained at 5.0 and 7.5 μM BA compared to lower concentrations of BA. Over 80% of microshoots
rooted and rooted shoots were successfully acclimatized to ex vitro conditions. 相似文献
12.
P. Jha C. B. Yadav V. Anjaiah V. Bhat 《In vitro cellular & developmental biology. Plant》2009,45(2):145-154
An efficient in vitro plant regeneration protocol through somatic embryogenesis and direct shoot organogenesis has been developed for pearl millet
(Pennisetum glaucum). Efficient plant regeneration is a prerequisite for a complete genetic transformation protocol. Shoot tips, immature inflorescences,
and seeds of two genotypes (843B and 7042-DMR) of pearl millet formed callus when cultured on Murashige and Skoog (MS) medium
supplemented with varying levels of 2,4-dichlorophenoxyacetic acid (2,4-D; 4.5, 9, 13.5, and 18 μM). The level of 2,4-D, the
type of explant, and the genotype significantly effected callus induction. Calli from each of the three explant types developed
somatic embryos on MS medium containing 2.22 μM 6-benzyladenine (BA) and either 1.13, 2.25, or 4.5 μM of 2,4-D. Somatic embryos
developed from all three explants and generated shoots on MS medium containing high levels of BA (4.4, 8.8, or 13.2 μM) combined
with 0.56 μM 2,4-D. The calli from the immature inflorescences exhibited the highest percentage of somatic embryogenesis and
shoot regeneration. Moreover, these calli yielded the maximum number of differentiated shoots per callus. An efficient and
direct shoot organogenesis protocol, without a visible, intervening callus stage, was successfully developed from shoot tip
explants of both genotypes of pearl millet. Multiple shoots were induced on MS medium containing either BA or kinetin (4.4,
8.8, 17.6, or 26.4 μM). The number of shoots formed per shoot tip was significantly influenced by the level of cytokinin (BA/kinetin)
and genotype. Maximum rooting was induced in 1/2 strength MS with 0.8% activated charcoal. The regenerated plants were transferred
to soil in pots, where they exhibited normal growth. 相似文献
13.
Summary Shoots by direct and indirect organogenesis and somatic embryos were induced from tubercles excised from Ariocarpus kotschoubeyanus seeds germinated in vitro. Shoot formation was greatest (6.3 per explant) when explants were cultured on Murashige and Skoog (MS) medium supplemented
with 6-benzylaminopurine (BA; 13.3 μM) and α-naphthaleneacetic acid (NAA; 5.4 μM). Individualized shoots were rooted in half-strength MS; the addition of activated charcoal (1 g l−1) and the use of sun cap closures to seal containers improved the rooting of shoots. Nearly 20% of the explants produced somatic
embryos on media containing combinations of BA (8.9–22.2 μM) and NAA (0.5–5.4 μM). The establishment of plantlets in soil presented no significant problems. In vitro culture is a useful option for mass propagation of A. kotschoubeyanus and contributes to its conservation. 相似文献
14.
Xiaojiao Han Hongqiang Yang Kaixuan Duan Xinrong Zhang Haizhou Zhao Shuzhen You Qianqian Jiang 《Plant Cell, Tissue and Organ Culture》2009,96(1):29-34
The effects of sodium nitroprusside (SNP) on the multiplication, regeneration and rooting of Malus
hupehensis Rehd. var. pinyiensis Jiang in tissue culture have been investigated. The results showed that the multiplication of plantlets was promoted significantly
by applying 20 μM SNP to the Murashige and Skoog (MS) medium containing 2.0 μM 6-benzylaminopurine (BA) and 1.0 μM zeatin
(ZT). Multiplication of plantlets from the 1st subculture was more sensitive to SNP than that from the 4th or 7th subculture.
The differentiation and regeneration of adventitious shoots from leaves or cotyledons increased significantly when 20–30 μM
SNP was supplied to the medium MS containing 25 μM BA, 2.5 μM α-naphthaleneacetic acid (NAA) and 2.5 μM ZT. Adventitious shoots regeneration frequency from cotyledons was higher than that
from leaves at the presence of SNP. The rooting of plantlets was promoted by SNP significantly and the best result for rooting
was achieved in the half-strength MS medium containing 75 μM SNP. In addition, adventitious roots without callus distributed
at the base of shoots when SNP was supplied. 相似文献
15.
Micropropagation has been achieved in a promising larvicidal asteraceous taxon Spilanthes acmella L. using seedling leaf explants. The explants were reared on a variety of growth regulators, namely 2,4-dichlorophenoxyacetic
acid, 1-naphthalene acetic acid, Indole-3-butyric acid, N6-benzyladenine, and kinetin either alone or in combination on Murashige and Skoog’s (MS) medium. The best green and compact
callus was obtained on 1 μM NAA and 10 μM benzyladenine (BA) in 15 d. The callus on subculture to the same but fresh medium
after every 30 d differentiated an average of 12.90 ± 0.32 shoot buds in 50% cultures. Elongation in shoot buds occurred only
if they were transferred to NAA lacking MS+BA medium. An average number of 4.22 ± 0.83 shoots and 15 ± 0.84 shoot buds per
explant were obtained in 70.3% cultures on MS + 10 μM BA in 30 d. One hundred percent excised shoots rooted in MS(1/2) + 0.1 μM
IBA within 2 wk. The plants were gradually hardened and established in soil where they flowered and set viable seeds. The
regenerated plants were morphologically similar to the field grown plants and showed 100% larvicidal activity against malaria
and filarial vectors. 相似文献
16.
A protocol for plant regeneration from mesophyll and callus protoplasts of Robinia pseudoacacia L. was developed. For leaves from in vitro raised shoots, an enzyme combination of 2.0% cellulose and 0.3% macerozyme for
a digestion period of 20 h resulted in the best yield of protoplasts (9.45 × 105 protoplast/g fresh weight). Mesophyll-derived protoplasts started cell wall regeneration within 24 h of being embedded in
Nagata and Takebe (NT) medium supplemented with 5 μM NAA and 1 μM BAP followed by the first cell division on day three of
culture and micro-colony (32 cells) formation within day 7–10 in the same medium. However, using callus as the starting material,
a combination of 2.0% cellulose and 1.0% macerozyme for a digestion period of 24 h gave the highest protoplast yield (3.2 × 105 protoplast/g fresh weight). Cell wall regeneration in callus-derived protoplasts started within 24 h followed by the first
cell division on the day three (96 h) and the appearance of microcolonies of more than 32 cells by the end of first week (144 h)
of culture on solid WPM medium supplemented with 5 μM NAA and 1 μM BAP. Microcalli were visible to the naked eye after 45 days
on solid WPM medium. Proliferation of macro-calli was successfully accomplished on solid Murashige and Skoog (MS) medium with
5 μM NAA and 5 μM BAP. Both mesophyll and callus protoplast-derived calli produced shoots on MS medium with 0.5 μM NAA and
1 μM BAP within 25–30 days and multiplied on MS medium with 1.25 μM BAP. Excised microshoots were dipped in 1–2 ml of 2.0 μM
IBA for 24 h under dark aseptic conditions and transferred to double sterilized sand for rooting. The flasks containing sand
were inoculated with Rhizobium for in vitro nodulation. Forty-five plants transferred to pots in the glasshouse established well. 相似文献
17.
M. A. K. Azad S. Yokota F. Begum N. Yoshizawa 《In vitro cellular & developmental biology. Plant》2009,45(4):441-449
Somatic embryogenesis and subsequent plant regeneration were established from hypocotyl and internode explants collected from
in vitro-grown seedlings and in vitro-proliferated shoots, respectively. Somatic embryogenesis was significantly influenced by the types of auxin and cytokinin.
Friable calluses with somatic embryos developed well in Murashige and Skoog basal (MS) medium supplemented with 0.8–8.8 μM
6-benzylaminopurine (BA) and 2.0–8.0 μM 2,4-dichlorophexoxyacetic acid (2,4-D) or α-naphthaleneacetic acid (NAA). The maximal
frequency of embryogenic callus and somatic embryo formation were obtained when the MS medium was amended with 8.8 μM BA and
4.0 μM 2,4-D. The best embryo germination occurred in a hormone-free 1/2-MS medium. The highest percentage of shoot proliferation
was observed in embryogenic calluses in MS medium containing 2.0 μM BA and 1.0 μM NAA. In vitro-grown shoots were rooted in MS medium with 0.5–2.0 μM indole-3-butyric acid. Regenerants were transferred to vermiculite and
successfully established under an ex vitro environment in garden soil. 相似文献
18.
Branka Vinterhalter Dijana Krstić Milošević Teodora Janković Jelena Milojević Dragan Vinterhalter 《Central European Journal of Biology》2012,7(4):690-697
Gentiana dinarica Beck, rare and endangered species of Balkan Dinaric alps, was in vitro propagated (micropropagated) from axillary buds of plants collected at Mt. Tara, Serbia. G. dinarica preferred MS to WPM medium, with optimal shoot multiplication on MS medium with 3% sucrose, 1.0 mg l−1 BA and 0.1 mg l−1 NAA. Rooting was not clearly separated from shoot multiplication since BA did not completely inhibit root initiation. Spontaneous
rooting on plant growth regulator-free medium occurred in some 30% of shoot explants. Rooting was stimulated mostly by decreased
mineral salt nutrition and a medium with 0.5 MS salts, 2% sucrose and 0.5–1.0 mg l−1 IBA was considered to be optimal for rooting. Rooted plantlets were successfully acclimated and further cultured in peat-based
substrate. 相似文献
19.
Cultures of seven Daphne species: Daphne caucasica, D. cneorum, D. giraldii, D. retusa, D. jasminea, D. laureola and D. tangutica were established in vitro on MS/WPM based media. Five of the species responded best on MS-based media (D. tangutica, D. laureola, D. caucasica, D. retusa and D. giraldii), while the remaining two species performed best on WPM-based media (D. cneorum, and D. jasminea). Shoot proliferation was achieved from both apical and nodal explants. Shoots were sub-cultured from stock cultures, cut
into nodal explants 3–5 cm long and place vertically on basal media supplemented with different concentrations and combinations
of cytokinins and auxins. Individual species displayed different responses to the various cytokinins and auxins. Among species,
D. jasminea produced the greatest proliferation rate with an average of 7.84 + 0.6 shoots per explant on WPM supplemented with 2.32 μM
BA + 0.0045 μM TDZ + 0.054 μM NAA, while the best multiplication rate for the same species grown on the same media supplemented
with a single cytokinin (BA) and no auxin was 2.60 + 1.3 shoots per explant. Following multiplication, new shoots transferred
to the elongation trails and then 50–100 mm Shoots used for rooting experiments. Increased rooting efficiencies were observed
on in vitro-generated shoots with the two-layer medium or dipping methods over when PGRs were uniformly incorporated into
the medium. Maximum rooting frequencies (average) ranged from 59% in D. tangutica to 85% in D. jasminea. Following in vitro rooting, rooted shoots immersed in 0.01% solution of humates and planted into a standard horticultural
substrate composed and watered weekly with a solution containing half-strength MS salts. 相似文献
20.
An efficient in vitro regeneration system in kumquats (Fortunella crassifolia Swingle) was established. Explant types and orientations, concentrations and combinations of plant growth regulators were
evaluated for their influences on efficiency of plant regeneration. It was found that the optimum explant and its orientation
was epicotyl planted vertically with upper part upward, and a shoot regeneration frequency of 1.48 shoots per explant was
obtained on Murashige and Skoog (1962; MS) medium supplemented with 22.19 μM 6-benzyladenine (BA). A rooting percentage as
high as 74 % was obtained on 1/2 MS supplemented with 0.54 μM 1-naphthaleneacetic acid (NAA), 9.29 μM kinetin (KN), and 0.5
g dm−3 activated charcoal. 相似文献