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1.
Ryoko Imaichi 《Journal of plant research》1982,95(4):435-453
The origins of the first and second petiolar buds ofHypolepis punctata were clarified in relation to the early development of the leaf primordium, which arises from a group of superficial cells
of the shoot apical meristem. One of these superficial cells produces a two-sided leaf apical cell which subsequently cuts
off segments to make a well-defined cell group, called here the leaf apical cell complex, on the distal part of the leaf primordium.
Meanwhile, cells surrounding the leaf apical cell complex also divide frequently to form the basal part of the leaf primordium.
Two groups of basal cells of the leaf primordium located on the abaxial and the adaxial sides initiate the first and the second
petiolar buds, respectively. The initial cells are usually contiguous to the leaf apical cell complex, constructing the abaxial
and adaxial flanks of the very young leaf primordium. However, the first petiolar bud sometimes develops from cells located
farther from the leaf apical cell complex. These cells are derived from those originally situated in the peripheral region
of the shoot apical meristem.
This study was supported by a Grant-in-Aid for Encouragement of Young Scientists by the Ministry of Education, Science and
Culture, of Japan No. 474322 in 1979. 相似文献
2.
The morphogenetic responses of cultured stem explants of Sesbaniarostrata Brem. from various positions along the stem axis wereanalysed after treatment with four growth regulators (BAP, NAA,kinetin, and GAJ. Internodal explants formed adventitious shootbuds when cultured on a Murashige and Skoog basal medium withoutadded growth regulators. Histological studies of regenerated shoot buds revealed thatapproximately 30% of the buds resulted from the conversion ofa preformed root primordium (characteristic of this species)into a shoot bud without a callogenesis phase. Each bud whichoriginated from a single root primordium grew into a leafy shoot.Preformed root primordia of stem explants of Sesbania rostratamay constitute an excellent model for physiological researchon plant differentiation. Key words: Organogenesis, adventitious bud, preformed root primordium, conversion, Sesbania rostrata 相似文献
3.
Ryoko Imaichi 《Journal of plant research》1983,96(3):159-170
The third petiolar bud ofHypolepis punctata appears on the basiscopic lateral side of the petiole above the fairly developed first petiolar bud. This investigation clarified
the fact that the third bud is formed neither by the activity of the meristem of the first bud nor by the meristem directly
detached from the shoot apical meristem, but is initiated in the cells involved in the abaxial basal part of the elevated
portion of the leaf primordium. Thus the third bud is of phyllogenous origin. This investigation further revealed that the
cells to initiate the third bud are originally located in the abaxial side of the leaf apical cell complex like the cells
to initiate the first bud, but are not incorporated into the meristem of the first.
After the first, second and third petiolar buds have been initiated, they are carried up into fairly high regions on the petiolar
base by the intercalary growth which occurs in the leaf base below the insertion level of the first and the second buds. 相似文献
4.
Kulkarni Anjali A. Thengane S.R. Krishnamurthy K.V. 《Plant Cell, Tissue and Organ Culture》2000,62(3):203-209
In vitro studies were initiated with Withania somnifera (L.) Dun. for rapid micropropagation of selected chemotypes using nodes, internodes, hypocotyls and embryo explants. Direct
regeneration of shoot buds was observed in MS basal medium supplemented with various concentrations of either benzyladenine
(BA) or thidiazouron (TDZ) depending on the explant. Nodal explants formed multiple shoots both from pre-existing and de novo buds on Murashige and Skoog's medium (MS) containing 0.1–5.0 mg l−1 BA and a ring of de novo shoot buds on MS medium containing 0.2 and 0.3 mg l−1 TDZ. Internodal explants formed shoot buds on MS with 1.0 and 5.0 mg l−1 BA while the hypocotyl explants gave rise to multiple shoots only on MS with 0.5 mg l−1 BA. Isolated embryos gave rise to many shoot buds on MS with 0.2 and 0.3 mg l−1 TDZ. The shoot buds elongated and rooted either on MS medium with 0.01 mg l−1 BA or on half strength MS medium lacking growth regulators, which depended upon the growth regulator used in the shoot bud
induction medium. Except for the embryo-derived plantlets, all other plantlets could be acclimatized with 100% success.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
5.
Lance C. Heath Shih-Foong Chin Donald Spencer Thomas J. V. Higgins 《Plant Cell, Tissue and Organ Culture》1993,35(1):43-48
Regeneration of subterranean clover (Trifolium subterraneum L.) was achieved by both shoot organogenesis and somatic embryogenesis. Shoots derived via organogenesis were initiated from the hypocotyls of mature imbibed seed. The hypocotyl, including the emerging radicle, was sliced longitudinally into two halves and cultured on shoot induction medium. After 30 days, adventitious shoots were formed from the hypocotyl region while the radicle showed no development. Shoots were then subcultured onto shoot multiplication medium and finally onto a root initiation medium. Histological studies revealed that shoots arose de novo and did not originate from pre-existing meristems. In the second regeneration protocol, shoot apical meristems from young seedlings were induced to form callus. Following four to six weeks culture in the dark, somatic embryos appeared spontaneously on the calli. A majority of embryos had a well-defined root pole, two cotyledonary lobes, and were capable of germination, albeit at a low frequency. Regenerated plants obtained from both protocols appeared phenotypically normal. 相似文献
6.
细枝木麻黄离体培养过程中愈伤组织和再生芽的细胞组织学观察 总被引:1,自引:0,他引:1
为探讨细枝木麻黄(Casuarina cunninghamianaMiq.)愈伤组织分化过程的细胞组织学,对离体培养条件下的愈伤组织进行扫描电子显微镜和石蜡切片观察,分析愈伤组织的细胞分裂、分化以及芽再生的发生过程。结果表明,新鲜外植体培养于愈伤组织诱导培养基上,伤口处的薄壁细胞开始脱分化,培养1周后形成明显的愈伤组织;继续培养2周后,胚性愈伤组织形成,且表层细胞启动分化形成芽原基;培养4周,可肉眼观察到胚性芽原基,数量增多并逐渐分化形成不定芽;培养至第6周,生成不定芽,并大量增殖和分化。因此,细枝木麻黄是通过愈伤组织分化形成胚状体的途径进行植株再生的,为建立细枝木麻黄组织培养高效再生体系提供了理论依据。 相似文献
7.
The development of axillary buds, terminal buds, and the shoots extended from them was studied inHydrangea macrophylla. The upper and lower parts in a nonflower-bearing shoot are discernible; the preformed part of a shoot develops into the
lower part and the neoformed part into the upper part (Zhou and Hare, 1988). These two part are formed by the different degrees
of internode elongation at early and late phases during a growth season, respectively. Leaf pairs in the neoformed part of
the shoot are initiated successively with a plastochron of 5–20 days after the bud burst in spring. The upper axillary buds
are initiated at approximately the same intervals as those of leaf pairs, but 10–30 days later than their subtending leaves.
Changes in numbers of leaf pairs and in lengths of successive axillary buds show a pattern similar to the changes in internode
lengths of the shoot at the mature stage. The uppermost axillary buds of the flower-bearing shoot often begin extending into
new lateral shoots when the flowering phase has ended. The secondary buds in terminal and lower axillary buds are initiated
and developed in succession during the late phase of the growth season. Internode elongation seems to be important in determining
the degrees of development of the axillary buds. Pattern of shoot elongation is suggested to be relatively primitive. Significances
of apical dominance and environmental conditions to shoot development are discussed. 相似文献
8.
Segments taken from flower-stalk internodes of Oncidium Sweet Sugar formed somatic embryos and shoot buds directly from wound surfaces or via nodular masses proliferation within
1.5 months, when cultured on a Gelrite-gelled 1/2-MS basal medium supplemented with thidiazuron (0.1–3 mg l−1) in darkness. In light, when subcultured, these nodular masses proliferated into green compact callus, and produced somatic
embryos, shoot buds and/or yellowish abnormal structures spontaneously. Supplementing 0.1–1 mg l−1 NAA enhanced embryo formation, but retarded proliferation of shoot buds and yellowish abnormal structures. Somatic embryos
that directly formed from wound surfaces of flower stalk explants usually developed into abnormal structures, but the callus-derived
embryos could germinate into PLBs and eventually developed to normal plantlets on a hormone-free basal medium for 3–4 weeks.
Both the embryo-and shoot bud-derived regenerants developed into healthly plantlets when potted in sphagnum moss and acclimatized
in the greenhouse.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
9.
The effect of copper sulphate on differentiation and elongation of shoot buds from cotyledonary explants of Capsicum annuum L. cv X-235 was investigated. Shoot buds were induced on medium supplemented with 22.2 μM BAP and 14.7 μM PAA. Elongation
of shoot buds was obtained on MS medium containing 13.3 μM BAP + 0.58 μM GA3. Both shoot induction and elongation media were supplemented with different levels of CuSO4 (0–5 μM). The levels of CuSO4 in the induction as well as elongation medium highly influenced the shoot bud formation and their subsequent elongation.
Highest number of shoot buds per explant was obtained when the concentration of CuSO4 was increased 30 times to the normal MS level. Shoot buds formation frequency i.e., the number of shoots formed per explant
was increased two fold as compared to those formed on control. Elongation both in terms of percentage and length of shoots
was better than that on control. Healthy elongated shoots were rooted on MS medium supplemented with 5.7 μM IAA. Rooted plantlets
were transferred to field conditions. 相似文献
10.
Summary A method for adventitious shoot induction from petiole explants of Heracleum candicans is reported. Shoot buds were induced on Murashige and Skoog (MS) medium with 4.4μM 6-benzylaminopurine (BA) and 1.1 μM 2,4-dichlorophen-oxyacetic acid (2,4-D). A wound response in the presence of BA and 2,4-D at the time of culture was necessary
for inducing shoot buds. The shoot bud regeneration was significantly influenced by size, type and orientation of explants
on the culture medium. These shoot buds developed into 4–5 cm shoots upon transfer to a medium containing 1.1μM BA and 0.5 μM α-naphthaleneacetic acid (NAA). The regenerated shoots formed rooted plantlets on MS medium supplemented with 4.9 μM indole-3-butyric acid (IBA). About 15 plants were established in the field for further evaluation. 相似文献
11.
Zhijian Li Robert L. Jarret Roy N. Pittman James W. Demski 《In vitro cellular & developmental biology. Plant》1994,30(4):187-191
Summary Thidiazuron (TDZ) was utilized to induce adventitious shoot formation from the hypocotyl region of cultured seed explants
of peanut (Arachis hypogaea L.). Excision of the radicle from seed explants was more stimulatory to shoot initiation than removal of the epicotyl alone.
Removal of both the radicle and the epicotyl from seeds resulted in a 37-fold increase in the frequency of shoot production
when compared to intact seeds. Half seed explants with epicotyl and radicle removed produced the greatest number of shoots
per explant. Explants from mature seeds were more responsive to TDZ than immature seed-derived explants. A 1-wk exposure to
10 μM TDZ was sufficient to stimulate the initiation of adventitious shoots that subsequently developed into plants. High frequency
of shoot initiation was readily induced in a variety of genotypes ofA. hypogaea and a wild peanut (A. glabrata). Plants regenerated from shoots induced by TDZ were phenotypically normal and fertile. 相似文献
12.
In vitro culture of hypocotyl explants from Kandelia candel, a common mangrove species, on hormone-free Murashige and Skoog (MS) medium resulted in shoot formation. Since the hypocotyls showed good potential for in vitro shoot multiplication, the process of bud primordium formation was analyzed from a histological viewpoint. A wound periderm first appeared at the top, exposed cut surface of the explants. The wound-induced meristem continued to divide giving rise to suberized cells oriented towards the cut surface. After formation of the suberized cell layers, the meristem and its inner derivatives differentiated into multilayered, uniformly packed parenchyma cells. Bud primordia differentiated from the dense cytoplasmic cells of the wound-induced meristem just beneath the suberized layer near the severed vascular bundles. Each explant produced several visible shoot buds. Furthermore, histological sections revealed that additional bud primordia were present within the explant just underneath the suberized cells and that these bud primordia appeared to be arrested in their development. The fact that additional bud primordia were present within the explant suggests that further manipulation of the explant is helpful to maximize the potential of this system. 相似文献
13.
Kallahally Sugnanachar Nagesh C. Shanthamma N. Bhagyalakshmi 《Acta Physiologiae Plantarum》2009,31(4):699-704
The occurrence of strong polarity towards shoot bud induction and the effect of cytokinin(s) on each segment of stem axis,
encapsulation and storability of de novo Shoot buds of Curculigo orchioides Gaertn. (Hypoxidaceae) have been documented in the present communication. Maximum number of shoot buds arising de novo from
the stem discs (cross section) explanted from proximal end on MS medium fortified with BAP and KIN 1 mg/L each. Stem discs
from distal end were less efficient in shoot bud induction. A combination of two cytokinins (BAP and KIN) as a synergistic
effect on shoot buds induction from each segment of stem axis. Stem discs in inverted position produced shoot buds from the
lower surface, showing strong polarity within the explant. Further, storability and shoot development of sodium alginate encapsulated
shoot buds of Curculigo orchioides were tested on half-strength Murashige and Skoog (MS) basal medium fortified with coconut water (10% v/v). The frequency
of regeneration from encapsulated shoot buds was affected significantly by concentration of sodium alginate and the duration
of exposure to calcium chloride. Shoot buds encapsulated with 2.5% sodium alginate dissolved in MS basal salts solution recorded
significantly higher shoot development than other treatments. A relatively short (5 min) incubation with calcium chloride
solution provided uniform encapsulation of shoot buds that gave the highest percentage (68%) of shoot development. Encapsulated
shoot buds could be stored at 4°C for 50 days without reduction in viability as oppose to non-encapsulated shoot buds, which
showed 9.5% viability after 20 days at 4°C. Encapsulated shoot bud developed into normal shoots. Based on the present observations
an improved protocol may be developed for the rapid multiplication and conservation of the endangered species—C. orchioides. 相似文献
14.
15.
Kaur R. Sood M. Chander S. Mahajan R. Kumar V. Sharma D.R. 《Plant Cell, Tissue and Organ Culture》1999,59(3):227-229
Valeriana jatamansi Jones is an important medicinal plant. This wild herb is being exploited for its roots and rhizomes which contain valepotriates,
which are highly effective against leprosy. The aim of this study was to establish a practical method for rapid and large-scale
multiplication of V. jatamansi by induction of shoot proliferation from shoot buds. The sterilized explants were established on solid medium supplemented
with benzyl adenine alone or in combination with indole-acetic acid or naphthalene acetic acid. The buds cultured on nutrient
medium supplemented with BA and IAA or NAA formed shoots, which after 3-4 weeks produced roots on the same medium. One hundred
per cent survival was obtained on hardening and field establishment of well rooted shoots.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
16.
Flowering stems are formed under long-day conditions on root explants of chicory (Cichorium intybus L.) cultured in vitro while under short days, only vegetative growth is observed. Under short-day conditions (12 h), stem elongation is induced by treating newly formed shoot apices with GA3 (1 l, 10–3M). No flower buds were formed on the GA3-induced stems. Long days seem to be indispensable for the induction of flower buds on the elongated stem. 相似文献
17.
The seedling development of an undescribed Malaccotristicha species was observed by using seedling culture and microtomy to infer the evolution of body plan with a focus on the root, which is a developmentally leading organ of most Podostemaceae. The young seedling has a small primary shoot apical meristem and a primary root apical meristem. The shoot meristem develops into a plumular ramulus, and the root meristem, into a cylindrical radicle with no root cap. The radicle transforms to a dorsiventral, flattened, capped primary root. An adventitious root develops endogenously on the lateral side of the hypocotyl and is similar to the primary root. This is a new pattern in Podostemaceae. Comparison of this and described patterns of Podostemaceae (and the sister-group Hypericaceae) suggests that the radicle was lost in the early evolution of Podostemaceae and instead adventitious roots replaced it as a leading organ. 相似文献
18.
SYMMETRY AND DEVELOPMENT OF BUTOMUS UMBELLATUS (BUTOMACEAE) AND LIMNOCHARIS FLAVA (LIMNOCHARITACEAE)
George J. Wilder 《American journal of botany》1974,61(4):379-394
The prostrate rhizome of Butomus umbellatus produces branch primordia of two sorts, inflorescence primordia and nonprecocious vegetative lateral buds. The inflorescence primordia form precociously by the bifurcation of the apical meristem of the rhizome, whereas the non-precocious vegetative buds are formed away from the apical meristem. The rhizome normally produces a branch in the axial of each foliage leaf. However, it is unclear whether the rhizome is a monopodial or a sympodial structure. Lateral buds are produced on the inflorescence of B. umbellatus either by the bifurcation or trifurcation of apical meristems. The inflorescence consists of monochasial units as well as units of greater complexity, and certain of the flower buds lack subtending bracts. The upright vegetative axis of Limnocharis flava has sympodial growth and produces evicted branch primordia solely by meristematic bifurcation. Only certain leaves of the axis are associated with evicted branch primordia and each such primordium gives rise to an inflorescence. The flowers of L. flava are borne in a cincinnus and, although the inflorescence is simpler than that of Butomus umbellatus, the two inflorescences appear to conform to a fundamental body plan. The ultimate bud on the inflorescence of Limnocharis flava always forms a vegetative shoot, and the inflorescence may also produce supernumerary vegetative buds. Butomus umbellatus and Limnocharis flava exhibit a high degree of mirror image symmetry. 相似文献
19.
Summary A number of cytokinins induce shoot buds on leaves obtained from embryonal tissue (diploid) or endosperm tissue (triploid) of Dendrophthoe falcata cultured in vitro. The buds develop either by division of an epidermal cell which finally is organized into a shoot meristem; or the epidermal cell first produces a callus which subsequently gives rise to shoot buds. Buds do not develop in the absence of cytokinins. Injury to the leaf plays a major role in the distribution and number of shoot buds formed. Normal leaves on the plant do not regenerate buds even in the presence of a cytokinin. 相似文献
20.
S. R. Thengane D. K. Kulkarni V. A. Shrikhande K. V. Krishnamurthy 《In vitro cellular & developmental biology. Plant》2001,37(2):206-210
Summary Regeneration of adventitious shoots from the medicinal plant Nothapodytes foetida (Weight) Sleumer Syn. Mappia foetida (family Ieacinaceceae) has been achieved using different seedling explants. Direct, regeneration of shoot buds was observed
in Murashige and Skoog's (MS) basal medium supplemented with various concentrations of thidiazuron. The optimum levels of
thidiazuron concentrations were 0.91–4.45 μM. Leaf explants formed more shoots followed by hypocotyls or cotyledons. The shoot buds elongated and rooted on MS basal medium
with N6-benzyladenine (0.88–2.22 μM) and indole-3-butyric acid (0.49 μM). 相似文献