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81.
Regeneration of de novo shoots, roots and flowers has been obtained on inflorescence explants of tomato (Lycopersicon esculentum Mill.). Indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and -naphthaleneacetic acid (NAA) were added in a 3×3×3 factorial combination with kinetin, each at 0.001, 0.1 and 10 M concentrations. Direct shoot formation occurred on media with 10 M kinetin and 0.001 M IAA or NAA. Root formation was observed on media with 0.1–10 M IAA, IBA or NAA. Flower formation occurred on elongated shoots with several leaves on media with 10 M IAA and 0.1 M kinetin. Shoot organogenesis was increased by substituting 10 M zeatin or N6-benzyladenine (BA) for kinetin. Eleven tomato cultivars were tested for their ability to undergo de novo shoot regeneration on the improved medium. All tomato cultivars were capable of shoot morphogenesis with a mean number of shoots per explant that ranged from 1.3 (Red Alert) to 5.3 (Large Red Cherry). Histological studies revealed that active cell divisions occurred in subepidermal and cambial tisue during the first week of culture. Meristematic centers of dividing cells were evident by day 14, and well-developed shoot apices and leaf structures were observed on 50% of the explants 28 days after culture initiation.Abbreviations BA
N6-benzyladenine
- IAA
Indole-3-acetic acid
- IBA
Indole-3-butyric acid
- 2iP
N6-[2-isopentyl]adenine
- NAA
-naphthaleneacetic acid
- PGR
plant growth regulator 相似文献
82.
The effect of leaf source and developmental stage on shoot organogenic potential of sweetgum (Liquidambar styraciflua L.) leaf explants 总被引:1,自引:1,他引:0
Leaf explants harvested from shoot proliferating cultures and intact plants of Liquidambar styraciflua Variegata were placed on solidified Woody Plant medium supplemented with 0.1 mgl-1 (0.5 M) naphthaleneacetic acid and 2.5 mgl-1 (11.1 M) benzyladenine to initiate shoot meristems directly. Leaves from intact plants produced over 4 times more adventitious shoots than leaves from in vitro shoots and had a greater tendency to form shoots on the lamina. The relative developmental age of leaf tissue used dramatically influenced the shoot organogenic response observed for leaf explants from intact plants of L. styraciflua Variegata and Moraine.-Leaves that were either 20% or 50% of full size and still actively expanding were superior to other developmental stages for shoot organogenesis. As developmental leaf age increased throughout the period of leaf expansion, the number of shoots forming on the petiole stub remained constant, whereas shoot formation on the lamina increased 8 fold. Shoots derived from Variegata leaves rooted well and grew normally as plants. Differences in rooting ability and plant size could be detected between groups that had been separated according to explant source (in vitro vs. intact plant) and the location of shoot formation (petiole vs. lamina). 相似文献
83.
Axillary buds were induced from immature shoot explants taken from terminal buds of branches from 29- and 34-year old ponderosa pines (Pinus ponderosa Dougl ex Laws). The effect of collection time, position on the donor tree from which the explants were taken, and plant growth regulators on axillary bud formation was investigated. Explants from branches taken in late October formed axillary buds, whereas explants from branches collected in February 1988 produced a large amount of callus. The ability to form axillary buds was significantly greater for explants from the upper crown than from the lower portion of the tree. Explant elongation occurred and basal needle primordia swelled on Murashige & Skoog media (MS) containing 2.2 M 6-benzyladenine (BA) and 5.4 M naphthalenacetic acid. When transferred to a MS medium containing 4.4 M BA, 59% of explants formed axillary buds. 相似文献
84.
Free- and bound-polyamine levels were estimated in successive segments of the mung-bean hypocotyl. Three aliphatic polyamines (putrescine, spermidine and spermine) were found in proportions which depended on the state of maturation. In young cells, most of the polyamines were located in the protoplasm whereas in older cells they were mostly bound to the cell walls. Spermidine was always the main bound polyamine, and putrescine, the main free polyamine.Abbreviation EDTA
ethylenediaminetetraacetic acid 相似文献
85.
用植物体内天然存在并具有很高活性的玉米素(t-Z)和异戊烯基腺苷(iPA)作为配基,分别与Sepharose-4B偶联,制成亲和吸附介质,分离、纯化菜豆(Phaseolus vulgaris)黄化幼苗下胚轴中的细胞分裂素结合蛋白。一种分子量为15.5 kD(简称ZBP),只含一个多肽链;另一种分子量为165 kD(简称IBP),含有两种亚基,分子量分别为43 kD和40 kD。对ZBP的结合活性进行了研究,发现ZBP与t-Z结合时的解离常数(Kd)为3.2×10- 7 m ol/L。经计算,每个ZBP分子只有一个t-Z结合位点 相似文献
86.
影响油菜子叶外植体不定芽高频率再生的因素 总被引:29,自引:0,他引:29
采用7个甘蓝型和2个白菜型油菜品种研究了影响子叶外植体芽再生的一些因素和不同基因型的子叶外植体的离子体培养反应和芽再生能力。结果表明,苗龄4d的幼苗叶子含2,4-D0.5-1.2mg/L和6-BA0.2mg/L的培养基培养2或6d后再转到分化培养基上培养,芽再生率34%-46%。 相似文献
87.
《Mechanisms of development》1998,70(1-2):15-24
Patterning events that occur before the mid-blastula transition (MBT) and that organize the spatial pattern of gene expression in the animal hemisphere have been analyzed in Xenopus embryos. We present evidence that genes that play a role in dorsoventral specification display different modes of activation. Using early blastomere explants (16–128-cell stage) cultured until gastrula stages, we demonstrate by RT-PCR analysis that the expression of goosecoid (gsc), wnt-8 and brachyury (bra) is dependent on mesoderm induction. In contrast, nodal-related 3 (nr3) and siamois (sia) are expressed in a manner that is independent of mesoderm induction, however their spatially correct activation does require cortical rotation. The pattern of sia and nr3 expression reveals that the animal half of the 16-cell embryo is already distinctly polarized along the dorsoventral axis as a result of rearrangement of the egg structure during cortical rotation. Similar to the antagonistic activity between the ventral and the dorsal mesoderm, the ventral animal blastomeres can attenuate the expression of nr3 and sia in dorsal animal blastomeres. Our data suggest that no Nieuwkoop center activity at the blastula stage is required for the activation of nr3 and sia in vivo. 相似文献
88.
Sandra Aparecida de Oliveira Maria de Ftima Pires da Silva Machado Alberto Jos Prioli Claudete Aparecida Mangolin 《In vitro cellular & developmental biology. Plant》1995,31(1):47-50
Summary
Cereus peruvianus seedlings were used as a source of stem explants to determine the effective conditions for inducing and maintaining callus
tissues in a state of rapid growth, as well as to obtain plants regenerated from callus cultures. Factorial combinations of
2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin in MS medium were tested, and we concluded that the 18.1µM 2,4-D and 18.6 or 27.9µM kinetin combinations were suitable for callus induction. The cactus shoots were produced from the friable callus; root elongation
occurred within 2 wk in medium without 2,4-D and with 18.6µM kinetin. This method can be used to rapidly produce manyC. peruvianus plants. 相似文献
89.
大西洋马铃薯是经济价值很高的炸片型加工品种,逆境胁迫下,易产生褐变、空心等问题,影响加工品质。为获取抗逆境胁迫的优质转基因新品种,采用根癌农杆菌介导法,以大西洋马铃薯的茎段为外植体,建立了快速,简便,高效的遗传转化体系。从共培养到转化植株获得只需7-8周,转化频率达80%。结果表明茎段是较好的转化受体,硫代硫酸银可以有效促进不定芽分化并提高再生频率。PCR、Southern杂交分析证明外源基因已经成功整合到马铃薯再生植株的基因组中。该转化体系为大量开发转基因马铃薯植株,进而筛选优质的马铃薯炸片加工型新品种奠定基础。 相似文献
90.
Vanilla planifolia is a tropical orchid mainly known for the aromatic flavor of its cured pods. Callus cultures were initiated from leaf and
nodal explants of V. planifolia. Leaf explants showed better callus initiation than the nodal explants with callus biomass production maximal when cultured
on Murashige and Skoog (MS) basal medium containing 4.52 mM 2,4-dichlorophenoxy acetic acid and 2.22 mM benzyladenine (BAP).
Callus transferred to MS basal medium supplemented with 13.32 μM BAP, and 13.43 μM naphthaleneacetic acid (NAA) showed superior
growth response and produced 14.0 ± 1.0 shoots with an average length of 3.6 ± 0.1 cm after 40 d. Subsequent transfer of the
proliferated shootlets to MS basal medium supplemented with 8.88 μM BAP and 8.08 μM NAA produced 12.3 ± 0.14 plantlets with
an average height of 3.6 cm ± 0.10 cm. All plantlets produced profuse rooting within 35–40 d after transfer to half-strength
MS basal medium supplemented with NAA in combination with indole-3-acetic acid. Rooted plantlets were transferred for hardening,
with 80% of the plantlets becoming successfully established in the field. Potentially, more than 100,000 plantlets could be
produced within eight subcultures from callus obtained from leaf explant through the methods described here. 相似文献