Free radical scavenging activity from different extracts of leaves of Bauhinia vahlii Wight & Arn.

The objectives of this study were to determine phenolic content and antioxidant activities of chloroform, acetone, methanol and hot water extracts of Bauhinia vahlii leaves. The hot water extract afforded the highest yield (6.3%) while the lowest yield was obtained from the chloroform extract (2.1%). The methanol extract contains higher levels of total phenolics (48.7 ± 0.7 g GAE/100 g extract), tannins (21.7 ± 0.7 g GAE/100 g extract) and flavonoids (10.3 ± 0.2 RE/100 g extract). The extracts were subjected to assess their antioxidant potential using various in vitro systems such as DPPH, ABTS⁺, FRAP, OH, β-carotene linoleic acid bleaching system, phosphomolybdenum reduction and Fe²⁺ chelation. It is concluded that the methanolic extract of B. vahlii leaves have strong antioxidant potential. Further study is necessary for isolation and characterization of the active antioxidants, which may serve as a potential source of natural antioxidants.     

Plant regeneration from axillary buds of a mature tree of Ficus religiosa

Dormant axillary buds of nodal explants collected from a mature (35-year-old) tree of Ficus religiosa L. sprouted on MS medium supplemented with 6-benzyladenine (BA, 5 mg l^–1) and indole-3-butyric acid (IBA, 0.2 mg l^–1 ) within 4 days. Multiple shoots were obtained when these explants were transferred to MS medium containing 1.5 mg l^–1 BA and 1.5 mg l^–1 adenine sulphate (ADS). These multiple shoots (1 cm) were allowed to elongate to a height of 4–5 cm by maintaining them on MS medium containing 2 mg l^–1 BA, 0.5 mg l^–1 1-naphthalene acetic acid (NAA), and activated charcoal (0.3% w/v). Nodal segments taken from these in vitro-proliferated shoots yielded multiple shoots when cultured on the multiple shoot-inducing MS medium mentioned above. Root induction in these shoots (4–5 cm in height) was achieved by transferring them onto MS medium supplemented with 2 mg l^–1 IBA and 0.1 mg l^–1 NAA for 1 week; upon transfer to half-strength MS basal medium these shoots exhibited root proliferation. These rooted plantlets were successfully established in soil after a short period of acclimatization. Received: 17 April 1997 / Revision received: 2 September 1997 / Accepted: 20 September 1997     

In vitro plant regeneration of leguminous trees (Albizia spp)

Hypocotyl explants of three leguminous forest tree species, Albizia amara, A. lucida and A. richardiana, have differentiated shoot buds on B₅ basal medium. Maximum number of shoots per explant developed on basal medium augmented with 2,4-D (0.1 M) in A. amara (2) and BA (10 M) for both A. lucida (2) and A. richardiana (1.6). Higher concentrations of auxins in the medium, in general, enhanced rooting and callusing but cytokinins promoted the growth of green calli. BA enchanced the differentiation of shoots in the three species. The in vitro grown shoots of A. amara and A. richardiana, after subculturing on B₅+1 M IAA developed roots (up to 30–40%). These plants have been successfully transferred to the field.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - BA 6-benzylaminopurine - BM Gamborg's B₅ medium with 0.9% agar+3% sucrose - IAA Indole-3-acetic acid - IBA Indole-3-butyric acid - Kn Kinetin - NAA -naphthaleneacetic acid     

棒花羊蹄甲和薯叶藤的学名订正

分布于云南西双版纳的棒花羊蹄甲Bauhinia claviflora L. Chen和海南的薯叶藤B. dioscoreifolia L. Chen长期被认为是国产特有种植物,实际上分别是广泛分布的缅甸羊蹄甲B. nervosa (Wall. ex Benth.) Baker和牛蹄麻B. khasiana Baker。作者依命名法予以归并。     

Multiple shoot induction and callus regeneration in Sarcostemma brevistigma Wight & Arnott, a rare medicinal plant

An efficient micropropagation protocol based on multiple shoot induction and callus regeneration has been standardized in Sarcostemma brevistigma, a rare medicinal plant. The nodal cuttings were cultured on MS medium supplemented with BA (0.5–8 μM) or Kn (0.5–8 μM) alone or in combination with NAA (0.5–1.5 μM). Maximum multiple shoot induction was observed on MS medium supplemented with 4 μM BA. On this medium, 100% cultures responded with an average number of 11.3 shoots per explant. However, the average shoot length was limited to only 0.9 cm on this medium. The addition of 1 μM NAA along with 4 μM BA gave rise to an average number of 10.9 shoots with an average shoot length of 1.8 cm. Luxuriantly growing callus was obtained on MS medium supplemented with BA (5 μM) and 2,4-D (2 μM). The callus was subcultured on MS medium supplemented with BA (2–15 μM) or Kn (2–15 μM) alone or in combination with NAA (0.5–2 μM) for shoot organogenesis. Optimum callus regeneration was obtained on MS medium supplemented with 10 μM BA and 1 μM NAA. On this medium, 100% cultures responded with an average number of 13.4 shoots per culture. The shoots obtained via multiple shoot induction and organogenesis were rooted on half-strength MS medium supplemented with NAA (1–7 μM) or IBA (1–7 μM). IBA was better than NAA in terms of both the percentage of cultures that responded and the average number of roots per explant. The rooted shoots were successfully transplanted to soil with 86% success. This standardized protocol will help to conserve this rare medicinal plant.     

In vitro regeneration of Norway maple (Acer platanoides L.)

Regenerants were produced from axillary buds, but not from petiole segments, greenwood cuttings and leaf discs. Petiole segments and greenwood cuttings responded by massive callus cell proliferation without adventitious shoot formation. The development of induced buds into shoots occurred on WPM medium containing kinetin. Vigorous shoots larger than 2.0 cm in length were successfully rooted in half strength WPM medium supplemented with 1.0 mg dm^-3 indole-3-butyric acid.     

羊蹄甲属中国特有种的花粉形态学

对羊蹄甲属植物11种中国特有种的花粉形态进行了研究。结果表明,花粉萌发孔类型均为三孔沟,少数还有合沟;花粉均具半覆盖层,表面纹饰有皱波状、皱波状-穿孔、疣状、孔穴-穿孔、穿孔-网状。依据Larsen(1975)的划分,这11种植物的花粉隶属于Integrifolia型、Glauca型和Curtisii型,我们根据花粉纹饰的差异在Integrifolia型下进一步划分了Auma亚型和Paucinervata亚型。     

In vitro plantlet regeneration from mature zygotic embryos of Pinus wallichiana A.B. Jacks

 Plantlet regeneration was achieved in blue pine (Pinus wallichiana A.B. Jacks) by organogenesis of mature zygotic embryos. The effect of various basal media and five cytokinins on adventitious bud induction, development and elongation was investigated. Half-strength Douglas fir cotyledon revised medium (DCR) supplemented with 2.5 μm N⁶-benzyladinine (BA) and 0.025 μM thidiazuron was found to be most effective in inducing adventitious buds. The effect of a BA pulse treatment was also tested, and the bud-forming capacity of each treatment was quantified. The elongation of adventitious buds was achieved on hormone-free half-strength DCR medium containing 2% sucrose and 0.05% activated charcoal. Rooting was induced in the elongated shoots with a 6-h treatment of indoleacetic acid and indolebutyric acid solutions (1 mM each). Rooted shoots were transplanted in the greenhouse for hardening and their survival percentage was 64.4 after 5 weeks and 45.7 after 6 months. Received: 11 September 1998 / Revision received: 10 February 1999 / Accepted: 26 February 1999     

In vitro regeneration patterns of Platycerium bifurcatum leaf cell suspension culture

A simple suspension culture system of Platycerium bifurcatum was developed where sporophytes could be regenerated directly from leaf cells or indirectly through an aposporous gametophyte stage under the same culture conditions. Single cells and aggregates of up to 100 cells developed aposporous gametophytes which later gave rise to sporophytes. Such gametophytes started apogamy when they were mostly less than 0.7 mm in length, bearing only rhizoids. In most cases, only one sporophyte was regenerated from one gametophyte. Aggregates of 500–1000 or more cells, on the other hand, regenerated sporophytes directly. Intercellular interaction was considered to be the physiological cause, and the separation of leaf cells to a certain degree drove the cells to embark on different regeneration paths. It is suggested that the possible existence of a threshold size of cell aggregates separates the two regeneration patterns. Received: 3 March 1997 / Revision received: 11 April 1997 / Accepted: 3 June 1997     

In vitro regeneration from excised leaves of Flaveria trinervia (Sprengel) C. Mohr

Flaveria trinervia (Compositae) leaves are used for the treatment of jaundice and fever. From the leaf callus cultures regeneration of plantlets has been achieved. The results showed that BAP greatly stimulated the bud formation in concentrations ranging from 2–5 mg l^–1 than at very low concentrations (0.2–1.0 mg l^–1). Roots developed on the regenerated shoots, over a range of treatments, but were most prolific in the medium containing 1 mg l^–1 IAA. Histological observations revealed that cultured spongy cells of the mesophyll were greatly enlarged and underwent repeated cell divisions leading to the formation of hard nodular callus from which shoot buds differentiated. The shoots obtained were readily rooted and transplanted into glass houses. Cytological studies of the callus showed abnormalities such as bridges, endomitosis and multinucleolate conditions. Root tip squashes of the regenerated plants showed no variations and were diploid in chromosome number.Abbreviations 2,4-D 2,4-dichlorophenoxy acetic acid - NAA napthalene acetic acid - IAA indole acetic acid - BAP 6-benzyl aminopurine - Kn kinetin     

In vitro regeneration of sesame (Sesamum indicum L.) from seedling cotyledon and hypocotyl explants

The goal of this study was to develop an efficient regeneration protocol to be used for genetic transformation of sesame. Published regeneration methods using benzyladenine (BA) and 1-naphthalene acetic acid (NAA) were unsuccessful for the cultivars used herein. Experiments were carried out using cotyledon and hypocotyl explants from the cultivar Mtwara-2. Later the optimised culture conditions were used to investigate the regeneration response of different genotypes. There was significant interaction between hormone treatments and macronutrients for shoot and root regeneration. Results also showed that shoot regeneration was significantly influenced by explant type. Shoots were only obtained from cotyledons whereas both cotyledons and hypocotyls could produce roots. Modified Murashige and Skoog (MS) medium with N6 macronutrients resulted in twice the shoot regeneration frequency obtained with ½MS macronutrients in the presence of thidiazuron (TDZ). The shoot regeneration frequency was significantly reduced when BA was used in place of TDZ. On shoot regeneration medium containing BA and NAA, only roots were formed. Replacing NAA with indole-3-acetic acid (IAA) greatly improved the regeneration of shoots. The optimum growth regulator combination for shoot regeneration was 20 μM TDZ together with 2.5 μM IAA, which gave a frequency of 63% and 4.4 shoots per regenerating explant for the best cultivar Ex-El. Genotypic differences were significant both for the number of explants regenerating shoots and the number of shoots produced per regenerating explant.     

Optimization of multiple shoot induction and plant regeneration in Indian barley (Hordeum vulgare) cultivars using mature embryos

Barley is the fourth most important crop in the world. Development of a regeneration system using immature embryos is both time consuming and laborious. The present study was initiated with a view to develop a regeneration system in six genotypes of Indian barley (Hordeum vulgare) cultivars as a prerequisite to transformation. The mature embryos were excised from seeds and cultured on MS medium supplemented with high and low concentrations of cytokinins and auxins respectively. The MS medium containing 3 mg/L N⁶-benzylaminopurine (BA) and 0.5 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) was found to be the most effective for multiple shoot formation in HOR7231 cultivar that could produce 12 shoots per explant. The other cultivars HOR4409 and HOR3844 produced a minimum number of adventitious shoots (1.33 and 1.67 respectively) on MS medium supplemented with 1 mg/L BA and 0.3 mg/L 2,4-D. The elongated shoots were separated and successfully rooted on MS medium containing 1 mg/L indole-3-acetic acid (IAA). The response of different barley cultivars was found to be varying with respect to multiple shoot production. This is the first report of multiple shoot induction and plantlet regeneration in Indian cultivar of barley which would be useful for genetic transformation.     

Inflated trichornes in flowers of Bauhinia (Leguminosae: Caesalpinioideae)

TUCKER, S. C., RUGENSTEIN, S. R. & DERSTINE, K. S., 1984. Inflated trichomes in flowers of Bauhinia (Leguminosae: Caesalpinioideae). An unusual kind of bifid multicellular inflated trichome is reported to occur on floral organs of II species of Bauhinia (Leguminosae-Caesalpinioideae), They occur on sepals, petals, stamens, carpels, receptacle, leaves, and stems, but not on all organs in each species. Their development in B. malabarica is described.     

Chromosomal-level genome assembly of the orchid tree Bauhinia variegata (Leguminosae; Cercidoideae) supports the allotetraploid origin hypothesis of Bauhinia

Cercidoideae, one of the six subfamilies of Leguminosae, contains one genus Cercis with its chromosome number 2n = 14 and all other genera with 2n = 28. An allotetraploid origin hypothesis for the common ancestor of non-Cercis genera in this subfamily has been proposed; however, no chromosome-level genomes from Cercidoideae have been available to test this hypothesis. Here, we conducted a chromosome-level genome assembly of Bauhinia variegata to test this hypothesis. The assembled genome is 326.4 Mb with the scaffold N50 of 22.1 Mb and contains 37,996 protein-coding genes. The Ks distribution between gene pairs in the syntenic regions indicates two whole-genome duplications (WGDs): one is B. variegata-specific, and the other is shared among core eudicots. Although Ks between gene pairs generated by the recent WGD in Bauhinia is greater than that between Bauhinia and Cercis, the WGD was not detected in Cercis, which can be explained by an accelerated evolutionary rate in Bauhinia after divergence from Cercis. Ks distribution and phylogenetic analysis for gene pairs generated by the recent WGD in Bauhinia and their corresponding orthologs in Cercis support the allopolyploidy origin hypothesis of Bauhinia. The genome of B. variegata also provides a genomic resource for dissecting genetic basis of its ornamental traits.     

Recognition profile of Bauhinia purpurea agglutinin (BPA)

Bauhinia purpurea agglutinin (BPA) is a Galbeta1-3GalNAc (T) specific leguminous lectin that has been widely used in multifarious cytochemical and immunological studies of cells and tissues under pathological or malignant conditions. Despite these diverse applications, knowledge of its carbohydrate specificity was mainly limited to molecular or submolecular T disaccharides. Thus, the requirement of high density polyvalent or multi-antennary carbohydrate structural units for BPA binding and an updated affinity profile were further evaluated by enzyme-linked lectinosorbent (ELLSA) and inhibition assays. Among the glycoproteins (gps) tested and expressed as 50% nanogram inhibition, the high density polyvalent GalNAcalpha1-Ser/Thr (Tn) and Galbeta1-3/4GlcNAc (I/II) glycotopes present on macromolecules generated a great enhancement of binding affinity for BPA as compared to their monomers. The most potent inhibitors were a Tn-containing gp (asialo OSM) and a I/II containing gp (human blood group precursor gp), which were up to 1.7 x 10(4) and 2.3 x 10(3) times more potent than monovalent Gal and GalNAc, respectively. However, multi-antennary glycopeptides, such as tri-antennary Galbeta1-4GlcNAc, which was slightly more active than II or Gal, gave only a minor contribution. Regarding the carbohydrate structural units studied by the inhibition assay, blood group GalNAcbeta1-3/4Gal (P/S) active glycotopes were active ligands. The overall binding profile of BPA was: high density polyvalent T/Tn and II clusters > Tn-glycopeptides (M.W. <3.0 x 10(3))/Talpha monomer > monovalent P/S > Tn monomer and GalNAc > tri-antennary II > Gal > Man and Glc (inactive). These findings give evidence for the binding of this lectin to dense cell surface T, Tn and I/II glycoconjugates and should facilitate future usage of this lectin in biotechnological and medical applications.     

In vitro induction of multiple shoots and plant regeneration in cotton (Gossypium hirsutum L.)

Induction of multiple shoots in cotton (Gossypium hirsutum L. cv. Anjali-LRK 516) has been achieved with cotyledonary nodes devoid of cotyledons and apical meristems. Explants from 35-day-old seedlings yielded the maximum number of shoots (4.7 shoots/explant) using Murashige and Skoog (MS) basal medium supplemented with 6-benzylaminopurine and kinetin (2.5 mg/1 each). Explants from 35-day-old seedlings raised in glass bottles produced a higher number of multiple shoots (8.3 shoots/explant) than those grown in glass tubes and cultured on the same shoot induction medium. Elongation of multiple shoots was obtained on liquid or agar MS basal medium without phytohormones. In vitro shoots were rooted on half-strength agar-solidified MS basal medium or with 0.05 or 0.1 mg/1 naphthaleneacetic acid. Hardening and survival of tissue culture plantlets was 95% under greenhouse conditions.Abbreviations BAP 6-Benzylaminopurine - GA₃ Gibberellic acid - MS Murashige and Skoog medium - NAA -Napthaleneacetic acid     

In vitro plant regeneration of Arachis correntina (Leguminosae) through somatic embryogenesis and organogenesis

In vitro protocols for plant regeneration of Arachis correntina through both somatic embryogenesis and organogenesis were developed using immature leaves as explants. Morphologically normal somatic embryos were obtained on culture media composed of 20.70 or 41.41 μM picloram (PIC) with the addition of 0.044 μM 6-benzylaminopurine (BA), resulting in a 33 and 24% of conversion into plants, respectively. The source of explants and the developmental stage of the leaves had a marked effect on somatic embryogenesis. The second folded immature leaves from in vitro growing plants were the most responsive producing up to 30% embryogenesis in MS+41.41 μM PIC. Embryos converted into plants after transfer to MS medium devoid of growth regulators and these plants were successfully acclimatised. Adventitious shoots were obtained on culture media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) or naphthaleneacetic acid (NAA) with or without 0.044 μM BA, achieving plant regeneration in the induction media. The highest percentage of bud formation was obtained on culture medium composed of␣MS+10.74 μM NAA+0.044 μM BA (12.5%). Roots were formed on all culture media tested. Regenerated plants were transferred to pots and grew well under greenhouse conditions.     

In vitro plant regeneration of spinach from mature seed-derived callus

Summary A system for the regeneration of spinach (Spinacia oleracea L.) from mature dry seed explants has been established. The response of two commercial spinach cultivars, ‘Grandstand’ and ‘Baker’, was examined. Callus proliferation was most prominent on MS medium supplemented with 9.3 μM of 6-furfurylaminopurine (kinetin) and 3.39 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Adventitious shoot formation was observed within 8 wk after callus was transferred onto regeneration medium. Shoot regeneration was best from callus induced on 9.3 μM kinetin and 4.56 μM 2,4-D. The regeneration medium contained 9.3 μM kinetin, 0.045 μM 2,4-D, and 2.89 μM gibberellic acid (GA₃). Shoots were rooted on hormone-free medium, and plants grown in a greenhouse showed normal phenotype. This system is beneficial in rapid propagation of spinach plants, particularly when only a limited number of seeds are available.     

In vitro plantlet regeneration of<Emphasis Type="Italic"> Schinopsis balansae</Emphasis> (Anacardiaceae)

A protocol for the in vitro regeneration of rooted plants from nodal single bud segments of 10-year-old Schinopsis balansae trees was developed. Nodal segments were harvested from actively growing shoots of plants grown from seeds and maintained in pots under greenhouse conditions, and from epicormic shoots obtained by forced flushing of branches. Culture of nodal segments on nutrient medium containing the mineral salts and vitamins of Murashige and Skoog medium at 1/4 strength (1/4 MS), supplemented with 100 mg l^–1 ascorbic acid, 3% sucrose, and 5–15 M 6-benzyladenine resulted in regeneration of multiple shoots. Rooting of regenerated shoots was observed in 1/4 MS medium with vermiculite as the substrate and supplemented with 7.5 M indolbutyric acid.