Induction,polarity and spatial control of cytokinesis in some abnormal subsidiary cell mother cells ofZea mays

Summary Cytokinesis in the subsidiary cell mother cells (SMCs) ofZea mays leaves grown in the presence of 5 mM of caffeine solution is usually partially inhibited. A continuous wall strip, resembling a portion of the subsidiary cell (SC) wall, is laid down in the preprophase microtubule band (PMB) cortical zone. Sometimes, the incomplete SC (SC) wall grows centripetally in the absence of a phragmoplast and the gap becomes smaller or closes. The SC nucleus escapes through the SC wall gap into the larger SMC compartment and may fuse with the other nucleus.The aberrant SMCs (a-SMCs) pass through another division cycle, reattempting to produce a SC. A typical PMB is found in the SC space, in the site of the previous PMB. Moreover, in some preprophase SMCs, the cytoplasm adjacent to the SC wall is traversed by a small number of microtubules. The preprophase nuclei are partly or totally separated from the PMB by the perforated SC wall and may lie far from the latter.Usually, one mitotic spindle is assembled. The cycling paired polarized nuclei appear to synchronize and their chromosomes line up together on a single metaphase plate. Although the mitotic spindle axis is diversely oriented, one of its poles tends to be stabilized in the proximity of the SC wall gap. These divisions separate abnormal cells. Most or all the cell plate edges fuse with wall regions far from the PMB cortical zone. However, when some of them approach the SC wall strips, they are attracted and intersect their rims. In rare occasions the cell plate, invading the SC space is guided by the PMB cortical zone to create a SC-like curved wall portion, in absence of a daughter nucleus.Observations show that the cell plate arrangement in redividing aberrant SMCs is not subjected to a strict spatial control. The disorder of polarization sequence generated by the SC wall ring and especially the perturbation of the spatial (and functional?) relationship between PMB-PMB cortical zone and the nucleus—mitotic spindle is a causal factor of the variable cell plate arrangements.     

Transfer of germ plasm from the secondary to the primary gene pool in pennisetum

Summary Germ plasm from the A-genome of Pennisetum purpureum Schum. (AABB) of the secondary gene pool was transferred to cultivated pearl millet (AA) [P. glaucum (L.) R. Br.] by pollinating cytoplasmicnuclear male-sterile (cms) pearl millet with fertile allohexaploid pearl millet x P. purpureum hybrids (AAAABB). Certain allohexaploids used as pollinators on cms pearl millet resulted in 14-chromosome diploid pearl millet progenies. Three types of diploid pearl millet plants were produced in addition to the expected 28-chromosome AAAB-genome plants: (1) cms plants with only the A-genome, (2) cms plants with the A- and A-genomes, and (3) fertile plants with the A- and A-genomes. The latter group has allowed the utilization of genes for fertility restoration, stiff stalk, maturity, height, and morphological characteristics from the A-genome of P. purpureum in the pearl millet breeding program. Production of monoploid gametes by the allohexaploids appeared to be genetically controlled.     

A suitable method for construction and cloning hybrid plasmids containing EcoRI-fragments of E. coli genome.

Summary A convenient procedure for the isolation of specificEcoRI-fragments ofE. coli genome and their amplification on Km-resistance plasmid vector CK 11 is described. The hybrid molecules were constructedin vitro usingEcoRI-digestion, followed by ligation. Then appropriatedE. coli strain was transformed with ligated DNA mixture and hybrid plasmids CK 11-arg ⁺, CK 11-his ⁺, CK 11-thr ⁺ and CK 11-leu ⁺ containing loci ofE. coli genome were selected by molecular cloning. The hybrid plasmids obtained consisted of oneEcoRI-fragment of initial plasmid CK 11 and one respective specific portion ofE. coli genome.     

Evaluation of structural and physiological plant characteristics in relation to the distribution of cadmium in maize inbred lines

To establish the structural and physiological characteristics related to the genotypic variation in Cd distribution between maize inbred lines (shoot Cd excluders and non-shoot Cd excluders), shoot and root morphological parameters were studied on plants grown in nutrient solution. Furthermore, the xylem sap composition and the desorbability of Cd from roots of these inbreds have been compared. No relationship between the morphological characteristics of either shoot (specific leaf area and leaf area ratio) or root (specific root length, specific surface area, and average diameter) and Cd distribution could be assessed. Cadmium concentrations in the xylem exudates from non-shoot Cd excluders were higher than those from shoot Cd excluders, but not related to citrate and malate concentrations. The absolute and relative amounts of Cd desorbed from roots of shoot Cd excluders were about twice as high compared to those of the non-shoot Cd excluders, especially at the lowest Cd concentration in solution. The absence of a relationship between shoot or root morphological parameters and Cd partitioning and the differences between both groups in the amounts of Cd desorbed, even at similar root Cd concentrations, indicate that the differential Cd distribution between shoot Cd excluders and non-shoot Cd excluders may be related to the observed differences in root Cd concentration, desorption characteristics and binding capacity of Cd inside and/or outside the root and its distribution within the roots.     

Identification and quantitation by GC-MS of zeatin and zeatin riboside in xylem sap from rootstock and scion of grafted apple trees

Zeatin and zeatin riboside were identified by full-scan gas chromatography-mass spectrometry (GC-MS) in xylem sap of clonal apple rootstocks (M.27, M.9 and MM.106). These rootstocks exhibit a wide range of control over tree size when grafted to a common scion. The concentrations of zeatin and zeatin riboside were measured by GC-MS selected ion monitoring (SIM) in shoot xylem sap and root pressure exudate obtained from these rootstocks and from trees of Fiesta scion grafted onto the rootstocks. Zeatin was the predominant cytokinin in xylem sap from the dwarfing rootstocks, M.27 and M.9, while zeatin riboside was the predominant cytokinin in xylem sap from the more invigorating rootstock MM.106. Cytokinin concentrations (ng ml^–1) in root pressure exudate and shoot xylem sap, (i.e. from above the graft union in composite trees), increased with increasing vigour of the rootstock, irrespective of whether the plants were non-grafted rootstocks, or were composite plants of Fiesta scion grafted onto the rootstocks. Cytokinin content (ng shoot^–1) of shoot sap differed with rootstock; the more invigorating (MM.106) had greater amounts of cytokinins than the more dwarfing (M.9 and M.27) rootstocks. These results are discussed in relation to possible influences of roots on the growth of shoots via cytokinin supplies in the xylem sap.     

An investigation of the role of solutes in the xylem sap and in the xylem parenchyma as the source of root pressure

Summary Solute osmotic potentials (_x) in the vessels of hydroponically grown maize roots were measured to assess the osmotic-xylem-sap mechanism for generating root pressure (indicated by guttation). Solutes in vessels were measured in situ by X-ray microanalysis of plants frozen intact while guttating. Osmotic potentials outside the roots (_o) were changed by adding polyethylene glycol to the nutrient solution. Guttation rate fell when _o was decreased, but recovered towards the control value during 3–5 days when _o was greater than or equal to –0.3 MPa, but not when _o was equal to –0.4 MPa. In roots stressed to _o = –0.3 MPa, _x, was always more positive than _o, and _x changed only slightly (ca. 0.05 MPa). Thus the adjustment in the roots which increased root pressure cannot be ascribed to _x, contradicting the osmotic-xylem-sap mechanism. An alternative driving force was sought in the osmotic potentials of the vacuoles of the living cells (_v), which were analysed by microanalysis and estimated by plasmolysis. _v showed larger responses to osmotic stress (0.1 MPa). Some plants were pretreated with abundant KNO₃ in the nutrient solution. These plants showed very large adjustments in _v (0.4 MPa) but little change in _x (0.08 MPa). They guttated by 4 h after _o was lowered to –0.4 MPa. It is argued that turgor pressure of the living cells is a likely alternative source of root pressure. Published evidence for high solute concentrations in the xylem sap is critically assessed.Abbreviations _o external water potential - _x osmotic potential of xylem sap - _v osmotic potential of vacuolar sap - EDX energy dispersive X-ray microanalysis - CSEM cryo-scanning electron microscope - LN₂ liquid nitrogen - PEG polyethylene glycol     

Daily fluctuations in water potential and associated ionic changes in Atriplex canescens

Summary Water potential () measurements of Atriplex canescens at the base of the Red Desert near Tipton in Wyoming, revealed a range between-15.5 to-45.1 bars. Minimum values coincided with the lowest air and soil temperatures, maximum with the greatest atmospheric evaporative demand. Change in exceeded 12 bars h^-1 during periods of rapidly moving storm systems. Changes in appeared to be independent of plant size, age, sex, and the spatial location of plants. Chemical analyses revealed that xylem sap was up to three times more concentrated at high than at low . It was observed that the flow rate of sap was greater at lower than at higher and that the increase in water movement accounted for the dilution of the baseline concentration of sap solutes. Together, Ca, Mg, K and Na contributed 58% of the mean osmolality of the xylem sap; the dominant ions, however, were K and Cl. We suggest that the ability of the species to respond rapidly to changing atmospheric conditions affords it a distinct advantage in a harsh environment.     

Aluminum-induced secretion of both citrate and malate in rye

Aluminum (Al)-resistant mechanisms responsible for Al-induced secretion of organic acids are poorly understood. In this study, we characterized the Al-induced secretion of both citrate and malate from rye (Secale cereale L. cv. King). Secretion of organic acids increased with increasing concentration (10, 30 and 50 M) and duration of Al treatments. Neither phosphorous (P) deficiency up to 15 days nor addition of 50M lanthanum, 50 M lead, 10 M cadmium, or 200 M manganese caused secretion of organic acids, suggesting that this secretion was a specific response to Al stress. Aluminum activated citrate synthase, the main enzyme for the synthesis of citrate, but its activation occurred only in the root tip. The elongation of roots of an Al-sensitive cultivar of wheat (Tritium aestivum L. cv. Scout 66) was not inhibited by 50 M Al in the presence of externally applied 50 M citrate or 400 M malate. The secretion of citrate and malate from intact rye roots exposed to 50 M Al corresponded to 31.3 ± 1.7 M and 11.5 ± 2.5 M, respectively, in the rhizosphere based on an assumption of a 2 mm thick unstirred layer around root tips. This result indicated that Al-resistance in rye was achieved by the Al-induced synthesis of citrate in root apices followed by Al-induced specific secretion of citrate from root tips.     

Isoenzymes of acid phosphatase in germinating peas

Summary Phloem exudation from Ricinus has been examined in plants subjected to changes in water balance induced by a number of means. The results have provided a clear demonstration that the phloem system can operate osmotically. When the availability of water in the xylem is reduced by withholding water, the rate of exudation decreases sharply and this is accompanied by a rise in the sap concentration. On removing the water stress, the rate increases rapidly with a corresponding fall in sap concentration.Small variations in water availability do not give significant results and may be buffered by responses from the plant itself. This could also explain the insignificant changes in sap composition during exudation previously reported, where exudation rate, which should bear some relation to sieve tube turgor pressure, seems independent of sap concentration. Fluctuations in exudation rate are large in comparison with the changes in sap concentration when severe water stresses are applied. This result, coupled with the observation that exudation will occur from plants under considerable water stress suggests the operation of a sugar pump capable of maintaining a high turgor pressure at the source against a considerable water potential gradient. The main pump is probably located in the leaves.Thus interpreted, the results seem to accord with the Münch pressure flow hypothesis in all significant aspects.     

The selective inhibition of hippocampal glutamic acid decarboxylase in zinc-induced epileptic seizures

The intracerebroventricular administration of Zn²⁺ (0.3 mol/10 l) causes epileptic seizures characterized by running fits, jumping, vocalization, fasiculation of facial muscles, myoclonic movements of the limbs and tonic-clonic convulsions. These episodes are blocked or reversed by -aminobutyric acid (0.4 mol/10 l). When assayed under conditions where pyridoxal phosphate was not added, the activity of glutamic acid decarboxylase decreased significantly in hippocampus from 18.9 to 15.3 and 9.7 mol¹⁴CO₂ formed/gram proteins/20 min, 15 and 30 min following administration of Zn²⁺. The inhibition of glutamic acid decarboxylase by Zn²⁺ was selective occurring only in hippocampus and not in the hypothalamus, amygdala, caudate or thalamus. The inhibition of glutamic acid decarboxylase was not due to a reduction in the concentration of endogenous pyridoxal phosphate which remained unaltered in hippocampus following Zn²⁺ administration.     

Embodying illness,embodying cancer

Individuals and societies embody illnesses in different ways, in part determined by the way a person knows and lives his or her diagnosis and prognosis. Based on research in Northern Italy, on the experiences and meanings of cancer and on the practice of nondisclosure of the diagnosis, we find nondisclosure reflects a world divided - life/death, good/bad, mind/body — with the unwanted converted to other. The strong association of cancer with death, suffering, and hopelessness in much of Italy, coupled with the tremendous power attributed to naming and sentencing makes nondisclosure a major mechanism for keeping the condemned in this social world, and keeping death, decay, and suffering in the other. It is the social reality that is dominant here, such that informing a patient of cancer can be tantamount to social death.

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Résumé Les individus et les sociétés incorporent la maladie de façon différente, déterminée en partie de comment une personne connait et vit son diagnostic et prognostic. A partir de la recherche des experiences des significations du cancer et de la pratique de ne pas dire la diagnostic au Nord de l'Italie, on a remarqué que l'habitude de ne rien dire reflète un monde séparé entre la vie et la mort, entre le bon et le mal, entre l'esprit et le corps, de sorte que ce qui West pas voulu soit transfomé en l'autre. L'association forte du cancer à la mort, à la souffrance, au désespérance en toute l'Italie, unie au grand pouvoir donne au fait de dénommer et de donner une sentence, rend ne pas dire un méchanisme important pour garder le condamnd dans ce monde social et pour garder la mort, la décadence et la souffrance dans l'autre. C'est la réalité sociale qui est ici dominante, tel que le fait d'informer un patient de cancer soit comme une mort sociale.

     

The biotin-dependent sodium ion pump glutaconyl-CoA decarboxylase from Fusobacterium nucleatum (subsp. nucleatum)

Membrane preparations of Fusobacterium nucleatum grown on glutamate contain glutaconyl-CoA decarboxylase at a high specific activity (13.8 nkat/mg protein). The enzyme was solubilized with 2% Triton X-100 in 0.5M NaCl and purified 63-fold to a specific activity of 870 nkat/mg by affinity chromatography on monomeric avidin-Sepharose. The activity of the decarboxylase was strictly dependent on Na⁺ (K _m=3 mM) and was stimulated up to 3-fold by phospholipids. The glutaconyl-CoA decarboxylases from the gram-positive bacteria Acidaminococcus fermentans and Clostridium symbiosum have a lower apparent K _m for Na⁺ (1 mM) and were not stimulated by phospholipids. In addition only the fusobacterial decarboxylase required sodium ion for stability and was inactivated by potassium ion. By incorporation of this purified enzyme into phospholipids an electrogenic sodium ion pump was reconstituted. The enzyme consists of four subunits, (m=65 kDa), (33 kDa), (19 kDa), and (16 kDa) with the functions of a carboxy transferase (), a carboxy lyase ( and probably ) and a biotin carrier (). The subunits are very similar to those of the glutaconyl-CoA decarboxylases from the gram-positive bacteria. With an antiserum directed against the decarboxylase from A. fermentans the - and the biotin containing subunits of the three decarboxylases and that from Peptostreptoccus asaccharolyticus could be detected on Western blots.     

Indole butyric acid induces regeneration of phenotypically normal apricot (Prunus armeniaca L.) plants from immature embryos

A prerequisite for most transformation systems is an efficient and reliable method to regenerate phenotypically normal plants. Immature embryos or cotyledons were cultured at three developmental stages (stage 1, 2 and 3, PF=3, 30–60, and 100, respectively) from two unrelated apricot genotypes, Zard and NJA82. Explants were cultured on MS media supplemented with either BA or TDZ at four concentrations (0, 0.5, 5.0 or 20 M) and 2,4-D at 0 or 1 M. Stage 1 embryos cultured on MS medium without growth regulators formed embryoid-like structures. Shoot primordia induction was greatest with stage 2 cotyledons on media containing 5–20 M TDZ and 1 M 2,4-D, although shoot morphology was abnormal, especially with the highest level of TDZ. In another factorial experiment, stage 2 cotyledons were cultured on media containing TDZ (0, 5, 7.5, 10, 15 or 20 M) in combination with either no auxin, 1 M 2,4-D, 1 M IBA, or 5 MIBA. Regeneration percentages of 80% or more were observed on media containing 1–5 M IBA and 5–10 M TDZ. The medium containing 5 M IBA and no TDZ exhibited the highest frequency of phenotypically normal plantlet regeneration.Abbreviations BA 6-benzylaminopurine - IBA indole-3-butyric acid - 2,4-D 2,4 dichlorophenoxyacetic acid - 2iP 2-isopentenyladenine - MS Murashige and Skoog basal medium - NAA 1-naphthaleneacetic acid - PF percent fill [(embryo length/seed length) × 100] - TDZ thidiazuron [N-phenyl-N(1,2,3,-thidiazol-5-yl)-urea] - WPM McCown's woody plant medium     

Influence of phosphate and nitrate supply on root hair formation of rape,spinach and tomato plants

Summary Experiments with tomato, rape and spinach in nutrient solutions have shown that the formation of root hairs is strongly influenced by phosphate and nitrate supply. Decreasing the phosphate concentration of the nutrient solution from 100 to 2 M P resulted in an increase of root hair length from 0.1–0.2 to 0.7 mm of the three plant species. Root hair density also increased by a factor of 2–4 when the P concentration was lowered from 1000 to 2 M. The variation of these two root properties raised the root surface area by a factor of 2 or 3 compared to plants well supplied with P. Root hair length was closely related to the phosphate content of the root and shoot material. On the other hand, spinach plants grown in a split-root experiment produced root hairs in solutions of high P concentration (1000M P) if the major part of the total root system was exposed to low P concentration (2 M P). It is therefore concluded that the formation of root hairs does not depend on directly the P concentration at the root surface but on the P content of the plant.Similar experiments with nitrate also resulted in an increase in length and density of root hairs with the decrease of concentration below 1000 M. In this case marked differences between plant species occurred. At 2 M compared to 1000 M NO₃ root hair length of tomato increased by a factor of 2, of rape by a factor of 5 and of spinach by a factor of 9. Root hair length was correlated, but not very closely, to the total nitrogen content of the plants. It is concluded, that the influence of nutrient supply on the formation of root hairs is a mechanism for regulating the nutrient uptake of plants.Dedicated to Prof. Dr. E. Welte on the occasion of his 70th anniversary.     

Effects of ganglioside GM1 on the thermotropic behavior of cholera toxin B subunit

Summary The B, or binding, subunit of cholera enterotoxin forms a pentameric ring structure in the intact toxin, and also when the subunit is isolated from the A subunit. The thermal denaturation of the B subunit ring was examined by differential scanning calorimetry in the presence and absence of ganglioside G_M1, its natural receptor. In the absence of ganglioside an irreversible endotherm was observed with maximal excess apparent heat capacity, C_max, at 74.6° C. When the ganglioside was added in increasing amounts, multiple transitions were observed at higher temperatures, the most prominent having a C_max at 90.8° C. At high ganglioside concentrations, the 74.6° C transition was not observed. In addition to the thermodynamic results a model is proposed for the interaction of G_M1 and B subunit pentamer. This model is derived independently of the calorimetric results (but is consistent with such data) and is based upon considerations of the geometry of the G_M1 micelle-B subunit pentamer.Abbreviations M_r molecular weight in daltons - G_M1 H³Neu-AcGgOse₄Cer^* = Gall 3Ga1NAc1 4Gal-[3 - 2NeuAc]1 4Glc1 1Cer (asterisked form follows the recommendations of the IUPACIUB Commission on Biochemical Nomenclature, Ref. 3) - R molar ratio of G_M1 to B monomer - DSC differential scanning calorimetry - C_max excess apparent heat capacity - C_max maximal value of C_ex - t_m temperature (° C) at C_ex = C_max - t_1/2 peak width in °C at C_ex = C_max/2 - H_cal calorimetric enthalpy - C _p ^d van't Hoff enthalpy - C _p ^d change in specific heat accompanying denaturation     

Water uptake and transport in lianas and co-occurring trees of a seasonally dry tropical forest

Water uptake and transport were studied in eight liana species in a seasonally dry tropical forest on Barro Colorado Island, Panama. Stable hydrogen isotope composition (D) of xylem and soil water, soil volumetric water content (_v), and basal sap flow were measured during the 1997 and 1998 dry seasons. Sap flow of several neighboring trees was measured to assess differences between lianas and trees in magnitudes and patterns of daily sap flow. Little seasonal change in _v was observed at 90–120 cm depth in both years. Mean soil water D during the dry season was –19 at 0–30 cm, –34 at 30–60 cm, and –50 at 90–120 cm. Average values of xylem D among the liana species ranged from –28 to –44 during the middle of the dry season, suggesting that water uptake was restricted to intermediate soil layers (30–60 cm). By the end of the dry season, all species exhibited more negative xylem D values (–41 to –62), suggesting that they shifted to deeper water sources. Maximum sap flux density in co-occurring lianas and trees were comparable at similar stem diameter (DBH). Furthermore, lianas and trees conformed to the same linear relationship between daily sap flow and DBH. Our observations that lianas tap shallow sources of soil water at the beginning of the dry season and that sap flow is similar in lianas and trees of equivalent stem diameter do not support the common assumptions that lianas rely primarily on deep soil water and that they have higher rates of sap flow than co-occurring trees of similar stem size.     

The carotenoids of Flavobacterium strain R1560

The main carotenoid of Flavobacterium strain R1560 has been identified as (3R,3R)-zeaxanthin. Also present were small amounts of 15-cis-phytoene, phytofluene, -carotene (7,8,7,8-tetrahydro-, -carotene plus 7,8,11,12-tetrahydro-, -carotene), neurosporene, lycopene, -zeacarotene, -carotene, -carotene, -cryptoxanthin, rubixanthin, 3-hydroxy--zeacarotene and several apo-carotenals. Zeaxanthin production was inhibited by nicotine (10 mM), and lycopene and rubixanthin accumulated. The biosynthesis of zeaxanthin is discussed in terms of pathways and also of half-molecule reaction sequences. The presence of zeaxanthin may be a characteristic of a group of Flavobacterium species, and may thus be useful in the taxonomic classification of these organisms.     

Partitioning of water resources among plants of a lowland tropical forest

Source water used by plants of several species in a semi-evergreen lowland tropical forest on Barro Colorado Island, Panama, was assessed by comparing the relative abundance of deuterium, D, versus hydrogen, H (stable hydrogen isotope composition, D) in xylem sap and in soil water at different depths, during the dry season of 1992. Ecological correlates of source water were examined by comparing xylem water D values with leaf phenology, leaf water status determined with a pressure chamber, and rates of water use determined as mass flow of sap using the stem heat balance method. Soil water D values decreased sharply to 30 cm, then remained relatively constant with increasing depth. Average D values were-13, for 0–30 cm depth and-36.7 for 30–100 cm depth. Soil water D values were negatively associated with soil water content and soil water potential. Concurrent analyses of xylem water revealed a high degree of partitioning of water resources among species of this tropical forest. Xylem water D of deciduous trees (average=-25.3±1.4) was higher than that of evergreen trees (average=-36.3±3.5), indicating that evergreen species had access to the more abundant soil water at greater depth than deciduous species. In evergreen shade-tolerant and high-light requiring shrubs and small trees, D of xylem water was negatively correlated with transpiration rate and leaf water potential indicating that species using deeper, more abundant water resources had both higher rates of water use and more favorable leaf water status.     

Evidence for wheat-rye nucleolar competition (amphiplasty) in triticale by silver-staining procedure

Summary Amphiplasty in hexaploid triticale, the artificial amphiploid of tetraploid wheat and diploid rye, is analyzed for the first time using a modified, highly reproducible, silver-staining procedure. A comparative analysis of metaphase somatic cells by phase contrast, C-banding and silver-staining of the hexaploid triticale cv. Cachirulo and its parents, namely, the tetraploid durum wheat cv. Enano de Andujar and the diploid rye cv. Petkus has been made. Two silver-stained nucleolar organizer regions (Ag-NORs) (the chromosome pair 1 R) are observed in all rye plants analyzed, whereas four Ag-NORs (chromosome pairs 1 B and 6 B) are found both in the tetraploid wheat parent and in the triticale. The rye Ag-NORs are absent in the triticale. Since the Agstaining reaction of NORs can be considered as an indication for genetic activity, the silver procedure can be used to visualize gene functionality at the rDNA sites with conventional light microscopy and, consequently, the modified Ag-staining method described can be very useful in analyzing the amphiplasty phenomenon in natural or artificial hybrid combinations and derivatives in the Triticum group and its relatives.     

Development of shoots and roots in anther-derived callus of Azadirachta indica A. Juss.—a medicinal tree

Callus originated in microsporangial wall layers and connective tissues of anthers containing uninucleate microspores on Nitsch's or Murashige and Skoog's medium supplemented with growth regulators. A higher percentage of cultures (43) produced callus on Nitsch's medium containing 10 M indole-3-acetic acid + 1 M 6-benzyladenine. After 13–15 weeks, green nodular structures and prominent roots developed in 25% of the cultures on Murashige and Skoog's medium + 10 M -naphthaleneacetic acid + 1 M kinetin. Multiple shoots were induced in this anther-derived callus when subcultured on Murashige and Skoog's medium augmented with 4.44 M 6-benzyladenine + 0.53 M -naphthaleneacetic acid along with 18.75 M polyvinylpyrrolidone. The excised shoots formed roots after subculturing on Murashige and Skoog's medium + 4.90 M indole-3-butyric acid + 18.75 M polyvinylpyrrolidone, thus developing complete plantlets. Examination of callusing anthers also revealed two- to multi-celled pollen masses with intact exine.Abbreviations BA 6-benzyladenine - CW coconut water - 2,4-d 2,4-dichlorophenoxyacetic acid - GA₃ gibberellic acid - HCl hydrochloric acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid - KMnO₄ potassium permanganate - MS Murashige & Skoog's medium - NAA -naphthaleneacetic acid - NB Nitsch's medium - PVP polyvinylpyrrolidone