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Streptomyces venezuelae P(10) could produce extracellular chitinase in a medium containing 0.6% colloidal chitin that was fermented for 96 hours at 30 degrees C. The enzyme was purified to apparent homogeneity with 80% saturation of ammonium sulfate as shown by chitin affinity chromatography and DEAE-cellulose anion-exchange chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the enzyme showed a molecular weight of 66 kDa. The chitinase was characterized, and antifungal activity was observed against phytopathogens. Also, the first 15 N-terminal amino-acid residues of the chitinase were determined. The chitin hydrolysed products were N-acetylglucosamine and N, N'-diacetylchitobiose.

A field experiment was conducted to study the effect of arbuscular mycorrhizal association in mulberry saplings var. S1, together with two levels of phosphate, on growth characters, leaf yield and phosphorus uptake. The experiment was conducted in the period 1995 to 1997 at the Technical Service Centre, Kashipur, Purulia (West Bengal) under rainfed, lateritic soil conditions. Pooled data analysis revealed that there was no significant variation among the treatments in most of the characters except height of plant and leaf moisture percentage. Plant height in both treatments with Glomus mosseae was significantly less than in the others, while there was significant reduction in moisture percentage in G. fasciculatum with 25 kg of phosphate and G. mosseae with 10 kg of phosphate ha–1 year–1 than in other treatments. There was no significant season–treatment effect on any of the parameters. Considering all the quantitative and qualitative characters, G. fasciculatum together with the most economic dose of phosphate showed more promising performance than G. etunicatum and G. mosseae with different doses of phosphate fertilizer. At 80% of the recommended dose of inorganic phosphate fertilizer, Rs 534.0 were earned as net profit.

Elevated plasma Homocysteine level is an independent risk factor for age related (senile) cataract. Certain nutritional deficiencies, in particular Folate, Vitamin B(12), Vitamin B(6) relate inversely with Homocysteine level. This study was undertaken to evaluate the plasma level of Vitamin B(12), Folate, and Homocysteine of cataract patients and to study the interplay between them. Serum Homocysteine level is significantly increased in cataract patients when compared with control (p0.001). There was a significant decrease in the level of Folate as compared with control (p0.001). There was a negative correlation between Homocysteine vs. Vitamin B(12) (p0.01) and Folate (p0.01) in the Cataract patients. Our findings suggest that increased plasma Homocysteine level is associated with decreased plasma levels of Folate and VitaminB(12) in Cataract patients, which might have a possible role in the root cause of cataract pathogenesis.

Generally, the failure of major machinery parts is due to fatigue damage. Because of the structural inhomogeneity of metals, fatigue damage may sometimes occur significantly below the yield strength of the material due to microplastic deformation at low stress levels. Commercial En-8 grade steel (widely used for making secondary metalworking products) was used to estimate the fatigue damage response during cyclic loading nearer to the fatigue endurance limit. Estimation of fatigue damage was carried out with the aid of a nondestructive testing (NDT) method, that is, Elastosonic measurement of fatigue damping coefficient and slope of fatigue damping curves. Results indicate that fatigue damage increases in annealed En-8 steel with an increase in peak stress and with an increase in the number of cycles. However, for hardened and tempered En-8 steel, experimental results may not provide a true indication of fatigue damage during fatigue loading nearer to the endurance limit, most likely due to the more homogeneous structure. Generally, fatigue failure occurs in this grade of steel due to microcrack generation in the cementite of the pearlite phase of annealed steel.

Actual nitrogen fixation of root nodules of differentAlbizia-rhizobium symbioses, was compared with the potential nitrogen fixation of isolated bacteroids. The potential nitrogen fixation exceeded actual nitrogen fixation in all symbionts. After addition of nitrate the actual nitrogen fixation decreased more than did potential nitrogen fixation in effective symbiosis, whereas in a less effective symbiosis, the actual and potential nitrogen fixation increased as a result of better photosynthate supply to the roots and nodules. As confirmed by correlation analysis, the nitrogen fixation and photosynthetic yield of suboptimum symbioses were relatively enhanced by dressing with inorganic nitrogen fertilizer.

The agar gel double diffusion test was evaluated for detection of nuclear polyhedrosis virus infecting the silkworm, Bombyx mori L. (BmNPV). The test was successful using alkali-dissolved BmNPV as antigen. The antiserum raised against dissolved BmNPV gave positive results with a wider range of antigenic concentrations compared to antiserum raised against undissolved BmNPV. Gel plates prepared using phosphate buffered-saline as dissolving medium for agarose gave sharper and clearer precipitation bands compared to those made with sodium carbonate-saline as diluent. Sharp bands were obtained when the experiment was carried out at 25°C, whereas at higher temperature (35°C), the bands were diffused. The test was able to detect antigen concentration as low as 2 × 106 OBs/ml (18.9 μg/ml of antigen protein).

Jute fiber was grafted by acrylonitrile and methylmethacrylate monomers in raw and bleached condition. It was also noted that optimum grafting takes place after about 4 h of grafting. It was also noted that in bleached jute fiber, the grafting percentage is higher at all stages of grafting but the tenacity value at the highest add-on is practically the same as that of raw fiber with much less add-on. The crystalline orientation of the grafted jute fiber was correlated with the fiber tenacity. The moisture regain (%) of the fiber after grafting showed a decreasing trend with an increase in grafting percentage. No structural change of the fiber occurred due to grafting. © 1995 John Wiley & Sons, Inc.

Despite the prevalence of starch-hydrolyzing enzymes in bacilli, relatively few have been studied in detail. In an attempt to isolate an effective α-amylase-producing strain, Bacillus globisporus BH-1b has been isolated. The strain requires few nutritional supplements and shows induction in the presence of galactose. 2% potassium nitrate and pH 7.2 emerged as optimum for the fermentation medium. The durability of the enzyme has also been tested at a low pH and a high temperature.

Raw and partially delignified jute fibers were grafted with acrylonitrile and methyl meth-acrylate monomers, using the redox system of initiation with ceric ammonium sulfate. Grafting was also carried out in a mixed monomer system with acrylonitrile and methyl methacrylate monomers in different proportions. The optimum grafting condition depends on the duration of grafting treatment and proportion of grafting monomers. The monomers entered the fiber matrix with high add-on and, at still higher graft add-ons, the ultimate fibers suffered disintegration. The surfaces were increasingly covered with grafted materials and longitudinal cracks developed on the fiber surface with higher add-on. © 1993 John Wiley & Sons, Inc.

Jute stick was treated with white-rot fungus for incubation periods of 6 days (MBA) and 12 days (MBB). The infrared spectra of fungus treated samples (MBA and MBB) and control jute stick (MBC) were analyzed and compared. The bands attributed mainly to hemicellulose show an increase in absorbance intensity ratios (A v /A 2900 ) with increaae of incubation time. Similarly the bands attributed to lignin show an increase in the absorbance intensity ratios with increase of incubation time. Increase in the intensity of 1635 cm -1 band with increases of incubation time was observed.

Jute stick was bleached with sodium chlorite and alkaline hydrogen peroxide solutions. The infrared (IR) spectra of bleached samples and jute stick were analyzed and compared. The bleached samples were characterized by higher absorbance intensity ratios (Av/A2900) of the bands attributed to hemicellulose. Among the bleached samples the chlorite-bleached sample showed higher intensity for the bands mentioned. The bands attributed to lignin are either absent or very weak in the chlorite-bleached jute stick as compared to that of peroxide-bleached jute stick, although some residual lignin was present in the substrate. The 1635 cm−1 band attribute to the vibration of adsorbed water molecules in the noncrystalline regions in cellulose appears as a sharp peak in chlorite-bleached jute stick and as a shoulder in peroxide-bleached jute stick. This can be attributed to the difference in the nature of the two bleaching processes.

Defatted jute stick was treated with sodium hydroxide solution (2% w/v) at ambient temperature (∼ 32∼C) and boiling water bath temperature (95–97°C). Infrared (IR) spectra of defatted jute stick and alkali-treated jute stick were studied. The IR spectra of the alkalitreated jute stick were conspicuous by the absence of the 1730 cm−1 band, as compared to that of jute stick. Another characteristic feature of the alkali treated jute sticks is the absence of the band at 1240 cm−1, which is replaced by the 1265 and 1225 cm−1 bands; other bands in the above samples also recorded significant changes.

Background. Microbial and fungal cellulases are known to hydrolyse cellulose, which is ingested as plant mate rial by herbivorous/omnivorous fishes. Microbial enzymes have enormous advantage of being produced in large quantities by established fermentation techniques. The present investigation aims to optimize the environmental and nutritional parameters for fermentation to enhance cellulase production by two bacterial strains isolated from fish gastrointestinal tracts. Materials and methods. Two bacterial strains, Bacillus subtilis CY5 and Bacillus circulans TP3, isolated from the gastrointestinal tracts of common carp, Cyprinus carpio L., and Mozambique tilapia, Oreochromis mossam bicus (Peters, 1852), respectively were identified as potent cellulase producers. Both strains were cultured in tryp tone soya broth for 24 h at 32 ± 2oC, when average viable count of 9.75 · 10 7 cells · mL –1 culture broth was obtained. This was used as the inoculum for the production medium. The fermentation medium was seeded with 1.0%, 2.0%, 3.0%, 4.0%, and 5.0% inoculum (tryptone soya broth) and incubated in static culture at 40oC to stan dardize the inoculum size for fermentation. The effect of different production parameters, such as fermentation condition, moisture, pH, temperature, inoculum size, and nitrogen sources on cellulase production by the isolat ed bacterial strains were studied. Results. Cellulase yield was highest (26 U in B. subtilis and 20.2 U in B. circulans ) in solid-state fermentation (SSF). Enzyme production in both the isolates increased in an optimum pH range of 7.0 to 7.5. Minimum cellulase production was observed at 45oC, while maximum production was obtained at 40oC. To standardize the fermenta tion period for cellulase production, production rate was measured at 12-h intervals up to 120 h. Enzyme produc tion increased for 96 h of fermentation in both strains, and decreased thereafter. The enzyme production increased with increased inoculum size up to 3.0 percentage points. Asparagine as the nitrogen source was most effective in B. subtilis CY5, while beef extract proved useful in optimizing enzyme production by B. circulans TP3. Conclusion. The results of this study will help to standardize the requirements for optimum production of cellu lase by cellulase-producing fish gut bacteria and might contribute towards better fish feed formulation incorpo rating plant ingredients, especially in the larval stages when the enzyme system is not efficient .

—Silkworm larvae infected transovarially with Nosema bombycis were fed with an aqueous suspension of Bavistin (50% carbendazim w/w) at 2 and 3% concentrations. The treatments increased the survival of worms and reduced the pebrine infection in the lot significantly, although complete elimination of infection was not observed. Significant beneficial effects of the treatments at 2 and 3% were also observed with respect to larval, cocoon and cocoon shell weights and cocoon to shell ratio. However, treatments with Bavistin at 4% concentration produced an adverse effect on cocoon characters.

Two trace elements, copper (Cu) and zinc (Zn) in serum are elevated in cancer patients since both areconstituents of super oxide dismutase (SOD) as metalloenzyme, the enzyme that scavenge free radicals andactivated oxygen species in the body. The study of 52 cancer patients comprising of 31 carcinoma stomachand 21 breast cancer showed the elevation of both of these trace elements in serum when compared to 32healthy controls and effected the kidney functions as a consequences. Serum Cu and Zn were estimated byAtomic Absorption Spectrometer (AAS), analyzed statistically by student "t" test and marked elevationwas observed in cancer patient compared to healthy controls. Serum Cu and Zn values were 98.13 ± 17.49μg/dl 99..57 ± 13.91 μg /dl respectively in 38 healthy subjects and these trace metals were 156.23 ± 31.02 μg/dl and 171.86 ± 35.15 μg/dl in 52 cancer patients showing significant elevation (P

A soil isolate of Bacillus stearothermophilus was found to synthesize thermostable alpha-amylase. The enzyme was purified to homogeneity by ammonium sulfate fractionation and IECC on DEAE-cellulose column. The purified enzyme was considered to be a monomeric protein with a molar mass of 64 kDa, as determined by SDS-PAGE. The enzyme showed a wide range of pH tolerance and maximum activity at pH 7.0. The temperature tolerance was up to 100 degrees C with more than 90% catalytic activity; the maximum activity was observed at 50 degrees C. Divalent metal ions exhibited inhibitory effect on the enzyme activity. However, proteinase inhibitor did not react positively.

Degraded gum, obtained from the waste liquor after degumming of decorticated ramie with hot dilute alkali, can replace one-third of the urea-formaldehyde resin required for making jute-stick particle board.

Les resultats du greffage de fibres brutes et blanchies montrent que l'acrylonitrile est greffe sur la lignine et la cellulose

The reactions of bis(acetylacetonato)oxovanadium (IV) hydrate, VO(acac)2H2O, with different chelating ligands (containing at least one NH2 group) have been studied. In dry refluxing toluene, heterochelates of the type [VO(acac)(Lsbnd;L)]0(or+)·nH2O (where LL = neutral or monoanion of bidentate chelating ligands; n = 0–1) have been isolated. On the other hand, dibasic tridentate (LH2) or dibasic tetradentate (L′H2) Schiff bases replaced all the acetylacetonate anions from VO(acac)2H2O to produce VO(L)H2O or VO(L′) in refluxing toluene or ethanol. Analogous reactions of VO(acac)2H2O with aminoacids, aminoalcohols, semi- and thiosemi-carbazide in ethanol, methanol, water-ethanol or water-acetone mixture, produced a variety of mixed ligand complexes of oxovanadium(IV) ion involving Schiff bases, many of which show subnormal magnetic moments at room temperature. In the course of this study several mixed ligand oxovanadium(IV) complexes with neutral acetylacetone (or glycine) have also been isolated. The reactions of VO(acac)2H2O with chelating amino ligands in presence of even trace amount of water invariably result in the template syntheses of Schiff base chelates, which has been discussed qualitatively The electronic spectra of these chelates have been interpreted with the help of either C2V or C4V local symmetry. The elemental analyses, i.r. spectral data and cryomagnetic data have also been used to characterise the complexes.

DNAs have been isolated from various Oryza species and studied using physical techniques. The percent of guanine plus cytosine has been determined by thermal denaturation. While the base composition varied between the species, no heterogeneity in the base pair distribution was observed. Renaturation kinetics data of DNAs from different species show that the proportion of repeated DNA sequences vary considerably depending on the DNA content per cell, whereas the nonrepetitive DNA component remains relatively constant. These results suggest that in addition to a small range of DNA variation between the species, changes in the base composition and proportion of repeated sequences have accompanied divergence of the species within the genus.

Twenty-three newly synthesized mixed-ligand complexes of oxo-vanadium(IV) and oxo-vanadium(V) were studied for antimicrobial activity. Eight of these complexes were found to have microbicidal properties. The complexes [NH4][VO(gl)2]H2O (gl-H2 = glycolic acid) and [VO(ACOAP)(acac-H)]H20 (ACOAP-H2=Schiff base of acetylacetone and orthoaminophenol, acac-H=acetyl-acetone) show broad bactericidal spectra, while the complexes [VO(ACSAM)2]OH (ACSAM-H = Schiff base of acetylacetone and sulphanilamide) and [VO(CSSAM-H)2]H2O (CSSAM-H =Schiff base of 3-carboxy salicylaldehyde and sulphanilamide) possess pronounced antidermatophytic properties. The latter is inhibitory to plant pathogenic fungi as well. Plant tumour producing Agrobacterium tumefaciens is effectively inhibited in vitro by the complex [VO(ACTSC-Na)(acac)]H2O (ACTSC-H2 = condensation product of acetylacetone and thiosemicarbazide). Minimum inhibitory concentrations of all the active complexes are within the values of 0.125-2.00 mg/ml. Out of the 7 active complexes tested for 50% inhibition of conidial germination of Helminthosporium oryzae, a rice plant pathogen, only 1 complex, viz. [VO(acac) (ACACAACD)] (ACACAACD(H)NH4 equal Schiff base of acetylacetone and ammonium 2-amino-1-cyclopentene-1-dithiocarboxylate) shows a positive result. The effective concentration is 0.55 mg/ml. Three vanadium complexes were tested for insect sterilant and ovicidal properties on the red cotton bug, Dysdercus koenigi. The complex [VO(HASA-Na) (acac)]H2O (HASA-H2 = Schiff base of orthohydroxyacetophenone and anthr anilic acid) was found to be a suitable male sterilant.

In vitro culture ofBrassica alba anthers on a growth medium containing inorganics of KB5 and organics, iron, sucrose and hormones of B5 resulted in a very high response of anthers (93.75%) towards callus induction. All the calli transferred to regeneration media responded favourably even after six months of callus induction. Numerous torpedo-shaped embryoids developed in clusters at many sites from each callus mass. Secondary embryogenesis and multiple shoot formation was also observed in many cases. The number of embryoids and plantlets produced by one embryogenic anther were as high as 169.8 and 17 respectively. 87% of the regenerated plants were haploids.

A glucomannan, isolated by fractionation of the alkali-soluble hemicelluloses of sunn-hemp fibre (crotalaria juncea linn), had [α] -45° and, on hydrolysis, yielded glucose, mannose, and xylose in the molar ratios 1.2:1:0.07. The methylated polysaccharide contained an average of ≈45 hexose residues, whereas the corresponding value for the nitrate derivative was 49. Structural studies showed that the glucomannan has a main chain of (1→4)-linked β-D-glucopyranosyl and -mannopyranosyl residues. The molecule appears to have an average of one branch point, through position 6 of both glucose and mannose residues of the main chain. Both D-glucopyranosyl (87%) and d-mannopyranosyl (13%) residues were present as non-reducing end groups. D-glucose and d-mannose occur in the chain both as alternate and contiguous units.

A hydrocarbon utilizing strain of Arthrobacter globiformis Lb isolated from local soil has been found to yield lysine 3.4 g l−1, keeping the medium optimal for pH, C- and N-sources. Addition of antibiotics and micronutrients to that optimal media stimulated cell growth and enhanced lysine yield.

SUMMARYNuclear DNA syntheses have been measured microspectrophotometrically in course of meiotic nuclear development inNeurospora crassa. The purpose of the study has been to establish the timing of these DNA syntheses in relation to meiosis and in the formation of its final products in an ideal genetic material, where the products of the meiotic division can be recovered and identified. Spectrophotometric analysis has indicated that the last premeiotic DNA replication is completed before caryogamy; a postmeiotic DNA replication takes place at the tetrad of the nuclei level; and finally a second postmeiotic DNA replication occurs in the ascospores to result in eight binucleated ascospores. The timing of postmeiotic replication is compatible with the models explaining gene conversion through the postulated mechanisms involving heteroduplex formation.

Regeneration of rice plantlets (Oryza sativa L.) from calli originated from leaf sheath cells was made possible. This was possible in tissues initially grown in media containing 2.4-D (2.4-dichlorophenoxyacetic acid) at low temperature and illumination. The slow growing tissues were subsequently subjected to growth conditions at an elevated temperature and higher illumination with addition of kinetin and IAA and without 2.4-D. The suitability of leaf sheath cells for protoplast technology is indicated by this success.

Significant differences have been observed in the steady-state permeation of gases through symmetric and asymmetric (Loeb-type) cellulose acetate membranes. The studies were made with O2, N2, Ar, Kr, Xe, and CO2 in the temperature range from -5 to 85°C and at subatmospheric pressures. The differences in permeation behavior may reflect structural differences between the symmetric membranes and the dense surface layer (“skin”) of the asymmetric membranes. The overall mechanism of gas permeation through the symmetric membranes appears to be one of “solution-diffusion,” similar to that observed with many other nonporous polymeric membranes. In the case of the asymmetric membranes, this mechanism is probably modified by the presence of micropores or other imperfections in the dense surface layer. Cellulose acetate exhibits two second-order transitions in the presence of the penetrant gases, one between 60 and 70°C and the other near 15°C. The transitions were observed with both types of membranes.

The results of treatment of meiotic cells of Lilium longiflorum by cycloheximide at the time of chiasma initiation and formation suggest that in the sequential phases of nuclear development, complete chiasma suppression resulting in achiasmate cells is attained prior to a quantitative reduction of chiasma frequency. Reduction of chiasma frequency and complete suppression are believed to be based on two different mechanisms.

Pineapple-fibre holocellulose was extracted with alkaline solutions of increasing concentration to give hemicellulose fractions I–III. Purified fraction I (major component) contained d -xylose, l -arabinose, and 4-O-methyl- d -glucuronic acid in the molar proportions 10:0.6:1, and an average of ∼116 sugar residues, whereas its methylated product contained ∼94 sugar residues. Structural studies of the hemicellulose and its arabinose-free portion showed it to be a (1→4)-linked β- d -xylan with approximately every tenth residue carrying a 4-O-methyl-α- d -glucopyranosyluronic acid group at O-2 and every sixteenth residue carrying an l -arabinofuranosyl group at O-3.

It has been found that when one of the alkali metals is brought into electrical contact with some other metals like aluminium, cadmium, magnesium, etc., the contact resistance of the junction undorgoes remarkable variations under the influence of an electrical stress. The exact nature of the variation depends primarily upon the contact-combination of the metals. However, the nature and magnitude of the electrical pulse and polarizing voltage, the pressure applied to the surface junction, etc., play important roles in determining the finer characteristics of the variation. The prosent paper gives a brief account of our investigations on the potassium-aluminium surface combination only. A tentative explanation of these phenomena has been suggested on the basis of formation and disruption of an intermediate oxide layer under appropriate electrical conditions.

The ultrastructure of nuclear membrane and cytoplasmic lamellae have been studied at meiotic prophase in the microsporocytes of Lilium in vivo and in vitro in presence and absence of mitomycin C. Meiocytes were fixed in glutaraldehyde and OsO4 and sections were stained in uranyl acetate and lead citrate. The nuclear pores have been found to be octagonal in shape with eight microcylinders. The pore complexes are probably detached from the nuclear wall during the breakdown of the latter. At diffused stage in the mitomycin treated meiocytes triple layered unit membranes have been seen to form cytoplasmic lamellae. Two structural components, small dense granules and exceedingly thin filaments, have been seen always to be associated with these lamellae. These lamellae stain basophilic. They later arrange into stacks and change over to tubular ellipsoid forms. Sometimes these threelayered unit membranes have been seen to dissociate from chromatin at the time of the breakdown of the nuclear wall. The significance of the formation of these cytoplasmic lamellae has been discussed.The author thanks Prof. J. Straub, Dr. I. Anton-Lamprecht for their interest in this study and to Mrs. S. Sen, Miss B. Meyer and Mr. D. Bock for help. Financial grants from Alexander von Humboldt Stiftung and MaxPlanck-Gesellschaft are acknowledged gratefully.

The chlorite holocellulose of mesta fiber (Hibiscus cannabinus) was extracted with alkaline solutions of successively increasing concentration and finally with alkaline borate solution. Hemicellulose fractions (I–IV) were thus obtained. Analytical data are recorded for each fraction.Partial acid hydrolysis of the mesta hemicellulose gave 2-O-(4-O-methyl-α-D-glucopyranosyl uronic acid)-D-xylopyranose. Methanolysis and hydrolysis of the fully methylated hemicellulose (fraction II) gave a mixture of 3-O-methyl-D-xylose, 2,3-di-O-methyl-D-xylose, 2,3,4-tri-O-methyl-D-xylose, and 2-O-(2,3,4-tri-O-methyl-α-D-glucopyranosyl uronic acid)-3-O-methyl-D-xylopyranose in the approximate molar ratio of 1.6:34:1:6.4. The number-average molecular weight of the methylated polysaccharide was 18,400 ± 500 (degree of polymerization, 110 ± 3). The number-average molecular weight of the original hemicellulose (fraction II) was found to be 23,000 ± 500 (degree of polymerization, 164 ± 3). On the basis of this and other evidences it is suggested that the polysaccharide is composed of chains of 144 (1 → 4)-linked β-D-xylopyranose residues having approximately every seventh residue carrying a terminal 4-O-methyl-α-D-glucuronic acid residue linked through position 2. A small degree of branching in the backbone of D-xylose is indicated.

Isolated mesophyll protoplasts of Brassica juncea (L.) Czern., cv. RLM 514 upon culture in suitable growth medium, regenerated cell wall, underwent cell division and formed cellular colonies. Subsequent induction of embryoid (embryogenesis) and shoot bud (organogenesis) formations in such cell masses resulted in regeneration of 186 and 42 plantlets respectively.

Different enzymes were tested for isolation of intact protoplasts from pollen tetrads. About 80% isolation was achieved from pollen tetrads of Cajanus cajan and Zea mays and about 60% from Luffa cylindrica and Lycopersicon esculentum after 4 h of treatment with 5% cellulase. When these mononucleate protoplasts were incubated in presence of 0.05 M CaCl2 in 0.3 M glucose at pH 10.5, 70-80% fusion was achieved. Fusion was rare in sodium nitrate solutions.

A simple squash technique has been proposed to study the somatic chromosomes of crucifers. Essentially the technique consists of pretreatment with alpha-bromonaphthelene followed by fixation in methanol, acetic acid (1:1) and Newcomer's fluid, and staining with aceto-orcein. Consistent and excellent preparations have been obtained in rapeseed, cabbage, cauliflower, radish, turnip and Iberis spp.

Segregation of genes controlling expression of anthocyanin pigmentation in rice (Oryza sativa L. subsp. indica) leaf blade and leaf sheath was examined in the microspore-derived plants. The segregation pattern of marker genes was found to fit closely the expected gametic segregation ratios among microspore-derived green as well as albino plants. Microspore-derived in vitro regenerated plants expressed genetic traits similar to seedlings. The results indicate that the germ cell culture technique can be of significance while monitoring gene action, i.e. anthocyanin synthesis at monoploid phase of plant development.

The potentials of isolated plant protoplasts for fundamental and applied research studies of crop plants are being appreciated more than ever as discussed by many workers recently (1,2). Solanurn mammosum L. is an exotic Solanaceous species and is considered a promising source of solasodine for pharmaceutical industries (3). This communication reports on the success that we attained in isolation and regeneration of cultured cell protoplasts of this medicinal crop plant.

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The pectic substance of onion was treated with the enzyme polygalacturonase and then extracted with 70% ethanol to remove galacturonan and araban components respectively. The resulting material was methylated and fractionated to yield pure methylated galactan which on hydrolysis gave 2,3,4,6-tetra-, 2,3,6-tri-, and 2,3-di-O-methyl-D-galactose. Polysaccharide material containing 91·2% galactose, was isolated by separating the crude pectic substance on a DEAE–cellulose column followed by fractionation. Periodate oxidation studies were carried out on these two galactan-rich fractions. The structure of the repeating unit of galactan is discussed in the light of these results.