Somatic hybrids between Brassica juncea (L). Czern. and Diplotaxis harra (Forsk.) Boiss and the generation of backcross progenies

An attempt to transfer genes from droughttolerant Diplotaxis harra, a wild relative of Brassica species, to an elite oil-yielding cultivar, B-85, of mustard (Brassica juncea) was made through protoplast fusion, as the two plant systems are sexually incompatible. By following the standard protocol for PEG-mediated protoplast fusion followed by high pH, high Ca(++), DMSO treatment and appropriate cell-culture technique, 16 presumptive somatic hybrid plants could be regenerated. Chromosomal analysis of four such somatic hybrids revealed that three of them were asymmetric. Analysis of morphological characters, meiotic chromosomes, and esterase isoenzyme pattern revealed that all the somatic hybrids were different from each other. Furthermore four chromosomes of each genome could undergo homoeologous pairing at meiosis indicating the possibilities for genetic recombination and chromosomal rearrangements. Irregular distribution of chromosomes at anaphase-II at meiosis has been a consistent feature of these plants. Eventually, pollen of all the somatic hybrids showed complete infertility preventing the recovery of any selfed seed. Nevertheless, ovule fertility of one somatic hybrid was not totally impaired as it had set some seeds upon backcrossing with the B. juncea parent. The esterase isoenzyme banding pattern of 24 individual progeny plants of this backcross provided evidence for their recombinant nature. It was thus confirmed that a transfer of genetic traits from Diplotaxis harra to B. juncea had indeed taken place. Furthermore, it was conceptualised that a transfer of alien genes through the protoplast-fusion technique is primarily possible in situations where meiotic pairing of the chromosomes of the two participating genomes generates recombinant gametocytes which can pass through subsequent filial generations.

Characterisation and identification of broad spectrum antibiotic producing Streptomyces hygroscopicus D 1.5

A streptomycete strain D1.5 capable of producing broad spectrum antiobiotic was isolated from soil. The morphological, cultural, physiological and biochemical characters were studied, compared to known species and identified as Streptmoyces hygroscopicus. Antibiotic activity of the strain was tested against both Gram positive and negative bacteria as well as fungi. It exhibited complete resistance to beta-lactum antibiotics.

Effect of different fractions of petroleum ether (60-80 degrees) extract of the seeds of Lagerstroemia speciosa (Linn. ex Murray) Pers. on some microorganisms

In a model experiment, seed extracts were applied to different bacterial test organisms. Different fractions of seed extracts in petroleum ether (60-80 degrees C) of Lagerstroemia speciosa (Linn. ex. Murray) Pers. when applied to both Gram positive and Gram negative test bacteria, some fractions showed high antagonistic activity.

Alpha-amylase production in lactose medium by Bacillus circulans ACB

Alpha-amylase production by Bacillus circulans ACB was studied in various cultural conditions. During nutrient optimisation, it was found that 2% lactose can be utilized by the strain as source of carbon providing better growth and enzyme yields than starch. Ammonium sulfate of the basal medium can be replaced by ammonium nitrate for better growth and alpha-amylase activity. The strain demonstrated significant enhancement in alpha-amylase production when grown at pH 6.6.

Screening and identification of antibiotic producing strains of Streptomyces

About 450 actinomycetes were isolated from nearly 100 soil samples collected from different parts of West Bengal. The isolates were screened on the basis of their inhibitory effect against test organisms. Finally two potent antibiotic producers were chosen having maximum inhibitory effect on both gram positive and gram negative test bacteria. On the basis of morphological, structural, physiological and biochemical characters, the two potent antibiotic producers were identified as Streptomyces violaceus-niger and S. antibioticus.

Effect of different fractions of methanolic extract of the seeds of Dolichos biflorus on some microorganisms

Extracts from different parts of plants (1) including seeds are reported to act upon pathogenic microorganisms. A few active principles were isolated. The present preliminary report shows significant role of the seeds of Dolichos biflorus (Linn), locally known as Kulthi, against some test organisms using different fractions of defatted seed extracts with methanol.

Micropropagation of an elite Darjeeling tea clone

Shoot cultures of Camellia sinensis (L.) O. Kuntz var. T-78, an elite Darjeeling tea clone, were established from cotyledonary nodes and shoot tips of germinated seedlings as well as from nodal explants of field grown plants. Shoot multiplication rate ranged from 4x in nodal explants to 35x in cotyledonary nodes after 18 weeks of culture. Rooting was achieved in 80-90% micro-shoots by either placing them on an inductive medium for 10 d and then transferring shoots to hormone-free medium, or by treating micro-shoots with a chronic dose of IBA (500 mg/l) for 30-40 min. Rooted plants were established in soil under glasshouse condition at 60% frequency after hardening phase of 4-6 weeks. The regenerated plants show a constant chromosome number of 2n=30 and are morphologically true to type. This procedure can be applied for conservation and utilisation of an elite clone of Darjeeling tea.

Somatic embryogenesis in protoplast derived calli of cultivated jute, Corchorus capsularis L

Protoplasts were isolated from cotyledon, hypocotyl and mesophyll cells of Corchorus capsularis L., a major fibre crop, by one step enzyme digestion method. They were further cultured successfully on modified KM-8p (Kao and Michayluk, 1975) medium to form microcalli. The required cultural conditions could be used to achieve 34% to 78% plating efficiency, depending upon the source of protoplasts. Hypocotyl protoplasts gave the highest plating efficiency. On transfer to regeneration medium, somatic embryos developed at high frequency. The present success is a significant step forward in the development of meaningful plant cell culture methods for application in jute.

Isolation and cloning of Bacillus thuringiensis var Kurstaki HD73 toxin gene and construction of a chimaeric gene for expression in plants

Necessity for the production of transgenic crop plants of India, capable of expression of insecticidal Bt protein in plant to combat lepidopteran pest damage has been strongly felt. Bacillus thuringiensis Kurstaki HD73 crystal protein coded by CryIA(c)73 gene has been found to be sufficiently effective against the major pests of jute and chickpea. An attempt to isolate the gene and make its use in a chimaeric gene construct for expression in plant was carried out. The plasmid CryIA(c)73 gene was cloned and tailored at the 3' end. The expression of the truncated gene was monitored in the minicell systems of E. coli. The entomocidal property was found to be fully retained by the gene product. Deletion of the nucleotides at the 5' end was carried out and chimaeric gene construct of cryIA(c)73 was made in such a way that it was fused in frame with GUS gene under the control of the caMV 35S promoter with Nos polyadenylated terminus. Such a chimaeric gene construct was used as the passenger of a Ti plasmid derived plant vector with kanamycin gene (NPTII) as the additional plant marker. Transformation through infection of tobacco and mustard plant cells in culture was carried out. Plants regenerated from the transformed cells showed the presence of GUS gene indicating the expression of the cloned fused gene. Also, Northern analysis established the presence of cryIA(c)73 gene transcripts in the transgenic plants.

Interaction of T-DNA border sequences and Ti-plasmid vir functions of Agrobacterium results in differential single-stranded linear T-DNA molecule production and plant transformation

The mechanism of Agrobacterium mediated genetic transformation of plants is dependent upon certain genetic function of the chromosome of the bacterium as well as on Ti-plasmid borne vir loci and the border sequences of T-DNA. The organisationally variable forms of the naturally occurring border sequences amongst Ti-plasmid types are differentially responsive to gene products of vir loci concerned with T-strand production. Additionally, the production of stable transformants is dependent upon vir gene products effective after T strands are produced. The interaction of border sequences from different strains of Agrobacterium with vir proteins encoded by various helper plasmids revealed that functional differences do exist amongst vir gene products contained in the type of helper plasmids used.

Plant regeneration through somatic embryogenesis from suspension culture-derived protoplasts of Paspalum scrobiculatum L

Protoplasts were released from embryogenic suspension culture of Paspalum scrobiculatum and cultured in either liquid or semisolid KM medium supplemented with 2,4-D in the dark at 24°C with or without a feeder layer. Cell wall formation was observed in 75% of the plated protoplasts. Microcolonies developed after 10 d of culture, which in turn formed callus upon transfer to M-2 medium (Nayak and Sen, 1989). The highest plating effeciency (ca 7%) was obtained in thin-layer liquid culture. The macrocalli formed somatic embryos which regenerated to plantlets. The plantlets were grown to flowering plants upon transfer to soil.

Isolation method for lysine-excreting mutants of Arthrobacter globiformis

To improve the yield of lysine by the isolate, auxotrophic mutants were isolated. Among the mutants, only one auxotrophic mutant required vitamin B12. This mutant produced alpha-alanine. About 200 mutants resistant to the lysine analog S-(2-aminoethyl)-L-cysteine were isolated and some of them produced well above the wild type.

Cholinergic vasodilatory effect of an imidazoindole on the nephrosclerosis of hypertensive rats

Pyridino [1,2-a] imidazo [5,4-b] indole (Compound 1) has been reported previously as an antihypertensive agent. Parenteral introductions of Compound 1 in spontaneously hypertensive rats (SHR) and in normotensive dogs have been found to reduce systolic blood pressure (SBP) in those animal models. Later studies have shown cholinomimetic effects of Compound 1 in animal tissue preparations and in live animals. Our experiments showed that daily oral administration of Compound 1 minimized the development of hypertensive nephrosclerosis and prevented premature death in male SHR. Compound 1 also potentiated cholinergic activity in isolated rabbit hearts. It is suggested that cholinergic vasodilation by Compound 1 is responsible for the hypotensive effect and prevention of nephrosclerosis in SHR.

Plant regeneration from mesophyll protoplasts of Diplotaxis muralis, a wild crucifer

Mesophyll protoplasts from leaves of aseptically grown shoot tips of Diplotaxis muralis were isolated (6.2-7.1×10(5) protoplasts/g fresh weight of tissue) using one step enzyme digestion. The protoplasts (71% viability) underwent divisions (4.2+0.1%) on plating in M8PS2 medium and ultimately formed calli with 0.45+0.03% plating efficiency. Plant regeneration could be achieved both through embryogenesis and organogenesis. The efficiency of plant regeneration through organogenesis was 9 times higher than embryogenesis. Forty eight out of 52 plants regenerated so far from 3 independent experiments were normal with respect to fertility and meiotic chromosomal behavior.

"Erussica", the intergeneric fertile somatic hybrid developed through protoplast fusion between Eruca sativa Lam. and Brassica juncea (L.) Czern

Hypocotyl calli-derived protoplasts of two cultivars of Brassica juncea (2n=36), a major oil-seed crop, were fused with normal as well as γ-irradiated mesophyll protoplasts of Eruca sativa (2n=22). The irradiation of the Eruca fusion partner increased the plating efficiency as well as the morphogenic potentiality of the fusion products over the normal fusion. Fertile plants could be regenerated from such fusion products. Analysis of 63 out of 181 plants regenerated showed that, indeed, 11 somatic hybrids (2n=58) and 10 partial somatic hybrids (chromosome number ranged between 50 and 56) had been obtained. Pollen viability (0%-82.9%) and seed set (0%-50%) of the hybrids indicated them to be useful for future studies.

Plant regeneration through somatic embryogenesis from suspension cultures of a minor millet, Paspalum scrobiculatum

Compact, friable and embryogenic calli were initiated from immature inflorescences and young leaf bases of one week old seedlings of Paspalum scrobiculatum cultured on MS medium supplemented with 2,4-D. A stable, embryogenic suspension culture was initiated from these calli and maintained in a liquid version of the same MS medium. Embryogenic calli and somatic embryos were obtained by plating suspension culture cells onto semi-solid medium containing 2,4-D. Complete, normal plantlets developed on 2,4-D free medium at a high frequency from somatic embryos. NAA and BAP in the medium promoted plant development.

Intergeneric somatic hybrid production through protoplast fusion between Brassica juncea and Diplotaxis muralis

The need to transfer genetic traits from Diplotaxis muralis (2n=42) to Brassica juncea (2n=36), a major oil seed crop of the tropical world, was realised. Since the two plant types are sexually incompatible, attempts were made to evolve parasexual hybrids as the result of protoplast fusion. Protoplasts of hypocotyl-derived calli of two cultivars of B. juncea were fused with normal and γ-irradiated mesophyll protoplasts of Diplotaxis muralis. Regeneration of 110 plants from the fused products was successfully achieved. Upon analysis of some of them, we realised that true somatic hybrids and partial somatic hybrids had been generated. Thus the primary goal of evolving intergeneric hybridisation products between these two plant types was fulfilled.

Regeneration of plants from mesophyll protoplasts of the wild crucifer Eruca sativa Lam

Protoplasts isolated from mesophyll cells of Eruca sativa Lam., cultured on suitable medium, underwent sustained cell divisions to form calli. The plating efficiency was found to be 0.4%. The protoplast-derived calli subsequently produced plantlets through organogenesis (15.71%) and somatic embryogenesis (11.25%). Regenerated plants exhibited normal appearance. These results indicate potential to introgress desirable traits from this wild crucifer into important oilseed and cole Brassicas by protoplast fusion and hybrid recovery.

Synovial sarcoma

Joints and adjacent tissue are probably the site of origin of synovial sarcomas. From the literature review, however, it appears that in some instances synovial sarcoma may be of extra-articular soft tissue origin. This type of tumor should be considered highly malignant. It appears that the incidence is low among black Americans. The etiology is not known definitely, but trauma is incidental rather than a predisposing factor.

In vitro segregation of marker genes in anther cultures of rice

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.

Endobronchial tuberculosis in an adult

Although endobronchial tuberculosis has been thought to be a common childhood illness, this report is of endobronchial tuberculosis in an adult, who presented with chronic cough, a normal chest radiograph, and tuberculin conversion. The lesions were discovered at bronchoscopy, which showed complete resolution when repeated after six months of antituberculous therapy.

Cutaneous sporotrichosis presenting as soft tissue sarcoma

Sporotrichosis is not an uncommon disease. Lymphocutaneous involvement is the common characteristic but systemic dissemination from the primary skin lesion has been observed. The disease is progressive but spontaneous resolution, in rare instances, has been observed. Multiple, fungating, ulcerated, tumorous cutaneous lesions, fixed to the underlying tissue, often pose a difficult diagnostic problem, as in this case. The disease has been frequently related to occupational exposure to plant life, but handling of infected animals may be a source of infection in rare instances.

Regeneration of plantlets from mesophyll protoplasts of Brassica juncea (L.) Czern

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.