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The Structural and Drainage Patterns of the Wastern Ghats in the Vicinity of the Palghat Gap

Development of Mineral Resources of Western Rajasthan

Solutions of 3,4-dihydro-6,7-methylenedioxyisoquinoline (1) and analogues2–5 and9 as well as isoquinolines7 and8 in certain samples of CDCl3, CCl4, DMSO-d6 or acetone-d6 gave rise to anomalous1Hnmr spectra with extreme line broadening, signals due to protons at C-l and C-3 most often not being seen. The spectra of1 and3 were most striking in this respect.1Hnmr spectra of the quaternary salt10 and the model schiff base11 were normal. Several hypotheses for the observed line broadening have been considered and rejected, a slow equilibrium1 ⇆13 being one of them. NaBH4 reduction of1 and2 followed by mass spectrometric analysis of the crude tetrahydroisoquinolines16 and17 ruled out a slow equilibrium1 ⇆14 and2 ⇆15 as contributory cause for line broadening. The crude reduction products unexpectedly contained N-ethyl species22 and25. Their formation is rationalised

The gold-quartz and gold-bearing sulfide lodes of the Kolar field consist of north-striking, steeply west-dipping zones of en echelon veins, lenses, and stringers in intensely deformed and altered Precambrian schistose amphibolites (metabasalt), generally at or near contacts with massive amphibolite of the central zone or with granular amphibolite (metadolerite and metagabbro) or fibrous amphibolite (metapyroxenite?). The richest ore shoots are localized along crests and troughs of en echelon cross folds, and the highest grade mineralization has been found on either side of the Mysore North fault along the major axis of cross- folding. Vein mineralogy, the character of wall-rock alteration, and other features indicate the deposits to be of high-temperature hydrothermal origin.

Callus cultures derived from stem explants of Tylophora indica (Fam. Asclepiadaceae) show a broad spectrum of tissue differentiation and regenerative potentialities over a wide range of nutrient conditions resulting in the production of roots, shoots, bipolar embryos and plantlets. This has been investigated and interpreted on a histological basis. Studies on the morphogenesis of embryos have shown that only such embryonal cells which were deeply embedded with in the callus parenchyma showed an ontogenic development reminiscent of ovular embryogeny whereas in those organized in the superficial layer of the callus the sequence of embryogeny was entirely different. Free cells growing in agitated liquid media first developed into filamentous structures and eventually, by repeated intercalary divisions, organized into bipolar embryos. Development of accessory embryos through cleavage and budding in the callus, differentiation of amphicribral vascular nodules, and meristematic colonies organized into spheres of parenchyma were also observed. These alternative morphogenetic events probably reflect the biochemical subtleties occurring within the callus as a result of an inadequacy or an imbalance of the various constituents in the culture medium.

Introduction ..... ... ...... ....... .. .. ... 587 Early Developments in Plant Embryo Culture 588 Applications of Embryo Culture ......... 589 Recent Developments in Embryo Culture 591 M ed ia .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 591 Use of Plant Extracts 598 Amino Acids 600 Carbohydrates 601 Use of Agar 603 Effects of Auxins 604 pH of Media 606 Temperature and Light 607 Gases 607 Experimental Embryology 608 Culture of Bryophyte Embryos ......... 608 Culture of Fern Embryos 608 Culture of Gymnosperm Embryos 609 Culture of Angiosperm Embryos ......... 610 Conclusion 614 Literature Cited 616

1. Each spikelet in Setaria italica Beauv. is borne lateral to a bristle axis as are also the smaller bristles of a bristle shoot to a principal bristle axis. Therefore, the bristle shoot as a whole, and not the individual bristle, must be regarded as the morphological and homologous equivalent of a spikelet. 2. Microsporogenesis in this species is normal, and the divisions are of the successive type. The pollen grains are three-celled at shedding. 3. The ovule is anatropous, bitegmic, and crassinucellate. A narrow endostome, formed by the excessive growth of the inner integument, is hooded by part of the outer integument. A pair of nucellar cells abutting the micropyle becomes hypertrophied and richly protoplasmic. 4. A linear tetrad of megaspores is formed, and the innermost is functional. The embryo sac is organized in the usual fashion. Rarely the egg shows conspicuous lateral hooks otherwise found only in synergids. The synergids and the several, multinucleate antipodal cells commence to degenerate b...

SUMMARY The flower comprises two trimerous whorls of perianth lobes, of which the labellum is supplied by four to six vascular strands and the rest by three bundles each. Some of the mesophyll cells become enlarged and contain raphides. The fertile stamen is quadrilocular. At the tetrad stage only the epidermis and the fibrous endothecium persist, while the two middle layers and tapetum disintegrate. The tapetal cells are uninucleate and the microspores remain together in tetrads. The pollen grains are bicelled at the time of shedding. The tricarpellary inferior ovary bears an indefinite number of bitegmic anatropus ovules arising from three parietal placentae. The hypodermal archesporial cell differentiates directly into the megaspore mother cell which gives rise to a linear tetrad of megaspores. The upper dyad cell rarely degenerates before the division is completed. In one instance a row of five cells was noticed. This might have arisen from two superposed megaspore mother cells or from an extra division of one of the megaspores. The chalazal megaspore functions. The mature embryo sac is usually six-nucleate, probably due to a suppression of the last division of the two chalazal nuclei. The single antipodal cell degenerates early and may not be seen in mature embryo sacs. The two polar nuclei may fuse to form the secondary nucleus or degenerate without fusion. Syngamy occurs, but triple fusion is delayed or is omitted altogether so that there is no endosperm formation. The first division of the egg is transverse. The mature embryo is ovoid in shape and undifferentiated. It has no suspensor haustoria and is enclosed within the seed coat formed by the outer integument. Various abnormalities have been recorded. Evidence is presented to indicate that parthenogenetic development of the egg is possible and does occur in some ovules. In such embryo sacs the undischarged pollen tube is usually seen beside the egg, but parthenogenetic embryos have also been observed in embryo sacs that had apparently not received a pollen tube at all. These observations have been confirmed by chromosome counts during division stages of the egg as well as in cells of the pro-embryo. Occasionally an embryo sac receives more than one pollen tube. Both the male nuclei of a pollen tube or the male nuclei of different pollen tubes may fertilize the egg, indicating the possibility of polyploid embryos.

Photoisomerisation of (Z)-4-(2-acetoxybenzylidene)-2-phenyloxazolin-5-one gave the E-isomer. The stereochemistry of each form was established by successive treatment with alkali and acid: the former gave an o-hydroxycinnamic acid and the latter a coumarin. Catalytic (10% palladium–carbon) hydrogenation of (Z)-α-benzoylamino-o-benzyloxy[β-2H]cinnamic acid and cyclisation (dicyclohexylcarbodi-imide) of the resulting phenolic acid gave 3-benzoylamino-3,4-dihydro[4-2H]coumarin. The trans-orientation of the hydrogen atoms in this product, revealed by n.m.r. spectroscopy, showed that hydrogenation of the cinnamic acid had occurred in a cis manner with high stereoselectivity.

Differentiation of shoots and roots or unorganized proliferation could be induced in tissue cultures of Solanum xanthocarpum when callus tissues habituated to a medium containing 2.4-D and meso-inositol were transferred to an auxinfree medium or to a medium in which the ratio of auxin and meso-inositol had been altered.

RECENTLY, we began a study of the morphogenetic effect of various factors on the gemmae of Marchantia polymorpha and Lunularia cruciata. These structures offer excellent material for such studies, since they are readily obtainable in quantity at all seasons of the year, are large enough to be handled readily, but small enough to be economical of space and require no special equipment for their study beyond some Petri dishes and a dissecting microscope. We have found that they are sensitive to treatments of many kinds; but for some reason they seem to have been overlooked, for we have been able to find only one paper on experimentation with them—that of Nagai1, who plasmolysed them with rather interesting results.

Analysis of tissue cultures of Solanum xanthocarpum subjected to the influence of different plant hormones such as 2,4-D, IAA, IBA, kinetin and GA singly and in synergistic combinations showed changes in the steroidal content indicating chemical regulation by auxins.

Diosgenin and beta-sitosterol were isolated from Solanum xanthocarpum callus, crystallized, and chemically characterized. That these metabolites, particularly diosgenin, form in significant amounts in tissue culture may prove useful.