• Volume 99, Issue 1

      February 1989,   pages  1-81

    • Some observations on the chemistry and taxonomy of the tribe Bignonieae

      M Satyavathi M Radhakrishnaiah L L Narayana

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      Chemotaxonomy of 12 taxa of the tribe Bignonieae investigated resemble one another in the presence of syringly radicals, caffeic acid, gentisic acid, vanillic acid unknown phenolic compound L(68/69) uniformly positive activity of polyphenolase and overlapping incidence of several classes of secondary chemical constituents, phenolic compounds and unusual (non-protein) amino acids. The quantified chemical data indicate that Bignonieae are homogenous taxon and the taxa are closely related. The present study does not support the creation of Pyrostegineae and Oroxyleae.

    • Use of cuticular studies in distinguishing species ofDalbergia

      Parveen Farooqui N Venkatasubramanian V K Nallasamy

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      Cuticular characters were studied in 3 species ofDalbergia. In the closely related and often confusing speciesDalbergia latifolia andDalbergia sissoides, it has been found that the two species can be distinguished on the basis of cuticular characters. Epidermal cells of the lower epidermis ofDalbergia latifolia are prominantly papillate while those ofDalbergia sissoides are non-papillate. Some other interesting characters of the epidermis are also described.

    • Structure and development of fruit wall ornamentations inPergularia daemia (Forsk.) Chiov (Asclepiadaceae)

      P M Kuriachen Yash Dave

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      The follicle ofPergularia daemia (Forsk.) Chiov is ornamented with large number of branched and unbranched soft spines. The spine initiate before anthesis. It develops from the epidermal and subepidermal (ground tissue) layers of the ovary wall. A mature spine consists of an epidermis enclosing parenchymatous ground tissue with vascular strands and laticifers. Two types of trichomes, uniseriate multicellular and multiseriate multicellular, are present on the spine and fruit surface. The cuticle on the fruit surface is thick with a waxy coating. Stomata present on the fruit surface are slightly raised.

    • Histochemical and histoenzymological changes during heartwood formation in a timber treeShorea robusta

      A Kumar S K Datta

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      Histochemical and histoenzymological parameters in terms of starch, lipids, proteins, nucleic acids, phenolics and peroxidase, succinate dehydrogenase, acid phosphatase, ATPase and glucose-6-phosphatase have been studied in the wood ofShorea robusta. The young branch before the formation of the heartwood and one having just initiation of the heartwood have been studied to understand the histochemical and histoenzymological changes involved in heartwood transition. Significant changes have been marked during the transition. Peroxidase is highly active in the sapwood, however its activity becomes moderate in the transition zone and undetectable in heartwood. Succinate dehydrogenase activity remains intense throughout sapwood and transition zone. There is a remarkable increase in the acid phosphatase activity from sapwood to transition zone. Lipids are absent in the heartwood.

    • Loss of inoculated rhizobial population due to epigeal germination of seed and the influence of methods of inoculation on soybean yield

      K S Jauhri N S Subba Rao

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      A quantitative determination of the loss of inoculated rhizobial population due to epigeal germination of soybean seeds has been made. This loss increased with increasing levels of gum arabic used as an adhesive. With increasing soil moisture content and the depth of sowing, the loss was significantly reduced. In a related study when granular inoculant application was compared with conventional seed inoculation, no significant difference was noticed with regard to grain yield of soybean.

    • Ultimate fibres in tossa jute (Corchorus olitorius L.) and their utilization in selection

      Md Abbas Ali

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      An experiment was conducted with 11 indigenous genotypes and two cultivated varieties of tossa jute and studied the length, breadth and length/breadth ratio of ultimate fibre cells. The study indicated the highest mean length of fibre cells in the top part of the stem followed by middle and bottom parts. The mean breadth of fibre cells was notably large in the bottom part with a diminishing trend towards the middle and top parts. Among the genotypes and varieties studied, accession no. 1497 was found to have the highest mean length (3229·5 μ) of fibre cells in the top followed by middle (2488·7 μ) and bottom (1649·9 μ) parts. The highest breadth of fibre cells (20 μ) was observed in accession no. 1493 and the lowest breadth (15·3 μ) was obtained in accession no. 1497 in top part of the stem. The highest length/breadth ratio (211·20) was also observed in accession no. 1497 in top part of the stem.

    • Periphytic algae 1. Diurnal productivity and N2 fixation by microalgae colonized on an artificial substratum

      Naithirithi T Chellappa

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      The colonization of microalgae on an artificial substratum was successfully carried out by glass-slide method. After 30 days of colonization, a detailed investigation was undertaken to evaluate diurnal chlorophylla content, productivity and N2 fixation. Filamentous heterocystous blue-green algae were predominant on the glass-slide and pennate diatoms formed a sub-dominant group. The diurnal productivity pattern of periphytic algae showed an initial increase, followed by a characteristic mid afternoon dip, a peak at 16·00 h and a decrease thereafter. Higher primary production was observed in 2 μg/l of nitrate and phosphate amended series and inhibitory trend at higher concentration. The pattern of nitrogenase activity showed a strong correlation to temperature variation and chlorophylla content. C14 (Na2HC14O3) method was employed for primary productivity and acetylene reduction technique for nitrogenase activity. The results were analysed statistically.

    • Growth and population dynamics of an exotic weedParthenium hysterophorus Linn

      H N Pandey S K Dubey

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      Growth and population dynamics of different cohorts of a serious exotic weedParthenium hysterophorus L. were studied for two years. The seedlings were recruited in 3 successive cohorts in the beginning of rainy season. The density, survivorship and half life declined in successive cohorts. Although all the cohorts suffered heavy mortality during seedling stage, it was 100% in cohort III. Cohort I showed better growth than cohort II. Growth and reproductive effort of the plant in surviving cohorts were adversely influenced by the density of their own cohorts as well as by the other cohort. The established cohort strongly influenced the growth of the newly recruited plants through resource competition and/or allelochemics.

    • Spectral reflectance characteristics of vegetation and their use in estimating productive potential

      P S Roy

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      Spectral properties of plants have been utilized in the context of their usefulness in studying vegetation from remote sensing platforms. A synthesis of data on spectral properties, vegetation types, growth and energy conditions provides valuable information about biomass and productivity. A comparison of capabilities and methodologies to quantify vegetation from remote sensing platforms is presented. An approach has also been made to estimate biomass production of various ecosystems.

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