• Volume 91, Issue 2

      April 1982,   pages  79-174

    • Chandrasekharania: a new genus of Poaceae from Kerala, India

      V J Nair V S Ramachandran P V Sreekumar

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      A new genus,Chandrasekharania and a new speciesChandrasekharania keralensis under it are being described from Cannanore District, Kerala.

    • Chromosome relationships of spinous solanums

      P B Kirti B G S Rao

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      Chromosome pairing was studied in reciprocal hybrids ofS. integrifolium andS. indicum and theF1S. integrifolium × S. surattense. Pairing was generally close and meiosis regular with higher chromosome associations. All hybrids were highly sterile. Such sterility could be due to the formation of unbalanced gametes following pairing and exchange between partially homeologous chromosomes.S. integrifolium, S. indicum, S. surattense along withS. melongena and its wild forms form a closely related group of taxa.

    • Groundnut rust—its survival and carry-over in India

      P Subrahmanyam D McDonald

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      Groundnut rust has become an important disease in India, particularly in the South, probably because of extensive and continuous cultivation of the crop. Uredospores present on crop debris in the field, and on pods or seeds in storage at ambient temperatures, lost viability within 6 weeks. They retained viability for long periods when stored at −16° C. Neither teliospores nor any collateral or alternate hosts were found. Seeds heavily contaminated with viable uredospores and sown in sterile soil gave rise to disease-free seedlings. There should be no risk of spread of rust from properly treated seed samples.

    • Correlated promotion of ray-floret growth in chrysanthemum by potassium chloride, gibberellic acid and sucrose

      P Pardha Saradhi H Y Mohan Ram

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      The role of 10−2 M, 2×10−2 M, 4×10−2 M potassium chloride, gibberellic acid (10−5 M; GA3) and sucrose (5×10−2 M) (used individually and in various combinations) in the elongation growth of excised ray-florets ofChrysanthemum morifolium var. Jyothsna, was investigated. KCl (10−3 M) caused 33·3% increase in elongation as compared to control (16·7%). With GA3 and sucrose the percentage of elongation recorded was 39·8 and 28·9 respectively. Maximal growth response (82·8%) was recorded in KCl (4×10−2 M)+GA3 (10−5 M)+sucrose (5×10−2 M). When used in combination either with GA3 or sucrose, KCl showed an almost additive effect, whereas in the presence of both it acted synergistically. It is inferred that the increased turgor resulting from sucrose-promoted potassium uptake along with GA3-caused tissue extensibility accounts for enhanced floret growth.

    • Nuclear behaviour during heartwood formation inAcacia auriculiformis A. Cann.

      K V Bhat J D Patel

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      Nuclear behaviour is studied inAcacia auriculiformis A. Cann. with reference to aging in both axial and ray parenchyma cells (contiguous to vessels and away from the vessels). The size of the nucleus and nucleolus reduces gradually towards the inner sapwood and at last they disappear at the heartwood boundary. Nuclei show lobing, fissuring, fragmentation and contraction in this zone prior to their disintegration. Thus a gradual loss of vitality of parenchyma cells during aging is noted. The parenchyma cells contiguous to vessels seem to be more actively involved in formation of heartwood extractives.

    • Identity ofFicus macrocarpa Wt.ex King (=F. amplocarpa nom. nov.) andF. guttata (Wt.) King — A reinvestigation with anatomical evidence

      E Govindarajalu P Masilamoney

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      The two interesting and endemic but hitherto taxonomically indistinguishable and confused south Indian species ofFicus (F. guttata andF. macrocarpa) were reinvestigated both exomorphologically and anatomically. With the help of data thus obtained their original specific status instead of recently reduced ranks has been restored, better and dependable distinguishing characters have been blocked out and the existing confusions, inaccuracies and inconsistencies in literature have all been rectified. Revised descriptions, illustrations and a workable key are presented. Vegetative anatomy and the descriptions and illustrations of male flowers are given for the first time.F. amplocarpa is proposed as a new name forF. macrocarpa in view of its being a later homonym. It is established that these two taxa belong to sectionNeomorphe King and not toRhizocladus Endl. AnatomicallyF. amplocarpa is considered to be less speciallized thanF. guttata.

    • The genusJackiella in South India

      Ram Udar Adarsh Kumar

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      Jackiella ceylanica Schiffn.ex St. andJ. javanica var.cordifolia Schiffn. are being reported for the first time from India. The taxonomic details of the two taxa together with a discussion of the tenability of two varieties ofJ. javanica Schiffn. namely var.cordifolia and var.cavifolia have been given.

    • Geocalyx Nees—a rare marsupial gerus from India

      Ram Udar S C Srivastava Dhirendra Kumar

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      Taxonomic details ofGeocalyx graveolens Nees recently discovered from the Valley of Flowers in western Himalayas (altitude ca 4670 meters) have been provided. The discovery of this genus in the above area not only extends its range of distribution in the Himalayas but also coastitutes a new record of this taxon in Indian bryoflora. The plants are monoecious and characterized by undulating stem, bifid leaves which are flat or ascending, and bifid underleaves. The androecial and gyaoecial branches are ventral and axillary. The marsuplum arises initially as tuber-like structure (often 2–8 in number on the ventral surface of a plant) and, at maturity becomes cylindrical with numerous rhizoids studded on its surface.

    • Ontogeny of the paracytic stoma: Variations and modifications

      Parveen Farooqui

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      It was generally believed that the topography of the cells surrounding the guard cells in the mature condition indicate their mode of development. However, it has now been established that more than one ontogenetic type may correspond to a single mature type, or it may lead to the development of varied stomatal types. The paracytic stoma was studied from this viewpoint. It was found that it may be formed through one of at least eight different modes. These are classified and reviewed. The need to undertake studies on the ontogeny of this type of stoma in various groups of plants has been emphasized.

    • Growth response of some thermophilous fungi at different incubation temperatures

      S Singh D K Sandhu

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      Growth response of 21 thermophilous fungi at 10 different temperatures from 15–62° C has been studied. These fungi could be categorized into three groups, i.e., microthermophiles, thermotolerant and true thermophiles. The temperature relations of 6 thermophilous fungi namelyAspergillus tamarii, A. terreus var.aureus (microthermophiles),A. nidulans var.echinulatus A. viridi-nutans, A. fumigatus var.ellipticus andA. caespitosus (thermotolerant) are being reported for the first time. The growth rates of different fungi varied from 0·19–1·25 mm/hr at their optimum temperatures.Penicillium sp. the slowest andThermoascus sp. were the fast growing fungi.

    • Studies onBeggiatoa: Distribution and growth in aquatic habitats of visakhapatnam

      M R R Mohan A Narayana Rao

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      Beggiatoa is distributed in 11 of the 12 polluted aquatic habitats occurring on the sediment and decaying leaves as a thick white scum at 2, in detectable population at 6, and in very less population at 3 habitats where H2S necessary for its growth is produced. TheBeggiatoa spp. present in these habitats are considered as belonging to the 6 species described in Bergey’s manual.B. minima with less than 1·0,B. leptomitiformis with 1·66,B. alba with 3·32 and and 4·98 μ wide trichomes are distributed in 2, 6, 11 and 2 habitats respectively, which are fresh water, brackish and marine habitats.B. arachnoidea with 9·96,B. mirabilis with 17·0 andB. gigantea with 28·22 μ wide trichomes are present in only one brackish habitat.B. alba (3·32 μ) occurs alone at 2 habitats, and in association with either one or more of the otherBeggiatoa species at the remaining 9 habitats. ExceptB. mirabilis andB. gigantea, the others distributed in the 11 habitats could multiply in enrichment culture media that contained extracted rice straw pieces and waters from their respective habitats, and aggregate into visual white colonies, or loose clumps in a thick film on the surface of medium, rice straw pieces and glass.B. mirabilis andB. gigantea seem to be halophilic, truly autotrophic and more exacting than the other species that exhibited differences in salt tolerance when grown in crude enrichment culture media of differing, salt content. It appears that physiological strains or groups differing in salt tolerance may be existing in these species ofBeggiatoa.

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