• Volume 99, Issue 4

      August 1989,   pages  301-403

    • Seed coat and hypocotyl pigments in greengram and blackgram

      R N Pandey S E Pawar G J Chintalwar C R Bhatia

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      Three anthocyanins were found inVigna radiata (greengram) accessions with black seed coat, but were absent in cultivars having green seed coat.Vigna mungo (blackgram) had only one of them. The same 3 anthocyanins were found in cultivars with purple red hypocotyl ofVigna radiata accessions but were absent in the ones with green hypocotyls.Vigna mungo with purple red hypocotyls showed the presence of two anthocyanins. One common to both was identified as delphinidin-3-glucoside and the other is probably cyanidin-3-glucoside. Among the two accessions ofVigna radiata varsublobata examined, one was similar toVigna radiata accessions with black seed coat having delphinidin-3-glucoside and two other anthocyanins, while the other resembledVigna mungo having only delphinidin-3-glucoside in seed coat and both delphinidin and cyanidin-3-glucosides in hypocotyl. Chlorophyll content of the seed coats was in the following decreasing order: green, black, brown and yellow. Browning of the seed coat of cv TAP-7 after storage over a year was associated with reduction in chlorophyll content.

    • Ontogenesis ofin vitro shoot bud proliferation inSolanum sarrachoides Sendt.

      N Banerjee S Mukhopadhyay A K Sharma

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      In vitro direct induction of multiple shoot buds ofSolanum sarrachoides Sendt. was obtained from leaf segments using Murashige and Skoog’s basal medium supplemented with 6-γ-γ-(dimethylallylamino) purine (1·5–2·5 mgl−1). Maximum shoot bud proliferation was observed in the medium containing 2 mgl−1 and better growth of plants with well defined roots, leaves, flowers and fruits in the subsequent stages of development. Histological examination at different stages of development confirmed that the multiple buds produced on excised leaf segments arise adventitiously through the formation of numerous tiny protuberances. The complete sequence of events leading to multiple bud formation based on histological studies has been presented.

    • Potassium effect on tissue hydration and transpiration in cauliflower

      Sandhya Singh C P Sharma

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      Cauliflower (Brassica oleracea L. var. Botrytis L. cv. Pusi) grown with 0·2, 0·4, 0·8, 2·0 and 4·0 mM K produced best growth and optimum dry matter at 4 mM K. Suboptimal K supply caused decrease in tissue concentration of K and produced visible symptoms of K-deficiency. Leaves of low K plants showed decrease in stomatal aperture associated with increase in stomatal resistance and decrease in transpiration. At the same time, their specific leaf weight was high and relative water content was low, indicating poor tissue hydration. Low K leaves also showed increased accumulation of proline. The magnitude of the K-deficiency effects was related to the severity of K-deficiency. Observations suggest poor absorption-transport of water under K-deficiency.

    • Effect of environment on pigment ratios inDunaliella spp. from the salt pans of Gujarat

      Usha D Muraleedharan J I Goes Aditi Pant

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      The effect of varying salinity and pH of the medium on growth and pigment ratios ofDunaliella cells in culture was studied. Cell growth was found to be optimal at pH 8 and at intermediate salt concentrations of 1–2 M NaCl. Ninety per cent acetone extracts of cells grown in media containing up to 2 M NaCl showed two distinct absorption peaks with maxima at 433 and 663 nm due to carotenoids and chlorophylls. The ratio of carotene to chlorophyll appeared to be maximum for cells grown in 1 M NaCl and to increase with the age of the cells in culture.

    • Ecological and phytogeographical observations on the fern flora of Pithoragarh district (north-west Himalaya)

      N Punetha

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      A detailed account of ecology and phytogeography of the ferns of Pithoragarh district of Kumaon (north-west Himalaya) is discussed. Common mesophytic ferns are the species ofAdiantum, Athyrium, Cheilanthes, Christella, Dryopteris, Lygodium, Osmunda, Pseudocyclosorus andPteris. Polypodiaceous ferns are either epiphytes or lithophytes.Ceratopteris thallictroides is the only aquatic fern. From phytogeographical point of view it is observed that on the one hand the fern flora of this region bridges the floristics of eastern and western Himalaya, and on the other it resembles much with the fern flora of south China. About 70% ferns are common with Simla hills and 85% with Darjeeling and Sikkim himalaya.

    • Splash dispersal inRamulispora sorghi Olive and Lefebreve, the casual organism of sooty stripe of sorghum

      A H Rajasab A Ramalingam

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      The conidia ofRamulispora sorghi were produced in a mucilaginous mass and dispersed through splash-off and wash-off mechanisms during rain, while the sclerotia ofRamulispora sorghi were produced freely and attached superficially to the host leaf surfaces, dispersed through air over short distances and deposited on the sampling surfaces at the rate of 22 sclerotia/cm2/day.

      Greater number of conidia were monitored by splash traps during the kharif crop period as compared with that of rabi. The peak conidial dispersal was noticed during the 10-leaf stage—flag leaf growth stages of sorghum crop. Both incident water drops (splash-off) and flowing water drops (wash-off) liberated the conidia from the sporulating lesions. Peak liberation of conidia occurred with the water drops from 3–7 and most conidia were removed from the sporulating lesion within 60 s indicating the possible dispersal of the pathogen even during short traces of rain.

    • Growth strategies of early and late successional shrubs from a subtropical moist forest under two light regimes

      U Baruah P S Ramakrishnan

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      Two early successional shrubsMallotus indica Muell. andClerodendron infortunatum Gaertn. and two late successional shrubs,Litsea khasiana Meissn. andCombretum flagrocarpum Herb. were studied under both open and shade environments. The early successional species had greater dry weight allocation to the stem and leaf components and lesser allocation to the root component. Thus the early successional species had an exploitative strategy for effective light capture and utilization of nutrient enriched surface soil after clear-cutting of a forest. On the other hand, the late successional shrubs showed a reverse pattern in allocation. This was related for their survival and to make adequate growth in a competitive environment. These differential strategies of the two categories of shrubs was also reflected in the lower nutrient uptake efficiency and higher use efficiency of the late successional species compared to the early successional ones. Under shade the dry weight production of late successional species was reduced to a less extent than that of early successional species. This would presumably have a competitive advantage for the former category of species.

    • Architecture and growth patterns of early versus late successional shrubs of sub-tropical moist forests of north-eastern India

      U Baruah P S Ramakrishnan

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      Growth and architecture of early versus late successional shrubs are compared and contrasted to evaluate their leaf display characteristics. Early successional shrubs had a higher growth rate over an extended period of time compared to late successional shrubs. Inter-branch length and branch angle were greater for late successional species as compared to early successional ones. First- and second-order branch production over third-order branches was greater in late successional shrubs, whereas the reverse was the case for early successional ones. On the other hand, length contribution by all branch orders was higher for the early successional species. The bifurcation ratio was significantly higher for early successional species growing in the open as compared to late successional shrub species growing in shade. Early successional shrubs follow an exploitive strategy and make faster growth whereas late successionals have a conservative strategy for survival in shade.

    • Taxonomic position ofCentella asiatica (L.) Urban

      I A Hamal A K Koul

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      Centella asiatica is taxonomically distinct fromHydrocotyle sibthorpoides. This is substantiated by the light microscopic studies on chromosomes and scanning electron microscopic studies on morphological features of pollen and fruit.

    • Lichen genusCatillaria s. lat. in India

      G Pant D D Awasthi

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      The paper deals with the morphotaxonomic study of 10 species of the lichen genusCatillaria s. lat. from India. Three speciesCatillaria nilgiriensis, Catillaria obscura andCatillaria versicolor are new to science. Certain taxa reported earlier underCatillaria from India have been excluded from the present study for the reasons given against each.Catillaria metaleptodes (Nyl.) Zahlbr. andCatillaria manipurensis K Singh have respectively been transferred asBuellia metaleptodes (Nyl.) comb. nov. andProtoblastenia manipurensis (K Singh) comb. nov.

    • Auxin profile of gall and normal tissues ofProsopis cineraria (Linn.) Druce induced byLobopteromyia prosopidis Mani,in vitro andin vivo

      Vidya Ramani U Kant M A Quereshi

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      Effect of various auxins on the growth of gall and normal tissues ofProsopis cineraria (Linn.) Druce induced byLobopteromyia prosopidia Mani has been discussed. Differential response of gall and normal tissues to various auxins was observed. α-Naphthalene acetic acid (8 mg/l) and indole-3-acetic acid (4 mg/l) sustained excellent growth of gall and normal tissues respectively. Biochemical studies revealed hypoauxiny and high indole-3-acetic-acid oxidase activity in the gall tissues which have been discussedin vitro andin vivo conditions.

    • Histogenetic patterns and classification of the shoot-axis galls

      P Jayaraman

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      On the basis of observations made on more than 50 shoot axis galls on different host plants caused by fungi (in 2 plants), mites (in 4 plants) and insects (in 48 plants), the responses of different tissues of the stem to the cecidogenetic stimuli were elucidated. The analysis lends itself to the fact that the behaviour of various tissues of the shoot axes seems to be correlated to the initial position of the cecidogenetic agents. When the gall inducing organism is external on the stem, the epidermis or the outer cortex proliferate to form ‘covering growth’ gall; when the cecidogen is in the cortex, the entire cortex forms a ‘rinden’ type of gall. Likewise, the phloem, cambium, xylem and pith proliferate contributing primarily to the cecidogenesis when the cecidogen is positioned in these tissues. On the basis of the position of the gall inducing organism in the gall, and the tissues that contribute solely or primarily to the gall development, a classification of the shoot-axis galls is proposed.

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