Effect of Heat Stress on Grain Growth, Starch Synthesis and Protein Synthesis in Grains of Wheat (Triticum aestivum L.) Varieties Differing in Grain Weight Stability     

C. Viswanathan  & Renu Khanna-Chopra 《Journal of Agronomy and Crop Science》2001,186(1):1-7

The effect of heat stress on the components of grain weight was analysed in wheat ( Triticum aestivum L.) varieties differing in grain weight stability. The wheat varieties PBW154, Sonalika and Hindi62 were raised in the field (New Delhi, India; 77°12' E, 28°40' N, 228.6 m a.s.l.) at three dates of sowing: 19 November 1992 (DOS I), 14 December 1992 (DOS II) and 18 January 1993 (DOS III). The late-sown crop (DOS III) experienced 6–8 °C warmer temperatures during grain development than the crop sown at the normal time (DOS I). The heat susceptibility index (S) revealed that grain weight was less susceptible to heat in Sonalika and PBW154 than in Hindi62. Heat stress reduced both the grain growth duration (GGD) and the grain growth rate (GGR). The grain weight reduction in PBW154 and Sonalika was mainly due to a reduction in GGR, while that of Hindi62 was due to a reduction in GGD. In vivo studies on starch and protein synthesis in excised endosperm at 15, 25 and 35 °C revealed that both processes were more thermotolerant in Hindi62 than in PBW154. The grain starch content was stable in Hindi62 while that in PBW154 was significantly reduced under heat stress. The grain nitrogen content at maturity increased in both varieties under heat stress. It was concluded that the heat susceptibility of grain weight in Hindi62 was mainly due to a reduction in GGD, although GGR, starch and protein synthesis were more thermotolerant in developing grains of Hindi62 than in those of PBW154.  相似文献   

Spread of the bacterial fish pathogen Aeromonas salmonicida after importation of infected goldfish, Carassius auratus, into Australia     

JD HUMPHREY  LD ASHBURNER 《Australian veterinary journal》1993,70(12):453-454

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Surface order and stability of langmuir-blodgett films     

Schwartz DK  Garnaes J  Viswanathan R  Zasadzinski JA 《Science (New York, N.Y.)》1992,257(5069):508-511

Angstrom-resolution atomic force microscope images of Langmuir-Blodgett monolayers and multilayers of cadmium arachidate in air and under water show a dramatic change from a disordered arrangement to a crystalline lattice by the addition or removal of a single layer of molecules. The disordered surface is less stable than the ordered one to mechanical stresses such as atomic force microscopy tip forces or at the air-water contact line during contact angle measurements. The difference in the degree of order in the alkyl chains is attributed to the strong attractive interaction between headgroups in the presence of the divalent cation.  相似文献   

Bright Spots, Structure, and Magmatism in Southern Tibet from INDEPTH Seismic Reflection Profiling   总被引：8，自引：0，他引：8  

LD Brown  W Zhao  KD Nelson  M Hauck  D Alsdorf  A Ross  M Cogan  M Clark  X Liu  J Che 《Science (New York, N.Y.)》1996,274(5293):1688-1690

INDEPTH seismic reflection profiling shows that the decollement beneath which Indian lithosphere underthrusts the Himalaya extends at least 225 kilometers north of the Himalayan deformation front to a depth of approximately 50 kilometers. Prominent reflections appear at depths of 15 to 18 kilometers near where the decollement reflector apparently terminates. These reflections extend north of the Zangbo suture to the Damxung graben of the Tibet Plateau. Some of these reflections have locally anomalous amplitudes (bright spots) and coincident negative polarities implying that they are produced by fluids in the crust. The presence of geothermal activity and high heat flow in the regions of these reflections and the tectonic setting suggest that the bright spots mark granitic magmas derived by partial melting of the tectonically thickened crust.  相似文献   

Widespread divergence between incipient Anopheles gambiae species revealed by whole genome sequences     

Lawniczak MK  Emrich SJ  Holloway AK  Regier AP  Olson M  White B  Redmond S  Fulton L  Appelbaum E  Godfrey J  Farmer C  Chinwalla A  Yang SP  Minx P  Nelson J  Kyung K  Walenz BP  Garcia-Hernandez E  Aguiar M  Viswanathan LD  Rogers YH  Strausberg RL  Saski CA  Lawson D  Collins FH  Kafatos FC  Christophides GK  Clifton SW  Kirkness EF  Besansky NJ 《Science (New York, N.Y.)》2010,330(6003):512-514

The Afrotropical mosquito Anopheles gambiae sensu stricto, a major vector of malaria, is currently undergoing speciation into the M and S molecular forms. These forms have diverged in larval ecology and reproductive behavior through unknown genetic mechanisms, despite considerable levels of hybridization. Previous genome-wide scans using gene-based microarrays uncovered divergence between M and S that was largely confined to gene-poor pericentromeric regions, prompting a speciation-with-ongoing-gene-flow model that implicated only about 3% of the genome near centromeres in the speciation process. Here, based on the complete M and S genome sequences, we report widespread and heterogeneous genomic divergence inconsistent with appreciable levels of interform gene flow, suggesting a more advanced speciation process and greater challenges to identify genes critical to initiating that process.  相似文献   

Response surface optimisation of process variables for microencapsulation of garlic (Allium sativum L.) oleoresin by spray drying     

Priya Balasubramani  Rangaraju Viswanathan  Mariappanadar Vairamani 《Biosystems Engineering》2013,114(3):205-213

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Adoption of rubber-integrated farm-livelihood systems: contrasting empirical evidence from the Indian context   总被引：2，自引：0，他引：2  

P. K. Viswanathan  Ganesh P. Shivakoti 《Journal of Forest Research》2008,13(1):1-14

This paper examines the influence of important socio-economic, institutional/policy level factors in determining the adoption/non-adoption of rubber-integrated farming systems in traditional and non-traditional rubber-growing regions in India. The empirical analysis is based on a survey of rubber growers in the traditional rubber regions of Kerala (south India) and the non-traditional rubber regions of Assam, Meghalaya, and Tripura (north east India). In sharp contrast to Kerala, where smallholder responses toward adoption of rubber-integrated farming systems have been lukewarm, the emerging rubber economies (most of which are tribal communities) of north east (NE) India have shown interest in adopting rubber as an integrated farming system along with pre-existing land-use livelihood activities. The study clearly demonstrates contrasting empirical evidence of adoption of rubber-integrated farm-livelihood systems in the rubber-growing regions in Kerala and the NE states in India. The contrasting scenarios of adoption of rubber-integrated farming systems are mostly explained by region-specific factors dominated by socio-economic, institutional variables, and policy-level constraints, as also revealed by multivariate analysis. By and large, the findings of the study have significant bearing on the socio-economic outcomes and the existing institutional development paradigm underlying the rubber-development programmes introduced in India since independence. The study shows that the existing institutional arrangements and policies, which evolved historically to facilitate rubber area expansion in the traditional regions (including Kerala), have been highly instrumental in perpetuating rubber farming as a monoculture system. However, such an institutional mechanism proves to be highly redundant in the context of the NE states which are otherwise diverse in terms of integrated farm-livelihood systems and shifting cultivation.  相似文献   

Diagnosis and ultrasonographic appearance of hepatic metastasis in six cases of canine appendicular osteosarcoma (2005–2013)          下载免费PDF全文

L Cesario  LD Garrett  AM Barger  RT O'Brien  TM Fan 《Australian veterinary journal》2016,94(5):160-165

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Phytochemical and antimicrobial studies on Drynaria quercifolia   总被引：1，自引：0，他引：1  

N. Ramesh  M. B. Viswanathan  A. Saraswathy  K. Balakrishna  P. Brindha  P. Lakshmanaperumalsamy 《Fitoterapia》2001,72(8):283-936

Friedelin, epifriedelinol, beta-amyrin, beta-sitosterol, beta-sitosterol 3-beta-D-glucopyranoside, and naringin were isolated from the dried rhizome of Drynaria quercifolia. The methanol extract showed broad and concentration-dependent antibacterial activity.  相似文献   

High-level expression of SAG1 and GRA7 gene of Toxoplasma gondii (Izatnagar isolate) and their application in serodiagnosis of goat toxoplasmosis     

Velmurugan GV  Tewari AK  Rao JR  Baidya S  Kumar MU  Mishra AK 《Veterinary parasitology》2008,154(3-4):185-192

Toxoplasmosis, caused by Toxoplasma gondii, is a disease of economic importance in livestock, especially in sheep and goats, where it causes abortion. Although several serological tests are in use for diagnosis of infection, production of reliable reagents is a constraint. An 814 bp sequence coding for a truncated surface antigen surface antigen 1 (SAG1), a tachyzoite stage-specific protein, as well as a 657 bp sequence coding for granule protein 7 (GRA7), a dense granule protein were PCR amplified from the genomic DNA of T. gondii. The amplified products were ligated in pET-32b(+) and pET-32c(+) expression vectors, respectively and subsequently transformed into BL21(DE3)pLysS cells. A high-level expression of the histidine-tagged SAG1 and GRA7 fusion proteins were obtained after 7h of incubation. The recombinant proteins were purified using Ni-NTA column and were characterized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blot analysis using reference positive sera from goat, rabbit and humans at 1:100 dilution. Subsequently, the diagnostic efficiency of the recombinant proteins, either individually or as a cocktail of the recombinant proteins, was assessed with 56 reference goat sera by enzyme-linked immunosorbent assay (ELISA). The immunoreactivity of the refolded SAG1 and GRA7 was evidenced by high OD values. The reactivity of the recombinant proteins as a cocktail preparation was more than that of individual proteins in ELISA and could detect accurately the infection in goats. This is the first report of serological detection of caprine toxoplasmosis by ELISA using a cocktail of recombinant Toxoplasma proteins.  相似文献