Amersham Pharmacia Biotech & Science Prize. Transposition and evolution of antigen-specific immunity     

Agrawal A 《Science (New York, N.Y.)》2000,290(5497):1715-1716

Alka Agrawal grew up in Farmington Hills, near Detroit, Michigan, and earned her bachelor's degree in chemical engineering from the University of Michigan. Dr. Agrawal entered the pharmacology graduate school program at Yale University and began working in the laboratory of David Schatz, investigating the role of DNA repair proteins in V(D)J recombination. The development of an in vitro V(D)J cleavage system in the laboratory changed her focus and she began studying the cleavage mechanism as part of her doctoral research. Exposure to science policy at the National Academy of Sciences, and to science journalism through the AAAS Mass Media Science and Engineering Fellows Program, prompted Dr. Agrawal to pursue a career in science writing.  相似文献   

Effects of shade on arbuscular mycorrhizal colonization and growth of crops and tree seedlings in Central India   总被引：1，自引：0，他引：1  

Ashok Shukla  Anil Kumar  Anuradha Jha  Om Prakash Chaturvedi  Rajendra Prasad  Ajit Gupta 《Agroforestry Systems》2009,76(1):95-109

The study was conducted to investigate the effects of different light intensities (25, 50, 67, and 100% of full sun [open]) on arbuscular mycorrhizal (AM) colonization and growth of two intercrops (a rainy season crop, Phaseolus mungo Roxb. var. PU-35 and a winter crop, Triticum aestivum L. var. WH-147) and seedlings of two multipurpose tree species (Eucalyptus tereticornis Sm. [Clone C-7, ITC, Bhadrachalam] and Albizia procera Benth.) of Central India. The results showed that various plant growth parameters viz., shoot length, dry weight and phosphorus (P) uptake were adversely affected by low light intensity. Inoculations with AM fungi (Acaulospora scrobiculata Trappe, Glomus intraradix Schenck & Smith and an unidentified Glomus species) increased the plant growth on account of all measured parameters under tested light conditions. Mycorrhizal efficiency of different AM fungi varied in narrow range. AM inoculants were more efficient at higher light intensity in above mentioned plant species, except wheat. Data on colonization of P. mungo, T. aestivum, E. tereticornis and A. procera showed that formation of arbuscules, vesicles and sporocarp was delayed by lower light intensity. Colonization index of host roots and spore counts increased with increase in light intensity during successive months after inoculation. Data on effect of light regimes on microclimate of net house showed that lux meter reading decreased as per grades of shading nets used during both rainy and winter seasons. With increase in light intensity, ambient temperature, soil surface temperature and sub surface temperature at 15 cm depth increased, except that the ambient and soil surface temperature in control (open) were slightly lower than net house observations during January and February. Value of ambient temperature varied in narrow range, with in treatments as compared to soil surface and sub soil surface temperature at 15 cm depth. Soil surface temperature at 25% of full sunlight was less than respective control values by 2–11°C and sub soil temperature at 15 cm depth was less by 4–12°C. The values of different microclimate parameters varied in narrower range during winter season as compared to rainy season. While ranking the importance of two factors studied—light and AM fungi—for their effect on the growth and P uptake by different plant species, inoculations with AM fungi came in the first place (explained 50–82% variation) and light substantially increased the values of R ² in stepwise regression analysis (forward selection). The results suggest that AM inoculation may enhance the growth and P uptake of intercrops under tree shade and the tree canopy management is likely to increase the efficiency of AM inoculants in agroforestry systems. Use of excessive shading (25% of full sun or more) in nurseries may be avoided and PAR (photosynthetically active radiation) lamps may be used to increase growth and colonization index of tree seedlings.  相似文献   

Diversity in Indian sesame collection and stratification of germplasm accessions in different diversity groups   总被引：6，自引：0，他引：6  

I.S. Bisht  R.K. Mahajan  T.R. Loknathan  R.C. Agrawal 《Genetic Resources and Crop Evolution》1998,45(4):325-335

Sesame (Sesamum indicum L.) is one of the ancient oil crops, grown in India since over 5,000 years ago. Diversity in the Indian sesame collection (3,129 accessions), representing all eco-geographical regions, for a range of morphological and agronomic characters was studied. Wide variation in plant habit (plant height and branching pattern), pubescence of various plant parts (stem, leaf, corolla and capsule), flower colour and number of flowers per leaf axil, capsule characteristics (shape, size, number in the axil of a leaf and number of locules in a capsule), number of capsules per plant, number of seeds per capsule, mean seed weight, and yield per plant was recorded. A detailed multivariate analysis was performed on a set of 100 selected accessions representing different agro-ecological zones. The accessions were classified into 7 discrete clusters. The principal components analysis described the spatial relationship among the entities and confirmed groupings obtained through clustering. Based on the clustering pattern of 100 accessions, the entire collection was allocated to different clusters. Representation of various zones in 7 clusters gives us the opportunity to form distinct diversity groups making combined use of passport and characterisation data. These diversity groups would subsequently be used for sampling the accessions for building up a core collection of sesame, a project already operative at the NBPGR.  相似文献   

Modification of growth and yield responses of Amaranthus tricolor L. to sUV-B under varying mineral nutrient supply     

Suruchi Singh  Rima KumariMadhoolika Agrawal  Shashi Bhushan Agrawal 《Scientia Horticulturae》2009

The decrease in stratospheric ozone has heightened concern over the consequences of increasing solar UV-B radiation on plants. The present study was conducted to evaluate the interactive effects of supplemental UV-B (sUV-B: 280–320 nm) and mineral nutrients on a leafy vegetable amaranthus (Amaranthus tricolor L. var Pusa badi) under natural field conditions in a dry tropical environment. The nutrient treatments were recommended dose of NPK, 1.5 times recommended dose of NPK, 1.5 times recommended dose of N and 1.5 times recommended dose of K sUV-B radiation inhibited growth and biomass accumulation and altered the patterns of biomass partitioning. In K amended plants larger proportion of biomass has been translocated to roots which further increased under sUV-B treatment. The application of 1.5 times recommended dose of NPK reduced the magnitude of yield loss. The study shows that amaranthus is a potentially UV-B sensitive species and a higher NPK dose above the recommended is required to minimize the adverse impact of sUV-B.  相似文献   

PHYSIOLOGICAL AND BIOCHEMICAL RESPONSES RESULTING FROM CADMIUM AND ZINC ACCUMULATION IN CARROT PLANTS     

Rajesh Kumar Sharma  Madhoolika Agrawal  Shashi Bhushan Agrawal 《Journal of plant nutrition》2013,36(7):1066-1079

The interactive effect of cadmium (Cd) and zinc (Zn) bioaccumulation on physiological and biochemical characteristics of carrot (Daucus carota L. var Pusa Kesar) plants grown with different levels of Cd and Zn was examined. The combined application of Cd and Zn (Cd+Zn) had synergistic and antagonistic effects at low and high concentrations, respectively, on Cd accumulations in plants, chlorophyll b, and photosynthesis and transpiration rates. Whereas both low and high Cd+Zn concentrations had synergistic effects on Zn accumulation, ascorbic acid, protein content, total phenols, peroxidase activity, chlorophyll a, total, carotenoids and stomatal conductance. Bioaccumulation of Cd had strong and negative relationships with measured physiological and biochemical parameters. The study further showed that Cd and Zn in combination have more toxic effects on carrot plants as compared to their individual treatments. This study concludes that interactive effects of Cd and Zn on test plant depend on their ratios present in plants.  相似文献   

Sensory evaluation of and acceptability trials on biscuits prepared from raw and malted wheat (Triticum aestivum)-Bengal gram (Cicer arietinum) mixes with or without a green leafy vegetable     

Anuradha Goyle  Sunder Gujral 《Plant foods for human nutrition (Dordrecht, Netherlands)》1992,42(4):291-296

Biscuits were prepared by varying the amounts of the basic ingredients to arrive at the most acceptable recipe. The final recipe contained 40 g of mix, 40 g of jaggery and 20 g of ghee. Sensory evaluation of biscuits containing 5 or 10% colocasia leaf powder by composite scoring test and hedonic scale showed that the former type of biscuit was preferred over the latter. The acceptability trial conducted on 42, 3 to 6 year old children showed that biscuits from either malted mix with or without 7.5% colocasia leaf powder and raw mix were equally acceptable as shown by the analysis of variance.  相似文献   

Phenotypic plasticity in the interactions and evolution of species   总被引：1，自引：0，他引：1  

Agrawal AA 《Science (New York, N.Y.)》2001,294(5541):321-326

When individuals of two species interact, they can adjust their phenotypes in response to their respective partner, be they antagonists or mutualists. The reciprocal phenotypic change between individuals of interacting species can reflect an evolutionary response to spatial and temporal variation in species interactions and ecologically result in the structuring of food chains. The evolution of adaptive phenotypic plasticity has led to the success of organisms in novel habitats, and potentially contributes to genetic differentiation and speciation. Taken together, phenotypic responses in species interactions represent modifications that can lead to reciprocal change in ecological time, altered community patterns, and expanded evolutionary potential of species.  相似文献   

Mapping QTL for resistance to botrytis grey mould in chickpea     

Chetukuri?Anuradha  Pooran?M.?GaurEmail author  Suresh?Pande  Kishore?K.?Gali  Muthyl?Ganesh  Jagdish?Kumar  Rajeev?K.?Varshney 《Euphytica》2011,182(1):1-9

Botrytis grey mould (BGM) caused by Botrytis cinerea Pers. ex. Fr. is the second most important foliar disease of chickpea (Cicer arietinum L.) after ascochyta blight. An intraspecific linkage map of chickpea consisting of 144 markers assigned on 11 linkage groups was constructed from recombinant inbred lines (RILs) of a cross that involved a moderately resistant kabuli cultivar ICCV 2 and a highly susceptible desi cultivar JG 62. The length of the map obtained was 442.8 cM with an average interval length of 3.3 cM. Three quantitative trait loci (QTL) which together accounted for 43.6% of the variation for BGM resistance were identified and mapped on two linkage groups. QTL1 explained about 12.8% of the phenotypic variation for BGM resistance and was mapped on LG 6A. It was found tightly linked to markers SA14 and TS71rts36r at a LOD score of 3.7. QTL2 and QTL3 accounted for 9.5 and 48% of the phenotypic variation for BGM resistance, respectively, and were mapped on LG 3. QTL 2 was identified at LOD 2.7 and flanked by markers TA25 and TA144, positioned at 1 cM away from marker TA25. QTL3 was a strong QTL detected at LOD 17.7 and was flanked by TA159 at 12 cM distance on one side and TA118 at 4 cM distance on the other side. This is the first report on mapping of QTL for BGM resistance in chickpea. After proper validation, these QTL will be useful in marker-assisted pyramiding of BGM resistance in chickpea.  相似文献   

Molecular mapping of QTLs for yield and its components under two water supply conditions in rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)     

Akkareddy Srividhya  Lakshminarayana R. Vemireddy  Sakile Sridhar  Mudduluru Jayaprada  Puram V. Ramanarao  Arremsetty S. Hariprasad  Hariprasad K. Reddy  Ghanta Anuradha  Ebrahimali Siddiq 《Journal of Crop Science and Biotechnology》2011,14(1):45-56

Moisture stress is the major constraint to rice production and its stability in rainfed, mainly irrigated, and aerobic environments. Identification of genomic regions conferring tolerance to stress would improve our understanding of the genetics of stress response and result in the development of drought tolerant cultivars. In the present study, quantitative trait loci for drought response related traits and as well as grain yield were identified using a set of 140 recombinant inbred lines derived from a cross between the popular high-yielding variety, IR64 and the landrace, INRC10192. A total of 36 QTL were identified for grain yield and its components under control and stress conditions. Strikingly, a QTL cluster flanked by the markers RM38 and RM331 on chromosome 8 was found to be associated with grain yield, plant height, no. of productive tillers, chaffy grains, and spikelet fertility on secondary rachis and biomass under stress treatment. The genomic regions associated with these QTL under drought stress will be useful for the development of marker-based breeding for drought tolerant, high-yielding varieties suited to drought-prone areas.  相似文献   

Environmental factors influencing aphid transmission of potato virus Y and potato leafroll virus   总被引：1，自引：0，他引：1  

M. N. Singh  S. M. Paul Khurana  B. B. Nagaich  H. O. Agrawal 《Potato Research》1988,31(3):501-509

Summary The effect of temperature, relative humidity (RH) and light on aphid transmission of potato virus Y (PVY) and potato leafroll virus (PLRV) was studied using as vectorsMyzus persicae Sulz. andAphis gossypii Glov. Host susceptibility was enhanced by 48 h pre-inoculation exposure at 25°C and by 48 h post-inoculation exposure to 30°C. High RH (80%) in both pre- or postinoculation phases enhanced host susceptibility. Continuous fluorescent light (4000 lux) did not alter the rate of transmission of either virus. High RH (80–90%) and high temperature (25–30°C), when combined, increased virus transmission by 30–35%. Transmission rates were reduced by nearly 50% if RH was maintained at 50% in either of the two phases even if the temperature was 25 or 30°C. Both viruses were acquired by aphids earlier (13–20 days after inoculation) when the source plants were incubated at 25 or 30°C. Most virus was transmitted from plants inoculated with PVY 13 to 16 days and with PLRV 15 to 20 days previously. Transmission rates of PVY were enumerated from symptom expression on test plants and by Enzyme Linked Immunosorbent Assay (ELISA) whereas those of PLRV were enumerated from symptom expression alone.  相似文献