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   

Phosphorus uptake and use efficiency in different varieties of bread wheat (Triticum Aestivum L)     

HS Gill  Anoop Singh  SK Sethi  RK Behl 《Archives of Agronomy and Soil Science》2013,59(6):563-572

Thirty spring wheat varieties were evaluated and classified into eight different groups on the basis of their grain yield performance and phosphorus (P) uptake using Metroglyph analysis. Significant variability was observed for grain and biomass yield, plant height, P content in grain and straw, total P uptake and phosphorus harvest index and P use efficiency traits. Varieties WH 711 and PBW 343 exhibited high grain yield as well as high P uptake (HGY-HP). WH 283 and UP 2425 with high index score of 19 and 16 respectively, constituted the high grain yield-medium P uptake (HGYMP) group. Both these varieties, though had similar grain yield of 5348 kg/ha, but WH 283 (12.64 kg/ha) utilized much lower P as compared to UP 2425 (16.94 kg/ha). Moreover, WH 283 (81.64) also showed higher values for phosphorus harvest index (PHI) than UP 2425 (67.88%). P uptake of WH 283 was comparable with that of Raj 3765 (10.78 kg/ha) and grouped into high grain yield and low P uptake (HGY-LP) group. The grain yield performance of these two varieties with a relatively low P uptake is reflected in their high index score for P use efficiency thus, earmarking them for low P regimes. Variety HW 2006, despite low grain yields of 4665 kg/ha had high index score of 16 due to its higher value for Phosphorus Biological (PBER) and Economic Yield (PEER) Efficiency Ratio as it has effected least (7.18 kg/ha) P mobilization. In addition high P translocation in the grain was also observed for this variety. Inter-mating of genotypes like HW 2006, UP 2338 and HW 2016 with those belonging to HGY-HP (PBW 343 and WH 711) and HGY-LP (Raj 3765 and WH 283) would be an ideal strategy to develop the cultivars for efficient phosphorus use.  相似文献   

Filled Skutterudite Antimonides: A New Class of Thermoelectric Materials   总被引：2，自引：0，他引：2  

BC Sales  D Mandrus  RK Williams 《Science (New York, N.Y.)》1996,272(5266):1325-1328

A class of thermoelectric materials has been synthesized with a thermoelectric figure of merit ZT (where T is temperature and Z is a function of thermopower, electrical resistivity, and thermal conductivity) near 1 at 800 kelvin. Although these materials have not been optimized, this value is comparable to the best ZT values obtained for any previously studied thermoelectric material. Calculations indicate that the optimized material should have ZT values of 1.4. These ternary semiconductors have the general formula RM4X12 (where R is lanthanum, cerium, praseodymium, neodymium, or europium; M is iron, ruthenium, or osmium; and X is phosphorus, arsenic, or antimony) and represent a new approach to creating improved thermoelectric materials. Several alloys in the composition range CeFe4-xCoxSb12 or LaFe4-xCoxSb12 (0 < x < 4) have large values of ZT.  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   

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   

Novel role of photoinsensitive alleles in adaptation of soybean [Glycine max (L.) Merr.] to rainfed short growing seasons of lower latitudes     

Tripathi  Rachana  Agrawal  Nisha  Kumawat  Giriraj  Gupta  Sanjay  Kuchlan  Mrinal  Maranna  Shivakumar  Nataraj  Vennampally  Kuchlan  Punam  Satpute  Gyanesh K.  Ratnaparkhe  Milind B.  Rajesh  Vangala  Chandra  Subhash  Bhatia  Virender S.  Chand  Suresh 《Genetic Resources and Crop Evolution》2021,68(6):2455-2467

Soybean is a temperate photosensitive crop but has adapted to sub-tropical and tropical countries of lower latitudes also. Photoperiodic and maturity genes confer latitudinal adaptation in this crop. Genotyping of accessions of higher latitudes have shown the role of photoinsensitivity, conferred by recessive photoperiodic alleles (e1/e2/e3/e4), in adaptation of the crop to high latitudes but information is not available for lower latitudinal countries like India. We genotyped and calculated the photosensitivity of 101 cultivated Indian soybean varieties and found that majority of the varieties (86) were photosensitive and had the dominant alleles at these loci. Four genotypic classes (e1-as/E2/E3/E4, E1/e2/e3/E4, E1/e2/E3/E4 and E1/E2/e3/E4) were observed for varieties with recessive alleles. Photoinsensitive alleles at E1 and E2 loci significantly reduced the days to flower, maturity and photosensitivity percentage. Adaptive role of photoperiodic alleles was inferred from breeder seed requirement of these varieties for 35 years. Although the photosensitive class contributed 81% to the total seed requirement the weighted mean contribution of this class (380 Q/year) was far less than that of photoinsensitive class (648 Q/year). Photoinsensitivity is essential for perpetuation of crop in higher latitudes. Present report highlights the novel role of photoinsensitive alleles in adaptation of soybean to rainfed, short growing and sub-tropical conditions of lower latitudes by conferring earliness.

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Detection of Campylobacter Antibodies in Sheep Sera by a Dot‐ELISA Using Acid Extracts from C. fetus ssp. fetus and C. jejuni Strains and Comparison with a Complement Fixation Test     

K. GÜRTÜRK  &#x;. H. EK&#x;N  A. AKSAKAL  H. SOLMAZ 《Zoonoses and public health》2002,49(3):146-151

In this study, a dot‐enzyme‐linked immunosorbent assay (Dot‐ELISA) was evaluated in comparison with a complement fixation test (CFT) for the detection of Campylobacter antibodies in sheep sera. Acid glycine extracts (AGE) of both Campylobacter fetus ssp. fetus and Campylobacter jejuni strains that had been isolated from the gall‐bladder of slaughtered sheep was used as antigen in both tests. A total of 153 sheep sera from aborted (74) and slaughtered (79) sheep were examined by both Dot‐ELISA and CFT. Twenty‐two sera showed anti‐complementary activity were not suitable for CFT. Of the 22 sera showing anti‐complementary activity, two sera were found to be positive in Dot‐ELISA. Eighty‐eight (67.2%) of the remaining 131 sera were negative by both Dot‐ELISA and CFT using AGE of both Campylobacter strains whereas 43 sera (32.8%) gave different reaction patterns in Dot‐ELISA and CFT with the extracts of both Campylobacter strains. Twelve sera were positive by both tests using AGE of C. fetus ssp. fetus but CFT failed to detect antibodies in nine of these sera when AGE of C. jejuni was used. Twelve sera were positive by both tests only when AGE of C. fetus ssp. fetus was used. Eleven sera were positive only by CFT. Seven of these reacted only with the AGE of C. fetus ssp. fetus and four sera were positive by using AGE of both Campylobacter strains. The remaining eight sera were found to be positive only by dot‐immunobinding assay either with the AGE of both Campylobacter strains or with the AGE of one of the Campylobacter strains. It is concluded that Dot‐ELISA using AGE from C. fetus ssp. fetus could be employed for the detection of Campylobacter antibodies in sheep sera and the additional use of AGE from C. jejuni as antigen appeared not to be profitable for this purpose.  相似文献   

Productivity of Rice—Wheat Cropping System in a Part of Indo-Gengetic Plain: A Spatial Analysis     

N.K. Tyagi  A. Agrawal  R. Sakthivadivel  S.K. Ambast  D.K. Sharma 《Irrigation and Drainage Systems》2004,18(1):73-88

Investigations were made to study the effect of unequal distribution of canal water in land and water productivity of the rice—wheat cropping system in terms of head—tail relationship in Bhakra Canal command, Haryana. Information on water supply, agronomic practices, crop yield, etc.,were collected from 216 farmers comprising 36 farmers each from the head, middle, and tail watercourses of two minors during year 2000–01. The unequal supply of canal water and presence of marginal quality groundwater creates large variations in the cropping pattern, irrigation application, and land and water productivity of the irrigation system. The groundwater of tail reaches, being saline in nature, was about 25% less productive as compared to head reaches. The unavailability of canal water in the tail reaches creates more dependency on groundwater. Due to its poor quality the crop production in the tail reaches was less by 10 to 20% in case of wheat, and 20 to 40% in case of rice, as compared to head reaches. Groundwater transfer from head to tail reaches and cultivation of low water requiring salt tolerant crops/varieties would be helpful in reducing the productivity gap and increasing the profitability of the farms in the region.  相似文献