Evaluation of fungicides for the management of pearl millet [ Pennisetum glaucum (L.)] blast caused by Magnaporthe grisea

Blast disease caused by Magnaporthe grisea has emerged as a serious threat to pearl millet cultivation in India. Most of the hybrids being grown in India are susceptible to blast as not much efforts have been made to breed for blast resistance in pearl millet. In the absence of host plant resistance, the disease can be effectively managed with chemical fungicides. Therefore, nine fungicides, chlorothalonil, tricyclazole, hexaconazole, kasugamycin, benomyl, carbendazim, tebuconazole + trifloxystrobin, propiconazole and metalaxyl + mancozeb were tested for their efficacy to manage blast disease on a blast susceptible pearl millet line ICMB 95444. Different combinations of seed treatment and foliar sprays were tested: seed treatment alone, seed treatment + one spray, seed treatment + two sprays, seed treatment + three sprays. None of the fungicides was found effective when used as seed treatment. Results of this study clearly demonstrated that the disease can be effectively managed with three sprays of tebuconazole + trifloxystrobin (Nativo) or propiconazole (Tilt)

Prevalence and pathogenic diversity in pearl millet downy mildew pathogen populations in Maharashtra, India

Pearl millet fields were surveyed in Maharashtra, India during the rainy seasons of 2009 and 2010 to monitor onfarm downy mildew (DM) incidence and assess the pathogenic diversity among native populations of Sclerospora graminicola. Of the 131 fields surveyed in seven districts in Maharashtra, DM was observed in 72 fields in the range of 1–90%. DM was quite severe in Ahmednagar, Jalgaon, Aurangabad and Jalna districts with mean disease incidence of 56, 40, 35 and 32, respectively. Severe DM was observed on Pioneer 86M32, B 2301, GK 419, Tulsi, 535, 452 and several hybrids of unknown identity; whereas hybrids MRB 204, Nirmal 40, Sathya, Super 515, Super Boss, Tulja, XL 51, Great 555, Nuzvid 2301, Paras 51 and Sandeep were free from DM. Twenty six S. graminicola isolates collected during 2009–10 from Maharashtra were evaluated for pathogenic diversity on seven pearl millet host differential lines along with three isolates of S. graminicola collected earlier from the same region. Mean disease incidence on host differentials varied from 5 to 80%. S. graminicola isolates Sg 542, Sg 543, Sg 544, Sg 545, Sg 547, Sg 549, Sg 550, Sg 552, Sg 553, Sg 554 and Sg 555 showed > 50% mean DM incidence across host differentials. Highly virulent isolate Sg 542 collected from Deogaon, Aurangabad has been selected for the greenhouse screening of pearl millet lines being developed for Maharashtr

New Sources of Resistance to Multiple Pathotypes of Sclerospora graminicola in the Pearl Millet Mini Core Germplasm Collection

Downy mildew (DM), caused by Sclerospora graminicola (Sacc.) Schröt., is a highly destructive and widespread disease in most pearl millet [Pennisetum glaucum (L.) R. Br.] growing areas of Asia and Africa. Breeding for DM resistance continues to be an integral part of genetic improvement of pearl millet at ICRISAT, Patancheru, India. For the identification of new and diverse sources of DM resistance, a pearl millet mini core collection comprising 238 accessions was screened against eight pathotypes (Sg 384, Sg 409, Sg 445, Sg 457, Sg 510, Sg 519, Sg 526, and Sg 542) of S. graminicola collected from different geographical locations in India. Significant differences for DM reaction were observed among pathotypes, mini core accessions, and their interactions. Of the 238 accessions, 68 accessions were resistant (≤10% DM incidence) to pathotype Sg 510 followed by 40 accessions resistant to Sg 457. Resistance to pathotypes Sg 519, Sg 526, Sg 384, Sg 445, and Sg 542 was observed in 15, 27, 29, 30, and 34 mini core accessions, respectively. Resistance to two or more pathotypes was observed in 62 accessions. Several of these accessions also exhibited desirable agronomic traits. The multiple-pathotype-resistant germplasm accessions having desirable agronomic characteristics and collected from different agro-ecologies would be useful in breeding programs to develop pearl millet hybrids resistant to difficult-to-manage highly-virulent pathotypes of S. graminicola

Evaluation of designated hybrid seed parents of pearl millet for blast resistance

One hundred sixty designated B-lines (maintainers of male sterile lines) of pearl millet were screened for blast resistance under greenhouse conditions along with a resistant (ICMR 06444) and a susceptible (ICMB 95444) check against five pathotype-isolates (Pg 45, Pg 53, Pg 56, Pg 118 and Pg 119) of Magnaporthe grisea. Twenty three lines exhibited seedling stage resistance to 3-5 pathotypes. Of the 23 lines, nine (81B, ICMB 88004, ICMB 92444, ICMB 97222-P1, ICMB 02111, ICMB 06444, ICMB 07111, ICMB 09333 and ICMB 09999) were found resistant to all the five pathotypes. The identified blast resistant lines are agronomically superior breeding lines being hybrid parents designated at ICRISAT. Thus, these lines could be either used in the crossing programs to develop blast resistant hybrid parents or as one of the parents for the development of blast resistant hybrids to diversify the genetic base of blast resistance in future pearl millet hybrids

Azimuthal asymmetry in the risetime of the surface detector signals of the Pierre Auger Observatory

The azimuthal asymmetry in the risetime of signals in Auger surface detector stations is a source of information on shower development. The azimuthal asymmetry is due to a combination of the longitudinal evolution of the shower and geometrical effects related to the angles of incidence of the particles into the detectors. The magnitude of the effect depends upon the zenith angle and state of development of the shower and thus provides a novel observable, $(\sec \theta)_\mathrm{max}$, sensitive to the mass composition of cosmic rays above $3 \times 10^{18}$ eV. By comparing measurements with predictions from shower simulations, we find for both of our adopted models of hadronic physics (QGSJETII-04 and EPOS-LHC) an indication that the mean cosmic-ray mass increases slowly with energy, as has been inferred from other studies. However, the mass estimates are dependent on the shower model and on the range of distance from the shower core selected. Thus the method has uncovered further deficiencies in our understanding of shower modelling that must be resolved before the mass composition can be inferred from $(\sec \theta)_\mathrm{max}$.Comment: Replaced with published version. Added journal reference and DO

Reconstruction of inclined air showers detected with the Pierre Auger Observatory

We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than $60^\circ$ detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory.Comment: 27 pages, 19 figures, accepted for publication in Journal of Cosmology and Astroparticle Physics (JCAP

A search for point sources of EeV photons

Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical Journa

The Pierre Auger Observatory: Contributions to the 34th International Cosmic Ray Conference (ICRC 2015)

Contributions of the Pierre Auger Collaboration to the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The NetherlandsComment: 24 proceedings, the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands; will appear in PoS(ICRC2015

Promoter-anchored chromatin interactions predicted from genetic analysis of epigenomic data

Promoter-anchored chromatin interactions (PAIs) play a pivotal role in transcriptional regulation. Current high-throughput technologies for detecting PAIs, such as promoter capture Hi-C, are not scalable to large cohorts. Here, we present an analytical approach that uses summary-level data from cohort-based DNA methylation (DNAm) quantitative trait locus (mQTL) studies to predict PAIs. Using mQTL data from human peripheral blood ([Formula: see text]), we predict 34,797 PAIs which show strong overlap with the chromatin contacts identified by previous experimental assays. The promoter-interacting DNAm sites are enriched in enhancers or near expression QTLs. Genes whose promoters are involved in PAIs are more actively expressed, and gene pairs with promoter-promoter interactions are enriched for co-expression. Integration of the predicted PAIs with GWAS data highlight interactions among 601 DNAm sites associated with 15 complex traits. This study demonstrates the use of mQTL data to predict PAIs and provides insights into the role of PAIs in complex trait variation

Balancing repair and tolerance of DNA damage caused by alkylating agents

Alkylating agents constitute a major class of frontline chemotherapeutic drugs that inflict cytotoxic DNA damage as their main mode of action, in addition to collateral mutagenic damage. Numerous cellular pathways, including direct DNA damage reversal, base excision repair (BER) and mismatch repair (MMR), respond to alkylation damage to defend against alkylation-induced cell death or mutation. However, maintaining a proper balance of activity both within and between these pathways is crucial for a favourable response of an organism to alkylating agents. Furthermore, the response of an individual to alkylating agents can vary considerably from tissue to tissue and from person to person, pointing to genetic and epigenetic mechanisms that modulate alkylating agent toxicity