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S. Maurya, Rashmi Singh, D. Singh, H. Singh, U. Singh and J. Srivastava

Management of Collar Rot of Chickpea (Cicer Arietinum) by Trichoderma Harzianum and Plant Growth Promoting Rhizobacteria

Collar rot (Sclerotium rolfsii) of chickpea (Cicer arietinum) is one of the devastating soil-borne diseases of fungal origin, due to which 10-30% yield loss is recorded annually according to severity of the disease. Management of collar rot of chickpea is not feasible in the absence of effective soil fungicides. However, Trichoderma harzianum and plant growth promoting rhizobacteria (PGPR) have shown high efficacy against this disease in vitro as well as in the field. We used T. harzianum (104, 106 and 108 spore/ml) and two PGPRs (Pseudomonas fluorescens strain 4 and P. aeruginosa) as foliar spray with the fresh and heat inactivated microorganisms. Foliar application of T. harzianum (108 spore/ml) and P. fluorescens strain 4 (108 cfu/ml) showed maximum efficacy in reducing plant mortality as compared to the control. Foliar application of fresh-and heat-inactivated (121°C for 10 min) P. fluorescens strain 4, and T. harzianum reduced 15-25% plant mortality but P. aeruginosa showed very little disease control of 10-15%. However, regarding plant growth promotion, it was observed that fresh-and heat-inactivated P. fluorescens strain 4 showed maximum efficacy followed by fresh and heat inactivated P. aeruginosa and T. harzianum as compared to the control. The disease-controlling efficacy was also associated with the increase in phenolic acid synthesis in chickpea plants. The control of chickpea collar rot by biocontrol agents is safe and ecologically sound and appears to be a healthy approach to the disease control.

Open access

S. K. Pal and H. P. Singh

Abstract

In surveys covering human populations it is observed that information in most cases are not obtained at the first attempt even after some callbacks. Such problems come under the category of non-response. Surveys suffer with non-response in various ways. It depends on the nature of required information, either surveys is concerned with general or sensitive issues of a society. Hansen and Hurwitz (1946) have considered the problem of non-response while estimating the population mean by taking a subsample from the non-respondent group with the help of extra efforts and an estimator was suggested by combining the information available from the response and nonresponse groups. We also mention that in survey sampling auxiliary information is commonly used to improve the performance of an estimator of a quantity of interest. For estimating the population mean using auxiliary information in presence of non-response has been discussed by various authors. In this paper, we have developed estimators for estimating the population mean of the variable under interest when there is non-response error in the study as well as in the auxiliary variable. We have studied properties of the suggested estimators under large sample approximation. Comparison of the suggested estimators with usual unbiased estimator reported by Hansen and Hurwitz (1946) and the ratio estimator due to Rao (1986) have been made. The results obtained are illustrated with aid of an empirical study.

Open access

S. K. Pal and H. P. Singh

Abstract

This paper addresses the problem of estimating the population mean at the current occasion in two occasion successive sampling when non-response occurs on the current (second) occasions. Using the power transformation we have suggested classes of estimators of current population mean and their properties are studied. Optimum replacement strategies for the proposed estimators have been given and empirical studies are carried out to assess the performance of estimators. We have made suitable recommendation to the practitioners on the basis of the empirical study.

Open access

H. R. Chiary, A. Chaudhary and H. S. Singh

Abstract

Morphological Redescription and Molecular Characterization of Dactylogyrus labei (Monogenea, Dactylogyridae) from Catla catla: a New Host Record in India. Chiary, H. R., Chaudhary, A., Singh, H. S. - Dactylogyrus labei Musselius et Gusev, 1976 (atypical form) specimens were collected from host Catla catla from the river Brahmaputra, Guwahati, Assam, India. The Dactylogyrus samples were examined by morphological and molecular methods. This parasite was originally described from Labeo rohita from fish farm Kalyani, West Bengal, India, but the morphological study of sclerotized parts showed the existence of D. labei on Catla catla. This is the first record of D. labei from Catla catla in India.

Open access

A. Chaudhary, S. Mukut and H. S. Singh

Summary

Three species of digenetic trematodes are redescribed based on specimens collected from the intestine of freshwater fishes of Hastinapur and Meerut (U.P.), India: Allocreadium handiai (Pande, 1937) Madhavi, 1980 (Allocreadioidea: Allocreadiidae) from Mystus tengara (Hamilton, 1822) (Siluri-formes: Bagridae), Genarchopsis goppo Ozaki, 1925 (Hemiuroidea: Derogenidae) and Phyllodistomum chauhani Motwani & Srivastava, 1961 (Plagiorchioidea: Gorgoderidae) from Channa punctata (Bloch, 1793) (Perciformes: Channidae). The three species were subjected to morphological, morphometric and molecular analyses. The morphological study revealed that A. handiai, G. goppo and P. chauhani can be distinguished by their congeners on the basis of their morphology. Partial nucleotide sequences of the 28S ribosomal RNA gene were obtained from the three trematode species and deposited in the GenBank. A phylogenetic reconstruction based on the 28S rRNA gene placed the three studied species within their respective families and their validity is discussed. For the first time molecular data of newly collected material of these species from India were used for confirmation of their validity and to assess their phylogenetic relationships.

Open access

A. Chaudhary, C. Verma, V. Tomar and H. S. Singh

Summary

The nematode, Procamallanus spiculogubernaculus Agarwal, 1958 was found from the Stinging catfish, Heteropneustes fossilis (Bloch, 1794) from Ghazipur, Delhi, India. Morphological characterization, including scanning electron microscope observation supplemented with DNA sequences is provided. Specimens recently found are characterized by the presence of an unlined buccal capsule having a small basal ring, esophagus muscular and glandular, vulva position is slightly post-equatorial, tail conical, long, and ending in three digit-like processes, phasmids present at about mid-length and cloaca located at the posterior end. In this study the species P. spiculogubernaculus is validated on the basis of molecular data after 47 years from its original description. In the scanning electron microscope examination, the topology of mouth and sensory pits in anterior portion, while the phasmids and digit like processes in posterior portion is clearly observed. Molecular data of the 18S ribosomal RNA and mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were analyzed. Molecular phylogenetic analyses supported the validity of Procamallanus spiculogubernaculus and confirmed the paraphyletic status of the members of Procamallanus, Spirocamallanus, Camallanus and Paracamallanus. Taxonomic status of members of the family Camallanidae are briefly discussed along with the results of the systematic evaluation of P. spiculogubernaculus based on molecular data.

Open access

C. Verma, A. Chaudhary and H. S. Singh

Summary

Two species of Thaparocleidus Jain (1952a) were found harboring W. attu from the Ganga River at two localities, Meerut and Farrukhabad, Uttar Pradesh, India, during the period of 2013-2015. Morphology and morphometric study of specimens identified as Thaparocleidus gomtius (Jain, 1952a) Lim, 1996 and T. sudhakari (Gusev, 1976) Lim, 1996. Molecular analyses using the 18S rRNA gene confirmed the validity of T. gomtius and T. sudhakari and demonstrated that both the species clustered with other Thaparocleidus species from different geographical regions. We aim at reassessing the taxonomy and establishing the phylogenetic relationships among these two redescribed species with other representatives of the genus Thaparocleidus.

Open access

U Goswami, A Chaudhary, C Verma and H.S. Singh

Summary

The phylogenetic relationships of the nematode species Thelandros scleratus (Oxyurida: Pharyn-godonidae) and Physalopteroides dactyluris (Spirurida: Physalopteridae) were analyzed using the ribosomal 18S rRNAand the mitochondrial cytochrome C oxidase subunit genes. The nematodes were recovered from Brook's house gecko, Hemidactylus brooki (Reptilia: Gekkonidae) from Hast-inapur, Meerut (U.P.), India. The results demonstrated that T. scleratus shows 100% similarity with another sequence available from the same species and a close relationship (98-99%) with species of Parapharyngodon in both 18S rRNAand cox 1 regions. Regarding the nematode Physalopteroides. analysis showed a close phylogenetic relationship between P. dactyluris and several species of Phy-saloptera. This is the first sequence of 18S available for any species of the genus Physalopteroides

Open access

H. R. Chiary, A. Chaudhary and H. S. Singh

Abstract

The present study describes the molecular characterization of the monogenea Dactylogyroides tripathii (Tripathi, 1959) Gussev, 1973 infecting the gill filaments of fish, Puntius ticto from River Brahmaputra, Guwahati, Assam, India. This study shows the D. tripathii species identification resulted from the use of molecular data, particularly the 28S rDNA gene. We compared the 28S partial rDNA sequence of D. tripathii with same gene region of the other species of monogeneans available in GenBank. With this comparison, we determined that the sequence had a similarity with one available species of the genus Dactylogyroides Gussev, 1963 i. e., D. longicirrus and also with the species of Dactylogyrus from which this genus was distinguished.