Biocontrol potential of Alternaria sp. PMK2, against a devastating weed: Parthenium hysterophorus L     

Manpreet Kaur  Neeraj Kumar Aggarwal 《国际虫害防治杂志》2017,63(1):47-53

Parthenium hysterophorus (Asteraceae) is known as one of the most aggressive invasive weeds, causing severe economic, environmental, human and animal health problems in India and around the world. During a series of extensive surveys for natural enemies of P. hysterophorus, a leaf spot pathogen was isolated from the affected parts of the parthenium following the standard isolation techniques using potato dextrose agar (PDA) and parthenium dextrose agar (PeDA) media. Koch's postulates were performed and found satisfactory for the isolate and proved to be pathogenic to this weed. On the basis of cultural, morphological and molecular characteristics, the pathogen was identified as Alternaria sp. PMK2. The growth of the pathogen was studied on eight selected media and it exhibited varying degrees of growth on different media. Phytotoxicity of fungal cultural filtrates was also confirmed on parthenium leaves in laboratory conditions. Due to the virulent nature of the isolated pathogen, it may be selected for further studies to develop mycoherbicide for control of this devastating weed.  相似文献   

In vitro and in vivo evaluation of probiotic properties of <Emphasis Type="Italic">Enterobacter cloacae</Emphasis> in Kenyi cichlid, <Emphasis Type="Italic">Maylandia lombardoi</Emphasis>     

Nisha Rajagopalan Girijakumari  Kannapiran Ethiraja  Prabhu Narayanasamy Marimuthu 《Aquaculture International》2018,26(4):959-980

In this study, Enterobacter cloacae bacterium was isolated from curd and its antibacterial potential against the pathogen Plesiomonas shigelloides was evaluated using the freshwater ornamental fish Kenyi cichlid (Maylandia lombardoi). Among the bacterial isolates, E. cloacae exhibited tolerance to acidic pH 2 and demonstrated the highest antibacterial activity against P. shigelloides in various in vitro assays. Dietary supplementation of E. cloacae with prebiotic supplement 2% mannan oligosaccharide improved the growth performance and reduced the toxic metabolites such as nitrite in culture tank water of Kenyi cichlid. In vivo application of E. cloacae with mannan oligosaccharide significantly elevated (p?<?0.05) white blood cell counts (88.47?±?2.15 10³ mm^?3) and respiratory burst activity (0.243?±?0.007) of Kenyi cichlid when challenged with P. shigelloides. Intestinal morphology of Kenyi cichlid fish treated with probiotic and prebiotic combinations showed improved intestinal architectures. The present findings confirm that the isolated bacterium E. cloacae is a potential probiotic and can be used effectively to prevent infection of P. shigelloides in freshwater ornamental fish culture.  相似文献   

Potential and cost of carbon sequestration in Indian agriculture: Estimates from long-term field experiments     

H. Pathak  K. ByjeshB. Chakrabarti  P.K. Aggarwal 《Field Crops Research》2011

Carbon sequestration in tropical soils has potential for mitigating global warming and increasing agricultural productivity. We analyzed 26 long-term experiments (LTEs) in different agro-climatic zones (ACZs) of India to assess the potential and cost of C sequestration. Data on initial and final soil organic C (SOC) concentration in the recommended N, P and K (NPK); recommended N, P and K plus farmyard manure (NPK + FYM) and unfertilized (control) treatments were used to calculate carbon sequestration potential (CSP) i.e., capacity to sequester atmospheric carbon dioxide (CO₂) by increasing SOC stock, under different nutrient management scenarios. In most of the LTEs wheat equivalent yields were higher in the NPK + FYM treatment than the NPK treatment. However, partial factor productivity (PFP) was more with the NPK treatment. Average SOC concentration of the control treatment was 0.54%, which increased to 0.65% in the NPK treatment and 0.82% in the NPK + FYM treatment. Compared to the control treatment the NPK + FYM treatment sequestered 0.33 Mg C ha⁻¹ yr⁻¹ whereas the NPK treatment sequestered 0.16 Mg C ha⁻¹ yr⁻¹. The CSP in different nutrient management scenarios ranged from 2.1 to 4.8 Mg C ha⁻¹ during the study period (average 16.9 yr) of the LTEs. In 17 out of 26 LTEs, the NPK + FYM treatment had higher SOC and also higher net return than that of the NPK treatment. In the remaining 9 LTEs SOC sequestration in the NPK + FYM treatment was accomplished with decreased net return suggesting that these are economically not attractive and farmers have to incur into additional cost to achieve C sequestration. The feasibility of SOC sequestration in terms of availability of FYM and other organic sources has been discussed in the paper.  相似文献   

Pathogenic and genetic variability in <Emphasis Type="Italic">Tilletia indica</Emphasis> monosporidial culture lines using universal rice primer-PCR     

Rashmi Aggarwal  Aradhika Tripathi  Anita Yadav 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(3):333-342

Tilletia indica Mitra is the causal agent of Karnal bunt of wheat, an important disease prevalent in several countries. The disease is internationally quarantined and the pathogen due to its heterothallic nature shows high variability. In the present study, we compared the pathogenic behaviour of various isolates of T. indica collected from different geographical locations of India and genetically characterized monosporidial (Ms) culture lines raised from these isolates of the pathogen. Pathogenic variability revealed existence of three pathotypes based on aggressiveness on a set of differential host genotypes. Monosporidial culture lines viz., 5 each from KB1, KB2, KB4 and KB5 and three lines of KB3 were established and analyzed genetically using 12 Universal Rice Primers (URPs). Amplification showed 98.44% polymorphism and primer URP 13R produced 100% polymorphic bands. Maximum similarity (83%) was between KB1MsB and KB1MsD as calculated by Jaccard’s similarity coefficient, whereas, minimum similarity was between KB1MsC and KB4MsB; KB1MsE and KB3MsA (46%). Three groups were formed among all Ms culture lines. One major group consisted of 13 lines with approximately 70% similarity, the second group consisted of 7 culture lines showing 55% similarity and the third group consisted of 3 Ms lines. URPs were able to differentiate the Ms culture lines raised from different T. indica isolates and the results indicated heterogeneity in the pathogen population.  相似文献   

Structure—activity relationships in pyrethroid esters derived from substituted 2-phenoxy-3-methylbutanoic acids     

George Nisha  Muthuswamy Kalyanasundaram 《Pest management science》1992,35(1):21-25

Non-cyclopropane pyrethroid esters of different substituted 2-phenoxy-3-methylbutanoic acids have been synthesised using the three alcohols—3-phenoxybenzyl alcohol, α-cyano-3-phenoxybenzyl alcohol and 3, 4-methylene-dioxybenzyl alcohol. Among the 35 esters synthesised and tested against Culex quinquefasciatus Say, the Bancroftian filariasis vector, for both larvicidal and adulticidal activities, α-cyano-3-phenoxybenzyl 2-(4-fluorophenoxy)-3-methylbu-tanoate, with an LC₅₀ value of 2.5 × 10^?3 mg litre^?1 for larvicidal activity, and α-cyano-3-phenoxybenzyl-2-(4-chlorophenoxy)-3-methylbutanoate, with an LD₅₀ value of 30 times; 10^?4 ug insect^?1 for adulticidal activity, were found to be as effective as fenvalerate, a well-known non-cyclopropane pyrethroid ester. Structure-activity studies showed that the insecticidal activity is dependent on the nature and position of the substituent in the phenyl ring of the acid moiety and also on the type of alcohol moiety.  相似文献   

Feeding patterns of Indian giant flying squirrel(Petaurista philippensis,Elliot 1839) with reference to seasonal variation in central Gujarat,India     

Singh Nisha  Dharaiya Nishith 《林业研究》2019,(5):1959-1965

Indian Giant Flying Squirrel(Petaurista philippensis Elliot 1839)is widely distributed in South Asia and the only species of flying squirrel found in Gujarat.We studied the seasonal variation in its feeding behaviour at selected sites of Central Gujarat.Focal sampling was employed to study the behaviours and mainly feeding behaviours.Feeding analyses were consistent with other studies and indicated Madhuca longifolia as an important food resource.The diet of the species mainly consisted of pith,twig,seed,bark,petiole,young to mature leaves,flower and fruits of 20 species of plants of 15 families along with lichens,Vanda tessellata and Dendrophthoe falcata.Madhuca longifolia(25%)contributed most to the squirrel diet,followed by Diospyros melanoxylon(10%)and Terminalia tomentosa(9%).Among the plant parts consumed,pith formed the highest bulk as a food at 23%,followed by fruits(21%),bark(16%),twig(14%),flower(10%),seed(6%),leaf(6%),and bud(4%).The findings reveal the high dependency of flying squirrel on certain tree species.These tree species are well represented and distributed throughout central Gujarat,indicating that this area is important for the survival of this species and that the area should be conserved for protection and future management of this species.  相似文献   

Evaluation of zincated nanoclay polymer composite in releasing Zn and P and effect on soil enzyme activities in a wheat rhizosphere     

Nintu Mandal  Samar C. Datta  Kanchikeri M. Manjaiah  Brahma S. Dwivedi  Rajesh Kumar  Pramila Aggarwal 《European Journal of Soil Science》2019,70(6):1164-1182

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A novel and efficient method for identifying cotton leafroll dwarf virus infection in upland cotton (Gossypium hirsutum)     

Serina M. DeSalvio  Brianna L. Cheek  Robert N. Vaughn  Olufemi J. Alabi  John E. Holme  Nisha Jain  David M. Stelly 《Plant Breeding》2023,142(2):238-246

We report the development of a novel and more efficient, rapid, cost-effective and simple technique than current PCR-based identification methods for screening cotton (Gossypium hirsutum) plants for the presence of cotton leafroll dwarf virus (CLRDV). This protocol takes advantage of the PACE (PCR Allele Competitive Extension) system and uses PCR amplification of cDNA, coupled with sequence-specific fluorescent probes to differentiate between infected and uninfected cotton plants. This procedure has the potential for application in detection of other RNA viruses in a variety of other crops, by using primers specific for the RNA-dependent RNA polymerase (RdRP) gene and a widely conserved housekeeping gene in the host organism; in this case, the G. hirsutum polyubiquitin gene (GhUB).  相似文献   

Control of phytophthora leaf blight of taro (Colocasia esculenta) by fungicides and roguing     

A. Aggarwal  R. S. Mehrotra 《Phytoparasitica》1987,15(4):299-305

Six fungicides were evaluated under laboratory and field conditions for control of Phytophthora leaf blight of taro,Coloeasia esculenta, incited byPhytophthora colocasiae. Inin vitro tests Deraosan 65W was the most effective in inhibiting the mycelial growth of the test pathogen followed by Difolatan 80W, Fytolan (copper oxychloride), Apron 35F, Topsin-M 50W and Dithane Z-78 75W. Excellent control was obtained with Demosan 65W and Difolatan 80W, good control with Apron 35F, fair control with Fytolan, and poor control with Topsin-M 50W and Dithane Z-78 75W. Results ofin vivo tests were correlated with those of thein vitro tests. Roguing of infected leaves did not eradicate the pathogen but can only delay epiphytotics.  相似文献   

Estimation of combining ability in broilers from a full diallel cross     

C. K. Aggarwal  S. C. Mohapatra  S. P. Sinha  P. N. Sharma  S. D. Ahuja 《British poultry science》1979,20(2):185-190

1. A 4 × 4 complete diallel cross involving four broiler strains (two of Cornish stock and two of Rock stock) was made. Twelve males from each strain were concurrently mated to three pullets from each strain in single sire pens.

2. Body weight was measured from 1‐d‐old to 10 weeks of age every two weeks in the 2880 progeny obtained in five hatches.

3. General combining ability was highly significant for all traits except body weight at 1 d old. The specific combining ability was significant for 4‐, 8‐ and 10‐week body weights.

4. Maternal effects were evident for body weights at earlier ages but gradually declined with advancing age and were non‐significant for 8‐ and 10‐week weights.

5. Sex‐linked effects, although smaller in magnitude, were evident for body weights up to 6 weeks of age.  相似文献