Host substitution by Ixodes persulcatus (Acari: Ixodidae) larvae in the years of deep depression in the abundance of small mammals.     

I Uspensky  M Rubina 《Folia parasitologica》1992,39(2):171-176

A phenomenon of host substitution by the taiga tick (Ixodes persulcatus) larvae was observed by the authors in the western part of the Soviet Far East. In the mountain forests where the highest abundance of I. persulcatus was found, larvae usually fed on small mammals (primarily on Clethrionomys rufocanus, C. rutilus and Apodemus speciosus). Numerous larvae were found, however, on the mountain hare (Lepus timidus) in the years of deep depression in the abundance of small mammals. The host substitution is considered as one of the mechanisms stabilizing the abundance of I. persulcatus adults.  相似文献   

Does no-till wheat sowing in a rice-wheat cropping sequence cause surface-soil compaction?     

M. Saleem Akhtar  Ghulam Nabi  M. Mahmood-ul-Hassan 《Eurasian Soil Science》2008,41(11):1205-1212

Wheat planting in rice-harvested fields without land preparation is more economical, but the physical characteristics of the plant root sphere are not well documented. Comparative changes in the soil compaction in parallel fields used for no-till and conventional tillage were measured in replicated field trials for two soil types and in three randomly selected farmers’ fields. Weakly to moderately developed soils on recent to old Pleistocene calcareous alluvium were studied. They differed in their clay content. No-till wheat sowing resulted in a greater soil bulk density and a lower total porosity in the heavy-textured soils compared to the light-textured soil. In the light-textured Jhakkar soil, the no-till regime resulted in a greater infiltration at the saturated state and under most suction levels and a greater macroporosity compared to the conventional tillage. The silty clay Kotly soil had greater macroporosity in the conventional tillage than in the no-till regime. The wheat root growth and penetration seemed to be favored by the relatively low bulk density resulting from the conventional tillage, particularly in the silty clay loam soil. The dense layer restricted root penetration in the silty clay loam soil, while there was less resistance in the sandy loam soil. The study demonstrated the suitability of the no-till regime for specific soil types. Published in Russian in Pochvovedenie, 2008, No. 11, pp. 1362–1370. The text was submitted by the authors in English.  相似文献   

Bimetallic blends and chitosan nanocomposites: novel antifungal agents against cotton seedling damping-off     

Kamel A. Abd-Elsalam  Alexander Yu. Vasil’kov  Ernest E. Said-Galiev  Margarita S. Rubina  Alexei R. Khokhlov  Alexander V. Naumkin  Eleonora V. Shtykova  Mousa A. Alghuthaymi 《European journal of plant pathology / European Foundation for Plant Pathology》2018,150(1):57-71

Anthracnose disease caused by fungal pathogen Colletotrichum capsici is considered to be one of the most destructive diseases in chilli cultivation as it infects and leads to complete destruction of the crop by infecting the mature fruit in the field and/or during the storage period. The management of the disease is difficult due to the absence of any resistant cultivar and effective fungicide. The current study was initiated to evaluate the antifungal efficacy of the biosurfactant produced by strain Pseudomonas aeruginosa JS29 for biological control of anthracnose disease. The results revealed significant disease reduction using biosurfactant in plant assay which were challenge-inoculated with the fungal spore. In vitro experiments clearly showed that the biosurfactant can effectively inhibit the growth of both spore and mycelia of the pathogen. Moreover, the biosurfactant can also effectively inhibit the fungal growth in detached-fruit assay in different storage conditions. The study confirmed that the biosurfactant has tremendous potential to become a viable, cost-effective and environment-friendly alternative for managing anthracnose disease in field and in post-harvest storage condition.  相似文献   

Field evolved resistance to carbamates,organophosphates, pyrethroids,and new chemistry insecticides in <Emphasis Type="Italic">Spodoptera litura</Emphasis> Fab. (Lepidoptera: Noctuidae)     

Sarfraz Ali Shad  Ali H. Sayyed  Sahar Fazal  Mushtaq A. Saleem  Syed Muhammad Zaka  Muhammad Ali 《Journal of pest science》2012,85(1):153-162

Spodoptera litura Fab. (Lepidoptera, Noctuidae) is a polyphagous pest and has been shown to be resistant to a wide range of insecticides, which has led to sporadic out breaks of the pest and failure of crops. We were interested to establish if resistance to insecticides is diverse in different populations of S. litura collected from various areas with variable temperatures. We collected S. litura from eight different locations and compare the toxicity of insecticides. Resistance to the pyrethroids ranged from 20- to 11,700-fold compared with the Lab-PK (laboratory susceptible population). The resistance to bifenthrin was the lowest in a population collected from Multan and the highest to esfenvalerate in a population collected from Lodhran. Similarly, very high level of resistance to spinosad, indoxacarb, and methoxyfenozide was observed in all eight populations. In contrast, resistance to organophosphates was significantly lower than the pyrethroids, spinosad, indoxacarb, and methoxyfenozide, while toxicity of emamectin to field populations was similar to the Lab-Pk. The results are discussed in relation to integrated pest management (IPM) for S. litura with special reference to management of field evolved resistance to insecticides.  相似文献   

The phototransformation of a bis-2,3-diazabutadienyldisulfide to an aphicidally active 2,3-dihydro-1,3,4-thiadiazole     

Saleem Farooq  Adrian Steinemann  Theophil Schlaepfer 《Pest management science》1990,30(2):199-209

The pro-insecticide bis-(1-(4-chlorophenyl)-4-(pyrid-3-yl)-2,3-diazabutadien-1-yl)disulfide, I is photochemically transformed to the aphicidally active 5-(4-chlorophenyl)-2-(pyrid-3-yl)-2,3-dihydro-1,3,4-thiadiazole IIa .  相似文献   

Synergism of insecticidal action and effects on detoxifying enzymes in vivo of lambda-cyhalothrin and malathion by some nitrogen heterocycles in resistant and susceptible strains of Tribolium castaneum     

Richard M. Wilkins  Mushtaq A. Saleem  Candasamy Rajendran 《Pest management science》1995,43(4):321-331

The interactions of the synthetic pyrethroid, lambda-cyhalothrin and malathion were studied with purines, pyrimidines, caffeine and some other related nitrogenous compounds in resistant and susceptible strains of Triboliurn castaneum (Herbst.) The results were compared with those obtained with a known synergist, piperonyl butoxide (PBO) and precocene I. Adenine, cytosine, guanine, thymine and uracil synergised lambda-cyhalothrin, especially in the susceptible strain, with maximum effect at a 1:1 mass ratio, with the effect decreasing with increasing proportion of the heterocycle. The order of synergism of lambda-cyhalothrin was; precocene I > PBO > the nitrogenous compounds, in both resistant and susceptible strains. On the other hand, caffeine (lethal effect increased about twice), barbital (about twice), isobarbituric acid (less than twice) and bromacil (up to eight times) synergised malathion in malathion-resistant strains and antagonised in the susceptible strains. Total in-vivo esterases, carbox-ylesterases and cytochrome P₄₅₀ of susceptible and resistant strains showed significantly increased activity or content when treated with either insecticide plus a heterocyclic compound. Exceptions were with bromacil and malathion and for the malathion-specific strain, Kano-C with malathion and the N-heterocycles.  相似文献   

Occurrence of Cucumber mosaic virus Subgroup IA in tomato in Pakistan     

Akhtar  K. P.  Ryu  K. H.  Saleem  M. Y.  Asghar  M.  Jamil  F. F.  Haq  M. A.  Khan  I. A. 《植物病害和植物保护杂志》2008,115(1):2-3

Journal of Plant Diseases and Protection - Infection of tomato in Faisalabad, Pakistan with subgroup IA strain of Cucumber mosaic virus (CMV) is reported for the first time. The virus was detected...  相似文献   

Study of heritable variation and genetics of earliness in mungbean (<Emphasis Type="Italic">Vigna radiata</Emphasis> L. Wilczek)     

Aziz ur Rehman  Muhammad Amjad Ali  Muhammad Saleem  W. Tadesse 《Euphytica》2010,176(3):331-339

Fifty-five mungbean lines were evaluated for days to maturity and grain yield per plant. This material showed considerable range of variability for the target traits. Eight genetically diverse parents were selected and used for a full diallel set of crosses to study the mode of inheritance for earliness related parameters (days to flowering, days to maturity and length of reproductive phase) during summer 2005. The F₁ generation of these crosses was sown during the spring of 2006 and the selfed seeds were used to raise the F₂ generation during kharif season. The data recorded from two generations were subjected to genetic analysis. The formal ANOVA showed the significance of both additive and dominance effects for all the traits in both generations. Significance of D, H₁ and H₂ components also confirmed the contribution of both additive and dominance effects in controlling the inheritance of these traits. The estimates of narrow sense heritability were low to moderate except higher estimates for days to maturity in F₂ generation, while the broad sense heritability estimates were relatively higher. Seasonal and environmental effects were also found to be significant. In view of the complex nature of gene action for earliness, it is suggested that breeders should look for transgressive recombinants of earliness and other desirable attributes in later segregating generations to gain higher genetic advance. The variety NM92 was found to be the best source of earliness in mungbean breeding.  相似文献   

Short Response of Spring Wheat to Tillage,Residue Management and Split Nitrogen Application in a Rice-Wheat System          下载免费PDF全文

Khalid Usman  Ejaz Ahmad Khan  Fazal Yazdan  Niamatullah Khan  Abdur Rashid  Saleem Ud Din 《农业科学学报》2014,13(12):2625-2633

A field experiment was conducted to study the impact of tillage, crop residue management and nitrogen (N) splitting on spring wheat (Triticum aestivum L.) yield over 2 yr (2010-2012) in a rice (Oryza sativa L.)-wheat system in northwestern Pakistan. The experiment was conducted as split plot arranged in randomized complete blocks design with three replications. Treatments comprised six tillage and residue managements: zero tillage straw retained (ZTsr), zero tillage straw burnt (ZTsb), reduced tillage straw incorporated (RTsi), reduced tillage straw burnt (RTsb), conventional tillage straw incorporated (CTsi), and conventional tillage straw burnt (CTsb) as main plots and N (200 kg ha⁻¹) was applied as split form viz., control (no nitrogen & no splitting, N₀S₀); 2 splits of total N, half at sowing and half at the 1st irrigation (i.e., 20 d after sowing (DAS)) (NS₁); 3 splits of total N, 1/3 at sowing, 1/3 at the 1st irrigation, and 1/3 at the 2nd irrigation (NS₂); 4 splits of total N, 1/4 at sowing, 1/4 at the 1st irrigation, 1/4 at the 2nd irrigation (45 DAS), and 1/4 at the 3rd irrigation (70 DAS) (NS₃); and 4 splits of total N, 1/4 at the 1st irrigation, 1/4 at the 2nd irrigation, 1/4 at the 3rd irrigation, and 1/4 at the 4th irrigation (95DAS) (NS₄) as sub plots. The results showed that the most pikes m⁻², grains/spike, 1000-grain weight, grain yield, and N use efficiency (NUE) were obtained at zero tillage, straw retained and 4 splits application of total N (i.e., at sowing 20, 45 and 70 d after sowing). The results indicated that ZTsr with application of 200 kg N ha⁻¹ in 4 equal splits viz. at sowing 20, 45 and 70 d after sowing is an appropriate strategy that enhanced wheat yield (7436-7634 kg ha⁻¹) and N efficiency (28.6-29.5 kg kg⁻¹) in rice-wheat system.  相似文献   

Spatiotemporal changes in fungal growth and host responses of six yellow rust resistant near-isogenic lines of wheat     

K. Saleem  C. K. Sørensen  R. Labouriau  M. S. Hovmøller 《Plant pathology》2019,68(7):1320-1330

The objective of the present study was to investigate to what extent the macroscopic phenotype of incompatible host–pathogen interactions reflects differences in fungal development and host responses at the histological level. This was done by conventional and advanced microscopic analysis of six wheat near-isogenic lines differing by individual R genes and inoculated with an avirulent isolate of Puccinia striiformis. Wheat line AvocetYr15 had the lowest macroscopic infection type (IT) 0–1, in which fungal growth was stopped at early stages due to extensive expression of a hypersensitive response (HR) at all time points (4, 8 and 16 days post-inoculation, dpi) without any sign of haustorial bodies. AvocetYr5 and AvocetYr1 had IT 1, in which most fungal colonies developed secondary hyphae. Many colonies were encased by HR at 16 dpi, more extensively in AvocetYr1 than AvocetYr5. In AvocetYr6 (IT 2), HR was expressed after the formation of secondary hyphae at 4 dpi, after which fungal growth and HR increased simultaneously until most colonies became encased by HR. AvocetYr27 (IT 2–3) and AvocetYr17 (IT 4–5) showed similar fungal growth and HR at 4 dpi, where HR was only weakly expressed in a few host cells. Encasement of secondary and runner hyphae increased significantly in AvocetYr27, but at 16 dpi, HR was often circumvented by large, intermingled fungal colonies in both lines. No resistance responses were observed in Avocet S (susceptible control). The very different histological patterns conferred by the six R genes suggests differences in the timing of the host–pathogen recognition and onset of host defence pathways.  相似文献