Studies on pesticides based on coumarin. III. Synthesis and antifungal activity of substituted 4-methyl-coumarins and related compounds     

Rajvir Singh  Mrs V. Abrol  Bharat B. Gupta  Om P. Malik 《Pest management science》1988,23(2):103-107

A series of substituted 4-methylcoumarins was synthesised and the members tested for their toxicity towards mycelial growth of seven phytopathogenic fungi in culture. Rhizoctonia solani, Alternaria alternata and Fusarium solani exhibited maximum sensitivity to these compounds whereas Pythium aphanidermatum, Colletotrichum falcatum, Drechslera oryzae and Macrophomina phaseolina were relatively less sensitive. 6-Ethyl-3-n- propyl-7-hydroxy4-methylcoumarin ( I ) was relatively toxic towards all fungi except C. falcatum, P. aphanidermatum and M. phaseolina. The 6-n-butyl ( III ) and 6-(1, 1, 3, 3-tetramethylbutyl) ( VI ) derivatives were highly toxic to R. solani with EC₅₀, values of lμg ml^?1.  相似文献   

Studies on pesticides based on coumarin. II. Synthesis and antifungal activity of ten 2-alkyl-7, 8-dihydro-3-hydroxynaphtho[1,2-c]chromen-6-ones     

Bharat B. Gupta  Raj V. Singh  Om P. Malik  Hans R. Kataria 《Pest management science》1987,21(1):51-55

A series of 2-alkyl-7, 8-dihydro-3-hydroxynaphtho[1,2-c]chromen-6-ones was synthesised by the condensation of ethyl 3, 4-dihydro-1-oxonaphthalene-2-carboxylate with substituted phenols in the presence of POCl₃. The compounds were characterised and tested for their toxicity towards the mycelial growth of seven phytopathogenic fungi in culture. Drechslera oryzae, Rhizoctonia solani and Colletotrichum falcatum exhibited maximum sensitivity to these compounds whereas Macro-phomina phaseolina, Fusarium solani, Alternaria alternata and Pythium aphanidermatum were less sensitive. 2-Ethyl-7, 8-dihydro-3-hydroxy-naphtho[1,2-c]chromen-6-ones possessed greatest toxicity with EC₅₀ values ranging from 0.2 to 2.5 μg ml^?1 against all fungi except A. alternata and P. aphanidermatum.  相似文献   

Morphological and histochemical studies on the development of testis and spermatogenesis in the ruminal trematode of sheep, Paramphistomum cervi (Digenea: Paramphistomatidae)     

B C Gupta  V R Parshad  S S Guraya 《Folia parasitologica》1986,33(2):131-144

Morphological and histochemical changes accompanying testicular development and spermatogenesis have been described in the ruminal trematode Paramphistomum cervi during the course of its infection in sheep. Small testes of 4-week-old worms contain a few primordial germ cells. Spermatogonial cells appear first in 6-week-old worms and increase in number by the 10th week when the testes become large and follicular. Mature spermatozoa appear in the testes of 16-week-old worms. General pattern of spermatogenesis is the same as described for other trematodes, i.e. a single spermatogonium gives rise to 32 spermatozoa. Cytophore is formed at secondary spermatogonial stage. Various spermatogenic stages contain proteins, glycogen and phospholipids, however, the amount of phospholipids decreases as the maturation proceeds. The mature spermatozoa stain strongly with PAS. The enucleated residual mass contains HgBB-positive proteins and lipid granules. The morphological and cytochemical changes occurring during various spermatogenic stages have been correlated with corresponding histoenzymological changes in the cytoplasm. Frequency of spermatogenesis has been worked out which indicates that the transformation of secondary spermatogonia into spermatids is relatively fast as compared to transformation of primary spermatogonia into secondary spermatogonia and stages of spermateleosis.  相似文献   

Adsorption-desorption behaviour of flufenacet in five different soils of India     

Gajbhiye VT  Gupta S 《Pest management science》2001,57(7):633-639

Adsorption-desorption of the herbicide flufenacet (FOE 5043) has been studied in five soils from different locations in India (Delhi, Ranchi, Nagpur, Kerala and Assam) varying in their physicochemical properties. The organic matter (OM) content varied from 0.072 to 0.864%, clay content from 2.5 to 43.7% and pH from 4.45 to 8.35. The adsorption studies were carried out using a batch equilibration technique. Ten grams of soil were equilibrated with 20 ml of aqueous 0.01 M CaCl2 solution containing different concentrations (0-30 mg litre-1) of flufenacet. After equilibration, an aliquot of supernatant was taken out for analysis. During desorption, the amount withdrawn for analysis was replenished with fresh 0.01 M CaCl2 solution and further equilibrated. Desorption studies were carried out with the 30 mg litre-1 concentration of flufenacet only. The adsorption studies revealed that there was moderate to high adsorption of flufenacet considering the comparatively low organic carbon content in the five test soils. Average Kd values ranged from 0.77 to 4.52 and Freundlich KF values from 0.76 to 4.39. The highest adsorption was observed in Kerala soil (OM 0.786%; clay 25%; pH 4.45) followed by Ranchi, Nagpur and Delhi soils, and the lowest in Assam soil (OM 0.553%; clay 2.5%; pH 6.87). The trend in adsorption could be attributed to the chemical nature of flufenacet and the physicochemical properties of the soil such as pH, OM and clay contents. OM and clay contents were positively correlated whereas pH was negatively correlated. Soils having low pH, high OM and high clay contents showed higher adsorption. Desorption studies revealed that there was a hysteresis effect in all the soils. Hysteresis coefficient values (ratio of n(ad) and n(des)) varied from 0.09 to 0.45. The study implies that, because of its moderate to high adsorption, flufenacet is likely to persist in soil for some time. However, the possibility of its movement by leaching or surface run off is less.  相似文献   

First report of a geminivirus causing leaf curl disease on Trigonella corniculata evidenced by PCR using degenerate primers     

S. K. Raj  S. K. Pandey  G. Chandra  B. P. Singh  R. K. Gupta 《EPPO Bulletin》2001,31(1):115-117

A leaf curl and mottle disease was observed naturally affecting plants of Trigonella corniculata. A geminivirus was detected in infected plants by PCR using degenerate geminivirus primers and by Southern hybridization with a probe specific to tomato leaf curl begomovirus. This is the first report of a member of the Geminiviridae naturally occurring in T. corniculata.  相似文献   

Factors affecting cross protection of fusarium wilt of pigeon pea by soilborne nonpathogenic fungi     

A. Chakraborty  P. K. Sen Gupta 《Phytoparasitica》1995,23(4):323-334

Preinoculation of pigeon pea (Cajanus cajan (L.) Millsp.) seedlings with soilborne fungi nonpathogenic to pigeon pea, namely,Fusarium oxysporum f.sp.niveum; F. oxysporum f.sp.ciceris; F. solani f.sp.pisi; andCephalosporium sacchari, before challenge inoculation with the pathogenFusarium udum, or simultaneous inoculation of the seedlings with nonpathogen and pathogen was effective in controlling wilt of pigeon pea to a great extent. Inoculation with the nonpathogens before the challenge inoculation was more effective than simultaneous inoculation and gave up to 81.6% protection. The higher the spore concentration of the nonpathogenic fungi, the better was the degree of protection. The shorter the period was (in the range of 2–7 days) between nonpathogen inoculation and challenge inoculation, the greater was the degree of protection. Injury to the roots resulted in a decrease of the effect. Maximum disease reduction was obtained when the seedlings were kept at 20-30°C before inoculation; at 5°C and also at 40°C, protection was much less.  相似文献   

Effect of immunotherapy with a saline phenol extract of allogeneic tumour on E-rosette counts in horn cancer-affected cattle     

U K Batra  J R Sadana  R K Gupta 《Australian veterinary journal》1986,63(8):251-253

The mean percentage of cells forming rosettes with 2-aminoethyl isothiouronium bromide-treated sheep erythrocytes (EAETRFC) in the peripheral blood of 10 horn cancer-affected cattle (40.05 +/- 2.91) was significantly low in comparison to the value in unaffected control animals (58.61 +/- 1.68). Immunotherapy with a saline phenol extract of allogeneic tumour tissue resulted in a gradual increase in the mean percentage of EAETRFC on each subsequent week. The increase was statistically significant from the second week onwards and on the sixth week, the percentage of EAETRFC in horn cancer affected cattle (56.80 +/- 1.38) closely approximated the value in unaffected controls.  相似文献   

POST-PARTURIENT HAEMOGLOBINURIA OF DAIRY COWS     

B. Parkinson  B.V.Sc. A. K. Sutherland  B.V.SC  M.S. 《Australian veterinary journal》1954,30(8):232-236

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SEROLOGICAL DIAGNOSIS OF LARVAL CESTODES IN SHEEP     

Sally K.  Blundell-Hasell M.SC. 《Australian veterinary journal》1969,45(7):334-336

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THE BOVINE MUCOSAL DISEASE-SWINE FEVER VIRUS COMPLEX IN PIGS   总被引：2，自引：0，他引：2  

W. A. Snowdon  B.V.SC. E. L. French  M.SC  Ph.D. 《Australian veterinary journal》1968,44(4):179-184

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