42 research outputs found
Effects of Bacillus thuringiensis δ -endotoxin-fed Helicoverpa armigera on the survival and development of the parasitoid Campoletis chlorideae
With the deployment of transgenic crops expressing δ-endotoxins from Bacillus thuringiensis (Bt) for pest management, there is a need to generate information on the interaction of crop pests with their natural enemies that are important for regulation of pest populations. Therefore, we studied the effects of the Bt δ-endotoxins Cry1Ab and Cry1Ac on the survival and development of the parasitoid Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) reared on Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) larvae fed on Bt toxin-intoxicated artificial diet. The H. armigera larvae fed on artificial diet impregnated with Cry1Ab and Cry1Ac at LC50 (effective concentration to kill 50% of the neonate H. armigera larvae) and ED50 (effective concentration to cause a 50% reduction in larval weight) levels before and after parasitization resulted in a significant reduction in cocoon formation and adult emergence of C. chlorideae. Larval period of the parasitoid was prolonged by 2 days when fed on Bt-intoxicated larvae. No adverse effects were observed on female fecundity. The observed effects appeared to be indirect in nature, because no Bt proteins were detected through enzyme-linked immunosorbent assay in the C. chlorideae larvae, cocoons, or adults fed on Cry1Ab- or Cry1Ac-treated H. armigera larvae. The effects of Bt toxin proteins on C. chlorideae were due to early mortality of H. armigera larvae, that is, before completion of parasitoid larval development
Pathogenic, cultural, morphological and molecular variability among eight isolates of Alternaria solani, causing early blight of tomato
Among the fungal diseases infecting tomato crops, early blight caused by Alternaria solani (Ellis and Martin) Jones and Grout is one of the most catastrophic disease causing accountable losses. Further, all of the tomato cultivars presently under cultivation have succumb more or less to early blight disease. Therefore, the present studies were undertaken for the pathogenic, cultural, morphological and molecular variability among the isolates of A. solani. The results reveal all of the eight isolates of A. solani as pathogenic to tomato (Cv. Pusa Ruby) and showed variability amongst them. The test isolates could grow better on the basic culture medium potato dextrose agar; however, highest mycelial growth was recorded on the isolate AsLt (88.50 mm), followed by AsBd (82.36 mm) and AsHl (78.40 mm), with excellent sporulation. All of the eight test isolates exhibited a wide range of variability in respect of their mycelial and conidial dimensions and septation. RAPD-PCR analysis of the four most virulent A. solani isolates, using 13 OPA primers revealed that the isolates AsBd (Beed) and AsLt (Latur) were closely related with 85% genetic similarity whereas, the isolates AsHl (Hingoli) and AsJl (Jalna) were closely related with 50% genetic similarity, but distinct from that of AsLt and AsBd isolates. Key words: Tomato, Alternaria solani, isolates, pathogenic, molecular variability, virulent, primers
Temperature dependent properties of spray deposited Cu2CoSnS4 (CCTS) thin films (vol 28, pg 18891, 2017)
The original version of this article unfortunately contained an error in Sect. 3.3 Structural analysis Equation (7). The corrected version is published with this erratum (Eq. 7)