Mohammad Shahid

Effect of seed extracts of Withania somnifera, Croton tiglium and Hygrophila auriculata on behavior and physiology of Odontotermes obesus (Isoptera, Termitidae)

In addition to antibiotic properties, medicinal plants are important sources of chemicals with potential application as pesticides. The present study deals with antitermitic potential of seed extracts of Withania somnifera (Indian ginseng), Croton tiglium (jamalgoota) and Hygrophila auriculata (talimkhana). The seed extracts caused changes in tunneling behaviour, number of bacterial colonies in hindgut and activities of enzymes in midgut of Odontotermes obesus. C. tiglium showed the lowest LT50 (12.85 and 2.65 h) among the three seed extracts at concentrations of 50% (half dilution of the extract) and 100% (extract without dilution), respectively. There was no tunneling in soil treated with 100% concentration of seed extracts of W. somnifera and C. tiglium. Numbers of bacterial colonies in the gut of termites from soils treated with 50% and 100% concentrations of the three plants did not differ significantly, but they differed from those in termites from untreated soil. At 50% concentrations of seed extracts of the tested plants, the difference in hindgut enzyme activities was not obvious, however, at 100% concentrations the enzyme activities in the termites from soils treated with seed extracts significantly differed from controls and differences were also recorded between the plants.

Sequencing of 28SrRNA Gene for Identification of Trichoderma longibrachiatum 28CP/7444 Species in Soil Sample

Most of the Trichoderma species are morphologically very similar and were considered for many years as a single species. Since new species were discovered, a consolidated taxonomical scheme was needed and proposed and defined nine morphological species aggregates. DNA methods brought additional valuable criteria to the taxonomy of Trichoderma which are being used today for studies that include identification and phylogenetic classification. Most isolates of the genus Trichoderma that were found to act as mycoparasites of many economically important aerial and soil-borne plant pathogens. Trichoderma has attained importance for substitute of chemical pesticides and hence an attempt was intended to corroborate the positive relatedness of molecular and morphological characters. A fungal strain of Trichoderma longibrachiatum 28CP/7444 was isolated from a soil sample collected from Barabanki district of Uttar Pradesh, India. The universal primers were used for amplification of the 28S rRNA gene fragment and strain characterized by using 28S rRNA gene sequence with the help of ITS marker. It is proposed that the identified strain Trichoderma longibrachiatum 28CP be assigned as the type strain of a species of the genus Trichoderma based on phylogenetic tree analysis together with the 28S rRNA gene sequence search in Ribosomal Database Project, small subunit rRNA and large subunit rRNA databases. The sequence was deposited in GenBank with the accession number JX978541. Thus an integrated approach of morphological and molecular markers can be employed to identify a superior strain of Trichoderma for its commercial exploitation.

Effect of Iron Fortified Wheat Flour on the Biology and Physiology of Red Flour Beetle, Tribolium castaneum (Herbst)

Iron overload in the fortified flour can influence the life stages and physiology of the insects. The present study was carried out to evaluate the effect of commercially available premix iron fortified flour as well as effect of different concentrations of post-mix iron fortified flour (30–5 ppm) on biology of red flour beetle, Tribolium castaneum (Hebrst.). Larval and pupal duration, total developmental time, fecundity and larval weights in two consecutive generations of beetle were compared with control treatment. Amylase and protease activities of gut of the beetle were also measured in premix and postmix flours. Results showed that larval mortality increased in two sources of premix iron flour when compared with control. Larval weight was reduced in first generation only. The larval mortality was significantly higher in 30 ppm postmix iron fortified flour than in other postmix concentrations and control treatment. The larvae of T. castaneum fed on two sources of premix and in various concentrations of postmix iron fortified flour revealed an increase in amylases and decrease in protease activities.

Role of Secondary Metabolites Produced by Commercial Trichoderma Species and their Effect Against Soil Borne Pathogens

The study was focused on the identification of the major secondary metabolites produced by the Trichoderma spp and soil borne pathogens. Trichoderma harzianum (Th. Azad) and Trichoderma viride (01PP) are two microorganisms used as active agents in a variety of commercial bio pesticides and bio fertilizers and widely applied on field and greenhouse crops. The production, isolation, biological and chemical characterization of the major secondary metabolites produced by these strains is done during this study. Metabolites are organic compounds that are used in, or created by, the chemical reactions happening in every cell of living organisms. In this paper we are studying about the production of secondary metabolites from Trichoderma species against soil borne pathogens at 27oC at different time intervals. Higher the concentration of secondary metabolites, greater will be the efficiency against soil borne pathogens