GENBBIOCHEMICAL GENETIC INDICES FOR INSECT RESISTANCE IN MAJOR SPECIES OF GENUS CYMBOPOGON

Abstract

The main objective of this study was to evaluate some selected clones of lemon grass and citronella which characterized by different synergism in producing pest natural product. The base population of genus Cymbopogon consisted of 27 clones oflemongrass and citronella developed from four different resources of roselle through co-cultivation system to study genetic variability and selected particular clones. Data were recorded on seven quantitative characters considering essential oil yield components on Cymbopogon clones while in resources of roselle eight characters were also recorded according to infestation characters in the two seasons. Genotypic variation were noted for all characters in two plants.

The estimates of heritability, analysis of variance, means performance, regression and correlation were calcualted. Volatile oil content and essential oil yield were determined. The constituents of essential oil for the four clones were analyzed by using GC/MS technique. Qulitative and quantitative variations were detected through 24 variant components. The anti-insect activity of the selected clones of volatile oil of lemongrass and citronella were studied. Most of selected clones caused marked effects on pink cotton boll worm through determined LC30, 50,90. The value of active ingradients such as terpens were outlined the nature of genes participated in controlling resistance.