STUDIES ON THE MOLECULAR CHARACTERIZATION OF INSECTICIDAL RESISTANCE IN Plutella xylostella (L.)
KrishiKosh
View Archive InfoField | Value | |
Title |
STUDIES ON THE MOLECULAR CHARACTERIZATION OF INSECTICIDAL RESISTANCE IN Plutella xylostella (L.)
|
|
Creator |
SUNITHA, V
|
|
Contributor |
SINGH, T.V.K
|
|
Subject |
insecticides, pesticides, pesticide resistance, biological phenomena, animal developmental stages, selection, land resources, genetics, plutella xylostella, toxins
MOLECULAR, INSECTICIDAL RESISTANCE, Plutella xylostella (L.) |
|
Description |
Insecticidal resistance and molecular characterization studies against third instar larvae of DBM (Plutella xylostella L.) were carried out at Bt Lab, Dept. of Entomology, College of Agriculture, Rajendranagar, Hyderabad and CICR, Nagpur. The larvae of DBM collected from in and around Hyderabad of Andhra Pradesh were reared in the laboratory. The third instar larvae obtained from field population were tested against acephate, cypermethrin, spinosad, cartap hydrochloride and Cry2Ab by using leaf dip method of bioassay to calculate LC50 values. The LC50 values of the acephate, cypermethrin, spinosad, cartap hydrochloride and Cry2Ab were 0.10 %, 0.08 %, 0.003 %, 0.01 % and 0.3 μg/ml, respectively, which were further used to quantify the resistance in P.xylostella of parental generation (F0) from Andhra Pradesh, Karnataka and Delhi populations. The survivals from F0 generation were reared to next generation (F1). Resistance development studies were carried out with third instar larvae of F1 generation by applying a concentration of 80.00 % mortality in every generation for selection from F1 to F3 generations against all the test insecticides and Cry2Ab toxin. Studies on resistance revealed that 2.57 folds, 0.17 folds and 1.27 folds resistance was developed against acephate, in F3 generation of Andhra Pradesh, Karnataka and Delhi populations, respectively. In case of cypermethrin, 1.00 folds, 2.33 folds and 3.00 folds resistance in F3 generation of Andhra Pradesh, Karnataka and Delhi populations, respectively. Resistance studies further revealed development of 1.00 folds, 1.50 folds and 1.00 folds resistance against spinosad, 1.33 fold, 2.28 and 1.26 folds resistance against cartap hydrochloride, respectively, in F3 generation of Andhra Pradesh, Karnataka and Delhi populations, respectively. In case of Cry2Ab toxin 1.98 folds, 1.49 folds and 1.35 folds resistance was recorded in F3 generation of Andhra Pradesh, Karnataka and Delhi populations, respectively. The rate of development of resistance from F1 to F3 generations increased in all the three populations against all the test insecticides (acephate, cypermethrin, spinosad, cartap hydrochloride) and Cry toxin (Cry2Ab), except against acephate in Karnataka. The Andhra Pradesh and Delhi populations did not developed resistance against spinosad from F1 to F3 generations. The selected strains of acephate, cypermethrin, spinosad, cartap hydrochloride and Cry2Ab exhibited no cross-resistance against emamectin benzoate, chlorantraniliprole and flubendiamide, in all the three populations. Crosss resistance ratios by the selected strains were below one which indicates that cross resistance was not developed against the selected strains of acephate, cypermethrin, spinosad, cartap hydrochloride and Cry2Ab, except the Delhi cypermethrin selected strain (D.CyR) which displayed development of cross resistance against flubendiamide. The degree of resistance acquired by the P.xylostella in field level was assessed by continues spraying of the cabbage fields with double the dose of four conventional insecticides i.e., acephate, cypermethrin, spinosad and cartap hydrochloride against the normal field dose and the studies demonstrated that high resistance was developed against cypermethrin followed by acephate, spinosad and cartap hydrochloride. Molecular characterization of DBM was done with the survivals and controls of the test insecticides (acephate, cypermethrin, spinosad, cartap hydrochloride) and Cry toxin (Cry2Ab) of three regions (Andhra Pradesh, Karnataka and Delhi). The DNA was extracted and amplified with ten primers. The highest number of amplicons was produced by the primer ABA-08 and lowest was recorded with ABA-10 primer in Andhra Pradesh population. Karnataka population showed highest polymorphism with primer ABA-13 and lowest with ABA-2 primer and in Delhi populations highest polymorphism was found with primer ABA-13 and lowest with ABA- 09 primer. The allelic distribution of ten primers with all the test insecticides and Cry toxin treated survivals was studied. Based on the band scoring, ABA-02 primer produced a specific amplicon of 750 bp which was present in control population of F0, F1, F2, F3 generations and was not present in survivals of acephate treated population. ABA-04 primer produced specific amplicon with 800bp size in survivals of the acephate treated population and was absent in control population of Andhra Pradesh. The ABA-12 primer yielded specific amplicon with a size of 820bp in acephate and Cry2Ab treated survivals and which was absent in control population of Delhi.The cluster analysis studies revealed that as the selection pressure increased, genetic variation decreased. |
|
Date |
2016-06-07T13:39:18Z
2016-06-07T13:39:18Z 2012 |
|
Type |
Thesis
|
|
Identifier |
http://krishikosh.egranth.ac.in/handle/1/66932
|
|
Language |
en
|
|
Relation |
;D9244
|
|
Format |
application/pdf
|
|
Publisher |
ACHARYA N. G. RANGA AGRICULTURAL UNIVERSITY
|
|