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ThesisItem Restricted Effect of Bt cotton on important insect pests and their natural enemies(Punjab Agricultural University, Ludhiana, 2017) Jagdeep Kaur; Aggarwal, NaveenThe studies on the effect of Bt cotton on some important pests and their natural enemies were conducted at Punjab Agricultural University, Ludhiana during 2015 and 2016. The Cry toxin concentration estimation at the three trophic levels of Bt cotton plant, prey (Aphis gossypii Glover) and predators, Cheilomenes sexmaculatus (Fabricius) and Chrysoperla zastrowi sillemi (Esben-Petersen) revealed maximum Cry1Ac and Cry2Ab concentration in cotton leaves in the treatment of 60 days old Bt plants and minimum concentration in cotton leaves of 40 days old Bt plants. While, in similar experiment with Bt cotton leaves, prey (Bemisia tabaci Gennadius) and predators (C. sexmaculatus and C. z. sillemi), maximum Cry toxins concentration in Bt cotton leaves was observed at 70 days and minimum concentration in 110 days old Bt plants. In the tritrophic experiment of Bt cotton, aphid and C. sexmaculatus at second trophic level, we found mean values of 0.24, 0.41µg/g FW of Cry1Ac and Cry2Ab toxins respectively, in aphids reared on Bt cotton. Whereas, in Bt cotton, whitefly and C. sexmaculatus tritrophic experiment, 0.31, 0.52 µg/g FW of Cry1Ac and Cry2Ab toxins were detected in whiteflies. Further, the flow of these toxins in the predator, C. sexmaculatus adults has been recorded with the values of 0.04, 0.09 µg/g FW of Cry1Ac and 0.07, 0.19 µg/g FW of Cry2Ab toxins in case of aphid and whitefly feeding. In the tritrophic experiment of Bt cotton, aphid and C. z. sillemi at second trophic level, mean values of 0.20, 0.38 µg/g FW of Cry1Ac and Cry2Ab toxins respectively, were recorded in aphids reared on Bt cotton. Whereas, in Bt cotton, whitefly and C. z. sillemi tritrophic experiment, 0.24, 0.37 µg/g FW of Cry1Ac and Cry2Ab toxins were detected in whiteflies. At the third trophic level in predator, C. z. sillemi adults, 0.06, 0.07 µg/g FW of Cry1Ac and 0.08, 0.09 µg/g FW of Cry2Ab toxins were recorded in case of aphid and whitefly feeding.When the Bt toxin reared prey, A. gossypii and B. tabaci were used in the tritrophic feeding bioassay experiments with C. sexmaculatus and C. z. sillemi, no significant indirect effects of Cry toxins were observed on the various developmental and reproductive parameters of both the predators. Though, slightly lower larval survival, fecundity, adult emergence and longevity were recorded in predators fed with Bt reared prey. In the abundance and diversity studies in Bt and non-Bt cotton under field conditions, a total of 70 and 73 species of arthropods distributed over 12 orders belonging to 48 and 50 families were found to be associated with the cotton crop during 2015 and 2016, respectively. Among the different categories of the pests, four species of target insect pests, nine species of sucking insect pests, 25 species of natural enemies and 32 and 35 species of non-target insects were recorded from Bt and non-Bt cotton during two years. BG II cotton did not significantly affect the arthropod abundance, species richness and diversity indices of arthropods with some exceptions of target insect pests (bollworms) as their population was negligible in the Bt treatments. The abundance of sucking insect pests was significantly more in Bt cotton plots during the year 2015 in comparison to 2016. Moreover, arthropod abundance, species richness and diversity indices were more under unprotected conditions as compared to treated plots in Bt and non-Bt cotton. On the whole, cultivation of BG II cotton did not pose any adverse effect on biodiversity including natural enemies found in cotton ecosystem.ThesisItem Open Access Morphological and biochemical plant characters in relation to resistance against some sucking insect pests in Bt cotton(Punjab Agricultural University, Ludhiana, 2017) Y. Krishnakumari Devi; Vijay KumarThe studies on morphological and biochemical plant characters in relation to resistance against some sucking insect pests in Bt cotton were carried out at Entomological Research Farm, PAU, Ludhiana during 2014 and 2015. Experiment on incidence of sucking insect pests on different cotton cultivars, revealed that leafhopper population was significantly higher on Bt cotton cultivar, RCH 773 (4.70 / 3 leaves), whitefly and thrips on Bioseed 6588 (7.47 and 2.47 /3 leaves, respectively). However, lower population of leafhopper, whitefly and thrips was recorded on the desi cotton cultivar, FDK 124 (1.78, 3.25 and 0.83/ 3 leaves, respectively). Incidence of sucking insect pests was also significantly higher at 130 Kg nitrogen as compared to 100 and 65 Kg nitrogen per acre. The population of leafhopper, whitefly and thrips showed significantly positive correlation with maximum and minimum temperature whereas evening relative humidity and rainfall has significantly positive correlation with leafhopper only. However, leafhopper and whitefly showed significant positive correlation with evaporation. Sunshine hours showed significant negative correlation with thrips but positive with whitefly. In another experiment on effect of various morphological plant characters revealed significant positive correlation with leafhopper population and gossypol gland on midrib. However, leafhopper, thrips and whitefly showed significant positive correlation with leaf lamina thickness and highly significant positive correlation with leaf area. Among the biochemical plant characters revealed that higher amount of total phenol, flavonols, O-dihydroxy phenol, tannins, total sugar and reducing sugars were recorded in cultivars infested with sucking insect pests over uninfested condition. Significantly higher biochemical content were recorded at lower level of nitrogen (65 Kg) followed by 100 and 130 Kg per acre. Leafhopper population had significant positive correlation with reducing sugar whereas whitefly and thrips with total sugar. However, thrips population showed significantly negative correlation with O-dihydroxy phenol. In another experiment on detection of the presence of Cry toxin revealed that highest amount of Cry1Ac and Cry2Ab was detected at 60 days after sowing as compared to 120 days after sowing. Higher expression of Cry toxin was recorded at high level of nitrogen (130 Kg) followed by 100 and 65 Kg. ELISA analysis showed presence of Cry toxin (Cry1Ac and Cry2Ab) in leafhopper nymphs and whitefly adults fed on Bt cotton cultivars and traces in honeydew excreted by whitefly feeding on Bt cotton cultivars.ThesisItem Open Access Evaluation and molecular characterization of hygienic traits in honey bee (Apis mellifera Linnaeus)(Punjab Agricultural University, Ludhiana, 2017) Mohindru, Bharathi; Chhuneja, Pardeep KumarStudies on ‘Evaluation and molecular characterization of hygienic traits in honey bee (Apis mellifera Linnaeus)’ were conducted at PAU, Ludhiana (India), during 2015-2017. The studies included screening of 100 A. mellifera colonies for comparative hygienic behaviour response, molecular characterization through genome wide and candidate gene based markers for hygienic behaviour, and validation of the selected hygienic colonies against Varroa destructor infestation. Out of the 100 colonies screened, 45 were hygienic, and 55 were non-hygienic out of which 42 were intermediary (71-80% removal of pricked brood) and 13 were the least hygienic (<71% emptying of pricked brood). After 24 h of brood pricking, mean brood removal was 83.65 per cent (range: 80.22-91.0 %) among 45 colonies while it was 73.05 per cent (range: 46.78-79.56%) in the remaining 55 colonies. In the seven selected most hygienic colonies, after 24 h, mean of 91.40 per cent brood was removed (range: 87.22-94.89%), while it was 47.63 per cent (range: 43.56-52.44%) in the three most non-hygienic selected colonies. The hygienic colonies took 20.6 h to express the hygienic trait while the non-hygienic colonies took 44.6 h. After 24 h of V. destructor inoculation into the brood in the hygienic colonies, 93.43 and 95.23 per cent mean of brood removal was recorded during autumn and spring, while in the non-hygienic colonies, it was only 61.90 and 77.24 per cent, respectively, to achieve cent per cent cleaning of cells, the hygienic colonies took a mean of 28 and 25.71 h, while non-hygienic colonies took 50.67 and 47.33 h, during autumn and spring, respectively. The five SSR markers, reported to be linked with hygienic behaviour, showed polymorphism, and did not differentiate the colonies among hygienic and non-hygienic groups. Out of the 40 SSR markers used to study the genetic diversity between the hygienic and non-hygienic colonies, 37 markers were polymorphic; the diversity index value ranged between 0.37-0.92, marker index value between 0.24-6.41 and the PIC value between 0.23-0.77. The clustering pattern between the hygienic and non-hygienic colonies for each of the three brood cycles produced by neighbour-joining dendrogram showed that the ten colonies (7 most hygienic and 3 most non-hygienic) divided into three clusters. The clustering pattern depicting all the three brood cycles together, also consisted of three clusters; cluster I with four hygienic colonies, cluster II with 3 hygienic and 2 non-hygienic colonies and cluster III consisted of one non-hygienic colony. The grouping pattern of all the colonies varied in all the three brood cycles except for two hygienic colonies (6H and 7H) which consistently formed one group. The newly designed 34 gene specific primers amplified all 300 genomic DNA samples from both the types of colonies with no length polymorphism observed between the hygienic and non-hygienic individuals. Sequencing of the three candidate genes revealed no variation, implying these as totally conserved genes. One gene GB19509 showed six differential SNPs between hygienic and non-hygienic colonies.ThesisItem Open Access Acaricide resistance and its biochemical and molecular bases in two-spotted spider mite, Tetranychus urticae Koch(Punjab Agricultural University, Ludhiana, 2017) Sharma, Rakesh Kumar; Bhullar, Manmeet BrarTwo-spotted spider mite (TSSM), Tetranychus urticae Koch (Acarina: Tetranychidae), has gained importance in view of their widespread occurrence as a pest on vegetables in Punjab. Studies were conducted to monitor the magnitude of acaricide resistance in T. urticae, against different acaricides viz., propargite, spiromesifen, fenpyroximate and fenazaquin collected from different vegetable growing areas (Amritsar, Hoshiarpur, Malerkotla and Patiala) of Punjab and its mechanism through biochemical and molecular diagnosis. The development of acaricide resistance has been screened in field populations of T. urticae and compared with a laboratory reared susceptible population based on toxicity bioassay using leaf disc dip technique. Patiala population was least susceptible to fenazaquin (RR 24.65) among all tested acaricides while Amritsar population was found to be highly susceptible (RR 6.67) Among all tested acaricides, fenpyroximate (0.00205 – 0.00954 per cent) was found to be the most toxic against all the tested populations except Malerkotla population.Therefore, low to moderate levels of resistance (3.19-24.65 fold) was observed in T. urticae to tested acaricides in Punjab. Biochemical and molecular analysis were done with Fenzaquin selected resistant population that was developed in the laboratory by giving selection pressure with fenazaquin up to 15 generations. Selection with fenazaquin significantly increased the activities of monooxygenases, GST and esterases by 3.21, 1.40 and 1.13-1.27 fold, respectively when compared to susceptible population proving their role in Fenazaquin mediated resistance. Molecular analysis of resistant and susceptible population revealed no changes in genes structure of mtCOI, CYP392A11 and CYP392A12 in the resistant compared to the susceptible population. However, expression profiling of nine different genes associated (CYP392A11, CYP392A12, CYP392A16, CYP392D2, CYP392D3, CYP392D6, CYP392D7, CYP392D8 and CYP392D10p) with METI resistance showed increased mRNA transcripts in CYP392A11, CYP392A12, CYP392D2 and CYP392D10p. The increased MFO activity in the resistant population corresponds to nearly twice fold increase in the expression of CYP392A11 and CYP392A12. The moderate level of resistance observed in the selected population may be attributed to both increased enzyme activity and gene expression. The target site mutation might not have any role in low to moderate level of fenazaquin resistance in mites. Enzyme and mRNA expression has the wide potential to be used as a fast and reliable tool for early detection of resistance against METI acaricides.ThesisItem Open Access Studies on bases of resistance in chickpea against gram pod borer Helicoverpa armigera (Hübner)(Punjab Agricultural University, Ludhiana, 2017) Ngangom, Uma Devi; Ravinder SinghStudies on bases of resistance in chickpea against gram pod borer H. armigera (Hübner) were conducted during rabi 2014-15 and 2015-16. Nine interspecific chickpea genotypes were evaluated under field and laboratory conditions. The test genotype, GLW 32 had recorded significantly lowest egg numbers 1.61 and 1.26 and larval populations 1.35 and 1.12 per five plants, lowest pod damage 8.17 and 4.49 per cent, lowest PRSR of 2 and highest grain yield of 1209.67 and 1277.00 kg/ha, during 2014-15 and 2015-16, respectively. Significantly highest larval and pupal duration and lowest survival were also observed in GLW 32 whereas, test genotypes GLW 8 and GLW 42 were on par with it during both the cropping years. Genotype GLW 32 recorded the lowest leaf damage score, lowest larval and pupal weight during 2014-15 and 2015-16 under detached leaf bioassays. Trichome density and length of non-glandular trichome on leaves showed non-significant and significant but negative correlation with number of eggs, larval population, larval weight, larval survival, per cent pod damage and PRSR. Total phenols, flavonol, o-dihydroxyphenols and tannins were found to be significantly but negatively correlated whereas, total soluble sugars was positively correlated with larval population, larval weight, per cent larval survival, per cent pod damage and PRSR. Among all the interspecific test genotypes, GLW 32 showed best performance biophysically as well as biochemically. So, we can use this genotype in breeding programe to develop resistant variety against H. armigera.ThesisItem Open Access Ecological impact of neonicotinoids on arthropod fauna of Bt cotton(Punjab Agricultural University, Ludhiana, 2017) Jasjinder Kaur; Vijay KumarThe studies on ‘Ecological impact of neonicotinoids on arthropod fauna of Bt cotton’ confirmed presence of 78 species of arthropods comprising predators, non-target, casual visitors, sucking pests and pollinators (33.33, 25.64, 19.23, 12.82 and 8.98%) at Bathinda. During 2015, diversity of sucking pests was higher in acetamiprid 20SP and dinotefuran 20SG while it was higher in imidacloprid 17.8SL and thiamethoxam 25WG; acetamiprid 20SP, dinotefuran 20SG and clothianidin 50WDG in 2016 after first, second and third spray. Diversity was lower in imidacloprid and thiamethoxam in both years. In predatory fauna and non targets, higher diversity was recorded in imidacloprid 70WS and thiamethoxam 30FS as compared to other treatments. Diversity of pollinators was higher in imidacloprid 70WS and thiamethoxam 30FS and in recommended doses of other neonicotinoids while it was lower in double doses of neonicotinoids. Mean population of whitefly, thrips, red cotton bug, dusky cotton bug and predatory species was minimum in acetamiprid @ 100 g/ha while jassid was minimum in dinotefuran 20SG @ 250g/ha and pollinators in clothianidin 50 WDG @ 60g/ha. The experiment on development of Chrysoperla zastrowi sillemi revealed longer larval period in acetamprid 20SP @ 50 g/ha when fed on neonicotinoid treated jassid (13.89 and 13.83 days) and whitefly (13.61 and 12.95 days) while it was minimum in imidaclorpid 70WS during 2015 and 2016, respectively. The number of jassid nymphs and whitefly adults consumed by larva was maximum in imidacloprid 70WS (286.40, 302.13 and 264.93 and 273.20), respectively in both the years whereas it was minimum in acetamprid 20SP @ 50 g/ha (250.47, 278.80 and 224.07, 246.20). The third experiment on ‘Residual effect of neonicotinoids on development of Bemisia tabaci’ revealed significantly higher fecundity in imidacloprid 17.8SL @ 50 g/ha (79.20 and 82.33 eggs/2 pairs) and lower in dinotefuran 20SG @ 125 g/ha (43.13 and 49.07 eggs/2 pairs) during 2015 and 2016, respectively. Minimum nymphal duration was recorded in imidacloprid 17.8SL @ 100 g/ha (12.99 and 12.06) and maximum in dinotefuran 20SG @ 125 g/ha (15.43 and 14.41 days). The growth index was significantly lower in dinotefuran 20SG @ 100 and 125 g/ha (4.26, 4.24 and 4.35, 4.12) during 2015 and 2016, respectively.