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Subject: Zoology × End date: 2018 × Start date: 2018 × Type: Thesis × Thesis Type: Ph.D ×
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    Effect of chlorpyrifos on the reproductive system of Metaphire posthuma (Vaillant, 1868) and Eisenia fetida (Savigny, 1826)
    (Punjab Agricultural University, Ludhiana, 2018) Avneet Kaur; Hundal, S.S.
    The present study was field-laboratory integrated approach to evaluate effects of pesticide on earthworms. The agricultural fields of South West (S-W) Punjab (Malout, Bathinda and Muktsar regions) and Punjab Agricultural University (PAU), Ludhiana were surveyed to monitor chlorpyrifos residues and check species and population density of earthworms. The residue level ranged from 0.014-0.044 mg/kg in Malout region, 0.018-0.116 mg/kg in Bathinda region and 0.010-0.056 mg/kg in Muktsar region of Punjab. The Metaphire posthuma was the predominant species found in S-W Punjab and PAU, Ludhiana and Lampito mauritii was also inhabiting these regions. The biochemical, histological, cytological and genotoxicity studies were also performed on former abundant species. The investigation revealed that the biological alterations were more pronounced in Kharif season than Rabi. Higher AchE activity during Rabi season and elevated GST activity during Kharif season was recorded in earthworms .The histological alterations were only observed in earthworms of S-W Punjab. Low differential, total coelomocyte count and higher DNA damage was reported in Kharif. The comparative study showed that PAU, Ludhiana is a zone with good agricultural practices. In laboratory two ecologically different earthworms i.e Metaphire Posthuma (endogeic) and Eisenia fetida (epigeic) were exposed to different doses of chlorpyrifos (2.5, 5.0, 7.5, 10.0 ml/l) in an artificial soil test following OECD guidelines. The significant decrease was observed in body weight, cocoon and hatchling number of both earthworms, at higher doses of chlorpyrifos (7.5 and 10.0 ml/l). The mortality as a result of morphological alterations was observed at higher doses of chlorpyrifos in earthworms. Further, these higher doses led to inhibition of activity of AchE and GST, decrease in total, differential count of coelomocytes and high DNA damage. Histological alterations were also observed in gonads of M. posthuma and E. fetida on exposure to higher doses. The field and laboratory studies revealed that earthworms are excellent bioindicators for assessing soil contamination caused by pesticides. The species specific response was observed, M. posthuma was found to be more sensitive as compared to E. fetida so, can used as standard test species to evaluate pesticidal toxicity.
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    Biological monitoring in cypermethrin induced albino rats
    (Punjab Agricultural University, Ludhiana, 2018) Kalra, Shasta; Sangha, G.K.
    Cypermethrin (CYP), a synthetic pyrethroid, was used in the present study to investigate its toxic effects on female and male albino rats at two sub-chronic dose levels of 1/25th and 1/50th of LD50 for four weeks. It was observed that CYP treatment at higher doses resulted in loose fecal pellets, hyperirritability alongwith reduced average daily feed and water intake. Net body weight gain was significantly lower in 1/25th of LD50 CYP treated female and male rats. Estrogen, progesterone and FSH hormones showed significant decrease in CYP treated female. Testosterone, FSH and LH decreased in cypermethrin treated male rats at both the doses. After four weeks of treatment, various organs were obtained after dissection and weighed. A significant decrease in the weight of liver was observed while kidney, adrenal and thyroid weights increased significantly in female and male albino rats treated with CYP (1/25th of LD50 and 1/50th of LD50).The weight of uterus increased in female rats and that of ovary and testis decreased in female and male rats respectively at higher dose of CYP. Increased ATPase, ACP, AKP, urea and creatinine levels were observed in plasma of rats administered CYP at both the doses. Low and high-dose treatments of rats with CYP significantly increased the levels of ALT, AST and NADPH Cytochrome C reductase in liver in a dose-dependent manner. Activity levels of catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx) and lipid peroxidation (LPO) were differentially altered in plasma, liver, kidney, brain and gonadal organs of treated female and male rats at both the doses of CYP. Decrease in phospholipids and increase in cholesterol levels were observed in ovaries and testis of treated female and male rats. Histoarchitectural changes were observed in liver, kidney and brain of CYP treated female and male rats. Maximum percentage of atresia was observed in CYP treated rats at higher doses. Testes revealed some distorted seminiferous tubules and reduced number of spermatozoa. Sperm motility and count decreased while sperm abnormalities increased in treated male rats. Increase in percent of chromosomal aberrations, frequency of micronucleated cells, SCE and average tail length of comets in CYP treated rats indicate that CYP has definite interactions with DNA in treated rats. Decreased gestation period, litter size, sex-ratio, reduced body weight and delay in developmental parameters of pups were also observed in CYP treated rats. The present study provides greater insight to the fact that CYP induces oxidative DNA damage and alters the biochemical parameters accompanied by degenerative histological changes in rats.