Pakistan Journal of Zoology 

About: Pakistan Journal of Zoology is an academic journal published by University of Punjab (new Campus). The journal publishes majorly in the area(s): Biology & Medicine. It has an ISSN identifier of 0030-9923. It is also open access. Over the lifetime, 3869 publications have been published receiving 17860 citations.

Incidence and Reproduction of Meloidogyne incognita on Vegetable Crop Genotypes

Abstract: In 2006-2008, a survey was conducted in 16 major vegetable production areas of the Punjab with the purpose of determining the incidence and distribution of Meloidogyne incognita and its reproduction on vegetable crop genotypes in nematode infested fields and in the green house. Two root knot nematode species. M. incognita and M. javanica, were identified from 260 samples. Meloidogyne incognita was the predominantly found species and was detected in 13.6% of all the fields surveyed. In the field, the average nematode incidence was 41.5% and ranged from 5.4% in fields planted with mustard to 94.4% in fields planted with okra. The root gall severity averaged 5.5 on scale of 0 to 9. Seventeen vegetable genotypes were evaluated for resistance to gall formation and reproduction by M. incognita. Resistance was identified only in cauliflower, mustard, and radish. The most susceptible genotypes were bitter gourd, carrot, cucumber, eggplant, lettuce, okra, pea, pumpkin, sponge gourd and watermelon meanwhile; three plant species cabbage, chilies, and coriander provided an intermediate host response. Some plant genotypes appeared to be hypersensitive as they exhibited heavy root galling but suppressed nematode reproduction. These included members of family Cucurbitaceae.

Comparison of heavy metals burden in two freshwater fishes Wallago attu and Labeo dyocheilus with regard to their feeding habits in natural ecosystem

Abstract: We examined Zn, Ni, Cr, Cu, Cd and Pb in the skin, gills, intestine, liver and muscle of two fresh water fishes, Wallago attu (Bloch and Schneider, 1801) and Labeo dyocheilus (McClelland, 1839). The aim of the study was to determine the metal accumulation pattern of two species occupying different feeding zones in the same habitat. Metals accumulated in the order Zn>Cr>Cu>Pb>Ni>Cd in the body of Wallago attu. Metal abundance in different organs of this fish was skin>gills>muscle>intestine>liver. Similarly, the order of metal accumulation in the body of Labeo dyocheilus was Zn>Cr>Cu>Pb>Ni>Cd, while metal abundance in different organs of this fish was in the order liver>muscle>skin>intestine>gills. The order of metals bioaccumulation in both the species was different, but in both species Zn was the highest and Cd was the least accumulated metal. Skin, gills, intestine, liver and muscle of Labeo dyocheilus accumulated 43%, 36%, 63%, 105%, 86%, higher metal concentrations as compared to that of Wallago attu. Overall, Labeo dyocheilus accumulated 65.2% extra heavy metals burden as compared to Wallago attu. Our findings suggest that omnivorous fish may bioaccumulate more heavy metals than the carnivorous fish in natural habitats.

Pesticide-induced changes in secretory activity of the thyroid gland in rats.

Abstract: The present study was conducted to examine the effect of organochlorine (Heptachlor, Benzene hexachloride (BHC)), organophosphorus (Malathion, Monitor) and pyrethroid (Karate, Talstar) insecticides on the thyroid secretory function in rats. Heptachlor (0.5 mg per rat), BHC (0.66 mg per rat) Malathion (0.06 mg per rat), Monitor (0.2 mg per rat), Karate (0.2 mg per rat), Talstar (0.5 mg per rat) were orally administered to young adult rats for 21 days. Serum concentrations of triiodothyronine (T3), thyroxine (T4) and thyrotrophin (TSH) were determined by using specific radioimmunoassays. Body weight was not affected by treatment with any insecticide except Talstar (P < 0.01). Among organochlorine and organophosphorus insecticides, treatment with BHC and Malathion, respectively, led to a significant decrease (P < 0.01) in serum concentration of T3 and T4. Administration of BHC and Malathion also increased (P < 0.01) TSH secretion. Treatment with both of the pyrethroid insecticides similarly induced significant suppression (P < 0.01) of serum T3 and T4 levels, and concomitant stimulation (P < 0.01) of TSH concentrations. The T4 / T3 ratio was decreased (P < 0.05) in rats treated with Karate but not with any other insecticide. These data indicate that immense care is warranted in the use of insecticides, because they not only affect the liver, kidney and other organs but also may alter the activity of the endocrine glands.

Incidence and Population Density of Plant-Parasitic Nematodes Infecting Vegetable Crops and Associated Yield Losses in Punjab, Pakistan

Abstract: Plant-parasitic nematode population densities were determined from 325 root and soil samples collected from vegetable growing areas in Pakistan. Yield losses associated with nematode presence were quantified on 19 vegetable crops during 2007 and 2009. The most abundant plant-parasitic nematodes detected, in order of decreasing frequency of infestation (percentage of samples), were Meloidogyne incognita (90%), Pratylenchus penetrans (30.2%), Tylenchorhynchus clarus (29%), Hoplolaimus columbus (15%), Paratrichodorus minor (7.5%), Xiphinema americanum (7.1%), M. javanica (7%), Belonolaimus longicaudatus (5.6%), Longidorus africanus (5%), and Helicotylenchus dihystera (3.2%). We observed ca 23% yield losses ranged from 2% for cabbage to 45% for squash, which is 35%, 80%, and 46% higher compared to developed countries, USA, and India, respectively. The main reason for more losses in Pakistan might be related to incognizant growers about the presence of nematodes and the damage they cause. Another reason might be non-availability of resistant crop cultivars and nematicides. Another possibility is that on small-sized farms with varied cropping histories and inattention to the pest-host-status one result appears to be a larger list of available nematode species, compared to farming practices in USA where only one or two nematode species become dominant. This study provides important information for extension specialists and creates awareness among growers about these hidden crop enemies. It also suggests the need for improved management measures to avoid crop losses.

Efficacy of Beauveria bassiana (Deuteromycotina: Hypomycetes) against different aphid species under laboratory conditions.

Abstract: In the recent study, the entomopathogenic fungus, Beauveria bassiana was used to evaluate its pathogenecity against adults of different aphid species i.e., Schizaphis graminum, Rhopalosiphum padi, Brevicoryne brassicae and Lipaphis erysimi, and their natural enemy Coccinella septempunctata. B. bassiana was found effective at all concentrations i.e., 1x10(6), 1x10(7) and 1x10(8) spores/ml on all aphid species, but the uppermost concentration (1x10(8) spores/ml) provided maximum control within short period of time (P less than 0.0001). B. bassiana with LC50 value of 6.28 x 10(5) proved to be lethal to B. brassicae after 3rd day. Mortality of L. erysimi was observed maximum on highest concentration of 1x10(8) spores/ml with LC50 value of 1.36 x 10(6), while the LT50 values were in range of 2.19-3.73 days for different aphid species treated at various concentrations. B. bassiana showed little or no detrimental effects to C. septempunctata. By testing the field efficacy of B. bassiana against aphid species, this insect pathogenic fungus can be used as potential biocontrol agent for the management of aphids.