398 research outputs found

    Observations on the mating behavior, spawn mass and larval development of Hydatina physis Linne, 1758 (Cephalaspidea: Hydatinidae) from Karachi

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    Reproduction of Hydatina physis was studied in a population from Karachi, Pakistan, including mating and egg laying behavior, spawn characteristics and development.Individuals first appear in the field in October and remain until March. The spawning occurs from mid-November till mid-February with a peak in December. During this period the individuals were also observed pairing. In captivity, mating lasts for 30 minutes, second mating occurs two days later. Oviposition occurs in a very interesting and unusual manner. The mother turns "up-side-down" with its food fully expanded and the shell completely hidden underneath, the expanded foot serves as protective cover to the eggs. Eggs are deposited in a complexly folded mass with a short stem and an adhesive disc. Capsules, arranged in a single layer, contain 4-6 eggs each of wich is 70 um in diameter. Development is planktotrophic and veligers hatch after 14 days at a temperature of 26-28 degrees Celsius

    Observations on spawning and egg capsule of Melongena bucephala (Lamarck)(Mollusca: Gastropoda) from the Karachi coast

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    No work has been done on the reproduction of Melongena bucephala from northern Arabian Sea (Karachi coast). This paper presents a description of spawning, egg capsule and macromophology of eggs of M. bucephala collected from the rocky shore of Buleji on May 28, 1986 at a tidal height of 0.5m. The individual was found in the act of spawning. The egg mass and development of M. bucephala from Karachi coast are also compared with the Hemifusus ternatanus from the Pacific Ocean (Amio, 1963)

    Response of salt stressed okra (Abelmoschus esculentus Moench) plants to foliar-applied glycine betaine and glycine betaine containing sugarbeet extract

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    AbstractThe present experiment was aimed at examining the ameliorative effect of foliar-applied glycine betaine (50mM GB) and glycine betaine containing sugarbeet extract (50mM GB) on various physiological and biochemical attributes of okra plants under salt stress. The experiment comprised of two okra cultivars (Arka-anamika and Sabaz-pari), two salt levels (0 and 150mM NaCl), and two GB sources (synthetic pure GB and sugarbeet extract) arranged in four replicates. Salt stress significantly suppressed the biomass production, yield, and different gas exchange attributes (A, E, Ci, and gs). Glycine betaine and proline contents in leaves, and Na+ and Cl− contents in both leaves and roots increased, while K+ and Ca2+ contents and K+/Na+ ratios decreased significantly. Foliar application of both pure GB and sugarbeet extract significantly reduced the adverse effects of salt stress on plant biomass production, plant yield, various gas exchange characteristics and leaf K+, Ca2+, Cl− and Na+ contents. However, GB and sugarbeet extract showed differential effects on A, gs, E, Ci, Ci/Ca ratio, leaf K+, Ca2+, and Cl− contents, and K+/Na+ ratio. Pure GB proved better than the sugarbeet extract in improving growth, while the reverse was true for plant yield under salt stress. However, with respect to different gas exchange attributes both GB and sugarbeet extract were found to be equally effective in reducing the adverse effects of salt stress on these photosynthetic attributes. Foliar-applied sugarbeet extract was found to be more effective as compared to pure GB in reducing the adverse effects of salt stress on K+ and Ca2+ uptake and K+/Na+ ratio in shoot and root of both okra cultivars. Thus, sugarbeet extract could be used to induce salt tolerance in economically important crop plants

    Acyclic diterpene alcohols isolated from four algae of Bryopsidophyceae and their toxicity

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    Three new acylic diterpenoids belonging to the class of phytol series have been isolated. They were obtained from the ethyl acetate soluble fractions of four siphonaceous green seaweeds, Bryopsis pennata Lamour., Caulerpa taxifolia (Vahl) C. Ag., Codium decorticatum (Woodw.) Howe and Valoniopsis pachynema (Mart.) Børg., collected from Karachi coast of Pakistan. Structures of these compounds were elucidated with the help of spectroscopic methods and confirmed by comparison with the known compounds. Even the known compounds are being reported for the first time from a green algal source. All the compounds were found to display a strong toxicity at all the three concentrations tested in the brine shrimp bioassay

    Characterization and evaluation of putative mutant populations of polyembryonic mango genotype Nekkare for dwarfing rootstock traits

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    Availability of dwarfing rootstocks is an important pre-requisite for improving productivity of mango orchards in India as it facilitates high density planting as well as impart uniformity within an orchard. An attempt was made to induce variability in polyembryonic mango genotype Nekkare for dwarfness by treating kernels with different doses of gamma radiation ranging from 15 to 35 Gy. Irradiation created significant variation in plant height, stem girth, number of nodes, inter-nodal length, number of leaves, leaf blade length and leaf blade width. The highest reduction in seedling height along with highest variation was observed at 35 Gy where the seedling height ranged from 11.50 to 33 cm with a mean of 23.12 cm as compared to mean plant height of 44.55 cm in control ranging from 33.50 to 56 cm. Further, the effect of irradiation on stomatal parameters was also investigated and the highest stomatal length and width was recorded at 15 Gy (63.39 μm) and 20 Gy (63.12 μm) respectively while 30 Gy treatment produced maximum stomatal density (13.85 per μm2). Furthermore, theconcentration of ABA was found to be highest (429.1 ng/gm) in morphologically dwarf (putative mutant) progenies of Nekkare. The results suggest effectiveness of induced mutation for developing dwarfing rootstocks in mango to be used in high density planting

    Profil ekspresije receptora hormona rasta (GHR), receptora čimbenika rasta sličnog inzulinu (IGFR) i gena leptina s biokemijskim i endokrinim profilom u jaradi crne bengalske koze (Capra hircus) tijekom različitih razdoblja pretpubertetskog rasta

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    The aim of this study was to evaluate the expression profile of growth hormone receptor (GHR), insulin like growth factor receptor (IGFR) and leptin genes, together with some blood biochemical (glucose, aspartate aminotransferase, AST; alanine aminotransferase, ALT) and endocrine (growth hormone and cortisol) parameters. For this purpose, blood samples were collected from 25 male and 25 female kids of the Black Bengal goat (Capra hircus), at days 15, 30, 60, 90, 120 and 150. Male kids gained more body weight compared to females. The glucose and cortisol levels significantly (P≤0.01) decreased with the advancement of age. AST, ALT, and growth hormone increased significantly (P≤0.01). In both sexes, plasma glucose level was negatively (P≤0.01) correlated with AST. In males both cortisol and GH levels were positively (P≤0.05) correlated with plasma glucose levels. In female kids only GH showed a positive (P≤0.05) correlation with glucose levels. Female kids had greater expression of the GH receptor, IGFR mRNA and Leptin mRNA on day 30 (P≤0.05) and day 150 (P≤0.01). GHR was only positively (P≤0.05) correlated with IGFR and LEP in female kids. On the basis of the results obtained from our research, we are able to conclude that the lower growth rate in female kids expressed more leptin, which stimulated the somatotrophic axis for the expression of GHR and IGFR during the prepubertal growth stage.Cilj istraživanja bio je procijeniti profil ekspresije receptora hormona rasta (GHR), receptora čimbenika rasta sličnog inzulinu (IGFR) i gena leptina zajedno s krvnim biokemijskim pokazateljima (glukoza, aspartat-aminotransferaza AST, alanin-aminotransferaza ALT) i endokrinim pokazateljima (hormon rasta i kortizol). U tu su svrhu 15., 30., 60., 90., 120. i 150. dan života uzeti su uzorci krvi od 25 muške i 25 ženske jaradi crne bengalske koze (Capra hircus). Muška je jarad imala veći prirast tjelesne mase u usporedbi sa ženskom. Razine glukoze i kortizola s porastom dobi znakovito su se smanjivale (P ≤ 0,01). AST, ALT i hormon rasta znakovito su porasli (P ≤ 0,01). Kod oba je spola razina glukoze u plazmi bila u negativnoj korelaciji (P ≤ 0,01) s AST-om. Kod muške su jaradi kortizol i hormon rasta bili u pozitivnoj korelaciji (P ≤ 0,05) s razinama glukoze u plazmi. Samo je u ženske jaradi hormon rasta pokazao pozitivnu korelaciju (P ≤ 0,05) s razinama glukoze. Ženska je jarad imala veću ekspresiju receptora hormona rasta, mRNA IGFR i mRNA leptina 30. dan (P ≤ 0,05) i 150. dan (P ≤ 0,01). GHR je bio u pozitivnoj korelaciji (P ≤ 0,05) samo s IGFR-om i leptinom u ženske jaradi. Na temelju rezultata ovoga istraživanja možemo zaključiti da niža stopa rasta u ženske jaradi dovela do veće ekspresije leptina, što je stimuliralo somatotropnu os za ekspresiju hormona rasta i IGFR-a u pretpubertetskom razdoblju

    Genomic affinity between Oryza sativa and Oryza brachyantha as revealed by in situ hybridization and chromosome pairing

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    Genomic affinity between Oryza sativa (2n = 24 AA), and Oryza brachyantha (2n = 24 FF) was assessed by using three strategies: genomic in situ hybridization (GISH), meiotic chromosome pairing, pollen andspikelet sterility. The chromosome pairing was examined in pollen mother cells of O. brachyantha, O.sativa and the hybrid between O. sativa and O. brachyantha. The hybrid was highly sterile with no pollen stain ability. Both parents showed regular meiosis with normal chromosome pairing. The F1hybrid exhibited limited chromosome pairing. On an average, 0-2 bivalents and 20-24 univalents were recorded at metaphase-1 and 0 - 1 univalent at diakinesis. The most frequent configuration was twobivalents and twenty univalent. The meiosis was highly irregular showing unequal distribution of chromosomes at anaphase, formation of multipolar bodies and variation in the cell cycle of both genomes. GISH revealed unequivocal discrimination of O. brachyantha chromosomes as appeared red from O. sativa chromosomes that fluoresced yellow. No cross hybridization was examined between the labeled genomic DNA of O. brachyantha and the chromosomes of O. sativa. Mitotic chromosomes of O. brachyantha and O. sativa, in the hybrid, were discriminated by GISH. High sterility in this hybrid could be due to abnormal meiosis and lack of pairing

    Screening of systemic fungicides and biochemicals against seed borne mycoflora associated with Momordica charantia

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    Study of seed borne fungi associated with bitter gourd seeds were conducted under in vitro condition in Department of Plant Pathology, Bahauddin Zakariya University, Multan, Pakistan. Two hundred (200) seed samples of Momordica charantia (bitter gourd) were collected from southern regions of Punjab province (Multan, Khanewal and Bahawalpur). Six fungal species were isolated out of which Aspergillus flavus showed highest percentage that is, 27.3% followed by Rhizopus stolonifer 17.98%, Alternaria alternata 13.34%, Aspergillus niger 5.23%, Myrothecium roridum 7.37% and Fusarium solani 6.69%. More number of fungi was observed by using blotter paper technique when compared with agar plate method. Of the three systemic fungicides used include ridomil gold MZ, bavistin, and score; and two low cost chemicals such as salicylic acid and boric acid. Ridomil gold MZ gave good results at all concentrations (20, 30 and 40 mg/10 ml) against all the isolated fungi compared with other fungicides. Salicyclic acid gave the best results against isolated fungi compared to boric acid.Key words: Myrothecium roridum, bitter gourd, salicyclic acid, southern Punjab, bavistin, Pakistan
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