Plasma growth hormone concentrations in female yak (Poephagus grunniens L.) of different ages:Relations with age and body weight     

M. Sarkar  U.A. Nandankar  B.K. Duttaborah  S. Das  M. Bhattacharya  B.S. Prakash 《Livestock Science》2008,115(2-3):313-318

The role of growth hormone (GH) in postnatal growth is well established. Its basal level and relation to growth performance in different age group yaks has not been characterized until now. To estimate the normal blood GH level in yaks, a total of eighty five female yaks were divided in to thirteen age groups. BW of all animals was recorded on two consecutive days per week and average of weekly BW was considered for growth rate calculation. Blood samples collected twice weekly for four consecutive weeks were assayed for GH by a direct, simple and highly sensitive enzyme immunoassay (EIA) on microtitre plates using the biotin–streptavidin amplification system and the second antibody coating technique developed for the first time in this species. The EIA was carried out directly in 100 μL of yak plasma. The sensitivity of EIA procedure was 20 pg/well GH, which corresponds to 0.2 ng/mL plasma For the biological validation of assay, 2 mature yaks were administered (10 μg, iv) with a synthetic analogue of GHRH and blood samples were collected at 15-min interval using indwelling jugular catheter beginning 2 h prior to GHRH injection till 8 h thereafter. In both the animals, sharp increases in GH concentrations were recorded 75 min post GHRH administration, which confirms the biological validation of the EIA. It was found that mean GH among the age groups differ (p < 0.05). With increasing age and BW, GH level decreased. The age groups with higher plasma GH showed higher growth rates (r = 0.73). In conclusion, a highly sensitive enzymeimmunoassay procedure has been developed for the first time to determine plasma GH levels in bovine (yak) plasma. A close relationship of plasma GH concentration with age, BW and growth rates was found in yaks.  相似文献   

An Update on Reproduction in Yak and Mithun     

BS Prakash  M Sarkar  M Mondal 《Reproduction in domestic animals》2008,43(S2):217-223

Yak and mithun are two domesticated herbivores of high economic importance to the farming community living in highlands. Improved yak and mithun production could significantly enhance the living standards of these highlanders. Over the years, their dwindling numbers have been a cause of serious concern. In view of the lack of knowledge on the reproductive physiology of these ruminants, studies have been undertaken to investigate their reproductive endocrinology in recent years. This paper attempts to present the latest information on the endocrine changes associated with their various reproductive processes viz. growth and puberty, oestrous cyclicity and oestrous behaviour, ovulation, and, pregnancy and parturition. The paper also provides the recent developments on research done towards the enhancement of yak and mithun reproductive efficiencies through endocrine and embryo biotechniques.  相似文献   

Visceral receptors and their afferents in the caudal mesenteric nerve of the duck     

Juthika Koley  Jyoti Sen Gupta  Pratima Pal  Somnath Bhattacharyya  S. P. Sarkar  B. N. Koley 《British poultry science》1982,23(4):315-324

1. The behaviour and reactivities of visceral receptors to different mechanical and chemical stimuli in single unit preparations from the caudal mesenteric nerve of adult ducks were studied to examine the physiological roles of such receptors.

2. In total, 83 single unit activities were recorded from the caudal mesenteric nerve.

3. Receptors were grouped according to their locations in different layers of the rectum as (i) over the branching points of the blood vessel or in the serosal layer, (ii) in the muscle layer or (iii) in the mucous membrane of the rectum.

4. All the receptors, both spontaneous and non‐spontaneous, responded to mechanical probing. Receptors of the muscle layer responded to distension also and showed a slowly‐adapting nature. Most of the receptors of the other two groups were of the rapidly‐adapting type.

5. Conduction velocity ranged from 0.76 to 34.6 m/s.

6. Sympathetic afferent fibres from the hind gut ascend along the intestinal nerve and join the caudal mesenteric nerve via the colonic ganglion.  相似文献   

Potential of variegated lady beetle Hippodamia variegata in management of invasive tomato potato psyllid Bactericera cockerelli     

Shovon Chandra Sarkar  Stephen Paul Milroy  Wei Xu 《Pest management science》2023,79(2):821-832

BACKGROUND

The tomato potato psyllid, Bactericera cockerelli (Šulc) is a new invasive pest in Western Australia, which may disperse across the whole of Australia within a few years and cause significant economic losses. Chemical control is the most widely used approach to manage B. cockerelli, but insect resistance, chemical residue and effects on non-target species have become an increasing concerned. Therefore, in this study, the biocontrol potential of variegated lady beetle, Hippodamia variegata (Goeze) was investigated. The impact of utilizing B. cockerelli as a food source on the predator's development and reproduction was assessed by formulating age-stage, two sex life tables. The predatory potential of H. variegata on B. cockerelli nymphs was assessed in a closed arena and the effects of releasing H. variegata for the control of B. cockerelli were then evaluated.

RESULTS

H. variegata could successfully develop and oviposit when feeding on B. cockerelli. However, both survival and the rate of development were higher for H. variegata feeding on Myzus persicae (Sulzer) than B. cockerelli or a mixed population of B. cockerelli and M. persicae. A type II functional response was observed for H. variegata. In the greenhouse, the releases of H. variegata larvae reduced the number of B. cockerelli nymphs by up to 66% and adults by up to 59%, which positively influenced the plant chlorophyll content and biomass.

CONCLUSIONS

This study demonstrated the potential of the resident generalist predator, H. variegata as a biocontrol agent for the invasive pest, B. cockerelli, which may help improving current management strategies. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

Captive Breeding of a Gangetic Leaffish Nandus nandus (Hamilton-Buchanan) with Three Commercial GnRH Preparations     

U. K. Sarkar  P. K. Deepak  R. S. Negi  W. S. Lakra 《Journal Of Applied Aquaculture》2013,25(4):263-272

Nandus nandus is a threatened fish species that plays a significant role in the nutrition of India, especially in the Northeastern states. In the present study, induced spawning of a threatened freshwater fish Nandus nandus (Hamilton-Buchanan) was conducted using three commercially available synthetic GnRH preparations viz., wova- FH, ovaprim, and ovatide in different intensities. The brooder females were injected one time and left to spawn in the spawning hapa. It was found that at different dosages (0.1 ml, 0.2, and 0.3 ml/kg of body weight) hormone wova-FH and ovaprim could induce the fishes to spawn. No spawning was observed by females treated with ovatide and in control set. The spawning time, fertilization rate, hatching rate, and survival rate were quantified in each set of experiment. The egg output/gm female was higher with the dosage of 0.3 ml in comparison to 0.1 ml/kg and 0.2 ml/kg of body weight of ovaprim and wova-FH. The statistical analysis showed significant effect (P < 0.05) between hormonal doses with latency period, fertilization rate, incubation period, hatching percentage, and egg output. The present study suggests that wova –FH and ovaprim at 0.3 ml/kg body weight of fish are more effective in induction of spawning of N. nandus.  相似文献   

Induction of polyploids in acid lime (Citrus aurantifolia) through colchicine treatment of in vitro derived shoot tip explants     

Lokesh Bora  Rangasamy Muthusamy Vijayakumar  Mathian Ganga  Narayanapillai Meenakshi Ganesan  Mangaldeep Sarkar  Manoj Kundu 《Plant Breeding》2023,142(1):118-127

Polyploid breeding is an effective tool to induce variability in the existing population, specifically in the crops having very narrow genetic base such as acid lime. Hence, an experiment was conducted to induce polyploidy in acid lime through colchicine treatment. Higher frequency of triploids were obtained in 250 μM colchicine treatment (27.27%), whereas combination of 3× (21.42%), 4× (13.33%) and aneuploid (6.67%) were induced at 500 μM colchicine treatment. Measurement of stomatal density and guard cell size of colchiploids revealed that the former one has negative relation with ploidy level and a positive relation was observed between guard cell size and ploidy level. Further, area and size of nuclei also had a positive relation with ploidy level. Hence, stomatal density, guard cell and nuclei size can be used effectively as morphological marker for preliminary polyploid screening. From the experiment, it can be concluded that 500 μM colchicine treatment of in vitro derived shoot tip explants of acid lime is optimum for creating maximum possible variability through polyploidization in the existing acid lime population.  相似文献   

Variation in spawning responses, egg and larvae productions from induced rohu (Labeo rohita) during pre-monsoon and monsoon seasons: Relationship with hormonal changes and oocyte responsiveness during final maturation     

Subrata Dasgupta  Sampad Kumar Sarkar  Niranjan Sarangi  Samir Bhattacharya 《Aquaculture (Amsterdam, Netherlands)》2009,290(3-4):320-326

Early induced spawning in captive rohu (Labeo rohita) often encounters with reduced spawning performances and devaluation of final product. The present study attempted to gain insight into the problems associated with poor performance of rohu during pre-monsoon spawning. A combination of sGnRHa and domperidone was used to induce final oocyte maturation (FOM) and ovulation in rohu during early (pre-monsoon, PM) and normal (monsoon, MN) spawning. The spawning performance parameters such as, spawning response, production and quality of egg and larvae showed significantly lower values (p < 0.05) in PM, when compared with MN spawning. The egg and spawn productions were recorded as 2.6 ± 0.05 and 2.41 ± 0.05 during the MN season, which were reduced by almost 50% in the PM season. Moreover the quality of egg and hatchling was devaluated significantly (p < 0.05) and exhibited higher percentage of mortality and abnormality in PM than those recorded in the MN season. The plasma concentration of carp gonadotropin (cGtH), 17β-estradiol (E) and 17α20β-dihydroxy-4-pregnen-3-one (DP) in relation to progress of FOM and ovulation at different seasons exhibited marked variation in hormonal profiles particularly in E and DP of PM fish. Higher initial plasma E (3.8 ± 0.3) and a distinct E peak clearly indicated the lack of transition from vitellogenic to post-vitellogenic stages that prevailed in PM rohu. Delayed DP and cGtH surge during FOM and ovulation resulted in longer latency period in spite of higher water temperature (31.5 °C) that prevailed during the PM period. In-vitro study on oocyte maturational competence (OMC) clearly depicted the lack of maturational competence in ovarian follicles during PM than MN in rohu. However priming the fish with purified carp gonadotropin (PCG) enhanced the acquisition of OMC in PM rohu in such an extent, that no marked seasonal differences (p > 0.05) in OMC were remained further, when compared with MN follicles. The PCG mediated acquisition of maturational competence was found to be dependent fully on new mRNA and protein synthesis in PM fish. The present study clearly demonstrated that the oocytes' unresponsiveness to hormonal induction was mainly responsible for reduced spawning performance in PM rohu, which could be ameliorated through PCG priming to achieve better spawning response in rohu during the pre-monsoon period. Thereby, the rohu fry production could be initiated successfully as early as May, allowing public and private hatcheries to produce larger age-0 rohu fingerlings ensuring reliable steady source of stocking materials for grow-out system earlier in the season.  相似文献   

Evaluation of fipronil nanoformulations for effective management of brown plant hopper (Nilaparvata lugens) in rice     

Neeraj Kumar  Najam Akhtar Shakil  Dhruba Jyoti Sarkar  Subhash Chander 《国际虫害防治杂志》2019,65(1):86-93

In this paper, we report the development, characterization and bioefficacy evaluation of fipronil nanoformulations against brown plant hopper (BPH); Nilaparvata lugens in rice. Nanoformulations were characterized for nanosizing and stability under variable conditions. Bioefficacy of nanoformulations were evaluated under field condition at farms of Indian Agricultural Research Institute, New Delhi during Kharif 2015. At milking stage BPH populations were above economic threshold level; followed by foliar application of fipronil nanoformulations at four doses (viz., 30, 45, 60 and 90 g a.i./ha) along with commercial formulation of fipronil. The mean mortality clearly indicated that all the insecticidal treatments were significantly superior over untreated control where, highest mortalities were observed in nanodispersions followed by monolithic dispersion and commercial formulation of fipronil. Treated plots 7 days after application @ 60 g a.i./ha has shown 93.47%, 86.89% and 80.47% reduction BPH population in nanodispersion, encapsulated monolithic dispersion and commercial formulation treated plots respectively. In comparison to commercial formulation @ 60 g a.i./ha yield has increased by 0.56 t ha^?1 (28.76%) and 0.26 t ha^?1 (14.04%) in nanodispersion and monolithic dispersion.  相似文献   

Growth and evapotranspiration pattern of rajmash (Phaseolus vulgaris L.) under varying irrigation schedules and phosphate levels in a hot sub-humid climate     

M. Kundu  S. Sarkar 《Agricultural Water Management》2009,96(8):1268-1274

Soil water and phosphorus availabilities play crucial role in yield and water use pattern of pulse crops. A field experiment with rajmash (Phaseolus vulgaris L.) as a test crop was carried out during the winter seasons of 2003-2004 and 2004-2005 on a sandy loam soil (Aeric Haplaquept) in eastern India. In the main plots, irrigation was applied when the cumulative pan evaporation reached: (i) 33 mm (CPE₃₃), (ii) 44 mm (CPE₄₄) and (iii) 66 mm (CPE₆₆). In sub-plots, four levels of phosphate fertilizer were applied at: (i) 0 (P₀); (ii) 30 (P₃₀); 60 (P₆₀) and 90 kg P₂O₅ ha⁻¹ (P₉₀). Irrespective of crop growth stage, the highest leaf area index (LAI), biomass, grain yield and water use efficiency were obtained under the combination of CPE₃₃-P₉₀. Magnitude of these parameters, in general, decreased with the decrease in irrigation frequency and phosphate levels. With the advancement of crop growing period, cumulative actual evapotranspiration (CAET) increased linearly. Best matching between CAET and cumulative pan evaporation data was recorded under CPE₃₃-P₉₀ treatments. A linear relationship with high coefficient of determination was obtained between total biomass and CAET. Present study showed that crop response factor (k_y) of the crop was 1.91.  相似文献   

Laccases de Polyporus versicolor dans le sol et la litiere     

J. Mayaudon  J.M. Sarkar 《Soil biology & biochemistry》1975,7(1):31-34

Laecases of Polyporus versicolor in soil and litter. The laccases forms A and B, prepared from Polyporus versicolor, were compared with the laccases liberated from soil and litter by means ofchromatography on G100 Sephadex and DEAE DE 52 Cellulose. It appears that the soil and litter enzymes were of the form A that is strongly electronegative. These results suggest that because of their negative charges, laccases A, were weakly adsorbed onto humic colloids. Consequently, protection might be given to the active sites of the enzymes without preventing the formation of “humo-laccases” complexes in soil and litter.  相似文献