Biological parameters of the endangered fish Chitala chitala (Osteoglossiformes: Notopteridae) from some Indian rivers     

U.K. Sarkar  R.S. Negi  P.K. Deepak  W.S. Lakra  S.K. Paul 《Fisheries Research》2008,90(1-3):170-177

Age, growth and maturity data of the freshwater feather back Chitala chitala (Hamilton-Buchanan, 1822) were collected from ten different geographical locations. Out of ten populations, maximum 6+ ages were recorded from four river basins namely river Bhagirathi, Koshi, Saryu and Ganga and the back calculated lengths at 6+ ages ranged from 1033.36–1073.63 mm. In rest of the locations, however, only 3+ age classes were recorded. Specific rate of linear growth (C_l) and specific rate of weight increase (C_w) showed decreases except in two locations. The specific rate of linear growth (C_l) and the specific rate of weight increase (C_w) increased at 3+ age class in the river Bhagirathi. Among other growth parameters, three distinct life stages of C. chitala were observed based on analysis of growth constant data. Analysis of variance (ANOVA) of the back-calculated length data of 10 populations indicated a significant difference (p < 0.05). Out of ten populations studied, six showed significant variation of growth in 1+ age class and two showed significant variation in 2+ to 6+ age classes. Length-weight relationship of the species from all the population was calculated and the coefficient of correlation (r) was at the significant level where the value of ‘b’ was almost 3 for all the locations studied. Male C. chitala attained maturity earlier (2+ age) whereas females matured at age 3+. The percentages of mature individuals also varied between river basins. Based on this study strategies can be proposed for sustainable exploitation of the species from wild populations.  相似文献   

Flowering in pineapple as influenced by ethephon and its combinations with urea and calcium carbonate     

H.C. Dass  G.S. Randhawa  S.P. Negi 《Scientia Horticulturae》1975,3(3):231-238

An investigation was carried out to increase the efficacy of ethephon by combining it with urea and calcium carbonate for induction of flowering in pineapple, with the main objective of lowering the concentration of ethephon. Ethephon at a concentration as low as 25 ppm in combination with urea (2%) and calcium carbonate (0.04%) was able to induce more than 90% flowering after 50 days of treatment. Addition of either urea or calcium carbonate increased the effectiveness of ethephon for induction of flowering. Ethephon treatments were found to be markedly superior to planofix and the control. In the case of the control, plants started flowering 250 days after treatment and completed it after 340 days. Apart from earlier flowering, ethephon treatments resulted in uniform ripening, and harvests were complete within 10 days, whereas in the control harvests continued for about 70 days. The increased efficacy of ethephon at a lower concentration for induction of flowering, with the addition of urea and calcium carbonate, is of great significance as this will lead to decreased costs and increased commercial use.  相似文献   

Haemagglutinating property of fowl pox virus     

S K Garg  M S Sethi  S K Negi 《The Indian veterinary journal》1968,45(3):186-191

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Microsatellite marker based analysis of genetic diversity in short day tropical Indian onion and cross amplification in related <Emphasis Type="Italic">Allium</Emphasis> spp.     

Anil Khar  K. E. Lawande  K. S. Negi 《Genetic Resources and Crop Evolution》2011,58(5):741-752

This paper deals with the diversity assessment of tropical Indian onion and cross amplification of genomic and EST-SSR markers in distantly related native wild species. Out of 60 SSRs, 10% genomic SSRs were able to amplify as compared to EST-SSR where 53.3% primers were able to reveal amplicons. Clustering revealed five groups and indigenous short day onion formed separate cluster from the exotic short day and long day onions. A. roylei accessions exhibited a dissimilarity index of 35.5% between themselves whereas ‘Pran’ and A. × proliferum grouped together at a genetic distance of 0.4. A. fistulosum accessions formed a tight cluster and distantly related wild species A. carolinianum, A. chinense and A. hookeri formed neutral nodes. Present results are important to aid in analyzing the diversity present in short day onion and its utilization in breeding programs. Further, this is the first time that three accessions of A. roylei Stearn were used and rare alleles amplified in wild species will aid in detecting population structure and molecular marker aided selection for interspecific hybrid development.  相似文献   

Evaluation of different serological tests for the diagnosis of goat pox using soluble antigens     

T. V. S. Rao  B. S. Negi 《Tropical animal health and production》1997,29(4):235-239

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Influence of soluble phosphorus fertilizer on the interaction between a vesicular-arbuscular mycorrhizal fungus and Azospirillum brasilense in barley (Herdeum vulgare L.)     

Mahima Negi  M. S. Sachdev  K. V. B. R. Tilak 《Biology and Fertility of Soils》1990,10(1):57-60

Summary Pot-culture studies were carried out to examine the response of barley (Hordeum vulgare L.) to inoculation with Azospirillum brasilense and Glomus versiforme, singly and/or in combination, under varying levels of nitrogenous [(¹⁵NH₄)₂SO₄] and soluble phosphatic (single superphosphate) fertilizers. The interaction between both the endophytes led to increased growth and nutrition of the barley plants. Roots from plants inoculated with Azospirillum brasilense and Glomus versiforme exhibited very low acetylene reduction activity. N₂ fixation in the plants increased with the increase in plant growth but the mycorrhiza alone gave a low level of N₂ fixation in the plants compared to combined inoculation with both the endophytes.  相似文献   

Effect of host plants on developmental and population parameters of invasive leafminer, <Emphasis Type="Italic">Tuta absoluta</Emphasis> (Meyrick) (Lepidoptera: Gelechiidae)     

S. Negi  P. L. Sharma  K. C. Sharma  S. C. Verma 《Phytoparasitica》2018,46(2):213-221

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most serious pests of tomato, capable of causing 100% crop losses under favourable conditions. We studied the effect of different host plants on developmental and population parameters of this pest at 25?±?0.5 °C temperature, 70?±?5% relative humidity and 12 L: 12D photoperiod. Host plant had significant effect on the developmental biology and the population growth parameters of the pest. The leafminer developed fastest on tomato leaves and slowest on potato tubers. Population growth parameters like intrinsic rate of increase, net reproductive rate, finite rate of increase, doubling time and weekly multiplication rate of T. absoluta were highest on tomato leaves and lowest on potato tubers. Mean generation time was minimum on tomato leaves and maximum on potato tubers. Females developed on tomato leaves were more fecund than other hosts. Though, tomato was found to be the most suitable host plant of T. absoluta, yet, the pest developed and grew successfully on other alternate hosts like potato (Solanum tuberosum L.), brinjal (Solanum melongena L.) and pepino (Solanum muricatum Aiton). These hosts can, therefore, play an important role in the survival, population build up and overwintering of the miner. Further, under favourable conditions the miner can become a serious pest on these crops and need to be monitored on these crops as well.  相似文献   

Ascertaining clonal fidelity of tissue culture raised plants of <Emphasis Type="Italic">Bambusa balcooa</Emphasis> Roxb. using inter simple sequence repeat markers     

Divya Negi  Sanjay Saxena 《New Forests》2010,40(1):1-8

One of the major applications of plant tissue culture technology is that the regenerants are genetically identical to the mother plant. Although, of the various methods of in vitro propagation, axillary branching method is regarded as the safest, the possibility of genetic variation (somaclonal variation) cannot be ruled out even in this method. In the present study, inter simple sequence repeat (ISSR) marker assay was employed to validate the clonal fidelity of in vitro raised Bambusa balcooa plantlets multiplied by enhanced axillary proliferation up to 33 passages. Fifteen ISSR primers generated a total of 99 amplicons among the tissue-cultured progenies. Analysis of ISSR patterns revealed that the bands were shared by both the parent clump and the in vitro raised plants confirming the genetic stability in the latter.  相似文献   

Utilization of fish byproducts as cattle feed: digestibility and nutritive value of a mixed fish meal including a shark liver meal     

S S Negi  N D Kehar 《The Indian veterinary journal》1968,45(2):151-157

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Single radial haemolysis for the detection of goat pox virus antigen and antibody     

A. K. Tiwari  B. S. Negi 《Tropical animal health and production》1996,28(1):117-120

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