Dormancy studies on Indian horse-chestnut (<Emphasis Type="Italic">Aesculus indica</Emphasis> Colebr.) under Kashmir conditions     

Mumtaz MAJEED  M. A. KHAN  Altamash BASHIR  A. H. MUGHAL 《中国林学(英文版)》2010,12(1):41-44

Studies were carried out in the Faculty of Forestry, Sher-e-Kashmir University of Agricultural Sciences & Technology of Kashmir, Shalimar of India during 2006 and 2007. The Indian horse-chestnut (Aesculus indica Colebr.), locally known as “Hanudun”, is one of the more important broad-leaved tree species of the Kashmir valley. No deep dormancy was observed in mature seeds. However, the seeds remained dormant due to unfavorable environmental conditions prevailing after seed dispersal. Both treatments of cold stratification were significantly superior to the control conditions, i.e., no stratification which showed no germination during the test period of 30 d. The effects of the two treatments (cold stratification for 15 or 30 d) also differed significantly. Germination was found to increase with an increase in the time of cold stratification. Chilling treatments of seeds for 30 d showed maximum germination of 80%, requiring the shortest time for germination, i.e., 20.51 d with a maximum evaluated germination value of 14.88. The other treatment with 15 d chilling showed lower germination of 60%, requiring a maximum number of germination days (27.31 d) with lower germination value of 3.26.  相似文献   

Performance of mono‐sex tilapia (Oreochromis niloticus) in rice field with different ditch size          下载免费PDF全文

Md. Akhtar Hossain  Md. Anisur Rahman Mridha  Abul Kalam Md. Azad Shah  Md. Nahiduzzaman  Md. Sharif Uddin 《Aquaculture Research》2015,46(8):1891-1901

The effects of ditch size on growth and production of mono‐sex tilapia, Oreochromis niloticus in rain fed concurrent rice–fish system were technically and economically evaluated for a period of 4 months. Three different ditch sizes were tried: 5%, 10% and 15% of the total cultivable rice field. The fish fingerlings stocking density (5000 ha^?1) and management practices were similar in all plots. The water temperature, dissolve oxygen, pH, Secchi disc visibility, ortho‐phosphate, ammonia nitrogen and alkalinity were found to be in the range of 31.5–31.9°C, 5.10–5.27 mg L^?1, 7.56–7.62, 34.81–35.41 cm, 0.88–0.96 mg L^?1, 0.014–0.021 mg L^?1 and 66.23–69.76 mg L^?1, respectively, and all the values were found suitable for tilapia fish farming. Sediment organic matter, available nitrogen and phosphorous were increased significantly (P < 0.05) in all plots after cultivating the fish. Larger ditch size (15% of the total land area) resulted in significantly (P < 0.05) higher specific growth rate, survival and fish production compared with the smaller (5%) and medium (10%) ditch sizes. However, significantly (P < 0.05) higher net income and benefit–cost ratio were obtained in medium ditch size with the values of 2.6% and 3.6% higher than the smaller and larger ditch sizes respectively. It is concluded that rice–fish farming in a rain fed ecosystem of Bangladesh with medium ditch size and stocking density of 5000 ha^?1 mono‐sex tilapia can achieve better economic return.  相似文献   

Histomorphological changes in digestive tract of golden mahseer (<Emphasis Type="Italic">Tor putitora</Emphasis>) during different developmental stages     

Prakash Sharma  M. S. Akhtar  A. K. Singh  Partha Das  Debajit Sarma 《Fish physiology and biochemistry》2016,42(6):1681-1698

Histomorphological changes in digestive tract of golden mahseer (Tor putitora) were examined in larvae [starting from hatching to 45 days post-hatching (dph)], fry, fingerling, and adult. Digestive tract appeared during hatching, on the dorsal side of yolk sac, as a straight tube with a narrow lumen. Mouth opening and appearance of liver and pancreas were observed at 2 dph, and subsequently anal opening, appearance of goblet cells in esophagus, and posterior intestine were evident at 3 dph. The remodeling of oral cavity in terms of epithelial stratification, appearance of taste buds, and goblet cells were observed in a window of 4–5 dph. Intestinal folding was found to be initiated at 8 dph. From 12 to 45 dph, thickening of oral and esophageal mucosal/extramucosal layers, increase in intestinal folding, increases in the density of goblet cells in entire gut were observed. Within the same time window, other histological changes such as disappearance of vacuoles in liver, and abundance of zymogen granules in pancreas were also observed. Supranuclear vesicles in mid-to-posterior intestine were found to be prominent from first feeding to 45 dph; however, this phenomenon was no longer evident in fry and fingerling. Overall, the increase in intestinal folding and complexity of extramucosal layer were found to be continuous from the first appearance to adult, and this inferred the fact that the nutritional physiology, in terms of digestion and assimilation, progressively changes throughout the life stages of golden mahseer. Findings of this study will, therefore, help in preparing diets for different life stages of this fish, and in addition, the present information widens the understanding of digestive physiology of golden mahseer.  相似文献   

The phytoplasma disease ‘mung bean phyllody’ is now present in Pakistan     

K. P. Akhtar  M. Dickinson  J Hodgetts  G. Abbas  M. J. Asghar  T. M. Shah  B. M. Atta  M. Ahmad  M. A. Haq 《Plant pathology》2010,59(2):399-399

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Vegetation structure of subtropical forest of Tabai,South Waziristan,Pakistan     

Lal Badshah  Farrukh Hussain  Naveed Akhtar 《Frontiers of Agriculture in China》2010,4(2):232-236

Phytosociological parameters, soil and temperature conditions, importance values of species, life form, leaf size, and biomass were investigated at the village Tabai during autumn 2006. There was very little difference in air and soil temperature due to similar elevation. There was a great difference in biomass production for various stands. The original vegetation structure has been altered due to deforestation and overgrazing. There is a need for restoration of the habitat.  相似文献   

土壤有机矿质复合体研究Ⅸ.钙键复合体和铁铝键复合体中腐殖质的性状特征   总被引：22，自引：6，他引：16  

徐建民  赛夫  袁可能 《土壤学报》1999,36(2):168-178

本文通过化学和仪器分析,研究了土壤中钙键复合体和铁铝键复合体中腐殖质的化学组成、分子结构和理化性状。结果表明,铁铝键复合体中腐殖质（包括故敏酸和富啡酸）的Ｃ、Ｈ、Ｎ一高于钙键复合体中腐殖质,Ｃ／Ｈ、Ｃ／Ｎ比则低于后者,铁铝键复合体腐殖质的分子结构中故敏酸的芳化度高于后者,而富啡酸的芳化度则低于钙键复合体。并且,铁铝键复合体中腐殖质的热稳定性和对金属离子的螯合亲和力皆高于钙键复合体。  相似文献   

Genetic analysis and identification of SSR marker linked to Phomopsis blight resistance in eggplant (Solanum melongena L.)     

Bhanushree Narayanswami  Bhoopal Singh Tomar  Jameel Akhtar  Tusar Kanti Behera  Ranjith Kumar Ellur  Rama Mithra V. Sevanthi  Jaiswal Sarika  Partha Saha 《Plant Breeding》2023,142(5):700-710

The present investigation was carried out to decipher inheritance of resistance and to identify linked SSR markers for Phomopsis blight resistance in eggplant. An F₂ population comprising 161 plants was developed from the cross of Pusa Kranti and BR-40-7. Genetic analysis was carried out using Chi square test. Artificial inoculation of fruits was carried out using pin prick method, and scoring was done as per the standard scoring scale. The F₂ plants segregated into 92 susceptible (77—highly susceptible, 15—susceptible): 69 resistant (17—highly resistant, 27—resistant, 25—moderately resistant) suggesting complimentary epistasis with ratio of 9:7. To identify the putatively linked markers to resistance gene, parental polymorphic markers were subjected to bulk segregant analysis (BSA), and two markers (emk03O04 and emf11A03) could differentiate resistant and susceptible bulk and co-segregated with resistance gene. The genetic distance between the identified markers was found to be 18.12 cM using QTL IciMapping V3.2 software depicting two new QTLs on chromosome number 6. The identified QTLs have great significant importance in marker assisted breeding programme.  相似文献   

A Sero-Epidemiological Study of Haemophilus Somnus Infection in Dairy Cattle     

Akhtar  S.  Farver  T.B.  Riemann  H.P. 《Veterinary research communications》1997,21(4):229-239

Akhtar, S., Farver, T.B. and Riemann, H.P., 1997. A sero-epidemiological study of Haemophilus somnus infection in dairy cattle. Veterinary Research Communications, 21 (4), 229-239Five repeated cross-sectional serological surveys of 790 dairy cattle in 4 dairy herds between December 1985 and February 1987 provided an opportunity to study the changes in the seroprevalence of Haemophilus somnus across the 5 surveys and with respect to some demographic and disease variables. The demographic variables included were age (heifers or cows) and farm, representing two groups of herds (two herds in each group, located in the Central and Northern Valleys of California). The serological status of cattle as either negative or positive against H. somnus, Campylobacter fetus and Leptospira hardjo were determined with enzyme linked-immunosorbent assays. Logistic regression analysis was used to compute maximum likelihood estimates of adjusted odds ratios and their respective 95% confidence intervals.The baseline risk of being H. somnus seropositive in the cattle observed at first sampling did not vary significantly during the study period after adjustment for the effects of covariates. Only at first sampling were cows about twice as likely to be H. somnus seropositive than heifers. At samplings 1 and 3, but not at 2 and 5, being in the herds of the Central Valley appeared protective. In contrast, at sampling 4 the cattle in herds in the Central Valley were about 7 times more likely to be H. somnus seropositive. C. fetus-positive cattle were about 3 times more likely to be H. somnus seropositive at sampling 1 only. The relationship between H. somnus status and L. hardjo was not significant during the study period.  相似文献   

Influence of soybean meal and sorghum grain supplementation on intake, digesta kinetics, ruminal fermentation, site and extent of digestion and microbial protein synthesis in beef steers grazing blue grama rangeland     

L J Krysl  M E Branine  A U Cheema  M A Funk  M L Galyean 《Journal of animal science》1989,67(11):3040-3051

Six beef steers (British x Brahman) cannulated at the rumen, duodenum and ileum (avg wt 334 kg) and three mature steers (British x British) cannulated at the esophagus were used in a replicated 3 x 3 latin square design and fed no supplement (C), .5 kg soybean meal (SBM) or .5 kg steam-flaked sorghum grain (SFS).head-1.d-1 (DM basis) while grazing blue grama rangeland. Periods of the latin square included a minimum of 14 d for adaptation and 11 d for esophageal masticate collection and digesta sampling. In September, October and November, respectively, forage collected by esophageally cannulated steers averaged 74.5, 88.8 and 71.0% grasses; 2.06, 1.53 and 1.77% N and 68.3, (P greater than .10) by treatment, but total N intake was greater (P less than .05) for SBM vs C and SFS treatments. No differences (P greater than .10) were detected among treatments in OM, NDF, ADF and N digestibilities in the rumen, small intestine or hindgut, but total tract OM digestibility was greater (P less than .10) for SBM and SFS than for C, and total tract N digestibility was greater (P less than .10) for SBM than for C or SFS. Duodenal ammonia N flow was greater (P less than .05) when SBM was fed that when SFS and C were fed, but microbial N and non-ammonia, non-microbial N flows and microbial efficiency were not altered by treatment. Likewise, ileal N flow was not affected (P greater than .10) by treatment. Particulate passage rate, gastrointestinal mean retention time, forage in vitro OM disappearance and in situ rate of forage NDF digestion also were not affected (P greater than .10) by treatments. Ruminal fluid volume was greater (P less than .05) for SFS vs SBM and C treatments, but no differences were noted in fluid dilution rate. Ruminal fluid ammonia concentration was greater (P less than .05) when SBM was fed than when SFS and C were fed (13.5, 9.9 and 8.7 mg/dl, respectively), whereas pH and total VFA concentrations were not different (P greater than .10). Proportion of acetate in ruminal fluid was less (P less than .10) for SBM and SFS than for C. Small amounts of supplemental SBM and SFS had little effect on forage intake, ruminal fermentation and site of digestion but both increased total tract OM digestion in steers grazing blue grama rangeland.  相似文献   

Investigation and modeling of air permeability of Cotton/Polyester blended double layer interlock knitted fabrics     

Ali Afzal  Tanveer Hussain  Mumtaz Hassan Malik  Abher Rasheed  Sheraz Ahmad  Abdul Basit  Ahsan Nazir 《Fibers and Polymers》2014,15(7):1539-1547

The aim of this study was to analyze and model the effect of knitting parameters on the air permeability of Cotton/Polyester double layer interlock knitted fabrics. Fabric samples of areal densities ranging from 315–488 g/m² were knitted using yarns of three different cotton/polyester blends, each of two different linear densities by systematically varying knitting loop lengths for achieving different cover factors. It was found that by changing the polyester content in the inner and outer fabric layer from 52 to 65 % in the double layer knitted fabric did not have statistically significant effect on the fabric air permeability. Air permeability sharply increased with increase in knitting loop length owing to decrease in fabric areal density. Decrease in yarn linear density (tex) resulted in increase in air permeability due to decrease in areal density as well as the fabric thickness. It was concluded that response surface regression modeling could adequately model the effect of knitting parameters on the double layer knitted fabric air permeability. The model was validated by unseen data set and it was found that the actual and predicted values were in good agreement with each other with less than 10 % absolute error. Sensitivity analysis was also performed to find out the relative contribution of each input parameter on the air permeability of the double layer interlock knitted fabrics.  相似文献