印度东北部(竹思)(竹劳)竹林凋落物的质量、分解动态和营养释放

(竹思)(竹劳)竹属是优先竹种,仅分布在印度东北部到孟加拉、尼泊尔、不丹和缅甸一带,其在森林生态系统的生态作用不为人知。由于凋落物质量、凋落物分解及营养释放形态的分析是了解任何系统中土壤肥力管理的基础,因此在卡查、阿萨姆和印度东北部的湿热带林中开展研究,目的是了解凋落物分解形态,研究目的如下:(1)凋落物的初期化学成分;(2)凋落物的失重和近似碳功能;(3)叶、箨凋落物的营养释放形态。用叶代技术测量思劳竹属叶和箨凋落物的分解损失。叶凋落物中含有较高浓度的氮、磷和钾,而箨凋落物中含有很高的碳、灰分和纤维素。失重以原干重来表示,并以时间呈指数下降。叶和箨指数的方程式如下:Y=175.38 e-0.3048x.,r=0.9689和Y=139.55 e-0.2674x.,箨凋落物的损失率比叶低,但它的C/N,L/N和L/P值较高。氮释放形式是两相同的,磷浓度的初期上升,而后呈下降趋势,而钾的释放则在整个分解过程发生。叶和箨凋落物中有机复合物的浓度在分解过程中下降。本文也对凋落物分解过程中保存土壤肥力的意义进行了讨论。     

Electrospinning of PHBV/ZnO membranes: Structure and properties

Polyhydroxy butyrate-co-valerate (PHBV) ?? Zinc oxide (ZnO) nano composite fibers were prepared using electrospinning. The structural and optical properties were studied using Fourier transform infrared spectroscopy (FT-IR), Xray diffraction (XRD) and photoluminescence study (PL). The morphology observed with scanning electron microscope (SEM) revealed no significant changes in the nano composite fibers as compared to bare polymer. The low concentration of ZnO nanoparticles resulted in an increase in overall crystallinity of the polymer matrix which was confirmed from FT-IR and XRD results. The photoluminescence (PL) study indicated the quenching of visible emission in the composite fibers. The ratio of UV to visible emission (I_uv/I_vis) intensity was found to be 12.8 times enhanced in the composite fibers compared to bare ZnO nanoparticles. The nanofibrous mats are self supported and hence offer potential applications in optoelectronic devices and the biomedical imaging.     

Variability in Grain Quality Characters of Upland Rice of Assam,India

The grain quality of 100 upland/ahu rice genotypes from Assam,India was assessed.The characteristics measured were grain length,grain width,cooked grain length,cooked grain width,grain elongation ratio after cooking,grain widening ratio after cooking,alkali spreading value,gel consistency,as well as starch,amylose,amylopectin and total soluble sugar contents.Considerable genetic variability among the 100 rice genotypes was observed for the characteristics under study.Analysis of variance revealed highly sig...     

Sustainability Attributes of a Small-Scale Betel Leaf Agroforestry System: A Case Study in North-eastern Hill Forests of Bangladesh

The Khasia ethnic community of Bangladesh has been a population of forest villagers in the north-eastern hill forests of Bangladesh since the early 1950s, practicing a betel leaf-based agroforestry system on land granted by the Forest Department. Taking a sample forest village of the Sylhet forest division as a case study, this article examines the sustainability attributes of betel leaf production in the agroforestry system. The presence of several positive attributes of sustainability including the composition of agroforestry, disease control, soil fertility management, profitability, socio-cultural acceptability and institutional support indicate that betel leaf production within the agroforestry system is stable under the prevailing traditional management system. Income from the sale of betel leaf is the principal livelihood means and villager’s reciprocal contributions help to conserve forest resources. However, problems with land ownership and regular agreement renewal need to be resolved for the sake of their livelihoods and forest conservation.

Identification and characterization of SSRs in <Emphasis Type="Italic">Clarias batrachus</Emphasis> and their application in population study

Magur Clarias batrachus is an indigenous catfish, commonly found in India, Nepal, Bhutan and Bangladesh. Presently, the populations of magur have declined rapidly in their natural habitat mainly due to overexploitation and habitat degradation. Understanding the population genetic structure of the species has significance in improvement of stocks and in conservation of the species. In the present study, simple sequence repeat (SSR) markers were used to differentiate the populations of magur, collected from three geographic locations. For this, a total of 31,814 SSRs were mined from the de novo assembled pooled of whole genome sequence data of C. batrachus. A bioinformatics pipeline with stringent criteria was applied to analyze the data which resulted in selection of 30,142 microsatellite loci falling in the intergenic region. Out of the 25 loci selected for primer development, 16 loci were successfully amplified and 9 loci were found to be polymorphic in this species. The average observed as well as expected heterozygosity in the loci across different stocks varied from 0.652 to 0.688 and 0.864 to 0.873, respectively. These three populations were further segregated into two clusters based on the NJ genetic distance. The Lucknow population formed one cluster, while the Bhubaneswar and Kolkata populations constituted another cluster. A comparable finding was also deduced from the STRUCTURE analyses. The results revealed significant variation among the populations of C. batrachus under study.     

Effect of three different oil cake-based diets on pond production performance of silver barb, Puntius gonionotus (Bleeker)

One of the three iso-nitrogenous (30% crude protein) and iso-energetic (15.0 MJ kg⁻¹ diet) oil cake-based diets (groundnut, D-1; soybean, D-2 and mustard, D-3) was fed to the fingerlings (6.61 ± 0.06 g) of silver barb ( Puntius gonionotus ) for 120 days in triplicate fertilized ponds (0.04 ha) with a stocking density of 9000 fish ha⁻¹. Fish were fed at 10% of their body weight for the first month, followed by 3% in the second and 2.5% in the third and fourth months of the culture period. The fish fed diets D-1, D-2 and D-3 grew from initial weights of 6.67, 6.67 and 6.50 g to 320.23, 298.23 and 305.13 g respectively. No significant variation ( P >0.05) was found in the growth and nutrient utilization of fish fed different dietary treatments. Net profits of Indian Rupees 67 385, 59 535 and 65 790 ha⁻¹ were obtained in fish fed D-1, D-2 and D-3, respectively, within 120 days of culture. The results of this study suggest the possibility of the use of mustard oil cake as a dietary protein source for pond culture of silver barb in addition to groundnut and soybean oil cakes without compromising the growth, nutrient utilization, production performance and economics of culture of this fish.     

Genotyping safflower (Carthamus tinctorius) cultivars by DNA fingerprints

Summary Carthamus tinctorius (2n = 2x = 24) (family Asteraceae), commonly known as safflower, is widely cultivated in agricultural production systems of Asia, Europe, Australia and the Americas as a source of high-quality vegetable and industrial oil. India ranks first in the production of safflower oil. Fourteen cultivars, widely cultivated in various agro-climatic regions of India, have been fingerprinted by RAPD, ISSR, and AFLP markers utilizing 36, 21 primers, and 4 primer combinations, respectively. On an individual assay basis, AFLP has proven to be the best marker system as compared with the other two markers applied as assessed by high discriminating power (0.98), assay efficiency index (33.2), marker index (18.2), resolving power (40.62), and genotype index (0.856). Thirty-six RAPD and 21 SSR primers could differentiate a maximum of eight and four cultivars, respectively, whereas, two AFLP primer combinations could fingerprint all the 14 cultivars. To understand genetic relationships among these cultivars, Jaccard's similarity coefficient and UPGMA clustering algorithm were applied to the three marker data sets. Mean genetic similarities ranged from 0.689 (AFLP) to 0.952 (ISSR). Correlation coefficient comparisons between similarity matrices and co-phenetic matrices obtained with the three markers revealed that AFLP displayed no congruence vis-a-vis RAPD and ISSR data. However, strong correlation was observed between RAPD and ISSR marker systems. This paper reports the start of molecular biology programme targeting nuclear genome of safflower, a major world oilseed crop about whose genetics very little is known.     

Allergenicity assessment of osmotin, a pathogenesis-related protein, used for transgenic crops

Genetic engineering can enhance abiotic stress tolerance of plants, thereby increasing productivity. The present study investigates allergenicity of osmotin protein used for developing transgenic crops. Bioinformatic analysis of osmotin was performed using SDAP and Farrp allergen databases. Osmotin was cloned in pET22b+ vector, purified to homogeneity, and analyzed for digestibility, heat stability, and IgE binding using atopic patients' sera. Osmotin showed 40-92% and 48-75% homology with allergens in SDAP and Farrp databases, respectively. These cross-reactive allergens were from apple, tomato, peach, capsicum, kiwi fruit, and cypress. Osmotin was resistant to pepsin digestion and heat treatment at 90 °C for 1 h. Osmotin protein showed dose-dependent inhibition with pooled patients' sera. It showed significant IgE binding with 22 of 117 patients' sera who were sensitized to tomato and apple, thus indicating cross-reactivity among tomato, apple, and osmotin allergens. In conclusion, osmotin was identified as a potential allergen and showed cross-reactivity with tomato and apple allergens.     

Acute myeloid leukaemia (M6B: pure acute erythroid leukaemia) in a Thoroughbred foal

A 10-week-old Thoroughbred filly was referred for anaemia of 4 weeks' duration. Haematology revealed severe anaemia and panleucopenia. Cytological examination of bone marrow smears revealed a myeloid to erythroid ratio <0.02:1 (reference range 0.5-2.4:1.0) and an abundance of erythroid precursor cells. The erythroid cell population included rubriblasts, prorubricytes and rubricytes, with only scant numbers of metarubricytes present. There were numerous mitotic erythroid cells, some of which were atypical and megaloblastic. These cytomorphological changes are consistent with pure acute erythroid leukaemia. No treatment was instituted and the filly died three days after presentation. This case illustrates the need to consider both haematology and bone marrow findings to establish a diagnosis of pure erythroid leukaemia. To our knowledge, there is no documented case of acute myeloproliferative disease in horses involving cells of erythroid lineage, but this condition should be considered a differential diagnosis for horses presenting with anaemia.