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41.
42.
The effects of introduction of common carp, Cyprinus carpio (L.). in polyculture with major Indian carps and silver carp were studied in fertilized and fed earthen ponds in Mymensingh, Bangladesh. Bottom-dwelling common carp were found to exert an influence on the quality and quantity of planktonic food organisms. The presence of common carp significantly increased (P < 0.05) the growth of other carps including the bottom-feeder mrigal. Cirrhinus mrigala (Hamilton). A significantly higher fish yield (P < 0.05) was observed in the fish ponds containing common carp when the combined yields of all species in three treatments were compared. 相似文献
43.
44.
Q. Ain J. Akhtar M. A. Haq Z. A. Saqib 《Communications in Soil Science and Plant Analysis》2016,47(22):2538-2546
A pot experiment was conducted to study the response of wheat to concurrent stresses of salinity and nickel (Ni)-toxicity. Soil was spiked with Ni (0, 20 and 40 mg kg?1) combined with two levels of salinity (control and 10 dS m?1) using Ni(ii) nitrate hexahydrate (Ni(NO3)2.6H2O) and sodium chloride (NaCl), respectively, in a completely randomized design with four replicates. Plants were harvested at the tailoring stage and the results showed that wheat growth was positively affected by Ni at 20 mg kg?1, and negatively at 40 mg kg?1 concentration both in control and at 10 dS m?1. Ni (20 mg kg?1) had a nonsignificant positive effect on tissue potassium (K+) and a significant negative effect on Na+ concentration. Moreover, Ni translocation from root to shoot and accumulation decreased by increasing the levels of Ni in both control and salinity treatments. It can be concluded that Ni at 20 mg kg?1 increased wheat growth by alleviating salinity stress; however, at 40 mg kg?1 it aggravated the plant stress and decreased the plant growth. 相似文献
45.
Caulerpa racemosa (sea grapes) and Ulva lactuca (sea lettuces) are edible green seaweeds and good sources of bioactive compounds for future foods, nutraceuticals and cosmeceutical industries. In the present study, we determined nutritional values and investigated the recovery of bioactive compounds from C. racemosa and U. lactuca using hot water extraction (HWE) and subcritical water extraction (SWE) at different extraction temperatures (110 to 230 °C). Besides significantly higher extraction yield, SWE processes also give higher protein, sugar, total phenolic (TPC), saponin (TSC), flavonoid contents (TFC) and antioxidant activities as compared to the conventional HWE process. When SWE process was applied, the highest TPC, TSC and TFC values were obtained from U. lactuca hydrolyzed at reaction temperature 230 °C with the value of 39.82 ± 0.32 GAE mg/g, 13.22 ± 0.33 DE mg/g and 6.5 ± 0.47 QE mg/g, respectively. In addition, it also showed the highest antioxidant activity with values of 5.45 ± 0.11 ascorbic acid equivalents (AAE) mg/g and 8.03 ± 0.06 trolox equivalents (TE) mg/g for ABTS and total antioxidant, respectively. The highest phenolic acids in U. lactuca were gallic acid and vanillic acid. Cytotoxic assays demonstrated that C. racemosa and U. lactuca hydrolysates obtained by HWE and SWE did not show any toxic effect on RAW 264.7 cells at tested concentrations after 24 h and 48 h of treatment (p < 0.05), suggesting that both hydrolysates were safe and non-toxic for application in foods, cosmeceuticals and nutraceuticals products. In addition, the results of this study demonstrated the potential of SWE for the production of high-quality seaweed hydrolysates. Collectively, this study shows the potential of under-exploited tropical green seaweed resources as potential antioxidants in nutraceutical and cosmeceutical products. 相似文献
46.
The presence of excessive amounts of heavy metals such as arsenic in the environment is a problem in many parts of the world. Many countries e.g., Bangladesh are already severely affected by arsenic contamination of soil and groundwater. Phytoaccumulation is a method in which plants are used to uptake heavy metals from soil. The genus Brassica has many species that can efficiently accumulate arsenic. Despite many studies on phytoaccumulation, little is known about the genetics of phytoaccumulation of Brassica. This study investigated the genetic effect on phytoaccumulation of arsenic in Brassica juncea L. and attempted to identify any morphological trait(s) for phytoaccumulation. Two cultivars of B. juncea namely, B. juncea cv. Rai and B. juncea cv. BARI-11 were chosen as parents for the study. A set of their morphological characteristics were selected to evaluate their potential as marker(s) for phytoaccumulation. A single concentration, 15 ppm of arsenic was used to study the genetic effect on phytoaccumulation using quantitative genetics. The results revealed that phytoaccumulation of arsenic (by the root and shoot systems) is heritable in the broad sense and polygenic in nature. The stem diameter was also found to be heritable in the broad sense and path analysis indicated that it has a significant direct effect on the shoot uptake. It is concluded that phytoaccumulation of arsenic in B. juncea (cvs. Rai and BARI-11) is a genetic phenomenon and stem diameter may be a potential marker of phytoaccumulation of arsenic in B. juncea (cvs. Rai and BARI-11). 相似文献
47.
Khan Sarzamin Mobashar Muhammad Mahsood Farid Khan Javaid Shahbaz Abdel-Wareth A. A. Ammanullah Haq Mahmood Asif 《Tropical animal health and production》2020,52(6):3233-3240
Tropical Animal Health and Production - Spirulina has been used as a food source from many years for human and animals because of its superior profile of nutrition. Spirulina (SPA) having antiviral... 相似文献
48.
Molecular mapping of Aegilops speltoides derived leaf rust resistance gene Lr28 in wheat 总被引:2,自引:0,他引:2
Durga Prasad Cherukuri Sudhir Kumar Gupta Ashwini Charpe Sunita Koul Kumble Vinod Prabhu Ram Badan Singh Qazi Mohammad Rizwanul Haq 《Euphytica》2005,143(1-2):19-26
In a segregating homozygous F2 population of bread wheat involving a leaf rust resistance gene Lr28 derived from Aegilops speltoides, six randomly amplified polymorphic DNA (RAPD) markers, three each in coupling and repulsion phase were identified as linked to Lr28, mapped to a region spanning 32 cM including the locus. The F2 and F3 populations were studied in the phytotron challenged with the most virulent pathotype 77-5 of leaf rust. A coupling phase linked RAPD marker S464721 and a repulsion phase linked RAPD marker S326550 flanked the gene Lr28 by a distance of 2.4± 0.016 cM on either side. The flanking markers genetically worked as co-dominant markers when analyzed together after separate amplification in the F2 population by distinguishing the homozygotes from the heterozygotes and increased the efficiency of marker assisted selection by reducing the false positives and negatives. One of the three RAPD markers, S421640 was converted to locus specific SCAR marker SCS421640 which was further truncated by designing primers internal from both ends of the original RAPD amplicon to eliminate a non-specific amplification of nearly same size. The truncated polymorphic sequence characterized amplified region marker (TPSCAR) SCS421570 was 70 bp smaller, but resulted in a single band polymorphism specific to Lr28 resistance. The TPSCAR marker was validated for its specificity to the gene Lr28 in nine different genetic backgrounds and on 43 of the 50 Lr genes of both native and alien origin, suggesting the utility of the SCAR markers in pyramiding leaf rust resistance genes in wheat. 相似文献
49.
The Sheanut tree (Vitellaria paradoxa C.F. Gaertn.) is highly valued for oil obtained from its seeds and frequently maintained in the semi-arid parklands of sub-Saharan Africa from Senegal to Uganda. Although variation has been noted for V. paradoxa subsp. paradoxa, few studies have been undertaken on patterns of phenotypic or genotypic diversity. Results are presented from 294 accessions collected in Ghana, using easily quantifiable morphological parameters. Productive mature trees varied from shrubby multi-stemmed individuals (height <5 m) to 30-m straight-boled trees with high compact canopies. The leaf lamina (tree mean ±% coefficient of variation of total mean) varied from 9.2 to 22.5 cm (±15.0%); seed length from 1.74 to 3.74 cm (±11.7%); and fat content from 29.1 to 61.9% of dry kernel weight (±9.4%). Clinal trends significantly correlated with location parameters that in turn related to environmental variation. Population variation of seed characteristics increased to the Northeast, perpendicular to the annual movement of the inter-tropical convergence zone. It is proposed that this is a consequence of past climatic changes, coupled with a lack of methodical selection for seed type when trees are maintained on agricultural land. Isozyme analysis revealed moderate to high levels of heterozygosity (He 0.2142) and high geneflow (Fst = 0.0124, Nm = 19.9), supporting results obtained from morphological studies. Isozyme and multivariate morphology analyses showed similar but weak geographical separation patterns. 相似文献
50.
The Sheanut tree (Vitellaria paradoxa Gaertn.), a multi-purpose species highly valued for the oil obtained from its seeds, is commonly maintained in the semi-arid
parklands of sub-Saharan West Africa. An inventory in the West Gonja District, Northern Region, Ghana, revealed that on intensively
farmed land this species constituted 79.7 ± 7.2% (Basal area = 2.19 ± 0.64 m2 ha−1) of the woody biomass, on low intensity farmland 84.2 ± 10.0% (2.16 ± 0.57 m2 ha−1) and only 10.2 ± 3.3% (0.92 ± 0.23 m2 ha−1) in unmanaged woodland, with similar environmental characteristics. No significant differences were found between total Sheanut
tree densities on different land use intensities, although as a proportion of all trees surveyed, large trees were more common
on farmed land. Participatory surveys revealed that these populations are a direct result of anthropic selection as local
farmers eliminate unwanted woody species on farmland, leaving only those Sheanut trees that meet criteria based on spacing,
size, growth, health, age and yield. Characteristics that could affect population dynamics during traditional management and
harvesting including short viability seeds and cryptogeal germination are also discussed with reference to unconscious selection.
Tree improvement is currently constrained, as true to type varieties are difficult to propagate. It is proposed that Sheanut
trees on farmland are semi-domesticated having been subject to long-term anthropic selection during cycles of traditional
fallow and crop cultivation.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献