Randomly amplified polymorphic DNA (RAPD) fingerprinting approach was applied to assess genetic diversity in different accessions
of rejuvenating and intellect-promoting ancient ayurvedic medicinal herb Bacopa monnieri (L.) Pennell collected from four Southern Indian states, along with in vitro micropropagated samples maintained in the laboratory
for 5 years. With the 10 analyzed primers, 110 distinct bands, in the size range of 250–870 bp were observed, and among which
14 (12.72%) were polymorphic. Among the random primers used, only OPD 02 generated highest percentage of polymorphism with
30.77. Whereas OPD 08 generated a maximum of 18 amplified bands, but with only 1% polymorphism. Cluster analysis done on the
basis of similarity co-efficient generated from RAPD profiles indicated all the accessions were divided into two sub-groups
based on genetic distances under one major cluster. Major cluster is only the lone loose group of the Bm.2 collected from
Kerala (KER) and in vitro micropropagated plant (IVMP) maintained in the lab. The other sub-group consisted of Bm.1 and Bm.3
collected from Tamil Nadu (TN) and Andhra Pradesh (AP) respectively, which are genetically similar and showed similarity with
accessions from Karnataka Bm.4 (KK). These two sub-groups were joined together at 0.66 genetic distance level. Overall, the
levels of genetic similarity within the accessions varied from 0.24 to 0.80, the matrix ranged from 0.36 to 0.80, with a mean
value of 0.68 indicating genetic similarity at low level. 相似文献
Phosphorus (P) is a limiting nutrient for most US Midwestern aquatic systems and, therefore, increases of P, through point or non-point sources (NPS) of pollution such as agriculture, causes eutrophication. Identifying specific NPS contributions (e.g., upland vs. stream channels) for sediments and P is difficult due to the distributed nature of the pollution. Therefore, studies which link the spatial and temporal aspects of sediment and P transport in these systems can help better characterize the extent of NPS pollution.
Materials and methods
Our study used fingerprinting techniques to determine sources of sediments in an agricultural watershed (the North Fork of the Pheasant Branch watershed; 12.4 km2 area) in Wisconsin, USA, during the spring, summer, and fall seasons of 2009. The primary sources considered were uplands (cultivated fields), stream bank, and streambed. The model used fallout radionuclides, 137Cs, and 210Pbxs, along with total P to determine primary sediment sources. A shorter-lived fallout radioisotope, 7Be, was used to determine the sediment age and percent new sediments in streambed and suspended sediment samples (via the 7Be/210Pbxs ratio).
Results and discussion
Upland areas were the primary source of suspended sediments in the stream channels followed by stream banks. The sediment age and percent new sediment for the streambed and suspended sediments showed that the channel contained and transported newer (or more recently tagged with 7Be) sediments in the spring season (9–131 days sediment age), while relatively old sediments (165–318 days) were moving through the channel system during the fall season.
Conclusions
Upland areas are the major contributors to in-stream suspended sediments in this watershed. Sediment resuspension in stream channels could play an important role during the later part of the year. Best management practices should be targeted in the upland areas to reduce the export of sediments and sediment-bound P from agricultural watersheds. 相似文献
BACKGROUND: The study reported here was undertaken to assess the presence of antibodies to Sarcocystis neurona in the serum of horses of North American origin that had been relocated for 1 year or more to India (ie, outside of the known endemic areas for S. neurona). HYPOTHESIS: The presence or absence of such antibodies should provide information concerning the persistence of such antibodies, or support the presence of chronic infection, or both. ANIMALS: A total of 228 Thoroughbred horses were sampled in India, of which 86 were of North American origin that had been in India between 1 and 13 years, 124 were Indian-born horses that had never been out of India, 8 were of Irish origin, 8 were of English origin, and 2 were originally from France. METHODS: Sera were tested using established western blot analysis. RESULTS: Of the Indian-born horses, 0.8% were test positive, and of the North American horses, 42% were test positive. All of the English and Irish horses were test negative, and the 2 French horses were test positive. CONCLUSIONS AND CLINICAL IMPORTANCE: These data indicate that antibodies against S. neurona can be detected for many years after horses have been removed from an endemic area and that this may be attributable to long half-life of the antibodies or to chronic infection and ongoing antibody production, or both. 相似文献
Shrimp farming industries are subjected to severe economic loss due to a disease called white spot syndrome, a viral disease caused by white spot syndrome virus (WSSV) in penaeid shrimp. Numerous active compounds in the market possess anti-viral activity against the white spot syndrome virus, yet the issue remains unsolved. The present study was carried out to determine the anti-viral activity of methyl 1-chloro-7-methyl-2-propyl-1h-benzo[d] imidazole-5-carboxylate (C13H15N2O2Cl) against WSSV. The anti-viral activity of the synthetic compound was determined in freshwater crabs. Crabs were divided into three different experimental groups: healthy control groups (N.C.) received NTE buffer, positive control group (P.C.) crabs received WSSV, and treatment group crabs received WSSV along with synthetic weight compound. Experimental groups were observed for 30 days post-infection. Three different organs (gills, muscles, and head soft tissue (HST)) were dissected from all three groups and analyzed using molecular-based techniques, including polymerase chain reaction (PCR), Western blot, and histopathology. Clinical signs of WSSV were observed in the positive and N.C. groups; however, the treatment group showed a 100% survival rate. Confirmation was done using PCR, Western blot, and histopathology. These results demonstrated that the given synthetic compound has significant anti-viral activity against WSSV.
Re-vegetation is the preferred long-term practice for managing Alcoa’s bauxite-processing residue storage areas. Residue sand
is the primary growth medium for rehabilitation; however, it is largely nutrient deficient. Although addition of organic and
inorganic amendments can provide short-term supply of plant-available nutrients, but quickly exhausted, thus long-term deficiencies
are often observed. The rapid transformation of added zinc into non-available pools is predicted as the main factor limiting
vegetation performance. 相似文献
In this study, we examined the necrosis phenotype on leaves of two cultivars of soybean (ZheA8901 and Nannong1138-2) that show varying level of resistance to soybean mosaic virus (SMV). The necrotic symptoms seen on inoculated and systemic leaves of soybean cultivar ZheA8901 were reminiscent of programmed cell death (PCD). The cell death phenotypes were evaluated using the TUNEL method, quantification of hydrogen peroxide (H2O2) and salicylic acid, callose production, as well as by monitoring expression of defence genes GmPR-1 and GmNPR1. Our results show that SMV inoculation induced PCD on ZheA8901 is associated with rapid increase in H2O2, increased SA and callose accumulation and higher defence gene expression. 相似文献
The looming water crisis and water-intensive nature of rice cultivation are driving the search for alternative management methods to increase water productivity in rice cultivation. Experiments were conducted under on-station and on-farm conditions to compare rice production using modified methods of irrigation, planting, weeding and nutrient management with conventional methods of cultivation. Farm surveys were used to evaluate adoption of modified rice cultivation method. On-station experiments showed that, a combination of water-saving irrigation, young seedling or direct seeding, mechanical weeding and green manure application increased the rice water productivity though the largest yields were obtained for a combination of conventional irrigation, young seedling or direct seeding, mechanical weeding and green manure application. On-farm experiments demonstrated a yield advantage of 1.5 t ha−1 for the modified method over conventional method. We found, however, that yield advantages were not the sole factor driving adoption. Associated changes required in management, including the increased labour demand for modified planting, unwillingness of agricultural labourers to change practices, difficulties with modified nursery preparation and the need to replace cheaper women’s labour for hand weeding with more costly men’s labour for mechanical weeding, all reduced the chance of adopting the modified rice cultivation method. Risks associated with water-saving irrigation, such as uncertainty about the timing and amount of water release for irrigation affect adoption adversely as well. There was no incentive for farmers to adopt water-saving irrigation as water from reservoirs and electricity for pumping well-water are both free of charge. To date farmers continue to experiment with the modified cultivation method on a small part of their farms, but are unlikely to adopt the modified method on a large-scale unless policies governing water management are changed. 相似文献
The present study aimed to assess the potentiality of water soluble fungal pigments for dyeing on cotton yarn. Five different
shades of pigments were extracted from Monascus purpureus, Isaria farinosa, Emericella nidulans, Fusarium verticillioides, and Penicillium purpurogenum using ethanol. Maximum concentration of pigment was obtained from Monascus purpureus (red, 25.02±1.6 UA) followed by Penicillium purpurogenum (yellow, 23.05±0.3 UA). The optimum dyeing condition was observed at a pigment concentration of 1 gram, pH 5, temperature
80 °C, time duration 90 min, and a liquor ratio of 1:30 was found to be the optimal for dyeing. Maximum uptake of 80 % was
achieved with Monascus purpureus red pigment. Moreover, the effect of mordant in dyeing was evaluated by different mordanting methods. A strong variation
in shade and color depth could be achieved by using pre-mordanting method with alum and ferrous sulfate giving better wash
fastness properties when compared with post-mordanting or without a mordant. 相似文献