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11.
We used a null-balance porometer to measure leaf conductance of mature and primary leaves of natural seedlings, saplings, and trees ofPinus roxburghii (chir) during autumn at four sites at 1,320–1,930 m elevation in the central Himalaya of India. Our hypothesis that primary leaves had higher leaf conductance than mature leaves (needles in fascicles), based on measurements in other pines, was rejected. Comparisons on the same saplings and seedlings showed lower leaf conductance for primary leaves than for mature leaves. Primary leaves on seedlings and saplings also did not consistently have higher leaf conductance than mature leaves on near-by trees. Mature leaves on seedlings, however, did often have higher conductance than mature leaves on nearby trees. Mean values for leaf conductance (mmol m−2 s−1, based on total leaf surface area) ranged from 42–82 for mature leaves on trees, 60–121 for mature leaves on seedlings, and 28–67 for primary leaves on seedlings. Compared to published values for other pine species, conductance of mature leaves ofP. roxburghii is relatively low. Funding for this study was provided by grants from the United States National Science Foundation, INT-9312052 and INT-9404043. We appreciate the review of an early draft by Barbara Bond.  相似文献   
12.
The effectiveness of encasement and traditional techniques for planting red mangroves (Rhizophora mangle) in moderate to high wave energy environments was assessed. The three encasement types were the halflength PVC pipes, fulllength PVC pipes, and bamboo pipes. Plantings were conducted in August, 1997 at two locations in the Indian River Lagoon, Florida: Sebastian and Rocky Point. Furthermore, plantings were conducted in November, 1997 using fulllength encasements and conventional planting. Results indicate that seedlings planted within fulllength PVC encasements had the highest survivorship and growth because of their protection from waves and currents. Failure of seedlings within bamboo encasements seemed to be caused by insufficient light exposure. When comparing the two locations, a significantly greater growth was observed at the Sebastian location than at the Rocky Point location for the planting conducted in November, but not for those planted in August. No significant difference was observed in seedling survival when comparing those planted in August and November. However, there was a significantly greater growth in mangroves planted in August. With the exception of width of surf zone, there was no significant difference in the selected environmental parameters between the two locations.  相似文献   
13.
The genetic and demographic bottleneck analysis of Indian camel breeds was carried out utilizing 40 microsatellite markers. Allelic polymorphism was observed at 20 loci in the Indian dromedary breeds. A total of 66 alleles were scored. The average number of alleles, expected heterozygosity and polymorphic information content were, respectively, 3.25?±?0.27, 0.56?±?0.04 and 0.49?±?0.04 in Bikaneri; 3.25?±?0.25, 0.53?±?0.03 and 0.46?±?0.03 in Jaisalmeri; 3.0?±?0.21, 0.53?±?0.04 and 0.45?±?0.03 in Kachchhi and 3.1?±?0.19, 0.51?±?0.03 and 0.44?±?0.03 in Mewari breed. Higher genetic variation was observed in most numerous Bikaneri breed. Genetic distances were least between the breed pair Bikaneri and Jaisalmeri which was closely placed with the Kachchhi breed. The Mewari camels had relatively higher genetic distance from the other three Indian dromedary breeds. The bottleneck analysis revealed the presence of genetic bottleneck in all four breeds of Indian dromedary. However, the qualitative graphical method resulted in normal L-shaped distribution of allele frequencies in Jaisalmeri breeds and shifted mode in Bikaneri, Kachchhi and Mewari breeds. The demographic bottleneck analysis revealed minimum reduction (?9.65 %) in the population of camels in Jaisalmeri breeding tract as compared to that of Bikaneri (?14.18 %), Kachchhi (?27.78 %) and Mewari (?32 %) breeding tracts. Conclusively, the genetic bottleneck analysis could explain the demographic bottleneck in the Indian dromedary populations. Therefore, appropriate conservation and improvement efforts are needed in all four dromedary breeds with immediate attention on Mewari and Kachchhi breeds. The present study is the first report in demonstrating the genetic basis of demographic bottleneck in the Indian dromedary populations.  相似文献   
14.
Trypanosoma evansi infection typically produces wasting disease, but it can also develop into a neurological or meningoencephalitis form in equids. Trypanosomiasis in horses was treated with quinapyramine sulfate, and all the 14 infected animals were recovered clinically. After clinical recovery, four animals developed a neurological form of the disease at various intervals. Two of these animals treated with diminazene aceturate recovered temporarily. Repeated attempts failed to find the parasite in the blood or the cerebrospinal fluid (CSF), but all of the animals were positive in enzyme-linked immunosorbent assay. The calculation of the antibody index (AI) in the serum and the CSF and polymerase chain reaction (PCR) analysis of the CSF and brain tissue were carried out to confirm the neuro-infection. We found PCR and AI analyses of the CSF to be useful tools in the diagnosis of the neurological form of trypanosomiasis when the organism cannot be found in the blood or CSF. The increased albumin quotient is indicative of barrier leakage due to neuroinflammation. The biochemical changes in the CSF due to nervous system trypanosomiasis include increases in the albumin quotient, total protein, and urea nitrogen. It seems to be the first report on relapse of the nervous form of trypanosomiasis in equids even after quinapyramine treatment in endemic areas.  相似文献   
15.
This research contrasts the financial profitability of different agroforestry practices in community-based buffer zone management of Madhupur National Park (MNP), Bangladesh. This park is the second largest in Bangladesh and subjected to enormous anthropogenic pressure and land rights-related conflicts. This paper reports the different agroforestry practices of villagers in different modules of the buffer zone of MNP, identified by a participatory research approach. It then assesses the profitability of each module on the basis of cost–benefit analysis, net present value, internal rate of return, and annualized income. Results indicate three agroforestry systems were being practised in the buffer zone by the participants: agro-silviculture, agro-silvo-horticulture, and combined woodlot and agroforestry. Among these modules, agro-silvo-horticulture was the most profitable, followed by agro-silviculture then combined woodlot and agroforestry. We recognize that not all of the participants can practise intensive agroforestry; our results suggest that the community-based buffer zone management strategy for MNP would benefit from prioritizing agroforestry practices where possible. This will lead to more successful buffer zone management for the conservation of natural forests while supporting the development of local resource-dependent communities.  相似文献   
16.
A sub‐lethal nitrite toxicity trial was conducted using static conditions for a period of 96 h with fingerlings of Catla catla (21.4±3.6 g). Fingerlings were exposed to five concentrations of nitrite, that is, 1, 2, 4, 8 and 10.4 mg L?1 and a nitrite‐free control to study changes in haematological parameters. Nitrite caused an increase in immature erythrocyte population (7–24%) in lower concentrations (0–4 mg L?1) at 6 h while they were absent in higher concentrations. The total erythrocyte count was reduced at 6 h followed by an increase at 12 h with further reduction up to 96 h in all concentrations of nitrite. The 96‐h exposure resulted in 21.2–31.8% reduction in erythrocyte population in 1–10.4 mg L?1 nitrite. The haemoglobin content decreased progressively with increasing nitrite concentrations as well as exposure periods. Total leukocyte count decreased initially at 6 h in all treatments followed by an increase after 12 h, signifying development of a protective response of the body to nitrite stress. Blood glucose decreased initially up to 24 h followed by an increase through 96 h. Serum protein level decreased continuously with increasing exposure period. The study revealed that exposure to nitrite caused changes in almost all the haematological parameters in the fingerlings depending on the concentration as well as exposure period. Nitrite being one of the important inorganic nutrients often recorded at higher levels in intensively cultured ponds, the present study highlights its adverse impact on fish and stressed the need for the management of this nutrient in culture ponds.  相似文献   
17.
Arsenic contamination of shallow groundwater and related health problems are threats for the millions in endemic regions of West Bengal. Contamination of rice grain creates the food chain pathway of mineral arsenic besides drinking water contamination. Present study concentrated on association of arsenic concentration in irrigated water, paddy field soil and rice with the cropping seasons. Irrigated ground water arsenic concentration decreased significantly (p = 0.007) from summer (median 0.42 mg l?1) to winter (median 0.35 mg l?1). Carried over effect created significant decrease (p = 0.03) of paddy field soil arsenic concentration from summer (median 8.35 mg kg?1) to winter (median 6.17 mg kg?1). Seasonal variation was observed in rice straw (p = 0.03) but not in husk (p = 0.91). Arsenic concentration decreased significantly (p = 0.05) in the rice grains collected in winter season (median 0.23 mg kg?1) than the samples collected in the summer season (median 0.30 mg kg?1). In conclusion, seasonal effects need to be considered in case of human health risk assessment from arsenic consumption.  相似文献   
18.
Plant Foods for Human Nutrition - Ficus geniculata (FG) is one of the underutilized fig species in India and throughout the world. However, the different parts of the plant have numerous...  相似文献   
19.
Phenolic content and discoloration were determined for 13 commercial potato cultivars and 6 potato clones grown at 2 locations over a period of 5 successive years. Tubers from 6 potato cultivars and 5 potato clones resistant to the golden nematode were compared with tubers from 7 potato cultivars and 1 clone known to be susceptible to the golden nematode. Tubers from resistant plants were lower in phenols and discolored less than tubers from susceptible plants.  相似文献   
20.
Grain legumes, the important constituents of sustainability‐based cropping systems and energy‐limited vegetarian diets have long been the subject of scientific research. Tremendous technological strides were made in the so‐called orphan crops, in terms of both varietal improvement and generation of basic information. Despite recalcitrancy and high genotype dependency, in vitro culture techniques such as organogenesis, in vitro mutagenesis, embryo rescue and in vitro gene transfer have been deployed for improvement of several grain legumes and these played an important role in introgression of desirable genes from related and distant species and creation of additional genetic variability. Stable and reproducible regeneration protocols resulted in the development of genetically modified chickpea, pigeon pea, cowpea, mungbean, etc., while embryo rescue was deployed successfully for recovery of interspecific recombinants, a few of them exploited for the development of commercial cultivars. Nevertheless, doubled haploidy witnessed limited success and protoplast regeneration and in vitro mutagenesis remained of academic interest. The present review focuses on the progress, achievements, constraints and perspectives of using in vitro technology in grain legume improvement.  相似文献   
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