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排序方式: 共有193条查询结果,搜索用时 15 毫秒
1.
In May 1972, 0.309 ppm methoxychlor black fly larvicide was applied in a single test on the North Saskatchewan River. Eight to nine days later residues of 0.05-0.10 ppm methoxychlor occurred in sand 21-22 km downstream from the point of injection. Methoxychlor was not detected in water, insect larvae, shellfish, or muscle tissues of three fish species on the same sampling date. Perhaps because of relatively high oil content in goldeye fish, methoxychlor residues in muscle tissues were 1.0-1.5 ppm in 8 percent of those sampled, 0.21-0.99 in 21 percent, and 0.02-0.20 in 37 percent. In 34 percent of the goldeye fish no residues were detected. Goldeye and other fish collected before or 17 weeks after this injection did not contain detectable levels of methoxychlor. River water in two samples of the injected slug of water collected 6.5 km downstream from the point of injection contained 0.14 and 0.16 ppm methoxychlor. The suspended solids filtered from these sample contained 40 and 47 percent of this methoxychlor (437 and 892 ppm, respectively). Thus methoxychlor may act selectively against filter-feeding species, especially black fly larvae. 相似文献
2.
Per McCord Vanessa Gordon Gopesh Saha Jacqueline Hellinga George Vandemark Richard Larsen Mark Smith David Miller 《Euphytica》2014,200(2):269-279
Alfalfa (Medicago sativa L.) is an internationally significant forage crop. Forage yield, lodging resistance and spring vigor are important agronomic traits conditioned by quantitative genetic and environmental effects. The objective of this study was to identify quantitative trait loci (QTL) and molecular markers associated with increased forage yield, resistance to lodging, and spring vigor. A backcross population composed of 128 progeny was developed by crossing the breeding parents DW000577 (lodging susceptible) and NL002724 (lodging-resistant) and back-crossing an individual F1 plant to the maternal parent (i.e. DW000577). A linkage map of NL002724 was developed based upon the segregation of 236 AFLP, SRAP, and SSR markers among the backcross progeny. The markers were distributed among 14 linkage groups, covering an estimated recombination distance of 1497.6 centiMorgans (cM). Replicated clones of both parents and backcross progeny were evaluated in the field for estimated forage yield, lodging, and spring vigor in Washington and Wisconsin during 2007 and 2008. Significant QTL were found for all three traits. In particular, two QTL for lodging resistance were identified that explained ≥14 % of trait variation, and were significant in all years and locations. Major QTL explaining over 25 % of trait variation for forage yield were detected in multiple environments at two separate locations on chromosome III. Several QTL for spring vigor were located in the same or similar positions as QTL for forage yield, possibly explaining the significant correlation between these traits. Molecular markers associated with the aforementioned QTL were also identified. 相似文献
3.
Many fields have struggled to develop strategies, policies, or structures to optimally manage data, materials, and intellectual property rights (IPRs). There is growing recognition that the field of stem cell science, in part because of its complex IPRs landscape and the importance of cell line collections, may require collective action to facilitate basic and translational research. Access to pluripotent stem cell lines and the information associated with them is critical to the progress of stem cell science, but simple notions of access are substantially complicated by shifting boundaries between what is considered information versus material, person versus artifact, and private property versus the public domain. 相似文献
4.
Sanjeev Sharma K. Siddhnath N. K. Mehta Apurba Saha Shubham Gupta 《Journal Of Aquatic Food Product Technology》2013,22(8):808-820
ABSTRACTThe study aimed to evaluate the effects of carrot concentrated protein (CCP) as additive on the functional and textural properties of surimi from striped catfish (Pangasianodon hypophthalmus) during six months of frozen storage (?20°C). The CCP (82.22% crude protein) was used as an additive either a lone or with a synthetic cryoprotectant (sucrose-sorbitol-sodium tri-polyphosphate). Control was made with synthetic cryoprotectant only. Molecular weight of CCP was found to be 36 kDa. After six months, the results revealed that up to 50% of synthetic cryoprotectants could be replaced by CCP during frozen storage of surimi. Biochemical parameters such as protein solubility, Ca2+ATPase activity, and gel strength decreased significantly (p < .05) during storage. Treatment T-3 (CCP 0.5% + 50% of synthetic cryoprotectant) maintained quality of protein significantly superior (p < .05) in respect to denaturation and other functional and sensory attributes compared to all the treatments. The microstructure images of surimi confirmed that addition of CCP modified the ice crystal growth during frozen storage. This study suggests that CCP can be a potential additive to protect protein from denaturation along with partial replacement of chemical cryoprotectants. 相似文献
5.
P. Saha P. Kalia P. Sharma T. R. Sharma 《The Journal of Horticultural Science and Biotechnology》2013,88(5):480-486
SummaryIn order to understand the genetics of resistance to black rot disease caused by Xanthomonas campestris pv. campestris (Xcc) (Pammel) Dowson in cauliflower (Brassica oleracea var. botrytis L.) and to identify random amplified polymorphic DNA (RAPD) markers that segregate with the resistance genes, susceptible (‘Pusa Himjyoti’, female parent) and resistant (‘BR-161’, pollen parent) plants were crossed. Six generations of plants (30 P1, 30 P2,30 F1, 120 F2, 90 B1, and 90 B2) were evaluated for the presence or absence of black rot disease in a randomised block design with three replications. The pattern of segregation of resistance was tested by the χ2 test at the 5% level of significance. All F1 progeny plants were resistant, and the segregation of resistant and susceptible plants in the F2 and two backcross generations (B1 and B2) showed that a single dominant gene caused resistance to the black rot pathogen in ‘BR-161’. Three polymorphic RAPD markers (OPO-04833, OPAW-202538, and OPG-25625) were found by bulk segregant analysis, which produced unique amplicons 833 bp, 2,538 bp, and 625 bp in length, respectively. These markers were associated in coupling phase to the resistance allele. Best fit ratios of 3:1 (resistant:susceptible) in the F2 plants with the three RAPD markers, suggested that the markers were linked to the single gene controlling black rot resistance. These markers will be useful to identify more closely-linked markers and to develop black rot-resistant hybrid cauliflower varieties. 相似文献
6.
7.
The methanol extract of the Careya arborea Roxb. bark significantly reduced castor oil-induced diarrhoea in mice. This effect supports the local traditional use of the plant against diarrhoea. 相似文献
8.
Soil hydro-physical behaviour was studied under a 20-year old agroforestry plantation consisting of five multipurpose tree
species (Pinus kesiya Royle ex-Gordon, Alnus nepalensis D.Don, Parkia roxburghii G.Don, Michelia oblonga Wall. and Gmelina arboria Roxb.) maintained under normal recommended practices at Indian Council of Agricultural Research (ICAR) Complex, Umiam, Meghalaya,
India. The aim was to select tree species, which could act as better bio-ameliorant as well as provides higher economic return
in highly degraded soil of northeastern hill region of India. A site without vegetation (no tree) nearby the plantation was
also selected as control for comparison. Soil samples for various hydro-physical analysis, were taken from 0–15 and 15–30 cm
soil depth at a distance of 1 m from respective tree species during wet and dry season of 2003–2004. No appreciable differences
in relative contents of textural separates of sand, silt and clay were observed among various tree covers. Surface cover with
constant leaf litter fall and extensive root system increased soil organic carbon, helped in better soil aggregation, improved
water transmissivity and infiltrability and in turn, reduced soil erosion in the present study. However, due to variation
in quantity of leaf litter fall and root biomass, these parameters differed among tree species. Of the tree species, P. kesiya, M. oblonga and A. nepalensis were found to be rated best for bio-amelioration of soils as these tree covers had more root and shoot biomass and more litter
fall compared to other species. However, considering both timber production and improvement in hydro-physical behaviour, M. oblonga was found best among the tested tree species. The study, thus, suggested that inclusion of tree species M. oblonga in agroforestry system is a viable option for natural resource management and could sustain long-term soil productivity in
a highly degraded soil of this region as well as for food security of the resource poor people of North East India. 相似文献
9.
10.
Tea (Camellia sinensis) clones with shorter periods of winter dormancy exhibit lower accumulation of reactive oxygen species 总被引:1,自引:0,他引:1
Tea (Camellia sinensis (L.) O. Kuntze) is a perennial crop grown throughout the world. During winter, tea undergoes a dormancy period when growth of apical buds almost ceases, severely reducing the commercial yield of tea. Low temperatures prevail during the period of winter dormancy, which alone or in combination with high solar irradiance have the potential to induce oxidative stress in plants. We studied six tea clones under field conditions to test whether a relationship exists between oxidative stress and winter dormancy. Data on the behavior of the enzymatic antioxidative system was collected for all clones during different phases of winter dormancy. There was a strong positive correlation among clones between accumulation of reactive oxygen species (ROS) and the length of the dormancy period. Clones having shorter dormancy periods exhibited higher induction of antioxidative enzymes. Results suggest that efficient scavenging of ROS is a desirable feature in tea because it leads to lower accumulations of ROS during winter months and is associated with reduced winter dormancy. 相似文献