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排序方式: 共有346条查询结果,搜索用时 31 毫秒
71.
Madhav Prakash Thakur Peter B. Reich William C. Eddy Artur Stefanski Roy Rich Sarah E. Hobbie Nico Eisenhauer 《Pedobiologia》2014
Soil warming can affect plant performance by increasing soil nutrient availability through accelerating microbial activity. Here, we test the effect of experimental soil warming on the growth of the three invasive plant species Trifolium pratense (legume), Phleum pratense (grass), and Plantago lanceolata (herb) in the temperate-boreal forest ecotone of Minnesota (USA). Plants were grown from seed mixtures in microcosms of soils with three different warming histories over four years: ambient, ambient +1.7 °C, and ambient +3.4 °C. Shoot biomass of P. pratense and P. lanceolata and plant community root biomass increased significantly in soils with +3.4 °C warming history, whereas T. pratense responded positively but not significantly. Soil microbial biomass and N concentration could not explain warming effects, although the latter correlated significantly with the shoot biomass of P. lanceolata. Our results indicate that soil with a warming history may benefit some invasive plants in the temperate-boreal ecotone with potential impacts on plant community composition. Future studies should investigate the impact of warming-induced differences in soil organisms and nutrients on plant invasion. 相似文献
72.
Journal of Soils and Sediments - The remediation of diesel-contaminated hydrophobic soil is difficult due to the inability of aqueous phase remedial agents to infiltrate the soil. This novel... 相似文献
73.
Arakere Chunchegowda Udaya Shankar Siddaiah Chandra Nayaka Sathyanarayana Niranjan‐Raj Hanumanthaiah Bhuvanendra Kumar Munagala S Reddy Siddapura Ramachandrappa Niranjana Harishchandra Sripathy Prakash 《Pest management science》2009,65(10):1059-1064
BACKGROUND: The present study investigated the effect of seven Bacillus‐species plant‐growth‐promoting rhizobacteria (PGPR) seed treatments on the induction of disease resistance in cowpea against mosaic disease caused by the blackeye cowpea mosaic strain of bean common mosaic virus (BCMV). RESULTS: Initially, although all PGPR strains recorded significant enhancement of seed germination and seedling vigour, GBO3 and T4 strains were very promising. In general, all strains gave reduced BCMV incidence compared with the non‐bacterised control, both under screen‐house and under field conditions. Cowpea seeds treated with Bacillus pumilus (T4) and Bacillus subtilis (GBO3) strains offered protection of 42 and 41% against BCMV under screen‐house conditions. Under field conditions, strain GBO3 offered 34% protection against BCMV. The protection offered by PGPR strains against BCMV was evaluated by indirect enzyme‐linked immunosorbent assay (ELISA), with lowest immunoreactive values recorded in cowpea seeds treated with strains GBO3 and T4 in comparison with the non‐bacterised control. In addition, it was observed that strain combination worked better in inducing resistance than individual strains. Cowpea seeds treated with a combination of strains GBO3 + T4 registered the highest protection against BCMV. CONCLUSION: PGPR strains were effective in protecting cowpea plants against BCMV under both screen‐house and field conditions by inducing resistance against the virus. Thus, it is proposed that PGPR strains, particularly GBO3, could be potential inducers against BCMV and growth enhancers in cowpea. Copyright © 2009 Society of Chemical Industry 相似文献
74.
Brinjal plants ( Solanum melongena L.) grown under moisture stress conditions in a glasshouse were treated with three anti-transpirants, namely cycocel, limewash and potassium chloride, to study their influence on chlorophyll content, soluble protein and photosynthetic rate. Moisture stress imposed at each of the three growth stages decreased chlorophyll content, soluble protein and photosynthetic rate. Of the anti-transpirants investigated, cycocel performed better than limewash and po-tassium chloride. 相似文献
75.
Single blood samples from 106 pregnant and seven non-pregnant Karan Swiss cows and 104 pregnant and nine non-pregnant Murrah buffaloes were measured for oestrone and oestrone sulphate hormones by radioimmunoassay. Mean plasma oestrone level was below detection limit (less than 2.5 pg/ml) in non-pregnant and 1 month pregnant cows and buffaloes. In cows the mean oestrone level fluctuated narrowly between 10.25 and 26.65 pg/ml between the second and eight months of pregnancy, followed by a steep rise in the ninth and especially in the tenth month (151.24 pg/ml). In buffaloes mean oestrone concentrations were lower and fluctuated between 14.81 and 23.56 pg/ml during the second to ninth months of pregnancy, rising sharply in the tenth month to a peak of 47.37 pg/ml. Mean oestrone sulphate levels were below detection limit (less than 16 pg/ml) during non-pregnancy, first and second months of pregnancy in cows, increasing sharply thereafter to a peak of 6401.38 pg/ml in the tenth month of pregnancy. In buffaloes, low mean levels of oestrone sulphate were recorded in the non-pregnant and up to the fourth month of pregnancy with the levels rising sharply thereafter to a peak of 6559.82 pg/ml in the tenth month. The hormone levels were not significantly different in the two species (P greater than 0.01). The possibility of using oestrone sulphate measurement as a test of pregnancy confirmation has been indicated for both species. 相似文献
76.
A method of estimating progesterone in buffalo whole milk by EIA using progesterone 6 beta-OH-hemisuccinate-horseradish peroxidase as the enzyme label and an antiserum raised against progesterone-7 alpha-carboxyethyl-thioether-BSA was developed. The microtitration plates used in the assay were first coated with affinity purified sheep IgG developed against rabbit IgG. The immune reaction was performed by incubating a mixture of 1 microliter of whole milk (diluted to 20 microliters with assay buffer), 100 microliters of enzyme label and 100 microliters of antiserum for 90 min in the dark. After washing the plates, 150 microliters of the substrate solution was added. The mixture was incubated in the dark for 40 min before the reaction was stopped and the optical density was measured at 450 nm. The calibration curve was sensitive in the range 0.8-40 pg/well, corresponding to 0.8-40 ng/ml. Milk samples from cycling buffaloes were tested for progesterone concentration by running parallel EIA and RIA. A good correlation of 0.91 was obtained and the estimated values were similar using both techniques. The method has demonstrated about 10 times greater sensitivity than RIA in buffalo milk. 相似文献
77.
Partial characterization of phylogeny,ecology and function of the fibrolytic bacterium Ruminococcus flavefaciens OS14, newly isolated from the rumen of swamp buffalo 下载免费PDF全文
Phoompong Boonsaen Madoka Kinjo Suriya Sawanon Yutaka Suzuki Satoshi Koike Yasuo Kobayashi 《Animal Science Journal》2018,89(2):377-385
The fibrolytic rumen bacterium Ruminococcus flavefaciensOS14 was isolated from swamp buffalo and its phylogenetic, ecological and digestive properties were partially characterized. Isolates from rumen contents of four swamp buffalo were screened for fibrolytic bacteria; one of the 40 isolates showed a distinctive feature of solubilizing cellulose powder in liquid culture and was identified as R. flavefaciens based on its 16S ribosomal DNA sequence. This isolate, OS14, was employed for detection and digestion studies, for which a quantitative PCR assay was developed and defined cultures were tested with representative forages in Thailand. OS14 was phylogenetically distant from other isolated and uncultured R. flavefaciens and showed limited distribution among Thai ruminants but was absent in Japanese cattle. OS14 digested rice straw and other tropical forage to a greater extent than the type strain C94 of R. flavefaciens. OS14 produced more lactate than C94, and digested para grass to produce propionate more extensively in co‐culture with lactate‐utilizing Selenomonas ruminantium S137 than a co‐culture of C94 with S137. These results indicate that phylogenetically distinct OS14 could digest Thai local forage more efficiently than the type strain, possibly forming a symbiotic cross‐feeding relationship with lactate‐utilizing bacteria. This strain might be useful for future animal and other industrial applications. 相似文献
78.
Probal Jyoti Doley Kabita Sarma Pranab Chandra Kalita Ranjana Goswami Arup Kalita Rupan Sarkar Chethan Gollahalli Eregowda Parimal Roychoudhary Om Prakash Choudhary 《Anatomia, histologia, embryologia》2023,52(2):223-233
The present study was undertaken to characterize the ultrastructural morphology of the blood cells of commonly reared chickens in the state of Mizoram, India under backyard poultry farming. For this study, 2 ml of whole blood was aseptically collected from the wings veins of 12 chickens of three different breeds namely the Zoar, Aseel and Rhode Island Red and processed for ultrastructural imaging under standard protocols. Under scanning electron microscopy (SEM) the matured erythrocytes of Zoar, Aseel and Rhode Island Red appeared elliptical in shape while the leukocytes and thrombocytes appeared round in shape with variable surface modifications. Under transmission electron microscopy (TEM) the granules of the heterophils of Zoar, Aseel and Rhode Island Red appeared predominantly fusiform in shape, the granules of the eosinophils appeared round in shape and that of the basophils appeared pleomorphic in shape. The cytoplasm of the monocytes, medium-to-large lymphocytes and thrombocytes of Zoar, Aseel and Rhode Island Red under TEM appeared to be vacuolated and granular while that of the small lymphocytes appeared to be granular but non-vacuolated. The study concluded that the ultrastructural characteristics of the blood cells of the three breeds of chicken studied were almost similar to the blood cells of other birds reported earlier. 相似文献
79.
Ekambaranellore Prakash Patan Shaik Sha Valli Khan Thoguru Jonh Vivek Sreenivasa Rao Elu Singh Meru 《Journal of Forest Research》2006,11(5):329-335
In vitro clonal multiplication of Pterocarpus santalinus L. was achieved using mature nodal explants of a 10-year-old elite quality tree. Combinations of serial transfer technique
and incorporation of antioxidants (250 mg/l L-ascorbic acid and 50 mg/l citric acid) into the culture medium helped to minimize medium browning and improve explant survival
during shoot sprouting. About 70% of explants were sprouted on Murashige and Skoog (MS) liquid medium containing 4.4 μM 6-benzyladenine (BA). The explant harvest period also influenced the bud break and shoot sprouting in nodal explants. The
combination of 4.4 μM BA and 2.2 μM thidiazuron (TDZ) was found to be the most suitable growth regulator for obtaining the highest percentage of nodal segment
sprouting (74%–75%), the number of secondary shoots per primary shoot (two or three), the shoot length (5–6 cm), the number
of new nodal segments generated per active explant (four or five), and the multiplication coefficient (3.5) within 6 weeks.
Repeated subculturing of nodal explants obtained from shoot cultures enabled continuous production of healthy axillary shoots.
At the end of the sixth passage, about 90% of nodal explants produced five or six healthy green shoots, each being about 6.6 cm
long with six or seven nodes. Multiplication coefficient was also increased from the first subculture (5.4) to the sixth subculture
(8.3). The best rooting response was achieved on solidified half-strength MS medium supplemented with 4.9 μM indole-3-butyric acid (IBA). About 70% of the micropropagated plantlets were established successfully in 20-cm pots containing
a mixture of soil and farmyard manure (4 : 1 ratio) and formed new leaflets. 相似文献
80.
Endoglucanase has been isolated from Aspergillus aculeatus. The purified enzyme showed a single band and had a molecular weight of 45,000 Da as indicated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with a specific activity of 1.4 units/mg. The purified enzyme was identified as endoglucanase, showing a high specific activity toward CM-cellulose and low specific activity toward Avicel. The activity of the isolated enzyme was optimum at a pH of 5.0 and temperature of 40 degrees C, respectively. The isoelectric point of the enzyme was 4.3. T(m) was found to be 57 degrees C. The treatment of the endoglucanase with diethylpyrocarbonate resulted in the modification of the histidine residues present in the enzyme, with a concomitant loss of 70% of the original enzymatic activity. However, carbodiimide completely inactivated the endoglucanase. The results show that the enzyme is able to sustain 50% of its activity even when heated at 90 degrees C for a period of 5 h. Endoglucanase can be used in the controlled hydrolysis of cellulose and other cellulose-rich foods. It can be used in the development of targeted functional foods from agrimaterials for value addition in the food chain. 相似文献