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排序方式: 共有464条查询结果,搜索用时 31 毫秒
1.
Sabyasachi Banerjee Seema Singh Shailesh Pandey Maneesh S. Bhandari Amit Pandey Krishna Giri 《Forest Pathology》2020,50(2)
Wilt disease caused by Fusarium solani is a serious constraint to Dalbergia sissoo (shisham) plantations in northern India. In this study, the antagonistic potential of 40 bacterial isolates recovered from rhizophere soil of healthy shisham trees, and a well‐characterized Trichoderma species (Trichoderma virens) were tested for their possibility as biocontrol agents for F. solani. Two promising isolates (S1 and S15) were identified which inhibited pathogen growth, caused chitin degradation, produced siderophores and solubilized phosphate in vitro. Isolate S15 scored highest for hydrogen cyanide (HCN) production while isolate S1 was a non‐HCN producer. These two isolates were identified as Serratia marcescens (S1) and Pseudomonas azotoformans (S15) following sequence analysis of 16S rDNA. In dual culture assays, T. virens caused 80% inhibition of mycelial growth of the test fungus. The three selected antagonists when tested in planta in the glasshouse completely suppressed production of wilt symptoms on 12‐month‐old shisham plants. Further work is needed to ascertain the potential of these isolates to be used as biocontrol agents to manage shisham wilt under field conditions. 相似文献
2.
Seunghan Lee Vikas Kumar Beth Cleveland Nicholas Romano Goutham N Vemuri Amit K. Yadav Kristen Meiler Ronald W. Hardy 《Aquaculture Research》2020,51(10):4065-4074
The rapid global growth in fish farming and limited supply of fish meal (FM) has consequently reduced FM inclusion levels in compound feeds leading to a higher reliance on alternative protein sources. Sasya is a single cell protein (SCP) product that has a similar amino acid profile as FM. The aim of this study was to evaluate the effects of replacing FM with SCP on in vivo digestibility, growth, feed efficiency, whole‐body proximate/amino acid composition and gene expression levels of various hepatic enzymes in rainbow trout (Oncorhynchus mykiss). Three isonitrogenous (470 g/kg crude protein) and isolipidic (18 g/kg crude lipid) diets were formulated as follows: Diet 1: control (30% FM); Diet 2:24% FM + 6% SCP and Diet 3:18% FM + 12% SCP. Each diet was hand‐fed to triplicate tanks containing 30 rainbow trout fingerlings (4.99 ± 0.20 g) for 9 weeks. Apparent digestibility coefficients of SCP for dry matter, crude protein, lipid and energy were 60, 80, 93 and 74% respectively. Growth performance (final weight: 69–71 g), feed conversion ratios (0.91–0.94) as well as whole‐body protein and amino acid composition were unaffected by diets. However, Diet 3 significantly increased whole‐body crude fat and energy. Fish fed the SCP‐based diets had significantly higher expression for carnitine palmitoyltransferase‐1b (CPT1b), fatty acid delta 6 desaturase (FADS6) and fatty acid elongase 5 compared to the control. Overall, the quality of the SCP was similar as FM. Therefore, this product could enlarge the portfolio of alternative protein sources that can be used in fish diets and thus open a new market opportunity for use of a new feed resource in the feed industry. 相似文献
3.
Glucose transport and milk secretion during manipulated plasma insulin and glucose concentrations and during LPS‐induced mastitis in dairy cows 下载免费PDF全文
J. J. Gross H. A. van Dorland O. Wellnitz R. M. Bruckmaier 《Journal of animal physiology and animal nutrition》2015,99(4):747-756
In dairy cows, glucose is essential as energy source and substrate for milk constituents. The objective of this study was to investigate effects of long‐term manipulated glucose and insulin concentrations in combination with a LPS‐induced mastitis on mRNA abundance of glucose transporters and factors involved in milk composition. Focusing on direct effects of insulin and glucose without influence of periparturient endocrine adaptations, 18 dairy cows (28 ± 6 weeks of lactation) were randomly assigned to one of three infusion treatments for 56 h (six animals each). Treatments included a hyperinsulinemic hypoglycaemic clamp (HypoG), a hyperinsulinemic euglycaemic clamp (EuG) and a control group (NaCl). After 48 h of infusions, an intramammary challenge with LPS from E. coli was performed and infusions continued for additional 8 h. Mammary gland biopsies were taken before, at 48 (before LPS challenge) and at 56 h (after LPS challenge) of infusion, and mRNA abundance of genes involved in mammary gland metabolism was measured by RT‐qPCR. During the 48 h of infusions, mRNA abundance of glucose transporters GLUT1, 3, 4, 8, 12, SGLT1, 2) was not affected in HypoG, while they were downregulated in EuG. The mRNA abundance of alpha‐lactalbumin, insulin‐induced gene 1, κ‐casein and acetyl‐CoA carboxylase was downregulated in HypoG, but not affected in EuG. Contrary during the intramammary LPS challenge, most of the glucose transporters were downregulated in NaCl and HypoG, but not in EuG. The mRNA abundance of glucose transporters in the mammary gland seems not to be affected by a shortage of glucose, while enzymes and milk constituents directly depending on glucose as a substrate are immediately downregulated. During LPS‐induced mastitis in combination with hypoglycaemia, mammary gland metabolism was more aligned to save glucose for the immune system compared to a situation without limited glucose availability during EuG. 相似文献
4.
Amit Kaushik Navinder Saini Sunita Jain Poonam Rana R.K. Singh Rajinder K. Jain 《Euphytica》2003,134(2):231-238
Segregation for salinity tolerance and ISSR markers based molecular polymorphism were investigated in a F3 plant population raised via single-seed descent method from a cross between salt-tolerant indica rice variety CSR10 and salt-susceptible
premium traditional Basmati rice variety Taraori Basmati HBC19. A total of 130 F3plants were evaluated individually for salinity tolerance on 1–9 scale on the basis of seedling growth parameters; the average
score ranged between 1.7 to 8.3. Frequency distribution curve obtained using the salinity tolerance data of F3 population and a chi-square analysis, showed a good fit to a normal distribution. Eleven plants each in the category of salt-tolerant
and salt-susceptible were selected from the segregating F3 population for ISSR marker analysis. A total of 149 bands (4–11 bands per primer) ranging from 200 to 3530 bp were scored
for the two rice varieties and the selected CSR10 × HBC19 segregating F3 plants using 26 ISSR primers. Of these, 89 were monomorphic and 60 were polymorphic. Of the 60 polymorphic bands,36 and 20
bands were specific to CSR10 andHBC19 respectively. The remaining four bands were amplified using UBC primers 810,848, 853
and 886 and present in only some of the CSR10 × HBC19 F3 plants. Notably, ISSR primers with dinucleotide repeat motif and 5'-anchored end amplified more number of bands (7.0 bands/primer)
compared to3'-anchored dinucleotide primers (5.4bands/primer), but 3'-anchored dinucleotide primers revealed higher level
of polymorphism (2.6 polymorphic bands/primer) compared to 5'-anchoreddinucleotide primers (1.43 polymorphic bands/ primer).
While distribution of majority of the polymorphic bands were more or less in the expected ratios in salt-tolerant and/or salt-sensitive
F3segregating plants, but some of the bands amplified using UBC ISSR primers 823, 825,826, 849, 853, 864, 866 and 884 showed
highly skewed distribution. Such polymorphic bands stand greater chances of having a linkage with the genes/ QTLs for salinity
tolerance and shall be the target for further studies.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
The methanol extract of Butea monosperma seeds, tested in vitro, showed significant anthelmintic activity. 相似文献
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9.
Jürgen Gross Nina E. Fatouros Seppo Neuvonen Monika Hilker 《Journal of pest science》2007,80(3):139-143
The Palaearctic leaf beetle Chrysomela lapponica usually feeds upon willows in the northern region of its occurrence. However, in Central Europe, some populations are known
that have specialised on birch. In this study, we investigated the significance of other herbivores occurring together on
the same host plants as possible exploitative competitors of C. lapponica. Two populations were studied: a population from Finland specialised on the willow Salix
borealis, and a population from the Czech Republic, specialised on the birch Betula
pubescens. Abundances of folivorous and suctivorous insects on both host plants were recorded at both population sites. The willow
leaf beetle Phratora vitellinae was the most abundant herbivorous insect at both study sites on willow. A field study was conducted to examine the effects
of P. vitellinae on the performance of C. lapponica. The presence of P. vitellinae larvae on the same twig upon which C. lapponica larvae were feeding did not affect increase of body weight in C. lapponica larvae. Thus, the high resource availability of both willows and birches suggest that interspecific competition is unlikely
to be a selection factor driving the evolution of host shift in C. lapponica. 相似文献
10.
The impact of clonality on an endangered tree (Elaeocarpus williamsianus) in a fragmented rainforest
The occurrence and distribution of clonality in the endangered rainforest tree Elaeocarpus williamsianus (Elaeocarpaceae) was investigated using SSR and RAPD analyses for 170 apparent individual trees found across seven sites. The results obtained with the two molecular techniques were in complete agreement in showing that single clones are present in most of the E. williamsianus sites with two genets occurring at the largest and most adequately protected site. In addition, seed production, viability and germinability were determined for four of these populations. Fruit were produced in all four populations tested although sterile fruit were very common. Only two E. williamsianus trees representing different genets within the same site produced viable seed. The overall genetic diversity within E. williamsianus is much lower than expected and thus the potential for sexual reproduction has been significantly diminished. It is concluded that habitat fragmentation removed an existing balance between vegetative and sexual reproduction in this species. Such findings have added urgency to the management of this species which could include a reintroduction program incorporating the collation of all clones within selected sites. 相似文献