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21.
R.G. Saini M. Kaur B. Singh Shiwani Sharma G.S. Nanda S.K. Nayar A.K. Gupta S. Nagarajan 《Euphytica》2002,124(3):365-370
The genetic bases of leaf rust resistance in wheat (Triticum aestivum L.) line CSP44, selected from the Australian cultivar Condor, and Indian cultivar VL404, were studied. The reaction patterns
of CSP44 and VL404 against Indian races 12, 77, 77-1, 77-2, 77-3, 77-4, 77-5 and 108 were different from reaction patterns
shown by near-isogenic lines with known adult plant resistance (APR) genes, viz. Lr12, Lr13, Lr22b and Lr34. Although the reaction patterns of CSP44 and VL404 were similar to the near-isogenic line Tc+Lr22a, tests of allelism indicated absence of Lr22a in both CSP44 and VL404. On the basis of genetic studies, their resistances in field tests against race 77-5, the most virulent
race from the Indian sub-continent, were each ascribed to two genes. One of the two genes in each wheat was identified to
be the non-hypersensitive APR gene Lr34. The second APR genes in CSP44 and VL404 gave hypersensitive reaction types and were recessive and dominant, respectively.
The gene in CSP44 was designated Lr48and the gene in VL404, Lr49.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
22.
Is air-drying of soil samples an appropriate step in determining plant available potassium for corn?
Manbir Kaur Rakkar David Franzen Amitava Chatterjee 《Journal of plant nutrition》2016,39(13):1979-1988
Potassium (K) fertilizer recommendations are mainly based on air -dried soil samples which can lead to over- or under-estimation of plant available soil K. Three on-farm trials were conducted in North Dakota and Minnesota to determine the variation of soil test-K between air-dried (KDry) and field moist (KMoist) soil samples. The differences between KDry and KMoist decreased exponentially as soil K increased, but increased linearly with increasing soil moisture. Soil drying influenced the plant available soil K-test value, producing higher K values compared to the moist soil K. It is unclear based on these initial experiments which method might produce a more predictable K critical value to aid in directing K application for corn in this region. 相似文献
23.
Studies on reproductive biology are difficult but useful in species like Aegle marmelos (Linn.) Correa which is of considerable socio-economic importance and possess morphogenetic variation and qualities of wider
adaptability to different soils. Cytology, phenology, pollination, breeding system and natural regeneration of wild and cultivated
trees from India revealed the existence of diploid (2n = 18) and tetraploid trees (2n = 36) in Pachmarhi hills and only diploid
trees in Punjab plains and Shiwalik hills. The diploid and tetraploid trees showed normal meiosis and high pollen fertility.
Phenological events which included leaf fall, leaf emergence, floral bud break, flowering and fruiting are nearly the same
in wild and cultivated trees. Natural pollen transfer in the species was highly efficient. Levels of fruit set following open
pollination was quite high and is reduced considerably following hand pollination probably due to some injury caused to stigma
during experiments. Inspite of synchronous nature of anther dehiscence and stigmatic receptivity, selfing in a flower was
avoided due to herkogamy. Some selfing, however, occurred through geitonogamous mode as bagging of panicles yielded 12.21 ± 0.99
to 14.12 ± 0.91% fruit set. High pollen ovule ratio (9,250–10,600) indicated toward the obligate outbreeding nature. The species
suited to insect and wind mode of pollination. High amount of air borne pollen grains deposited on glycerine smeared glass
microscopic slides suggested towards the wind mode of pollination. Though flowers are dull coloured a variety of insects visited
the flowers due to sweet fragrance and stamen/pollen as food reward. Among insect pollinators, honey bee (Apis dorsata) was the major and legitimate pollinator while the rest were either minor pollinators or mere visitors. Inspite of high fruit/seed
set, natural regeneration through seeds was poor as fallen fruits were destroyed by fungal pathogens and white ants. The species
also propagated vegetatively through coppices and root suckers. It lacks agamospermy as bagging of emasculated flowers yielded
no fruit. It is inferred that ‘bael’ which lacks agamospermy reproduced successfully through gamospermy (xenogamy and geitonogamy)
and vegetative mode (coppices and root suckers). We also concluded that tetraploid trees growing in the Pachmarhi hills with
large sized fruits possessed better potentialities in horticulture if planted through root suckers or coppices. 相似文献
24.
In the present study, attempt was made to compare agar with gum karaya as gelling agent in micropropagation of rough lemon (Citrus jambhiri Lush.). Initially nodal segments were cultured on agar-gel MS medium containing benzyladenine (BA), kinetin (KN), zeatin (ZN) (1.0–2.5 mg L?1) and malt extract (200–1,200 mg L?1) to standardize the medium. Maximum shoot regeneration (66.66%) was observed with KN 2 mg L?1 with an average shoot length of 0.73 cm. Gum karaya and agar was then evaluated at different concentration and combinations in same medium. The shoot regeneration response on media gelled with 30 g L?1 gum karaya was 62.49% with an average shoot length of 0.80 cm. Regenerated shoots were rooted on MS medium gelled with agar and supplemented with different concentrations (0.5–2.5 mg L?1) of indole-3-acetic acid (IAA), naphthalene acetic acid (NAA), and indole-3-butyric acid (IBA). Maximum response (52.77 %) was observed with IBA 2.0 mg L?1 with an average number of 2.58 roots/shoot. A maximum of 53.47% cultures showed root regeneration with an average number of 2.91 roots/shoot in 30 g L?1 gum karaya-gel medium. Texture measurements revealed that firmness of gum karaya-gel medium was nowhere near to that of agar. However, in their capability of supporting growth and differentiation of explants they are equal to agar medium. Gum karaya forms less adhesive and gummy medium as compared to agar. This study indicates that gum karaya can be used as gelling agent in place of agar. 相似文献
25.
26.
Trans-endocytosis of CD80 and CD86: a molecular basis for the cell-extrinsic function of CTLA-4 总被引:1,自引:0,他引:1
Qureshi OS Zheng Y Nakamura K Attridge K Manzotti C Schmidt EM Baker J Jeffery LE Kaur S Briggs Z Hou TZ Futter CE Anderson G Walker LS Sansom DM 《Science (New York, N.Y.)》2011,332(6029):600-603
Cytotoxic T lymphocyte antigen 4 (CTLA-4) is an essential negative regulator of T cell immune responses whose mechanism of action is the subject of debate. CTLA-4 shares two ligands (CD80 and CD86) with a stimulatory receptor, CD28. Here, we show that CTLA-4 can capture its ligands from opposing cells by a process of trans-endocytosis. After removal, these costimulatory ligands are degraded inside CTLA-4-expressing cells, resulting in impaired costimulation via CD28. Acquisition of CD86 from antigen-presenting cells is stimulated by T cell receptor engagement and observed in vitro and in vivo. These data reveal a mechanism of immune regulation in which CTLA-4 acts as an effector molecule to inhibit CD28 costimulation by the cell-extrinsic depletion of ligands, accounting for many of the known features of the CD28-CTLA-4 system. 相似文献
27.
Various enzymes of the tricarboxylic acid cycle (TCA) viz., aconitase (E.C. 4.2.1.3), isocitrate dehydrogenase (E.C. 1.1.1.42), succinate dehydrognease (E.C. 1.3.99.1), fumarate reductase (NADH: fumarate oxido-reductase), fumarase (E.C. 4.2.1.2) and maltate dehydrogenase (E.C. 1.1.1.37) were detected in adult Haemonchus contortus (Nematoda: Trichostrongylidae), in vitro. Low activities of aconitase and isocitrate dehydrogenase suggested that the TCA cycle has a minor function and the pathway of CO2 fixation is the major pathway in the energy metabolism of the parasite. In vitro incubation in Tyrode's solution had no significant effect on TCA cycle enzymes and the worm was able to maintain normal metabolism for 12 h.The effects of dl-tetramisole and rafoxanide on various enzymes of the TCA cycle were studied in adult H. contortus. At 50 μg ml?1 varying degrees of succinate dehydrogenase and fumarate reductase activities were observed. At the same concentration, the activities of other enzymes remained unaltered. 相似文献
28.
Zimmerman KL Wilcke JR Robertson JL Feldman BF Kaur T Rees LR Spackman KA 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2005,34(1):7-16
BACKGROUND: The Systematized Nomenclature of Medicine (SNOMED) is an established standard nomenclature for the expression of human and veterinary medical concepts. Nomenclature standards ease sharing of medical information, create common points of understanding, and improve data aggregation and analysis. OBJECTIVES: The objective of this study was to determine whether SNOMED adequately represented concepts relevant to veterinary clinical pathology. METHODS: Concepts were isolated from 3 different types of clinical pathology documents: 1) a textbook (Textbook), 2) the Results sections of industry pathology reports (Findings), and Discussion sections from industry pathology reports (Discussion). Concepts were matched (mapped) by 2 reviewers to semantically-equivalent SNOMED concepts. A quality score of 3 (good match), 2 (problem match), or 1 (no match) was recorded along with the SNOMED hierarchical location of each mapped concept. Results were analyzed using Cohen's Kappa statistic to assess reviewer agreement and chi-square tests to evaluate association between document type and quality score. RESULTS: The percentage of good matches was 48.3% for the Textbook, 45.4% for Findings, and 47.5% for Discussion documents, with no significant difference among documents. Of remaining concepts, 40% were partially expressed by SNOMED and 14% did not match. Mean reviewer agreement on quality score assignments was 76.8%. CONCLUSIONS: Although SNOMED representation of veterinary clinical pathology content was limited, missing and problem concepts were confined to a relatively small area of terminology. This limitation should be addressed in revisions of SNOMED to optimize SNOMED for veterinary clinical pathology applications. 相似文献
29.
Three abortigenic Indian isolates of equine herpesvirus-1 (EHV-1) (Tohana, Hisar and Bikaner), along with two exotic abortigenic
isolates (AB4 and V592) and another EHV-1 isolate (Jind) obtained from a case of perinatal foal mortality, were studied for
variability. For this purpose, PCR and restriction endonuclease (RE) digestion techniques were used simultaneously as a DNA
fingerprinting system. Nine different regions of EHV-1 virus were amplified by PCR using primer pairs specific for the regions
and the products obtained from these regions were subsequently subjected to various restriction endonucleases to further assess
the variability in the number of RE sites as well as in their positions. No difference was observed in all the four abortigenic
isolates in terms of the size of different PCR products amplified by all the nine primer pairs, except for primer pairs ‘E’
and ‘C’. PCR products obtained with primer pair E revealed that Tohana and Bikaner isolates were most similar while Hisar
isolate was like V592 isolate. However, the PCR product obtained from Jind isolate had a size between the PCR products of
Hisar and Tohan/Bikaner isolates. The primer pair ‘C’ used to amplify the region between 1151 to 3679 in ‘Gene 1,2,3’ clearly
differentiated the EHV-1 isolate obtained from a case of perinatal foal mortality from isolates obtained from abortion cases.
This primer pair needs to be exploited more extensively for use as a potential marker for differentiating the EHV-1 isolates,
mainly the abortion cases from perinatal foal mortality ones. Restriction endonuclease studies done with PCR product of all
the isolates with various primer pairs did not reveal any changes in the position or number of RE sites present in the products
amplified, indicating no variation in different RE sites within the amplified PCR products. However, this study clarified
that all the Indian isolates belonged to the IP group of EHV-1. 相似文献
30.
The use of non-prion biomarkers for the diagnosis of Transmissible Spongiform Encephalopathies in the live animal 总被引:1,自引:0,他引:1
Scrapie and bovine spongiform encephalopathy (BSE) are major global concerns and the emergence of variant Creutzfeldt-Jakob disease (vCJD) has caused turmoil for blood transfusion services and hospitals worldwide. Recent reports of iatrogenic CJD (iCJD) cases following blood transfusions from Transmissible Spongiform Encephalopathies (TSE)-infected donors have fuelled this concern. Major diagnostic tests for BSE and scrapie are conducted post-mortem from animals in late stages of the disease. Although the lymphoreticular system is involved in the earlier pathogenesis of some forms of sheep scrapie and vCJD, which presents great opportunity for diagnostic development, other TSE diseases (some strains of scrapie, sporadic CJD (sCJD) and bovine BSE) do not present such a diagnostic opportunity. Thus, there is an urgent need for pre-mortem tests that differentiate between healthy and diseased individuals at early stages of illness, in accessible samples such as blood and urine using less invasive procedures. This review reports on the current state of progress in the development and use of prion and non-prion biomarkers in the diagnosis of TSE diseases. Some of these efforts have concentrated on improving the sensitivity of PrPSc detection to allow in vivo diagnosis at low abundances of PrPSc whilst others have sought to identify non-prion protein biomarkers of TSE disease, many of which are still at early stages of development. In this review we comment upon the limitations of prion based tests and review current research on the development of tests for TSE that rely on non-prion disease markers in body fluids that may allow preclinical disease diagnosis. 相似文献