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31.
Antinuclear antibody (ANA), a marker for autoimmune reactions, was detected in the sera of quails with Marek's disease (MD). The autoantibody was detected 3 weeks after infection in quails infected with chicken Marek's disease virus and 4 weeks after infection in quails infected with quail Marek's disease virus. The ANA titers were low and ranged from 10 to 40. A speckled type of nuclear fluorescence was the characteristic staining feature. In addition to the presence of ANA, immune complexes (IC) were also detected in the kidney glomeruli of quail infected with Marek's disease virus. Initially about 25-30% of the glomeruli in the kidneys of infected quails had IC deposits. In subsequent periods, the amount of IC deposit and the number of glomeruli showing IC also increased considerably. The findings of the present study suggested autoimmunity may play a pathogenic role in MD.  相似文献   
32.
Good soil structure is well recognised as a must for intensive cultivation. Various indices of soil structure suggested by earlier investigators had their own limited use in their application to the practical problems on the field. RICHARDS et al (1960) suggested compacted bulk density and hydraulic conductivity on the compacted samples as means of evaluating the structural status of soils. Problems of compaction, inadequate aeration and undesirable soil moisture relationships for growth of plants that are associated with soil structure depend on effective porosity (DAKSHINAMURTI, 1959) and porespace distribution in the soil for their solution. Hydraulic conductivity being related to the effective porosity should work out as a comparatively better index of soil structure. In the present investigation hydraulic conductivity and bulk density under varying conditions of compaction were studied and their significance and sensitivity as indices in comparison to other indices of soil structure were discussed.  相似文献   
33.
The aim of this study was to evaluate dietary dosages of Microcystis on the immune response and disease resistance against infections due to the opportunistic pathogen Aeromonas hydrophila in Labeo rohita fingerlings. Labeo rohita fingerlings were fed diet containing 0 (Control), 0.5, 1.0 and 5 g Microcystis powder kg?1 dry diet for 90 days. Three replicate groups of fish averaging 20 ± 2 g were fed for 3 months daily. At 30 days interval, samples were assayed for different biochemical [serum total protein, albumin, globulin, albumin:globulin (A:G) ratio] and immunological (superoxide anion production, lysozyme and serum bactericidal activity) parameters. The results demonstrate that fish fed Microcystis showed increased levels of lysozyme, serum bactericidal activity, serum protein and albumin (P ≤ 0.05) as compared with the control group. After 90 days, fish were challenged with A. hydrophila and mortality (%) was recorded up to day 10 postchallenge. The group fed 1.0 g Microcystis kg?1 dry diet showed the highest percentage survival (72%). These results indicate that Microcystis aeruginosa stimulates the immunity and makes L. rohita more resistant to infection by A. hydrophila when fed in dried form in feed.  相似文献   
34.
The genetic improvement of rice over past decades has led to the loss of several genes which are responsible for nutrient acquisition and soil-related stresses. Phosphorus (P) is a non-renewable resource and inevitable element of metabolic functions in plants. By pedogenesis process, organic matter contributes to renewing soil P in lesser extent. Therefore, improvement of the P use efficiency is one of the most imperative traits in rice breeding program, which is governed by quantitative trait loci (QTLs). QTLs controlling low P associated morphological and physiological traits in rice were investigated mostly during last one and half decade by using diverse mapping populations. Comprehensive and meticulous survey from literature, we found that to date 133 P associated QTLs of morpho-physiological traits were reported to be distributed on twelve chromosomes and majority of these QTLs localized on chromosome 1, 2 and 12. For the first time, a complete figure is presented in this review on chromosome wise with respective QTLs associated with low P for easy understanding and selecting markers for future prospect. Further, it is necessary to understand the molecular mechanisms and regulation of genes and traits associated with low P to develop tolerant rice cultivars using functional marker-assisted selection.  相似文献   
35.
Globisporangium Uzuhashi, Tojo & Kakish. (syn. Pythium Pringsheim) species cause many plant diseases, including Pythium damping-off, leaf and fruit blights, and root rots. Fungicide resistant isolates are selected by repeated use of a single active ingredient on infected crops without rotation. Previous studies demonstrated increased pathogenicity and radial growth in a mefenoxam resistant isolate of Pythium aphanidermatum when exposed to sub-lethal doses of fungicides and ethanol. In those studies, reproducibility of in vitro assays was difficult to achieve due to large variations among trials. This study aimed to examine two protocols for improved reproducibility during the assessment of biphasic dose-responses in mefenoxam-resistant isolates of Globisporangium ultimum and G. irregulare. Two different growth related endpoints, total growth area and total dry mass weight, were assessed. Assays were conducted using ten concentrations of mefenoxam ranging from 0.01 to 1,000 μg/ml. Statistically-significant stimulatory effects were observed in the two Globisporangium species using the two growth related endpoints. Because of its better reproducibility, mycelial growth area is recommended as an endpoint for future studies of chemical hormesis on growth of Globisporangium spp.  相似文献   
36.
Data on physical properties of seeds have significant importance for machinery and process equipments design. This study was conducted to investigate some physical properties of tung seed (Aleutites Fordii) namely, dimensions, 100 unit mass, arithmetic mean diameter, geometric mean diameter, sphericity, aspect ratio, surface area, bulk density, true density, porosity, terminal velocity and coefficient of friction. The applications of these properties are also discussed. The tung seed has an average of 13.24% (d.b.) moisture and 40.37% oil content. The average seed length, width, thickness were 22.61 mm, 20.35 mm, 13.95 mm, respectively. The average surface area of tung seed is 1084.20 mm2 while the sphericity and aspect ratio were 0.82 and 90.07%, respectively. The average bulk density of seed was 0.502 g/cm3 while the true density was 0.995 g/cm3, and the corresponding porosity was 49.88%. The terminal velocity was 8.3 m/s. The static coefficient of friction on three different contacting materials has been found out and the results showed that the mean value of static coefficient friction was least in case of aluminum sheet while it is highest for plywood.  相似文献   
37.
In order to characterize the cytoplasmic system in seven cytoplasmic-genic male-sterile lines (CMS; A lines) of rice, viz., V 20A, ‘Zhenshan 97A’, IR 46831A, ‘Madhu A’ (cms-WA), ‘Yar-Ai-Zhao A’ (cms-Gam), ‘Pankhari 203A’ (cms-TN) and Wu 10A (cms-bo) and their isonuclear maintainers (B lines), all possible crosses were made between CMS lines and maintainers (A × B) as well as between the maintainers themselves (B × B). Based on F1 pollen and spikelet fertility the CMS lines V 20A, ‘Zhenshan 97A’, IR 46831 A, ‘Madhu’ A possessing cms-WA cytoplasm were found to be genetically different from ‘Pankhari 203A’ (cms-TN), Wu 10A (cms- bo) and ‘Yar-Ai-Zhao A’ (cms-Gam) cytoplasms. Cms-bo and cms-TN cytoplasms appeared to be identical. Since the cytoplasms of the A lines are different from those of the B lines, the nuclear genes operating to cause the sterility might also be different in (A × B) and (B × B) crosses.  相似文献   
38.
Summary Divergence of 25 accessions of Brassica juncea of Indian, CIS (Commonwealth of Independent States, former USSR) and synthetic origin was studied by D2 analysis. On the basis of divergence, ten accessions were selected and crossed in a diallel fashion without reciprocals to study the combining ability and heterosis. None of the accessions was found to be a good general combiner for all the nine quantitative characters that were studied. Significant heterosis over better parent for single plant yield was recorded in CIS x Indian and synthetic x CIS crosses (5 each) followed by Indian x synthetic types (3). The analysis of component characters showed that the mean performance of the majority of hybrids was intermediate for five out of six yield attributing traits, thus exhibiting dominance or partial dominance effect. To estimate the contribution of such yield attributing traits towards heterosis for yield, a comparison was made among three parameters viz. heterosis over mid parent (MP), better parent (BP) and better yielding parent (BYP) of the concerned hybrid. It was observed that estimation of heterosis from BYP was a more accurate method to determine the contribution of component characters towards yield heterosis than the analysis based on MP and BP. From the component character analysis, it was concluded that characters like number of primary and secondary branches, number of siliqua per plant and siliqua density contributed significantly towards heterosis in yield. Plot level yield trials of two selected hybrids (Skorospieka II x RH30 and Donskaja IV x Varuna) over two growing seasons revealed 29.4 to 91.8% heterosis over BYP.  相似文献   
39.
N. Arumugam    A. Mukhopadhyay    V. Gupta    Y. S. Sodhi    J. K. Verma    D. Pental  A. K. Pradhan 《Plant Breeding》2002,121(2):168-170
Brassica carinata (BBCC), a potential oilseed crop for dry land agriculture, is sensitive to high temperatures during germination and early stages of growth, which thereby restricts the possibility of using the residual soil moisture available after the rainy season for its cultivation. To overcome this problem, a three‐genome hybrid, RCBB, was synthesized using Raphanus sativus (RR) and Brassica oleracea (CC) as donor sources for the desired heat tolerance. Protoplasts of RC hybrids obtained through sexual crosses between R. sativus (female) and B. oleracea (male) were fused with protoplasts of Brassica nigra (BB) to produce RCBB somatic hybrids. The hybrid colonies regenerated with an average frequency of 7.6%. Twelve out of 36 hybrids grown to maturity were characterized for their nuclear and organelle genomes. While all the hybrids showed the presence of B. nigra chloroplasts, 10 of the hybrids showed B. nigra‐specific mitochondria and two had Raphanus‐spedfic mitochondria. The somatic hybrids could be backcrossed to B. carinata.  相似文献   
40.
Brown planthopper (BPH, Nilaparvata lugens Stål) is the most devastating pest of rice in Asia and causes significant yield loss annually. Around 37 BPH resistance genes have been identified so far in indica, African rice varieties along with wild germplasms such as Oryza officinalis, O. minuta, O. nivara, O. punctata, O. rufipogon and O. latifolia. Genes/QTLs involved in BPH resistance, including Bph1, bph2/BPH26, Bph3, Bph6, bph7, BPH9, Bph12, Bph14, Bph15, Bph17, BPH18, bph19, Bph20, Bph21(t), Bph27, Bph27(t), Bph28(t), BPH29, QBph3, QBph4, QBph4.2, Bph30, Bph32, Bph33, Bph35 and Bph36, have been fine-mapped by different researchers across the globe. The majority of genes/QTLs are located on rice chromosomes 1, 3, 4, 6, 11 and 12. Rice plants respond to BPH attack by releasing various endogenous metabolites like proteinase inhibitors, callose, secondary metabolites (terpenes, alkaloids, flavonoid, etc.) and volatile compounds. Besides that, hormonal signal pathways mediating (antagonistic/synergistic) resistance responses in rice have been well studied. Marker-assisted breeding and genome editing techniques can also be adopted for improving resistance to novel BPH biotypes.  相似文献   
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