An immunoperoxidase monolayer assay for the detection of antibodies against swine influenza virus.

An immunoperoxidase monolayer assay (IPMA) has been developed to detect antibodies against swine influenza A virus (SIV) in pig sera. The test was evaluated by using sequential sera from pigs experimentally infected with H1N1 subtype of SIV. Two hundred field serum samples that had been examined by the hemagglutination inhibition (HI) test were also tested. Antibodies specific to SIV were detected as early as 3 days postinoculation (dpi) in the IPMA test as compared with 7 dpi by the HI test. Unlike HI, no serum treatment was required in the IPMA test. Regardless of the virus used in the test, IPMA detected antibodies to both H1N1 and H3N2 subtypes of SIV whereas HI detects antibodies against either H1N1 or H3N2, depending upon the virus used in the test. Results of this study indicate that IPMA is a useful test for screening of pig sera for SIV antibodies.     

Rapid detection of avian pneumovirus in tissue culture by microindirect immunofluorescence test.

An indirect immunofluorescence (IFA) test with a 96-well, flat-bottomed microplate was developed to detect avian pneumovirus (APV) antigen in Vero cell cultures. Samples of nasal turbinates and swabs from infraorbital sinuses and trachea were collected from 4-week-old poults experimentally inoculated with APV. The APV titers by tissue culture IFA staining were compared with that of visual reading of cytopathic effect (CPE). The ability of IFA staining to detect APV antigen correlated well with visualizing CPE. The use of IFA staining of Vero cell cultures allowed detection of APV in substantially less time than the use of visualizing CPE. In addition, the use of IFA allowed specific identification of the virus in cell culture.     

Effects of temperature and stabilizer on the viability of a live attenuated avian metapneumovirus vaccine

A commercial live attenuated, freeze-dried avian metapneumovirus vaccine, Pneumomune, was assessed for its viability at three different temperatures (5.6 C, 21 C, and 37 C). No significant reduction in virus titer was observed when the vaccine was stored at 5.6 C for a period of 24 hr. However, reductions in virus titer of 1 log10 and 2 log10 were observed after 24 hr at 21 C and 37 C, respectively. Batch-to-batch variation in virus reduction was also observed. The addition of a dye or a vaccine stabilizer to the vaccine preparation did not have any deleterious effect on the survival of vaccine virus.     

Effects of a mixture of NAA+BA on numbers and growth rates of tubers ofSolanum tuberosum L.

Summary A mixture of NAA at 10 mg 1¹+BA at 1 mg 1¹ caused increases in growth rates of treated tubers of potato. Sub-irrigation and foliage sprays with the same mixture caused tuber initiation and increased the growth rates of some of the tubers. In a field study substantial increases in tuber number and final tuber volume per plant were recorded.

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Zusammenfassung Die Faktoren, die die Knollenbildung und Wachstumsrate bestimmen, sind wenig bekannt. Die ?usserliche Anwendung verschiedener Wachstumsregulatoren, die getrennt auf Einzelknollen von Pflanzen, die in Spezialbeh?ltern wuchsen (Abb. 1), aufgetragen wurden, brachte wenig Ergebnisse, die kommerziell nützlich sein konnten. Eine Mischung aus NAA (10 mg/l) und BA (1 mg/l), in der selben Weise angewendet, schien jedoch das Wachstum der meisten behandelten Knollen zu f?rdern (Abb. 2). In einem 2. Versuch wurde die gleiche Mischung direkt auf ausgesuchte Knollen gegeben und es zeigte sich wieder eine Wachstumssteigerung bei einigen (Abb. 3d-f). Wurden die Wurzeln mit dieser Mischung behandelt, so beschleunigte sich das Wachstum einiger Knollen und in zwei von drei Pflanzen wurde das Wachstum des Knollenansatzes gef?rdert (Abb. 3g-j). Blattspritzungen führten zu einer starken Knollenbildung (Abb. 3k-m). In einem dritten Versuch wurden pro Woche 3 oder 7 Mal die Stengel gespritzt und das führte zu einem signifikanten Anstieg in der Knollenzahl und im Gesamtknollenvolumen/Pflanze (Tab. 2). Abweichungen von den genannten Konzentrationen oder im Verh?ltnis der beiden Wachstumsregulatoren ergaben einen Wirkungsverlust. Der Wirkungsmechanismus ist noch nicht gekl?rt.

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Résumé Les facteurs qui contr?lent la tubérisation et la croissance des tubercules ne sont pas très bien compris. Plusieurs substances régulatrices de la croissance ont été appliquées seules sur des tubercules de plantes cultivées dans des unités spéciales (fig. 1), mais peu d'information commercialement utilisable n'a p? en être tiré. Toutefois, un mélange de NAA (10 mg 1¹) plus BA (1 mg 1¹) appliqué de la même fa?on semble stimuler la croissance de la plupart des tubercules traités (fig. 2). Dans une seconde expérimentation, des applications du même mélange, faites encore directement sur les tubercules sélectionnés, favorisent la croissance de certains d'entre eux. Appliqué sur les racines, le mélange favorise la croissance de quelques tubercules ainsi que le début de tubérisation sur deux ou trois plantes (fig. 3g-j). Pulvérisé sur le feuillage, le mélange provoque une importante tubérisation (fig. 3k-m). Dans une troisième expérimentation en plein champ, la pulvérisation sur le feuillage trois à des accroissements significatifs du nombre de tubercules (tableau 2). Lorsqu'on s'écarte des concentrations établies ou du rapport des deux substances de croissance, ces effets disparaissent. Les mécanismes impliqués ne sont pas compris.

     

Chloroplast derived SSRs reveals genetic relationships in domesticated alliums and wild relatives

Genetic Resources and Crop Evolution - Alliums comprise of popular spices and used for various culinary purposes and nutraceuticals. Poor genetic characterization and scarce information regarding...     

Patterns of distribution of assimilates in tubers ofSolanum tuberosum L. with time

Summary Autoradiographic studies showed the patterns of arrival and subsequent distribution of¹⁴C-labelled assimilates in the potato tuber. The internal phloem was the principal route of entry of assimilates which subsequently became more evenly distributed throughout the tuber. The patterns of distribution within the tuber following a single pulse (1 hour) feeding of¹⁴CO₂ continued to change for more than seven days afterwards. Between three and seven days after feeding an area corresponding to the xylem became almost devoid of¹⁴C-label and after fourteen days the phloem strands appeared to have ceased to carry assimilates. These observations are discussed.     

Effect of substituting live feed with formulated feed on the reproductive performance and fry survival of Siamese fighting fish, Betta splendens (Regan, 1910)

This study aimed to elucidate the effect of partial or complete replacement of live feed (LF) (Tubifex) with formulated feed (FF) on the reproductive performance of Betta splendens. Three hundred B. splendens fry (average weight 0.19 ± 0.01 g) were equally distributed into five different groups, each with three replicates. They were fed for 105 days with following different diets: control (C)—100% LF; T1—75% LF, 25% FF; T2—50% LF, 50% FF; T3—25% LF, 75% FF, and T4—100% FF. Results showed that the average number of hatched larvae (654 ± 101) and fry survival after 2 weeks of rearing (428 ± 70), after completion of three spawning, were recorded highest in the control group, which was, however, not significantly different from the T1, T2, and T3 groups. At the end of the feeding trial, the highest hatching percentage (90.3%) was registered in the T2 group, which was not significantly different from the control and T1 groups. The T2 group also recorded highest fry survival (65.54%) after completion of three spawning, which was not significantly (P < 0.05) different from the T1 and T3 groups. Control diet contained higher saturated fatty acid (63.23%) than formulated diet (29.80%). In the whole-body tissue, highest level of EPA (0.42%) and DHA (3.13%) were found in the T4 group followed by T3 group. The DHA/EPA ration was recorded highest in the T2 group (10.96%), which did not differ significantly from the T1 and T3 groups. Significant positive correlation was observed between saturated fatty acid levels in fish whole-body tissue and number of hatched larvae (Y = 30.81 × −825.3, R ² = 0.968) and fry survival after 2 weeks of rearing (Y = 21.38 × −580.9, R ² = 0.967). Considering all these factors, it can be concluded that the live feed Tubifex can be replaced up to 50% without any adverse effect on the reproductive performance and fry survival of B. splendens.     

Analysis of the coat protein gene of Indian <Emphasis Type="Italic">Potato virus X</Emphasis> isolates for identification of strain groups and determination of the complete genome sequence of two isolates

Complete coat protein (CP) gene sequences of 66 Potato virus X (PVX) isolates were sequenced and compared with other PVX isolates. The CP gene of these isolates shared 93.9–100.0 % and 97.0–100.0 % identities among them at nucleotide and amino acid sequence level, respectively. Phylogenetic analysis with isolates of known PVX strain groups showed that all 66 isolates were found in clade I (strain groups 1, 3 and 4) and none of them in Clade II (strain groups 2 and 4). The Indian isolates had the 714 bp coat protein gene and were closer to clade I isolates with 92.9–99.5 % identities and distantly related to Clade II isolates (74.2 to 80.0 % identities). Hence, these isolates may belong to either of the strain groups 1, 3 and 4. A threonine residue at position 122 and glutamine residue at position 78 were found conserved in all the Indian isolates suggesting that these isolates cannot overcome Rx1gene and Nx gene mediated resistance, characteristic of group 1 and 3. However, unique amino acid substitutions were observed in Indian isolates and further studies are required to ascertain their role in symptom expression, virulence and host range. In addition, whole genome sequences of two isolates one each from Jalandhar (Punjab) and Kufri (Himachal Pradesh) were also determined. They were 6435 nts long with five ORFs and shared 81.4–97.2 % identities to clade I isolates from USA, Russia, India, Iran, China, Japan, Taiwan and 77.0 to 77.5 % identities with clade II isolates from Peru.