Agronomic Variability in Selected Triticum turgidum x T. tauschii Synthetic Hexaploid Wheats

Two trials were conducted at the Mexican National Institute of Agricultural Research Experiment Station at Yaqui Valley, Sonora, Mexico to investigate the nature and extent of agronomic variation in 50 synthetic hexaploid (SH) wheats (2n = 6x = 42, AABBDD) derived from Triticum turgidum (2n = 4x = 28. AABB) × T. tauschii (In = 2x = 14, DD) crosses for subsequent use in wheat improvement. Plant height, spike length, days to flowering, physiological maturity, grain yield, above-ground biomass at maturity, harvest index, yield components and test weight were determined.
Significant agronomic variation was observed among the germplasm evaluated. Outstanding SH genotypes were identified with higher grain yield, above-ground biomass at maturity, 1000-grain weight, and spikes m⁻² than the bread wheat ( Triticum aestivum L.) check cultivar Seri 82. Genotypic correlations of grain yield with other character traits show that grain m² was the most important determinant of gram yield (r = 0.993). Data on agronomic traits subjected to complete linkage cluster analysis resulted in classifying the genotypes into two distinct phenotypic groups excluding Seri 82. Groups generally corresponded to durum progenitors of the SH with significant group differences for all characters. This demonstrates use of practical numerical analysis procedures to describe agronomic variation in representative SH genotypes. Clustering by quantitativy traits may be valuable for identification of genotypes with divergent sources for breeding and agronomic purposes.     

Plasma 13,14-dihydro-15-keto-prostaglandin F2α concentrations in prepubertal dairy heifers challenged with oxytocin

Twenty-nine prepubertal Holstein heifers were assigned by age to one of three age groups to determine if the prepubertal bovine uterus could respond to an oxytocin stimulus. Group 1 heifers were 6 to 7 months of age (AGE1; n = 11), group 2 heifers were 8 to 9 months of age (AGE2; n = 11) and group 3 heifers were 10 to 11 months of age (AGE3; n = 7). Blood samples were collected via an indwelling jugular catheter. Four samples were collected at 15-min intervals prior to oxytocin administration to determine basal 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) concentrations. Each heifer received 100 IU of oxytocin i.v., blood sampling continued at 5 min intervals for the next 30 min and for an additional 90 min at 15-min intervals. Heifers were considered responders to oxytocin if mean PGFM concentrations increased at least 1.5 times the SD of their basal PGFM concentration. Age of the heifer (P less than .0001) and responder status (P less than .05) affected plasma PGFM. Plasma PGFM was higher in AGE1 and AGE3 heifers than AGE2 (P less than .0001). The number of responders was greatest at AGE3 (P less than .03) with AGE1 and AGE2 being similar. Mean basal PGFM was lower (P less than .04) at AGE2 than AGE1 with AGE3 being intermediate. In addition, basal PGFM at AGE1 tended to be lower (P less than .08) in the responders than in the non-responders, while AGE2 basal PGFM did not differ between responders and non-responders (P greater than .10).(ABSTRACT TRUNCATED AT 250 WORDS)     

Gastrointestinal stromal tumors in equids.

Eleven gastrointestinal neoplasms from 10 aged horses and 1 pony were examined grossly, his tologically, immunohistochemically, and (in two cases) ultrastructurally. Clinical signs were associated with two neoplasms, and the other nine tumors were incidental findings at laparotomy or necropsy. The neoplasms were solitary (9/11) or multifocal (2/11), well demarcated, serosal or mural masses of stomach (1), jejunum (1), ileum (3), cecum (5), and/or colon (2). Microscopic examination revealed discrete spindle cells arranged in compact patterns with fascicles and whorls or cribriform pattern with fascicles and rare palisades, often with a myxoid interstitial matrix. Three tumors infiltrated between the muscularis interna and the muscularis externa at the myenteric plexi. All neoplasms were vimentin positive, 3/11 were S-100 positive, 2/11 were muscle actin positive, and no neoplasm was positive for glial fibrillary acid protein, desmin, factor VIII, chromogranin, or neuron-specific enolase. Of the two tumors studied ultrastructurally, one contained an admixture of smooth muscle cells and cells resembling Schwann cells, and the second was populated by homogeneous fusiform mesenchymal cells separated by homogeneous matrix. Gastrointestinal stromal tumors (GIST) have been recognized in humans, more recently in dogs and nonhuman primates, and now in equids. Most of these tumors are comprised of a loosely arranged network of spindled cells separated by myxoid matrix. GIST may be composed of myogenic, neurogenic, combined myogenic and neurogenic, and undifferentiated mesenchymal cells.     

Response of Triticale Grain Yield and Yield Components to Number of Cuttings in a Mediterranean Environment

In six field experiments conducted over 2 years, the effect of one or two cuttings on grain yield of triticale (× Triticosecale Wittmack) were investigated. In addition, the relationships between triticale grain yield its components were analysed.
Grain yield of the uncut plots invariably exceeded the plots with one or two cuttings, regardless of the environment or year. The reductions in grain yield caused by one cutting ranged from 27 % to 60 % under rainfed conditions and 18 % to 20 % under irrigation. With two cuttings the reduction was 45 % to 70 % for rainfed, and 35 % to 48 % for irrigated conditions.
The yield components which most influenced grain yield of triticale under cutting treatment were the number of ears m⁻² in all six experiments and the number of grains per ear under rainfed conditions. At the rainfed sites in 1989 cuttings diminished the number of ears m⁻² mainly by increasing plant mortality. Nevertheless, at the rainfed sites of 1990 and at the irrigated site of both years, the reduction in the number of ears m⁻² with cuttings was due principally to a lower survival of tillers per plant.     

Acidic derivatives of the fungicide fenpiclonil: effect of adding a methyl group to the N-substituted chain on systemicity and fungicidal activity

A new acidic derivative of the fungicide fenpiclonil was synthesized containing a methyl group on the alpha-position of the carboxyl function of N-carboxymethyl-3-cyano-4-(2,3-dichlorophenyl)pyrrole. The phloem mobility of the resulting N-(1-carboxyethyl)-3-cyano-4-(2,3-dichlorophenyl)pyrrole was comparable with that of the former compound, but was higher at external pH 5.0. Unlike the derivatives previously synthesized, it was comparable with fenpiclonil in its fungicidal activity against the pathogenic fungus Eutypa lata.     

Effect of intrauterine bacterial infusions and subsequent endometritis on prostaglandin F2 alpha metabolite concentrations in postpartum beef cows.

Multiparous Angus and crossbred Angus cows were used to determine the effect of induced endometritis on plasma concentrations of 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) and progesterone (P4) and on duration of the estrous cycle of treatment. Beginning on the day of calving (d 0), blood samples were collected on alternate days. On three consecutive days, ranging from d 8 to 14 of the first postpartum estrous cycle, uterine horns were inoculated transcervically with either 3 x 10(9) colony forming units (cfu) of Actinomyces pyogenes and 1.5 x 10(9) cfu of beta-hemolytic Escherichia coli (treated; n = 9) in sterile PBS or with sterile PBS alone (control; n = 9). Samples of uterine fluid were collected by transcervical aspiration twice weekly from just before the start of each series of inoculations until the end of the experiment. Endometrial biopsies were collected transcervically between d 4 to 6 and 11 to 13 after inoculation. Based on clinical observations and results of bacterial cultures, all treated cows developed acute uterine infections. Controls did not develop uterine infections. Endometrial biopsies indicated that there were no significant diffuse or focal cellular reactions in response to the infection. The interestrous interval was greater (P less than .0003) for treated (27.7 +/- 1.0 d) than for control (20.6 +/- 1.0 d) cows, but P4 concentrations were similar between the two groups. Mean PGFM concentration and PGFM profiles were similar (P greater than .10) between treated and control cows before bacterial infusions. Bacterial infusions increased mean PGFM concentration (P less than .0001) and changed the shape of the PGFM profile (P less than .02).(ABSTRACT TRUNCATED AT 250 WORDS)     

Synthesis and phloem mobility of acidic derivatives of the fungicide fenpiclonil

A series of derivatives of the phenylpyrrole fungicide fenpiclonil was synthesized in which a carboxyl group was present at various sites of this non-phloem-mobile molecule. Using the Kleier model, all these acidic analogues were predicted to be moderately phloem-mobile, especially the N-substituted derivatives. One of these latter molecules, N-carboxymethyl-3-cyano-4-(2,3-dichlorophenyl)pyrrole, exhibited some fungicidal activity on the pathogenic fungus Eutypa lata, and was then tested as a phloem-mobile pesticide in the Ricinus system. The compound was indeed mobile in the sieve tubes and was not degraded to fenpiclonil in the phloem sap under our experimental conditions. Its concentration in the sap was closely correlated to the percentage of the undissociated form of the molecule in the external medium, and was similar under acidic conditions (external pH 4.6-5.0) to that of the herbicide glyphosate.     

Molecular characterisation of a field strain of bubaline herpesvirus isolated from buffaloes (Bubalus bubalis) after pharmacological reactivation

Two healthy buffaloes (Bubalus bubalis) in a herd which had not been vaccinated against infectious bovine rhinotracheitis (IBR), were selected for their seropositivity for anti-bovine herpesvirus type 1 (BoHV-1) glycoprotein E antibodies, and injected intramuscularly daily with dexamethasone for five consecutive days (day 1 to day 5) to reactivate any latent herpesvirus. Blood samples and nasal and vaginal swabs were collected daily from day 5 to day 15 from each buffalo for virological examination. All the vaginal swabs and blood samples were negative, but 13 of the 22 nasal swabs were positive; a cytopathic effect was observed in primary cultures of bovine fetal lung cells, and the viral isolates were identified as a herpesvirus by PCR. The viral strains were characterised by the sequence analysis of the genes coding for glycoproteins D and B, and the gene sequences were then used for phylogenetic analysis. The isolates from both buffaloes appeared identical at the level of the two genes, and were more closely related to bovine herpesvirus type 5 than to BoHV-1.     

TSL-1 antigens of Trichinella: an overview of their potential role in parasite invasion, survival and serodiagnosis of trichinellosis

The majority of studies on the immunobiology of Trichinella species have centred on the larval muscular phase (L1) with a view to identifying immunodominant antigens located on the surface of the cuticle and in the larval secretions; the nucleus of the parasite-host interaction. These antigens have been classified as eight groups (TSL-1-TSL-8), of which those belonging to the group TSL-1 have been most intensely studied. The principal constituents are glycoproteins, glycan carriers that contain a unusual sugar, the tyvelose (3,6-dideoxy-d-arabinohexose). Studies aimed at improving serodiagnostic techniques to detect trichinellosis indicate that these antigens are ideal candidates. They are capable of inducing a strong humoral response involving the generation of specific antibodies against beta-tyvelose, a sugar that seems to be exclusive to the Trichuroidea. Furthermore, these glycoproteins appear to fulfil an important function in the development and maintenance of the parasite in the muscular niche, and they appear to be fundamental for the invasion of the intestinal epithelium. It has also been demonstrated that specific monoclonal antibodies against tyvelose can mediate a degree of immunoprotection in the rat through the phenomenon known as rapid expulsion.