Effect of excess zinc and arbuscular mycorrhizal fungus on bioproduction and trace element nutrition of Tomato (Solanum lycopersicum L. cv. Micro-Tom)

ABSTRACT

The effect of excess Zn and arbuscular mycorrhizal (AM) fungus on bioproduction and trace element nutrition were investigated in tomato. In a completely randomized factorial design, the experimental treatments – Zn addition at 0 (normal) and 300 (excess) mg Zn kg^?1 soil, and AM inoculation (non-AM and Rhizophagus irregularis) – were set up in a growth chamber for 10 weeks. Generally, AM effects on the available Zn, Mn, Cu, and Fe in the rhizosphere soil were in tandem with the effects in host tissues. Under normal Zn condition, AM enhanced Cu availability in the rhizosphere, optimized the Cu:Zn balance in shoots, and increased the host biomass production. Excess Zn reduced mycorrhizal colonization in AM plants and the total plant biomass in both AM and non-AM plants. Although AM decreased the Zn concentrations in soil and host tissues under excess Zn, the distortions in host TE balance were not significantly ameliorated by the fungus. While Zn in fruit was within the safety threshold, Mn deficiency in the fruit was observed under excess Zn, alongside increased root-to-fruit Fe and Cu translocations. Mycorrhizal reductions in soil and tissue Mn concentrations were considered a minus in terms of probable symbiont amelioration of Mn:Zn in-balance under excess Zn. Additional microbe(s) that can enhance Mn homeostasis might be helpful in tomato under elevated soil Zn.     

Preventive effects of CIDR-based protocols on premature ovulation before timed-AI in Ovsynch in cycling beef cows

Ovsynch is a program developed to synchronize ovulation for timed breeding. In this paper, the authors investigate whether controlled internal drug release (CIDR)-based protocols prevent premature ovulation before timed-artificial insemination (AI) when Ovsynch is started a few days before luteolysis in cycling beef cows. Nine beef cows at 16 days after oestrus were treated with (1) Ovsynch, i.e. gonadotropin releasing hormone (GnRH) analogue on day 0, prostaglandin (PG) F(2alpha) analogue on day 7 and GnRH analogue on day 9 with timed-AI on day 10, (n=3); (2) Ovsynch+CIDR (Ovsynch protocol plus a CIDR for 7 days from day 0, n=3), or (3) oestradiol benzoate (OB)+CIDR+GnRH (OB on day 0 in lieu of the first GnRH treatment, followed by the Ovsynch+CIDR protocol, n=3). In the Ovsynch group (1) plasma progesterone concentrations fell below 0.5 ng/mL earlier (day 5) than in both CIDR-treated groups (2) and (3), where this occurred on day 8. Plasma oestradiol-17beta concentrations peaked on day 8 in the Ovsynch group and on day 9 in both CIDR-treated groups. The dominant follicle ovulated on day 10 in the Ovsynch group and on day 11 in both CIDR-treated groups. Thus, both CIDR-based protocols prevented premature ovulation before timed-AI in Ovsynch when the protocol was started a few days before luteolysis. This reflects the fact that progesterone levels remained high until the beef cattle were treated with PGF(2alpha).     

Sequential isolation of rotavirus from individual calves

An outbreak of neonatal calf diarrhea was studied on a breeding farm of Japanese indigenous beef cattle. During the breeding season of 1982, 43 calves were born over the period 27 February-28 April. All but one of the calves suffered from neonatal diarrhea and 5 died. Bovine rotavirus was isolated in cell cultures from fecal specimens of 39 (90.7%) of the 43 calves during the outbreak, strongly suggesting that this was the causative agent; the virus was readily isolated from 81 (83.5%) of 97 specimens of diarrhea. Rotavirus was subsequently isolated from the feces of 7 of the calves in early May, more than one month after the initial virus isolation in early March. Two of these calves were again rotavirus-positive in early June, 41 days after the second virus isolation. Diarrhea had ceased in all 7 calves in March. Some antigenic differences were shown by the neutralization test between the early and later isolates from one of these calves, suggesting either re-infection with a serologically different virus, or persistent infection with the original virus following antigenic modulation.     

Inhibitors of bovine parvovirus,coronavirus and rotavirus in precolostral and fetal bovine sera

Eleven, 11 and 2 of 11 precolostral sera from normal calves and 13, 14 and 9 of 14 sera from normal fetuses, 7 to 10 months of gestation, neutralized bovine parvovirus, coronavirus and rotavirus, respectively.When assayed by single radial immunodiffusion, all the sera contained IgG at 360 to 1400 mg/dl, and some of them had much smaller amounts of IgM or IgA. Most of the neutralizing activities against bovine coronavirus and rotavirus were readily inactivated by treatment with acetone or 2-mercaptoethanol. Some sera fractionated by Sephadex G-200 gel filtration or starch block electrophoresis had neutralizing activities against bovine parvovirus or coronavirus in fractions containing no detectable amounts of immunoglobulins. These observations seem to indicate the presence of substance(s), other than immunoglobulins, capable of inhibiting replication of bovine parvovirus, coronavirus or rotavirus. The chemical nature and the mode of action of the inhibitors await elucidation.     

Neutralizing antibody to bovine rotavirus in various animal species

A total of 288 serum samples were collected from 12 species of animals in various localities of Japan from 1975 to 1977. Neutralizing antibody to bovine rotavirus was found in serum samples from all the species, viz., horses, cattle, sheep, goats, pigs, dogs, rabbits, guinea pigs, rats, mice, chickens and human beings. The incidence of neutralizing antibody in titers of 1 : 2 or higher ranged from 31 to 100%, and high incidences exceeding 70% were obtained in horses, cattle, sheep, pigs, dogs, rabbits and human beings. High titers were most common in horses, cattle, sheep and pigs. These serological results suggest that rotaviruses occur commonly in these species of animals.     

Detection of transmissible gastroenteritis virus in feces from pigs by reversed passive hemagglutination

A reversed passive hemagglutination (RPHA) method was developed for the detection of transmissible gastroenteritis (TGE) virus in the fecal specimens from pigs. Ovine erythrocytes fixed with glutaraldehyde and treated with tannic acid were coated with anti-TGE virus swine antibodies, which were purified by affinity chromatographic technique linked with purified TGE virus. The RPHA test was done by the Microtiter method. Erythrocytes coated with purified specific antibodies were agglutinated by TGE virus, but not by porcine rotavirus or porcine enterovirus. The reaction was specifically inhibited by antiserum against TGE virus, confirming the specificity of the reaction. A litter of seven 3-day-old pigs was orally inoculated with TGE virus, and fecal specimens were obtained once a day and serum was obtained every 4th day. With the RPHA test, TGE virus was detected in the diarrheal feces; all of the inoculated pigs developed virus-neutralization antibody for the TGE virus. The RPHA test detected TGE virus in feces from pigs with naturally occurring diarrhea. The RPHA test detected TGE virus in 5 of 6 fecal specimens (80%), whereas the positive rate was only 50% (3/6) for the immunofluorescent staining of primary cultures of porcine kidney cells inoculated with the specimens. The advantages of the RPHA method are simplicity, high sensitivity, and rapid to do.     

Isolation of Fukuoka virus, a member of the Kern Canyon serogroup viruses of the family Rhabdoviridae, from cattle.

Four virus strains with identical antigenic properties were isolated from blood samples of 4 sentinel calves having a fever and leukopenea in cultures of HmLu-1 cells derived from baby hamster lung. The virus was identified as Fukuoka virus, classified as a member of the Kern Canyon serogroup viruses of the family Rhabdoviridae, on the basis of its antigenic properties.     

Energy metabolism in canine erythrocytes associated with inherited high Na+- and K+-stimulated adenosine triphosphatase activity

Energy metabolism in canine erythrocytes associated with inherited high Na+- and K+-stimulated adenosine triphosphatase [(Na,K)-ATPase] activity (HK cells) was compared with that in normal canine erythrocytes (LK cells). Activities of some of the glycolytic enzymes in the HK cells were significantly higher than those in LK cells. The concentrations of adenosine triphosphate (ATP) and glycolytic intermediates in HK cells were almost equal to those in LK cells. Glucose utilization and lactate production by HK cells in vitro and incorporation of [32P]orthophosphate or [14C]glucose into 2,3-diphosphoglycerate in HK cells were higher than in LK cells. Radioactivity of [32P]ATP in HK cells was lower than in LK cells, but increased to approximately that of LK cells when (Na,K)-ATPase of HK cells was completely blocked by ouabain. When HK cells and LK cells were incubated in the absence of glucose, the concentration of ATP in HK cells was decreased more than that of LK cells. Although ouabain reduced the rate of decrease in ATP in HK cells, the decrease in ATP in HK cells was still 2-fold that in LK cells. The half-life of HK cells was about one-half that of LK cells. The results indicated that glycolysis is greater in HK cells than in LK cells, and that the increased glycolysis in HK cells was stimulated by an increased rate of ATP breakdown for active cation transport by the (Na,K)-ATPase and by increased degradation of ATP for some other pathway, eg, glutathione synthesis. Thus, the increased demand for ATP in HK cells might result in shortening the lifespan of HK erythrocytes.