Host plant effect on competition among strains of Rhizobium leguminosarum

1990 ◽  
Vol 36 (12) ◽  
pp. 864-869 ◽  
Author(s):  
Michael F. Hynes ◽  
Michael P. O'Connell

Analysis of plasmid profiles was used to type Rhizobium leguminosarum biovar viciae strains isolated from nodules of peas, lentils and faba beans grown in two different soils. One soil was from a native pasture with no previous history of cultivation, the other was from a plot in a rotation study which included lentils every 2 years. The results indicated a strong preference of both peas and faba beans for strains having certain specific plasmid profiles. Strains belonging to one plasmid profile group (group 2) formed over half the nodules on peas grown in soil from the rotation plot but were never found on faba beans grown in the same soil, while strains from another group (group 5) formed nearly all of the nodules on faba beans grown in soil from the rotation plot, but no nodules on peas. Competitiveness for pea nodulation was correlated with an ability to catabolize homoserine, an amino acid found in large quantities in pea root exudate. Strains having plasmid profiles corresponding to those of strains that have been used in commercial inoculants over the last few years were isolated only rarely, regardless of the soil and host plant studied. Key words: Rhizobium, competition, plasmids, legumes, nodulation.

1989 ◽  
Vol 35 (6) ◽  
pp. 661-667 ◽  
Author(s):  
R. M. N. Kucey ◽  
M. F. Hynes

Populations of Rhizobium leguminosarum bv. phaesoli and bv. viceae in southern Alberta soils were measured over a period of 4 years using a most probable number method. Five fields cropped to bean (Phaseolus vulgaris L.), five fields cropped to pea (Pisum sativum L.), and two fields cropped to wheat were used as test sites. Legume crops had received appropriate legume inoculants. Fields were sampled in the fall of the crop year and in the spring of the following 3 years during which fields were cropped to nonlegumes or left fallow. Numbers of R. leguminosarum bv. phaseoli were 100 to 1000 times higher in fields that had been planted to bean than in fields that had been planted to pea or wheat. Fields that had been planted to pea maintained populations of R. leguminosarum bv. viceae 10 to 100 times higher than fields that had been planted to bean or wheat. Wheat fields, which had never had legumes grown in them, contained between 1 and 100 rhizobia per gram of soil of both biovars of R. leguminosarum, indicating that both biovars are native to southern Alberta soils. The numbers of rhizobia did not decrease in proportion to the population of other bacteria in the soil over the duration of the experiment. Plasmid profiles of soil Rhizobium isolates obtained in the last year of the experiment showed that none of the isolates had plasmid profiles similar to those of strains added as inoculants in the 1st year of the experiment. These results show that fields cropped to legumes and receiving rhizobial inoculants in this study maintained high populations of rhizobia for several years after harvest of the legume crop.Key words: Rhizobium leguminosarum bv. phaseoli, Rhizobium leguminosarum bv. viceae, nodule, plasmid profiles, inoculum potential, rhizobium competition.


Author(s):  
P. Bagavandoss ◽  
JoAnne S. Richards ◽  
A. Rees Midgley

During follicular development in the mammalian ovary, several functional changes occur in the granulosa cells in response to steroid hormones and gonadotropins (1,2). In particular, marked changes in the content of membrane-associated receptors for the gonadotropins have been observed (1).We report here scanning electron microscope observations of morphological changes that occur on the granulosa cell surface in response to the administration of estradiol, human follicle stimulating hormone (hFSH), and human chorionic gonadotropin (hCG).Immature female rats that were hypophysectcmized on day 24 of age were treated in the following manner. Group 1: control groups were injected once a day with 0.1 ml phosphate buffered saline (PBS) for 3 days; group 2: estradiol (1.5 mg/0.2 ml propylene glycol) once a day for 3 days; group 3: estradiol for 3 days followed by 2 days of hFSH (1 μg/0.1 ml) twice daily, group 4: same as in group 3; group 5: same as in group 3 with a final injection of hCG (5 IU/0.1 ml) on the fifth day.


Author(s):  
D. J. McComb ◽  
N. Ryan ◽  
E. Horvath ◽  
K. Kovacs ◽  
E. Nagy ◽  
...  

Conventional light and electron microscopic techniques failed to clarify the cellular composition and derivation of spontaneous and induced, intrasellar and transplanted pituitary adenomas in rats (1). In the present work, electron microscopic immunocytochemistry was applied to evaluate five adenohypo-physial tumors using a technique described by Moriarty and Garner (2). Spontaneously occurring pituitary adenomas (group 1) were harvested from aging female Long-Evans rats. R-Amsterdam rats were treated with 2 x 1.0 mg estrone acetate (HogivaI) s.c. weekly for 6 months. Pituitary adenomas in excess of 30 mg were removed from these animals to make up the tumors of group 2. Groups 3 and 4 consisted of estrogen-induced autonomous transplan¬ted pituitary tumors MtT.WlO and MtT.F4. Group 5 was a radiation-induced transplanted autonomous pituitary tumor MtT.W5. The tumors of groups 3,4 and 5 were allowed to proliferate in host rats 6-8 weeks prior to removal for processing. Tissue was processed for transmission electron microscopy (glutaraldehyde fixation, OsO4 postfixation and epoxy resin embedding), and electron microscopic immunocytochemistry (3% paraformaldehyde fixation and Araldite embedding).


Author(s):  
Mustafa Salah Hasan ◽  
Ayman Barzan Abdulgafor ◽  
Maher Saber Owain ◽  
Mohammed Ali Hussein ◽  
Qusay Mohammed Aboud ◽  
...  

This study aimed to evaluate the liver, kidney damage caused by S. typhimurium and to estimate the oxidative damage in association with this bacteria. A highly virulent isolates of S. typhimurium were obtained from the department of internal and preventive medicine/ College of Veterinary Medicine/ University of Baghdad. A twenty five local rabbits of both genders with age range (2-4 months) weeks old were used for this study, the rabbits were divided randomly into five groups each group contains 5 rabbits :- group 1: drenched orally with 5 ml of normal saline and consider as control group, group 2: were drenched orally with (5 ml) suspension which contain (5��109 CFU) of Salmonella typhimurium and regarded as infected group, group 3 were drenched orally with (5 ml) suspension which have (5��109 CFU) of Salmonella typhimurium then treated with a single dose of gentamicin alone at 0.05ml/kg (5mg/ml) orally after presence of signs (after 24hrs. post inoculation), group 4 were drenched (5 ml) suspension having (5��109 CFU) of Salmonella typhimurium then treated with a single dose of Ca-EDTA alone at 40mg/kg orally after presence of signs (after 24hrs. post inoculation) and group 5 were drenched (5 ml) suspension that contain (5��109 CFU) of Salmonella typhimurium then treated with a single dose of combined gentamicin at 0.05ml/kg (5mg/ml) orally after presence of signs (after 24hrs. post inoculation) and Ca-EDTA 40mg/kg after presence of signs (after 24hrs. post inoculation).The results of biochemical profile showed a significant increase (p less than 0.05) in ALT, creatinine and urea levels in infected group as compared with control group, while, the treated groups especially group 5 showed a significant improvement in ALT, Urea and creatinine levels which returned to relative normal levels as compared with infected group after 96hrs. post treatment. Also, the results of oxidative stress showed a significant increase in the levels of MDA in G2, G3, G4 and G5 after 48 hrs. post treatment, while the level of GSH showed a significant decrease in the level at 48hrs., both were returned to relative normal levels after 96hrs.post treatment especially in group 5.In conclusion, S. typhimurium can causing liver and kidney damage which is manifested by increase ALT, Urea and Creatinine. Also, MDA and GSH is increased due to salmonellosis.


2019 ◽  
Vol 17 (4) ◽  
pp. 354-364
Author(s):  
Hassan Al-Thani ◽  
Moamena El-Matbouly ◽  
Maryam Al-Sulaiti ◽  
Noora Al-Thani ◽  
Mohammad Asim ◽  
...  

Background: We hypothesized that perioperative HbA1c influenced the pattern and outcomes of Lower Extremity Amputation (LEA). Methods: A retrospective analysis was conducted for all patients who underwent LEA between 2000 and 2013. Patients were categorized into 5 groups according to their perioperative HbA1c values [Group 1 (<6.5%), Group 2 (6.5-7.4%), Group 3 (7.5-8.4%), Group 4 (8.5-9.4%) and Group 5 (≥9.5%)]. We identified 848 patients with LEA; perioperative HbA1c levels were available in 547 cases (Group 1: 18.8%, Group 2: 17.7%, Group 3: 15.0%, Group 4: 13.5% and Group 5: 34.9%). Major amputation was performed in 35%, 32%, 22%, 10.8% and 13.6%, respectively. Results: The overall mortality was 36.5%; of that one quarter occurred during the index hospitalization. Mortality was higher in Group 1 (57.4%) compared with Groups 2-5 (46.9%, 38.3%, 36.1% and 31.2%, respectively, p=0.001). Cox regression analysis showed that poor glycemic control (Group 4 and 5) had lower risk of mortality post-LEA [hazard ratio 0.57 (95% CI 0.35-0.93) and hazard ratio 0.46 (95% CI 0.31-0.69)]; this mortality risk persisted even after adjustment for age and sex but was statistically insignificant. The rate of LEA was greater among poor glycemic control patients; however, the mortality was higher among patients with tight control. Conclusion: The effects of HbA1c on the immediate and long-term LEA outcomes and its therapeutic implications need further investigation.


1994 ◽  
Vol 45 (3) ◽  
pp. 613 ◽  
Author(s):  
JM Carter ◽  
WK Gardner ◽  
AH Gibson

The response of faba beans (Vicia faba L. cv. Fiord) to seed inoculation with eight strains of Rhizobium leguminosarum biovar. viciae was examined in field experiments at six sites on acid soils in south-west Victoria. At two of the sites, two additional strains were examined, and in 1988, 14 strains were examined at one site. Very low natural populations of R. leguminosarum bv. viciae were found at the experimental sites. Most strains resulted in improved early nodulation and increased grain yield at all sites, when compared to inoculation with the commercial strain of rhizobia (SU391). Plant dry matter production and nitrogen accumulation in the plant shoot tissue was also increased at one site during the flowering period by some strains. Large visual differences between plots inoculated with SU391 and other strains were evident at most sites. Most uninoculated treatments were not nodulated and yielded very poorly. Treatments inoculated with the strain SU391 performed similarly to the uninoculated treatments.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Liu ◽  
Jing Li ◽  
Wanyu Zhang ◽  
Yihong Guo

AbstractOestradiol, an important hormone in follicular development and endometrial receptivity, is closely related to clinical outcomes of fresh in vitro fertilization-embryo transfer (IVF-ET) cycles. A supraphysiologic E2 level is inevitable during controlled ovarian hyper-stimulation (COH), and its effect on the outcome of IVF-ET is controversial. The aim of this retrospective study is to evaluate the association between elevated serum oestradiol (E2) levels on the day of human chorionic gonadotrophin (hCG) administration and neonatal birthweight after IVF-ET cycles. The data of 3659 infertile patients with fresh IVF-ET cycles were analysed retrospectively between August 2009 and February 2017 in First Hospital of Zhengzhou University. Patients were categorized by serum E2 levels on the day of hCG administration into six groups: group 1 (serum E2 levels ≤ 1000 pg/mL, n = 230), group 2 (serum E2 levels between 1001 and 2000 pg/mL, n = 524), group 3 (serum E2 levels between 2001 and 3000 pg/mL, n = 783), group 4 (serum E2 levels between 3001 and 4000 pg/mL, n = 721), group 5 (serum E2 levels between 4001 and 5000 pg/mL, n = 548 ), and group 6 (serum E2 levels > 5000 pg/mL, n = 852). Univariate linear regression was used to evaluate the independent correlation between each factor and outcome index. Multiple logistic regression was used to adjust for confounding factors. The LBW rates were as follows: 3.0% (group 1), 2.9% (group 2), 1.9% (group 3), 2.9% (group 4), 2.9% (group 5), and 2.0% (group 6) (P = 0.629), respectively. There were no statistically significant differences in the incidences of neonatal LBW among the six groups. We did not detect an association between peak serum E2 level during ovarian stimulation and neonatal birthweight after IVF-ET. The results of this retrospective cohort study showed that serum E2 peak levels during ovarian stimulation were not associated with birth weight during IVF cycles. In addition, no association was found between higher E2 levels and increased LBW risk. Our observations suggest that the hyper-oestrogenic milieu during COS does not seem to have adverse effects on the birthweight of offspring after IVF. Although this study provides some reference, the obstetric-related factors were not included due to historical reasons. The impact of the high estrogen environment during COS on the birth weight of IVF offspring still needs future research.


2013 ◽  
Vol 8 (1-2) ◽  
pp. 123-130
Author(s):  
MM Islam ◽  
M Asaduzzaman ◽  
ME Hoque ◽  
MB Meah

Forty four isolates of Phomopsis vexans from different eggplant cultivars collected from core eggplant growing regions of Bangladesh which were characterized using mycological characteristics. Variation exists among the isolates of Phomopsis vexans of Bangladesh covering two types of farm having two ecosystems and the isolates were grouped into five distinct groups based on their cultural properties. The highest sized ? conidia were observed in group -1 and the lowest size in-group -2. The highest sized ? conidia were recorded in group -5 and the lowest in-group –2. The highest pycnidial size noted in-group -3 and the smallest sized pycnidia were recorded in group –1. DOI: http://dx.doi.org/10.3329/jsf.v8i1-2.14635 J. Sci. Foundation, 8(1&2): 123-130, June-December 2010


1997 ◽  
Vol 65 (2) ◽  
pp. 267-273 ◽  
Author(s):  
I. A. Forsyth ◽  
F. E. Gebbie ◽  
J. Arendt

AbstractTo avoid winter scarcity of fresh goat milk, simple methods of advancing the season of kidding would be commercially valuable. A combination of long-day light treatment followed by melatonin is successful but other aspects of seasonality including coat growth are also reset. To investigate whether effects on breeding season and coat growth can be dissociated, British Saanen dairy goats (no. = 30) were randomly allocated to one of six groups. Control goats were untreated. Goats in the other five groups received 2 months of treatment with 20 h light: 4 h darkness (20L: 4D) and were then given 3 mg melatonin orally at 16.00 hfor 2 months. The treatments started on 11 January (group 1), 29 March (group 2), 14 June (group 3), 30 August (group 4) and 8 November (group 5). Weekly blood samples were taken for the measurement of progesterone to monitor ovarian activity and prolactin. Side patches (10 cm ×10 cm) were clipped monthly from alternate sides and weighed to measure coat growth. The onset of ovarian activity was advanced from a median date of 15 November in controls to 24 May in group 1 (P < 0·01), 16 August in group 2 (P < 0·05) and 18 October in group 3 (? < 0·05). Groups 4 and 5 showed no significant change in the onset of oestrus (median onset dates 8 November and 1 November, respectively). Group 1 goats came into season again with controls in November. In all except group 5, treatment interacted with time to affect significantly the growth of the coat. The pattern of coat growth was most altered (P < 0·001) in groups 1 and 2. This was associated with effects on plasma prolactin concentrations of light stimulation and melatonin suppression. Group 1 goats resynchronized with control goats to show a coat of normal weight in the winter following treatment. Division of milking goat herds into spring and autumn kidding groups is, therefore, a practical possibility, but effects on overall milk yield require study.


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