Production of viable male unreduced gametes in Brassica interspecific hybrids is genotype specific and stimulated by cold temperatures

<p>Abstract</p> <p>Background</p> <p>Unreduced gametes (gametes with the somatic chromosome number) may provide a pathway for evolutionary speciation via allopolyploid formation. We evaluated the effect of genotype and temperature on male unreduced gamete formation in <it>Brassica </it>allotetraploids and their interspecific hybrids. The frequency of unreduced gametes post-meiosis was estimated in sporads from the frequency of dyads or giant tetrads, and in pollen from the frequency of viable giant pollen compared with viable normal pollen. Giant tetrads were twice the volume of normal tetrads, and presumably resulted from pre-meiotic doubling of chromosome number. Giant pollen was defined as pollen with more than 1.5 <it>× </it>normal diameter, under the assumption that the doubling of DNA content in unreduced gametes would approximately double the pollen cell volume. The effect of genotype was assessed in five <it>B. napus</it>, two <it>B. carinata </it>and one <it>B. juncea </it>parents and in 13 interspecific hybrid combinations. The effect of temperature was assessed in a subset of genotypes in hot (day/night 30°C/20°C), warm (25°C/15°C), cool (18°C/13°C) and cold (10°C/5°C) treatments.</p> <p>Results</p> <p>Based on estimates at the sporad stage, some interspecific hybrid genotypes produced unreduced gametes (range 0.06 to 3.29%) at more than an order of magnitude higher frequency than in the parents (range 0.00% to 0.11%). In nine hybrids that produced viable mature pollen, the frequency of viable giant pollen (range 0.2% to 33.5%) was much greater than in the parents (range 0.0% to 0.4%). Giant pollen, most likely formed from unreduced gametes, was more viable than normal pollen in hybrids. Two <it>B. napus </it>× <it>B. carinata </it>hybrids produced 9% and 23% unreduced gametes based on post-meiotic sporad observations in the cold temperature treatment, which was more than two orders of magnitude higher than in the parents.</p> <p>Conclusions</p> <p>These results demonstrate that sources of unreduced gametes, required for the triploid bridge hypothesis of allopolyploid evolution, are readily available in some <it>Brassica </it>interspecific hybrid genotypes, especially at cold temperatures.</p

On Molecular Hydrogen Formation and the Magnetohydrostatic Equilibrium of Sunspots

We have investigated the problem of sunspot magnetohydrostatic equilibrium with comprehensive IR sunspot magnetic field survey observations of the highly sensitive Fe I lines at 15650 \AA\ and nearby OH lines. We have found that some sunspots show isothermal increases in umbral magnetic field strength which cannot be explained by the simplified sunspot model with a single-component ideal gas atmosphere assumed in previous investigations. Large sunspots universally display non-linear increases in magnetic pressure over temperature, while small sunspots and pores display linear behavior. The formation of molecules provides a mechanism for isothermal concentration of the umbral magnetic field, and we propose that this may explain the observed rapid increase in umbral magnetic field strength relative to temperature. Existing multi-component sunspot atmospheric models predict that a significant amount of molecular hydrogen (H2) exists in the sunspot umbra. The formation of H2 can significantly alter the thermodynamic properties of the sunspot atmosphere and may play a significant role in sunspot evolution. In addition to the survey observations, we have performed detailed chemical equilibrium calculations with full consideration of radiative transfer effects to establish OH as a proxy for H2, and demonstrate that a significant population of H2 exists in the coolest regions of large sunspots.Comment: 17 pages, 19 figures, accepted for publication in Ap

Presented at the third International Tropical Agriculture Conference (TROPAG 2019), Brisbane, Australia, 11–13 November 2019

Common bean (Phaseolus vulgaris L.) is a major component of agricultural systems and diets of the urban and rural populations of East and Central Africa, providing Fe and Zn essential to the health and well-being of African women and children, and protein essential for the entire household. However, bean consumption is limited by constraints such as long cooking time (CT). Cooking demands large amounts of water, fuel and time. It has negative effects on the environment, livelihoods, security and health. Genetic variability in cooking time is documented. Recent development of new breeding methods based on pedigree and genomic selection together with optimal contribution selection (OCS) offers an opportunity to accelerate breeding for rapid CT and higher Fe and Zn grain content. Genotypic and phenotypic data of an African diversity pool, representing key bean market classes, were used to generate genomic estimated breeding values (GEBVs) for grain yield, CT, Fe and Zn. GEBV’s were weighted to maximise the desired outcome in an economic index. From 161 candidate bean genotypes with GEBVs, 67 were chosen for 80 matings within six major grain market classes. An additional 22 breeder nominated matings were included. The predicted outcomes in the first cycle showed a major improvement in population mean for index (+286.77 US$/ha), 6.2% increase in GY and 7.3% reduction in CT, with an achieved increase in population co-ancestry of 0.0753. A 30% reduction in the mean population CT and improved Fe (15%) and Zn (10%), is expected after 5 cycles of annual recurrent selection

Diversity Breeding Program on Common Bean (Phaseolus vulgaris L.) Targeting Rapid Cooking and Iron and Zinc Biofortification

Common bean (Phaseolus vulgaris L.) is a major component of agricultural systems and diets of the urban and rural populations of East and Central Africa, providing Fe and Zn essential to the health and well-being of African women and children, and protein essential for the entire household. However, bean consumption is limited by constraints such as long cooking time (CT). Cooking demands large amounts of water, fuel and time. It has negative effects on the environment, livelihoods, security and health. Genetic variability in cooking time is documented. Recent development of new breeding methods based on pedigree and genomic selection together with optimal contribution selection (OCS) offers an opportunity to accelerate breeding for rapid CT and higher Fe and Zn grain content. Genotypic and phenotypic data of an African diversity pool, representing key bean market classes, were used to generate genomic estimated breeding values (GEBVs) for grain yield, CT, Fe and Zn. GEBV's were weighted to maximise the desired outcome in an economic index. From 161 candidate bean genotypes with GEBVs, 67 were chosen for 80 matings within six major grain market classes. An additional 22 breeder nominated matings were included. The predicted outcomes in the first cycle showed a major improvement in population mean for index (+286.77 US$/ha), 6.2% increase in GY and 7.3% reduction in CT, with an achieved increase in population co-ancestry of 0.0753. A 30% reduction in the mean population CT and improved Fe (15%) and Zn (10%), is expected after 5 cycles of annual recurrent selection

Short- and long-term mortality after liver transplantation in patients with and without hepatocellular carcinoma in the UK.

BACKGROUND: The increasing demand for liver transplantation has led to considerable changes in characteristics of donors and recipients. This study evaluated the short- and long-term mortality of recipients with and without hepatocellular carcinoma (HCC) in the UK between 1997 and 2016. METHODS: First-time elective adult liver transplant recipients in the UK were identified and four successive eras of transplantation were compared. Hazard ratios (HRs) comparing the impact of era on short-term (first 90 days) and longer-term (from 90 days to 5 years) mortality were estimated, with adjustment for recipient and donor characteristics. RESULTS: Some 1879 recipients with and 7661 without HCC were included. There was an increase in use of organs donated after circulatory death (DCD), from 0 per cent in era 1 to 35·2 per cent in era 4 for recipients with HCC, and from 0·2 to 24·1 per cent for non-HCC recipients. The 3-year mortality rate decreased from 28·3 per cent in era 1 to 16·9 per cent in era 4 (adjusted HR 0·47, 95 per cent c.i. 0·35 to 0·63) for recipients with HCC, and from 20·4 to 9·3 per cent (adjusted HR 0·44, 0·36 to 0·53) for those without HCC. Comparing era 4 with era 1, improvements were more marked in short-term than in long-term mortality, both for recipients with HCC (0-90 days: adjusted HR 0·20, 0·10 to 0·39; 90 days to 5 years: adjusted HR 0·52, 0·35 to 0·75; P = 0·043) and for non-HCC recipients (0-90 days: adjusted HR 0·32, 0·24 to 0·42; 90 days to 5 years: adjusted HR 0·52, 0·40 to 0·67; P = 0·024). CONCLUSION: In the past 20 years, the mortality rate after liver transplantation has more than halved, despite increasing use of DCD donors. Improvements in overall survival can be explained by decreases in short-term and longer-term mortality

Liver transplantation outcomes after transarterial chemotherapy for hepatocellular carcinoma.

BACKGROUND: Transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC) awaiting liver transplantation is widespread, although evidence that it improves outcomes is lacking and there exist concerns about morbidity. The impact of TACE on outcomes after transplantation was evaluated in this study. METHODS: Patients with HCC who had liver transplantation in the UK were identified, and stratified according to whether they received TACE between 2006 and 2016. Cox regression methods were used to estimate hazard ratios (HRs) for death and graft failure after transplantation adjusted for donor and recipient characteristics. RESULTS: In total, 385 of 968 patients (39·8 per cent) received TACE. Five-year patient survival after transplantation was similar in those who had or had not received TACE: 75·2 (95 per cent c.i. 68·8 to 80·5) and 75·0 (70·5 to 78·8) per cent respectively. After adjustment for donor and recipient characteristics, there were no differences in mortality (HR 0·96, 95 per cent c.i. 0·67 to 1·38; P = 0·821) or graft failure (HR 1·01, 0·73 to 1·40; P = 0·964). The number of TACE treatments (2 or more versus 1: HR 0·97, 0·61 to 1·55; P = 0·903) or the time of death after transplantation (within or after 90 days; P = 0·291) did not alter the outcome. The incidence of hepatic artery thrombosis was low in those who had or had not received TACE (1·3 and 2·4 per cent respectively; P = 0·235). CONCLUSION: TACE delivered to patients with HCC before liver transplant did not affect complications, patient death or graft failure after transplantation

Crop Updates 2006 - Oilseeds

This session covers thirteen papers from different authors: 1. INTRODUCTION, Graham Walton, CONVENOR, Department of Agriculture 2. The performance of new TT canola varieties in National Variety Testing (NVT) WA, Fiona Martin, Research Agronomist, Agritech Crop Research 3. Comparison of TT Canola Varieties in Oilseeds WA Trials – 2005, Collated by G.H. Walton, Department of Agriculture, WA, from a collaboration between Oilseeds WA, Seed Companies, Agronomists and Growers 4. An overview of the potential for a Biofuels Industry in Western Australia, Anne Wilkins and Nathan Hancock, Department of Agriculture 5. Retrieval of fertile progeny from interspecific crosses between Brassica napus and B. carinata using microspore culture, Matthew Nelson, Marie-Claire Castello, Linda Thomson, Anouska Cousin, Guijun Yan and Wallace Cowling; School of Plant Biology (M084), The University of Western Australia 6. Advances in canola blackleg epidemiology and its implication in understanding and managing the disease, Moin Salam, Bill MacLeod, Ravjit Khangura, Jean Galloway and Art Diggle, Department of Agriculture 7. Effect of fertiliser phosphorus and nitrogen on grain yields and concentration of oil and protein of canola grain, R.F. Brennan, M.D.A. Bolland, Department of Agriculture 8. Effect of applying fertiliser potassium and nitrogen on canola grain yields and concentration of oil and protein in grain, R.F. Brennan, M.D.A. Bolland, Department of Agriculture 9. Effect of fertiliser nitrogen and sulfer on canola yields and concentration of oil in grain, R.F. Brennan, M.D.A. Bolland, Department of Agriculture 10. Uptake of K from topsoil and subsoil by canola, P.M. Damon and Z. Rengel, Faculty of Natural and Agricultural Sciences, The University of WA 11. Accumulation of P and K by canola plants, Terry Rose, Zed Rengel and Qifu Ma, Faculty of Natural and Agricultural Sciences, The University of WA 12. Varied response from applying nitrogen at late flowering in canola! Dave Eksteen, Agronomist, United Farmers Cooperative 13. To investigate the timing, rate and placement of nitrogen on canola – Jerdacuttup 2005, Dave Eksteen, Agronomist, United Farmers Cooperativ

Assessing the Time-Dependent Impact of Performance Status on Outcomes After Liver Transplantation.

BACKGROUND AND AIMS: Identifying how the prognostic impact of performance status (PS) differs according to indication, era, and time period ("epoch") after liver transplantation (LT) could have implications for selection and treatment of patients on the waitlist. We used national data from the United Kingdom and Ireland to assess impact of PS on mortality separately for HCC and non-HCC recipients. APPROACH AND RESULTS: We assessed pre-LT PS using the 5-point modified Eastern Cooperative Oncology Group scale and used Cox regression methods to estimate hazard ratios (HRs) that compared posttransplantation mortality in different epochs of follow-up (0-90 days and 90 days to 1 year) and in different eras of transplantation (1995-2005 and 2006-2016). 2107 HCC and 10,693 non-HCC patients were included. One-year survival decreased with worsening PS in non-HCC recipients where 1-year survival was 91.9% (95% confidence interval [CI], 88.3-94.4) in those able to carry out normal activity (PS1) compared to 78.7% (95% CI, 76.7-80.5) in those completely reliant on care (PS5). For HCC patients, these estimates were 89.9% (95% CI, 85.4-93.2) and 83.1% (95% CI, 61.0-93.3), respectively. Reduction in survival in non-HCC patients with poorer PS was in the first 90 days after transplant, with no major effect observed between 90 days and 1 year. Adjustment for donor and recipient characteristics did not change the findings. Comparing era, post-LT mortality improved for HCC (adjusted HR, 0.55; 95% CI, 0.40-0.74) and non-HCC recipients (0.48; 95% CI, 0.42-0.55), but this did not differ according to PS score (P = 0.39 and 0.61, respectively). CONCLUSIONS: Impact on mortality of the recipient's pretransplant PS is principally limited to the first 3 months after LT. Over time, mortality has improved for both HCC and non-HCC recipients and across the full range of PS