Fusarium wilt constrains mungbean yield due to reduction in source availability

Mungbean is an important source of plant protein for consumers and a high-value export crop for growers across Asia, Australia and Africa. However, many commercial cultivars are highly vulnerable to biotic stresses, which rapidly reduce yield within the season. Fusarium oxysporum is a soil-borne pathogen that is a growing concern for mungbean growers globally. This pathogen causes Fusarium wilt by infecting the root system of the plant resulting in devastating yield reductions. To understand the impact of Fusarium on mungbean development and productivity and to identify tolerant genotypes, a panel of 23 diverse accessions was studied. Field trials conducted in 2016 and 2021 in Warwick, Queensland, Australia under rainfed conditions investigated the variation in phenology, canopy and yield component traits under disease and disease-free conditions. Analyses revealed a high degree of genetic variation for all traits. By comparing the performance of these traits across these two environments, we identified key traits that underpin yield under disease and disease-free conditions. Aboveground biomass components at 50 % flowering were identified as significant drivers of yield development under disease-free conditions and when impacted by Fusarium resulted in up to 96 % yield reduction. Additionally, eight genotypes were identified to be tolerant to Fusarium. These genotypes were found to display differing phenological and morphological behaviours, thereby demonstrating the potential to breed tolerant lines with a range of diverse trait variations. The identification of tolerant genotypes that sustain yield under disease pressure may be exploited in crop improvement programs.

One Crop Disease, How Many Pathogens? Podosphaera xanthii and Erysiphe vignae sp. nov. Identified as the Two Species that Cause Powdery Mildew of Mungbean (Vigna radiata) and Black Gram (V. mungo) in Australia

Powdery mildew is a significant threat to mungbean (Vigna radiata) and black gram (V. mungo) production across Australia and overseas. Although they have been present in Australia for at least six decades and are easily recognized in the field, the precise identification of the pathogens causing this disease has remained unclear. Our goal was to identify the powdery mildew species infecting mungbean, black gram, and wild mungbean (V. radiata ssp. sublobata) in Australia. The internal transcribed spacer (ITS) and large subunit sequences of the ribosomal DNA and/or morphology of 57 Australian specimens were examined. Mungbean and black gram were infected by two species: Podosphaera xanthii and a newly recognized taxon, Erysiphe vignae sp. nov. Wild mungbean was infected only with P. xanthii. Mungbean and black gram powdery mildew ITS sequences from China, India, and Taiwan revealed the presence of only P. xanthii on these crops despite controversial reports of an Erysiphe species on both crops in India. Sequence analyses indicated that the closest relative of E. vignae is E. diffusa, which infects soybean (Glycine max) and other plants. E. vignae did not infect soybean in cross-inoculation tests. In turn, E. diffusa from soybean infected black gram and provoked hypersensitive response in mungbean. The recognition of a second species, E. vignae, as another causal agent of mungbean and black gram powdery mildew in Australia may complicate plant breeding efforts and control of the disease with fungicide applications.

Biotic and Abiotic Constraints in Mungbean Production-Progress in Genetic Improvement

Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] is an important food and cash legume crop in Asia. Development of short duration varieties has paved the way for the expansion of mungbean into other regions such as Sub-Saharan Africa and South America. Mungbean productivity is constrained by biotic and abiotic factors. Bruchids, whitefly, thrips, stem fly, aphids, and pod borers are the major insect-pests. The major diseases of mungbean are yellow mosaic, anthracnose, powdery mildew, Cercospora leaf spot, halo blight, bacterial leaf spot, and tan spot. Key abiotic stresses affecting mungbean production are drought, waterlogging, salinity, and heat stress. Mungbean breeding has been critical in developing varieties with resistance to biotic and abiotic factors, but there are many constraints still to address that include the precise and accurate identification of resistance source(s) for some of the traits and the traits conferred by multi genes. Latest technologies in phenotyping, genomics, proteomics, and metabolomics could be of great help to understand insect/pathogen-plant, plant-environment interactions and the key components responsible for resistance to biotic and abiotic stresses. This review discusses current biotic and abiotic constraints in mungbean production and the challenges in genetic improvement.

Characterization of Linkage Disequilibrium and Population Structure in a Mungbean Diversity Panel

Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] is an important grain legume globally, providing a high-quality plant protein source largely produced and consumed in South and East Asia. This study aimed to characterize a mungbean diversity panel consisting of 466 cultivated accessions and demonstrate its utility by conducting a pilot genome-wide association study of seed coat color. In addition 16 wild accessions were genotyped for comparison and in total over 22,000 polymorphic genome-wide SNPs were identified and used to analyze the genetic diversity, population structure, linkage disequilibrium (LD) of mungbean. Polymorphism was lower in the cultivated accessions in comparison to the wild accessions, with average polymorphism information content values 0.174, versus 0.305 in wild mungbean. LD decayed in ∼100 kb in cultivated lines, a distance higher than the linkage decay of ∼60 kb estimated in wild mungbean. Four distinct subgroups were identified within the cultivated lines, which broadly corresponded to geographic origin and seed characteristics. In a pilot genome-wide association mapping study of seed coat color, five genomic regions associated were identified, two of which were close to seed coat color genes in other species. This mungbean diversity panel constitutes a valuable resource for genetic dissection of important agronomical traits to accelerate mungbean breeding.

Palliative care for patients with advance chronic kidney disease

Over the past three decades there has been a dramatic rise in the number of patients with advanced chronic kidney disease. The fastest expanding group receiving dialysis has been the elderly. However, for those patients who are very elderly with co-morbidity, dialysis may not offer a survival advantage. Therefore, active conservative management is a growing service offered by many renal units in the UK and focuses on non-dialytic correction of fluid and electrolyes, management of renal anaemia, and assessment and management of symptoms. The five-year survival of a patient over 75 years of age starting dialysis is 20% and if a patient is over 75 years, has co-morbidity, or a poor performance status, dialysis may not offer any survival advantage. Whether a patient is managed by dialysis or by conservative management the symptom burden suffered is high. These symptoms are under-recognised and often managed poorly because of increased drug toxicity in renal failure. This complex group of patients require close working between renal, palliative care, medicine for the elderly, and community teams, to allow best quality of life and end of life care. This review describes some of the challenges in providing Advanced Care Planning for dialysis and conservatively managed patients, highlights the symptom burden of patients with advanced chronic kidney disease, and offers guidance in how to manage the symptoms effectively.

Factors influencing occupant-to-seat belt interaction in far-side crashes

Seat belt interaction with a far-side occupant's shoulder and thorax is critical to governing excursion towards the struck-side of the vehicle in side impact. In this study, occupant-to-belt interaction was simulated using a modified MADYMO human model and finite element belts. Quasi-static tests with volunteers and dynamic sled tests with PMHS and WorldSID were used for model validation and comparison. Parameter studies were then undertaken to quantify the effect of impact direction, seat belt geometry and pretension on occupant-to-seat belt interaction. Results suggest that lowering the D-ring and increasing pretension reduces the likelihood of the belt slipping off the shoulder. Anthropometry was also shown to influence restraint provided by the shoulder belt. Furthermore, the belt may slip off the occupant's shoulder at impact angles greater than 40 degrees from frontal when no pretension is used. However, the addition of pretension allowed the shoulder to engage the belt in all impacts from 30 to 90 degrees.

Immunogenicity of highly purified bovine insulin: a comparison with conventional bovine and highly purified human insulins

Twenty-six Type 1 diabetic patients previously treated for 10-20 months with twice daily conventional bovine isophane insulin (containing at least 1000 ppm proinsulin) were changed to highly purified (less than 1 ppm proinsulin) bovine isophane for 6 months (Switch group). Insulin antibody levels fell significantly from a geometric mean of 14.9 to 9.1 micrograms/l. Thirty-two patients with newly diagnosed Type 1 diabetes were treated with the same highly purified bovine isophane insulin twice daily for 6 months (Starter group). Their insulin antibody levels rose from a geometric mean of 1.9 to 8.2 micrograms/l in contrast to values of 1.4 rising to 16.3 micrograms/l in an age and sex matched historical control group treated from diagnosis only with twice daily conventional bovine isophane insulin. Lipoatrophy at injection sites developed in three (9%) in the Starter group treated with highly purified bovine isophane compared to 7 (22%) of those on conventional bovine isophane. Insulin dose and diabetic control did not differ between the groups. Starter and Switch groups were subsequently treated with semi-synthetic human isophane insulin for 6 months during which insulin antibody levels fell significantly from a geometric mean of 8.5 to 4.4 micrograms/l (p less than 0.001). We conclude that bovine insulin purified to less than 1 ppm proinsulin is significantly less immunogenic than its conventional proinsulin contaminated counterpart but even at this level of purity is still more immunogenic than human insulin of equivalent purity.

Factors governing the human immune response to injected insulin

Seventy-nine patients were observed prospectively during their initial period of treatment with conventional bovine insulins. Insulin antibody levels 6 months after starting insulin therapy did not correlate with age, gender or beta cell function at onset of treatment. Patients who required soluble insulin in addition to isophane insulin developed higher levels of insulin antibody. Patients bearing the HLA-B8, DR3 and C4AQO alleles had lower levels of insulin antibody, whereas those bearing DR7 produced significantly higher levels. Other alleles at the C4A, C4B, C2, factor B or Gm loci did not appear to have a significant effect on insulin antibody production. The hyporesponsiveness of B8/DR3/ C4AQO -positive individuals probably reflects a non-specific abnormality of immunity whereas the enhanced responsiveness of those positive for DR7 suggests the presence of a specific immune response gene for insulin.

Effects of new insulins on insulin and C-peptide antibodies, insulin dose, and diabetic control

24 diabetic patients stabilised on conventional bovine insulins and possessing insulin antibodies underwent a study of the immunological and clinical consequences of changes in both purity and species of their insulin preparations. After a 2-month run-in period patients were treated for 3 consecutive 4-month periods with (a) purified bovine insulin (20-40 ppm proinsulin), (b) highly purified porcine insulin, and (c) semisynthetic human insulin, without elective dose changes. Mean insulin antibody levels changed little on purified bovine insulin (22.2 leads to 23.4 micrograms/l) but fell on highly purified porcine (23.4 leads to 12.9 micrograms/l) and remained much the same on Semi-Synthetic human insulin. In contrast, C-peptide antibodies fell significantly and continuously throughout the study. The slower rate of fall in C-peptide antibody levels is likely to be due to the prolonged half-life of circulating exogenous proinsulin in the presence of insulin antibody. Although insulin dose remained constant the incidence of hypoglycaemic episodes did not increase and glycosylated haemoglobin levels rose significantly when patients were on porcine insulin. The deterioration in diabetic control may have been due to greater temporal mismatch between insulin needs and insulin availability with pork or human insulin than with beef insulins, and to reduced insulin antibody levels. The use of purer insulins which more closely resemble the human form can cause a significant reduction in levels of insulin and C-peptide antibodies. Although these changes may have other benefits they do not necessarily produce better diabetic control. Subcutaneous insulin regimens need to be tailored to the individual patient and, indirectly, to his antibody status.

C-peptide antibodies induced by bovine insulin therapy

Antibodies reactive with the C-peptide portion of proinsulin can be detected in the sera of patients on conventional bovine insulin regimes which include the soluble form. Direct and competitive binding studies demonstrate that C-peptide antibodies show species specificity but do not recognize free homologous C-peptide. This is likely to be due to conformational change following cleavage of C-peptide from the proinsulin molecule. Examination of sera from a large group of patients established on a standard insulin regime shows that C-peptide and insulin antibody levels do not correlate with each other and are likely to show different patterns of genetic control.