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Effect of salinity on morpho-physiological traits at reproductive stages of Oryza sativa
Get PDFSoil salinity is one of the most adverse environmental problems which restricts crop yield. Salinity affects rice plants very badly from germination to its maturity. Therefore, a pot experiment was conducted to study the salinity tolerance of rice genotypes viz. SAL655, STL15, PBRC37, Binadhan-8 and BRRI dhan28. The plants were grown under four salinity levels (0, 6, 9 and 12 dSm−1). Plant height, total number of green leaves hill−1, root dry weight, stem dry weight, total dry weight per hill, root shoot ratio was found to be decreased gradually with gradual increase in salinity levels as compared to the control. The genotype Binadhan-8 and PBRC37 showed the better performance in respect of all the parameters than other genotypes. Therefore, Binadhan-8 and PBRC37 were found more tolerant than other genotypes to salt stress
Efficient Breeding of Crop Plants
No full textIn crop breeding programs, the rate of genetic gain which is achieved using the traditional breeding is insufficient to meet the increased demand of food for the rapidly expanding global population. The main constraint with the conventional breeding is the time which is required in developing crosses, followed by selection and testing of the experimental cultivars. Although, using this technique, lot of progress has been made in increasing the productivity, the time has come to think beyond this and integrate the recent advances in the area of genomics, phenomics and computational biology into the conventional breeding program for increasing its efficiency. While doing this emphasis on proper characterization and use of plant genetic resources, defining the breeding objectives and use of recent advances in holistic way are also essential. Therefore, in this chapter, we first highlight the importance of plant breeding followed by significance of the plant genetic resources in the breeding program, need of ideotype breeding and the breeding objectives for important traits including resistance against various biotic and abiotic stresses. We then discuss the limitations of conventional breeding and advantages of genomics-assisted breeding. While doing this, we also discuss various molecular breeding tools and genomic resources as well as different approaches for efficient breeding including marker-assisted selection, marker-assisted recurrent selection and genomic selection. This is followed by importance of other non-conventional approaches including the recent one on gene editing, speed breeding and role of integrated data management and bioinformatics in the breeding programs. We also discuss the significance of phenomics and phenotyping platforms in the crop breeding as well as role of computational techniques like artificial intelligence and machine learning in analysing the huge data which is being generated in the breeding programs. Finally, we conclude with a brief note on the emerging challenges in breeding which need to be addressed and the thrust areas of research for the future
A comparison of immobilisation quality and cardiorespiratory effects of etorphine-azaperone versus etorphine-midazolam combinations in blesbok
No full textThe study compared immobilisation of blesbok (Damaliscus pygargus phillipsi) with etorphine and azaperone vs etorphine and midazolam. Twelve female blesbok, weighing 59.4 ± 2.8 kg, were used. Each animal randomly received Treatment 1 (T1) (etorphine, 0.07 ± 0.003 mg/kg + azaperone, 0.36 ± 0.02 mg/kg) and Treatment 2 (T2) (etorphine, 0.07 ± 0.003 mg/kg + midazolam, 0.20 ± 0.01 mg/kg) with a one-week washout period between treatments. Induction times were recorded followed by physiological monitoring for 45 minutes of immobilisation. Immobilisation was reversed with naltrexone (20 mg per mg etorphine). Recovery times were also recorded. Induction, immobilisation and recovery were scored with subjective measures. Inductions and recoveries did not differ between combinations, but the quality of immobilisation was significantly better with T1. Rectal temperature and blood pressure were significantly lower during T1. Both treatments resulted in severe hypoxaemia and impaired gas exchange, although overall hypoxaemia was more pronounced for T1. Animals treated with T2, however, exhibited a deterioration in respiration as the monitoring period progressed, possibly as a result of impaired ventilatory muscle function due to the effects of midazolam. Both combinations are suitable for adequate immobilisation of blesbok and should be selected based on the specific capture situation. Supplementation with oxygen is highly recommended
Fire regime and climate determine spatial variation in level of serotiny and population structure in a fire-killed conifer
Get PDFFire-killed serotinous trees are often dominant species in fire-prone regions with contrasting wet and dry seasons. We studied a serotinous fire-killed conifer (Callitris preissii, Cupressaceae) to identify the influence of fire regime and climate on geographic variation in level of serotiny, recruitment and population structure. We measured population size distributions, seedling recruitment and level of serotiny for sample stands across a climatic gradient from mesic coastal (including two islands) to semi-arid inland sites in SW Australia. Trees on islands were mostly non-serotinous and were only weakly serotinous on the adjacent mainland in the higher rainfall West coast region. In the semi-arid Goldfields and South inland, and the higher rainfall South coast region, trees were more strongly serotinous with up to six cohorts of closed cones retained on trees. Level of serotiny was stronger at the drier end of the climatic gradient where severe to extreme fire danger weather occurs most frequently, and where vegetation type (e.g., shrublands) supports frequent crown-type, stand-replacing fires. Recruitment was most abundant post-fire in all regions, but seedlings also established inter-fire where there was regular seed fall due to low level of serotiny or spontaneous release of seeds from old cones on trees with a high cone load. Population structures for mainland stands shifted from approximately reverse-J (indicating continuous recruitment) in mesic regions to mainly unimodal (establishment mostly after fire) in drier, inland regions, although some long-unburned inland stands showed occasional inter-fire recruitment, likely linked to high rainfall years. Unimodal population structures characterized islands, where previous studies have identified herbivory on seedlings by refugial populations of native macropods as a limiting factor on inter-fire establishment. Understanding landscape context, response to disturbance, biotic interactions and reproductive traits of dominant species is essential in conservation planning in a rapidly changing global environment
Prevalence of antinuclear antibodies and rheumatoid factor titers in dogs with arthritis secondary to leishmaniosis (Leishmania infantum)
No full textDogs with infectious arthritis may occasionally exhibit positive serum antinuclear antibody (ANA) and rheumatoid factor (RF) titers; however, relevant data are sparse for arthritis secondary to canine leishmaniosis (CanL) caused by Leishmania infantum. We determined the prevalence of positive serum ANA and RF titers in dogs with arthritis secondary to CanL. Blood samples from adult, client-owned dogs with purulent arthritis secondary to CanL, without any comorbidities, were collected for diagnostic purposes. Serum ANA titers were measured by immunoperoxidase test and RF titers by the Rose–Waaler latex test. Twelve of 23 dogs enrolled prospectively in our study had clinical arthritis, and 11 of 23 had subclinical arthritis. Based on LeishVet clinical staging, 7 dogs had clinical stage II disease, 11 had clinical stage III disease, and 5 had stage IV. None of the 23 dogs was seropositive for ANA; 3 of 23 were positive for RF. ANA and/or RF seropositivity, in dogs with CanL-associated arthritis, appears to be weak, if present at all. Based on our results, positive serum ANA and RF titers should not be expected in dogs with arthritis secondary to CanL
World Union of Wound Healing Societies position statement on the ethical considerations for wound care research in humans and animals
No full textThe Interaction between HLA‐DRB1 and Smoking in Parkinson's Disease Revisited
Get PDFBackground
Two studies that examined the interaction between HLA-DRB1 and smoking in Parkinson's disease (PD) yielded findings in opposite directions.
Objective
To perform a large-scale independent replication of the HLA-DRB1 × smoking interaction.
Methods
We genotyped 182 single nucleotide polymorphism (SNPs) associated with smoking initiation in 12 424 cases and 9480 controls to perform a Mendelian randomization (MR) analysis in strata defined by HLA-DRB1.
Results
At the amino acid level, a valine at position 11 (V11) in HLA-DRB1 displayed the strongest association with PD. MR showed an inverse association between genetically predicted smoking initiation and PD only in absence of V11 (odds ratio, 0.74, 95% confidence interval, 0.59–0.93, PInteraction = 0.028). In silico predictions of the influence of V11 and smoking-induced modifications of α-synuclein on binding affinity showed findings consistent with this interaction pattern.
Conclusions
Despite being one of the most robust findings in PD research, the mechanisms underlying the inverse association between smoking and PD remain unknown. Our findings may help better understand this association
Iron-Modified biochar strengthens simazine adsorption and decreases simazine decomposition in the soil
Get PDFCurrently, modified biochar has been successfully used in the remediation of soil polluted with heavy metals. However, the effects of the modified biochar on pesticides (such as simazine) are still unclear. Herein, the environmental fate of simazine, such as decomposition, leaching, and adsorption in unamended soil, in the soil amended with unmodified and modified biochar (biochar + FeCl3, biochar + FeOS, biochar + Fe) were evaluated. In addition, an incubation experiment was also performed to observe the influence of modified biochar on the microbial community and diversity in the soil. The results showed that modified biochar significantly decreased the decomposition of simazine in the soil compared to its counterpart. Modified biochar also reduced the concentration of simazine in the leachate. Compared with the control, soil microbial biomass in the soil amended with unmodified biochar, biochar + FeCl3, biochar + Fe, and biochar + FeOS was decreased by 5.3%, 18.8%, 8.7%, and 18.1%, respectively. Furthermore, modified biochar changed the structure of the microbial community. This shows that modified biochar could increase the soil adsorption capacity for simazine and change the amount and microbial community that regulates the fate of simazine in the soil. This study concludes that iron-modified biochar has positive and negative effects on the soil. Therefore, its advantages and side effects should be considered before applying it to the soil
Embodied interaffectivity in the emergence and maintenance of group cohesion
No full textCurrently, modified biochar has been successfully used in the remediation of soil polluted with heavy metals. However, the effects of the modified biochar on pesticides (such as simazine) are still unclear. Herein, the environmental fate of simazine, such as decomposition, leaching, and adsorption in unamended soil, in the soil amended with unmodified and modified biochar (biochar + FeCl3, biochar + FeOS, biochar + Fe) were evaluated. In addition, an incubation experiment was also performed to observe the influence of modified biochar on the microbial community and diversity in the soil. The results showed that modified biochar significantly decreased the decomposition of simazine in the soil compared to its counterpart. Modified biochar also reduced the concentration of simazine in the leachate. Compared with the control, soil microbial biomass in the soil amended with unmodified biochar, biochar + FeCl3, biochar + Fe, and biochar + FeOS was decreased by 5.3%, 18.8%, 8.7%, and 18.1%, respectively. Furthermore, modified biochar changed the structure of the microbial community. This shows that modified biochar could increase the soil adsorption capacity for simazine and change the amount and microbial community that regulates the fate of simazine in the soil. This study concludes that iron-modified biochar has positive and negative effects on the soil. Therefore, its advantages and side effects should be considered before applying it to the soil
Pentaploidization enriches the genetic diversity of wheat by enhancing the recombination of AB genomes
Get PDFAllohexaploidization and continuous introgression play a key role in the origin and evolution of bread wheat. The genetic bottleneck of bread wheat resulting from limited germplasms involved in the origin and modern breeding may be compensated by gene flow from tetraploid wheat through introgressive hybridization. The inter-ploidy hybridization between hexaploid and tetraploid wheat generates pentaploid hybrids first, which absorbed genetic variations both from hexaploid and tetraploid wheat and have great potential for re-evolution and improvement in bread wheat. Therefore, understanding the effects of the pentaploid hybrid is of apparent significance in our understanding of the historic introgression and in informing breeding. In the current study, two sets of F2 populations of synthetic pentaploid wheat (SPW1 and SPW2) and synthetic hexaploid wheat (SHW1 and SHW2) were created to analyze differences in recombination frequency (RF) of AB genomes and distorted segregation of polymorphic SNP markers through SNP genotyping. Results suggested that (1) the recombination of AB genomes in the SPW populations was about 3- to 4-fold higher than that in the SHW populations, resulting from the significantly (P < 0.01) increased RF between adjacent and linked SNP loci, especially the variations that occurred in a pericentromeric region which would further enrich genetic diversity; (2) the crosses of hexaploid × tetraploid wheat could be an efficient way to produce pentaploid derivatives than the crosses of tetraploid × hexaploid wheat according to the higher germination rate found in the former crosses; (3) the high proportion of distorted segregation loci that skewed in favor of the female parent genotype/allele in the SPW populations might associate with the fitness and survival of the offspring. Based on the presented data, we propose that pentaploid hybrids should increasingly be used in wheat breeding. In addition, the contribution of gene flow from tetraploid wheat to bread wheat mediated by pentaploid introgressive hybridization also was discussed in the re-evolution of bread wheat