Epigenetics and organic plant breeding

One characteristic of process oriented organic plant breeding is that all breeding activities from the initial crosses up to final variety propagation are performed under organic growing conditions, allowing the plant to interact with its target environment across all generations. However, it is often argued that it is sufficient to select under conventional farming and test the released varieties under organic farming conditions

Temperature Isotropization in Solar Flare Plasmas due to the Electron Firehose Instability

The isotropization process of a collisionless plasma with an electron temperature anisotropy along an external magnetic field ($T_\| ^e\gg T_\perp^e$, $\|$ and $\perp$ with respect to the background magnetic field) and isotropic protons is investigated using a particle-in-cell(PIC) code. Restricting wave growth mainly parallel to the external magnetic field, the isotropization mechanism is identified to be the Electron Firehose Instability (EFI). The free energy in the electrons is first transformed into left-hand circularly polarized transverse low-frequency waves by a non-resonant interaction. Fast electrons can then be scattered towards higher perpendicular velocities by gyroresonance, leading finally to a complete isotropization of the velocity distribution. During this phase of the instability, Langmuir waves are generated which may lead to the emission of radio waves. A large fraction of the protons is resonant with the left-hand polarized electromagnetic waves, creating a proton temperature anisotropy $T_\|^p < T_\perp^p$. The parameters of the simulated plasma are chosen compatible to solar flare conditions. The results indicate the significance of this mechanism in the particle acceleration context: The EFI limits the anisotropy of the electron velocity distribution, and thus provides the necessary condition for further acceleration. It enhances the pitch-angle of the electrons and heats the ions.Comment: To appear in Astrnonmy & Astrophysic

Epigenics and organic plant breeding

Presentation at the conference "Organic Plant Breeding: What makes the difference?

State of the art of existing breeding initiatives & actions planned to strengthen collaborations

State of the art of existing breeding initiatives3Introduction In order to strengthen organic breeding, it is important to know the state of the art of existing initiatives, programs and networks of organic breeding and breeding for organic, and in what crops most organic breeding is currently conducted. Although the number of organic breeding initiatives are growing, as a whole, organic breeding is still relatively marginal compared to conventional breeding. Next to more financial support, another solution to make organic breeding more effective is by improving collaborations. Collaboration can entail, among others, improved exchange of knowledge (breeding tools and approaches) or the exchange of material. In LIVESEED, several activities have been set up to improve collaboration, such as crop‐specific breeding activities, crop‐group activities and systems‐based breeding approaches. For each of these activities, timelines have been developed to strengthen collaborations. This shall improve on one side the capacity building of existing organic plant breeding programs for respective crops and help to identify breeding gaps for those crops, where no activity could be mapped so far

M3.5 ‐ Organic plant breeding in a systems‐based approach and integration of organic plant breeding in value chain partnerships

Developing organic breeding is a key challenge for the organic sector. It is necessary to better adapt varieties to the specific needs of the organic sector (disease resistance, taste, weed suppressing ability, etc). It is also important to enable the organic sector to face the requirements of the New Organic Regulation (EU 2018/848). From 2036, exemptions to the use non‐organic seeds will not be granted any more (Article 53, Regulation 2018/848). The active participation of breeders, farmers, processors, retailers and traders is crucial to develop organic breeding. They all play a critical role and share the responsibility in upscaling organic plant breeding and ensuring future food security, food quality and climate robust agriculture as well as integrity of the value chain. Even consumers could take part in supporting organic plant breeding with informed purchases. On the 12 of February 2019, IFOAM EU, the Louis Bolk Institute (Netherlands) and FiBL Switzerland co‐organized a workshop ‘Organic plant breeding in a system‐based approach and integration of organic plant breeding in value chain partnership’ as part of the Horizon 2020 project LIVESEED. The workshop took place at the largest organic trade fair at Nürnberg Messe biofach to reach out to different actors of the organic sector. The main objective of this workshop was to gather interested stakeholders across the value chain to discuss the responsibilities and their potential concrete engagements in facilitating organic plant breeding. Organized as a world café workshop 1, the participants had the opportunity to discuss three main issues: - Why should different value chain actors support organic plant breeding? - The advantage of organic plant breeding for the value chain (farmer, processors, traders). - The advantage of organic plant breeding for consumers and society (local and global). This report describes in detail the main conclusion of the discussions held during this workshop

The Cytoscan (TM) model E-II, a new reflectance microscope for intravital microscopy: Comparison with the standard fluorescence method

The Cytoscan(TM) Model E-II (Cytometrics Inc., Philadelphia, Pa., USA) is a newly developed instrument which functions as an intravital microscope and is small and easily portable. Through the use of orthogonal polarization spectral (OPS) imaging, the Cytoscan Model E-II delivers images of the microcirculation which are comparable to those achieved with intravital fluorescence videomicroscopy (IFM), but without the use of fluorescent dyes. The purpose of this study was to validate the Cytoscan Model E-II instrument against IFM. The experiments were carried out on striated muscle in the dorsal skinfold chamber of the awake Syrian hamster. The following parameters were measured in identical regions of interest in the same animal under baseline conditions and 0.5 and 2 h after a 4-hour period of pressure-induced ischemia: arteriolar diameter, venular diameter and venular red blood cell velocity. Bland-Altman plots showed good agreement between the two techniques for venular red blood cell velocity. As expected, arteriolar and venular diameters as measured by the Cytoscan were on average 5 mum smaller than the values from IFM, since the Cytoscan measures the red blood cell column width and IFM measures luminal diameter. Thus, OPS imaging can be used to make valid measurements of microvascular diameter and red blood cell velocity in tissues. Copyright (C) 2000 S. Karger AG, Basel

Resistant and susceptible pea lines harbour different root-rot pathogens and antagonistic fungi

Disease resistance encompasses the mechanisms that allow a plant to withstand or ward off a pathogen. The molecular responses of plants under pathogen attack and the underlying genetics have been extensively studied. However, resistance is not only a trait defined by the warfare between pathogen and host. In fact, resistance is an emergent phenotype of the interactions between the microbial community and the host. Fungal root diseases threaten pea (Pisum sativum L.) cultivation, and therefore a valuable protein source and important crop in low-input farming systems. Resistance in current pea varieties against multiple root pathogens is lacking. In order to acknowledge the rhizosphere microbiome as an integral part of the environment, 261 pea genotypes were screened for resistance on naturally infested field soil in a pot-based experiment. Thereof, eight lines with contrasting disease levels were selected and tested on four soils with different disease pressure in a follow-up pot experiment. Along root rot assessments, pea pathogens (F. solani, F. oxysporum, F. avenaceum, A. euteiches, P. ultimum and D. pinodella) and arbuscular mycorrhizal fungi were quantified in diseased roots using qPCR assays. The amount of fungal DNA detected in the roots differed among the pea genotypes and the four soils and a significant pea genotype x soil interaction was evidenced for several pathogen species. For example, the quantity of F. avenaceum in the roots mostly depends on the soil (two-way ANOVA, p < 0.01) and differs significantly between pea genotypes (p = 0.013). F. oxysporum and F. solani quantities showed significant pea genotype x soil interactions (p < 0.01 for both species). Significant correlations were found between F. avenaceum and F. solani quantity and root rot index (rs = 0.38, p < 0.01 and rs = 0.56, p < 0.01, respectively ). On the other hand, F. oxysporum quantity shows no relationship with root rot (rs = 0.007, p = 0.95). These results suggest differential roles of the microbes in the pea root rot and highlight the importance of incorporating the complexity of the soil microbiome at early stages of resistance screenings and breeding efforts. Resistance breeding against root rot will be challenged by the fact that soil microbes interact with each other and the plant and that their composition varies between different soils. Further insights into plant-microbe interactions and emerging molecular plant breeding tools will fuel future plant breeding