Biology subjects

Temme, A.

Publications and source records attributed to Temme, A..

4 recordsLinked to original sources

bioRxiv2026

Genotype and farm effects on yield and morphology reveal potential for breeding and site selection for sugar kelp

Seaweed cultivation has recently gained increased attention in North-West Europe as a sustainable source of biomass for biobased products. However, yields need to increase to make the seaweed sector economically viable. To achieve this, higher yielding varieties can be bred but this requires variation for yield and yield-related traits among genotypes. To reliably select high-yielding genotypes, an understanding is required of how both within-farm and between-farm environmental differences affect phenotypes and how to identify simple and reliable proxies for yield. In this study we evaluated growth of nine Saccharina latissima genotypes on two farms, 12 km apart, within the same season. We observed a threefold difference in yield among genotypes, demonstrating the potential for improvement through selection and breeding. Blade thickness and blade size-related traits were strongly correlated with yield, highlighting their potential to serve as rapid and non-destructive proxies for yield, thereby accelerating selection. Furthermore, we demonstrated the importance of adequate replication in farm trials to improve genotype performance estimation by correcting for within-farm spatial variation. Moreover, phenotypic variation was most explained by the genotype and environment, highlighting the importance of both genotype and site selection. Although genotype by environment interactions (GxE) were significant, its contributions were small, indicating stable genotype ranking across farms. Overall, these results are promising for breeding improved S. latissima as it indicates that genotype performance is consistent across close by locations and that local S. latissima populations harbour substantial phenotypic variation that can be used to breed for increased yield. Highlights- Local genetic resources harbour substantial variation in yield and morphology for breeding. - Minor GxE allows for breeding across farms. - Blade thickness and blade size related traits are good predictors of yield. - Correction for on-farm spatial variation improves genotype performance estimation.

genetics↗

bioRxiv2026

Challenges in Brillouin microscopy: Addressing heterogeneity and contamination for reliable biomechanical mapping of fresh brain tumors

Objective and RationaleBrain biomechanics is a rapidly evolving field, with mechanical properties influencing both normal development and pathological conditions such as cancer. Brillouin microscopy, a non-contact optical technique, offers a promising approach for studying the biomechanics of fresh brain tumors and organoids at subcellular resolution. However, challenges such as tissue heterogeneity and signal attenuation necessitate an in-depth evaluation of measurement strategies and potential confounding factors. MethodsFresh human brain tumor samples and tumor organoids were analyzed using Brillouin microscopy with 780 nm excitation. Measurements in the form of maps of various size were performed, and the impact of focal position, tissue heterogeneity and blood contamination on Brillouin data was assessed. Complementary Raman spectroscopy was performed as reference for tissue composition. ResultsBrillouin signal intensity decreased exponentially with depth, with valid measurements achievable up to 80 {micro}m. Low signal intensities at greater depths compromised data reliability due to fitting algorithm limitations. Structural heterogeneity, including different cell types, differentially affected signal attenuation. Blood contamination was identified as a major confounder, leading to erroneous biomechanical readings. Brillouin intensity maps provided essential quality control for accurate data interpretation. Raman spectroscopy identified the presence of blood and tissue-specific biochemical signatures, reinforcing the importance of multimodal analysis. ConclusionsBrillouin microscopy can effectively probe biomechanical properties of fresh brain tumors but is influenced by tissue heterogeneity and contaminants. Proper sample preparation, strategic focal positioning, and complementary techniques like Raman spectroscopy are critical for ensuring reliable data. These findings contribute to refining Brillouin microscopy protocols for neuro-oncological research and potential future clinical applications.

biophysics↗

bioRxiv2018

Coordination of trait responses to above and belowground resource limitation in cultivated sunflower (Helianthus annuus L.)

O_LIIn the face of resource limitations, plants show plasticity in multiple trait categories, including biomass allocation, morphology and anatomy, yet inevitably also grow less. The extent to which passive mass-scaling plays a role in trait responses that contribute to increased potential for resource acquisition are poorly understood. Here we assessed the role of mass-scaling on the direction, magnitude and coordination of trait plasticity to light and/or nutrient limitation in cultivated sunflower (Helianthus annuus). C_LIO_LIWe grew seedlings of ten sunflower genotypes for three weeks in a factorial of light (50% shade) and nutrient (10% supply) limitation in the greenhouse and measured a suite of allocational, morphological and anatomical traits for leaves, stems, fine roots, and tap roots. C_LIO_LIUnder resource limitation, plants were smaller and more biomass was allocated to the organ capturing the most limiting resource, as expected. Traits varied in the magnitude of plasticity and the extent to which the observed response was passive (scaled with plant mass) and/or had an additional active component. None of the allocational responses were primarily passive. Plastic changes to specific leaf area and specific root length were primarily active, and adjusted towards more acquisitive trait values under light and nutrient limitation, respectively. For many traits, the observed response was a mixture of active and passive components, and for some traits the active adjustment was antagonistic to the direction of passive adjustment, e.g. stem height, and tap root and stem theoretical hydraulic conductance. Passive scaling with size played a major role in the coordinated response to light, but correcting for mass clarified that the active responses to both limitations were more similar in magnitude, although still resource and organ specific. C_LIO_LIOur results demonstrate that both passive plasticity and active plasticity can contribute to increased uptake capacity for limiting resources in a manner that is resource, organ and trait specific. Indeed, passive adjustments (scaling with mass) of traits due to resource stress extends well beyond just mass allocation traits. For a full understanding of plants response to environmental stress both passive and active plasticity needs to be taken into account. C_LI

plant biology↗

bioRxiv2018

Vigour/tolerance trade-off in cultivated sunflower (Helianthus annuus) response to salinity stress is linked to leaf elemental composition

Developing more stress-tolerant crops will require greater knowledge of the physiological basis of stress tolerance. Here we explore how the variation among twenty cultivated sunflower (Helianthus annuus) genotypes for biomass decline in response to increasing salinity relates to leaf traits and leaf trait adjustments. Genotypes were grown in the greenhouse under five salinity treatments (0, 50, 100, 150, or 200 mM NaCl) for 21 days and assessed for growth, leaf physiological traits, and leaf elemental composition. Results showed that there was a trade-off in performance such that vigorous genotypes, higher biomass at zero mM NaCl, had both a larger absolute decrease and proportional decrease in biomass due to increased salinity. Contrary to expectation, genotypes with a low increase in leaf Na+ and Na+:K+ were no better at maintaining biomass with increasing salinity. Rather, genotypes with a greater reduction in leaf S and K+ content were better at maintaining biomass in the face of increasing salinity. While we found a trade-off between vigour and tolerance, some genotypes were more tolerant than expected. Further analysis of the traits underlying this trade-off will allow us to identify traits/mechanisms that could be bred into high vigour genotypes in order to increase their tolerance.

plant biology↗