Biology subjects

Dresboll, D. B.

Publications and source records attributed to Dresboll, D. B..

5 recordsLinked to original sources

bioRxiv2025

Five seasons with DeepRootLab: A unique facility for easier deep root research in the field

Deep-rooted crops accessing water and nutrients from deep soil layers enhance the resource base for crop production. However, studying these roots in field conditions is labor-intensive, limiting research scope. We established a field root research facility with 48 plots for replicated experiments. The facility includes 144 six-meter-long minirhizotron tubes and an AI-based pipeline for rapid root trait analysis. We also attempted to install access-tubes and customized ingrowth-core production for less-invasive root activity determination. Our study revealed significant differences in deep root density among species, particularly at depths of 2.5 to 4.5 meters, over five years. The less invasive studies using ingrowth-cores reached depths of 4.2 meters. Nutrient tracer 15N analysis showed marked differences in deep root activity among crop species. TDR sensors indicated varying water depletion in deeper soil layers, influenced by crop species and root growth patterns. We established a field facility for studying deep root growth and function, demonstrating its effectiveness in analyzing diverse deep-rooted plant species. This facility provides an ideal platform for conducting meaningful research in deep soil layers, yielding statistically and biologically significant results for agricultural applications.

plant biology↗

bioRxiv2024

Pseudomonas taxonomic and functional microdiversity in the wheat rhizosphere is cultivar-dependent and links to disease resistance profile and root diameter

Diversity within lower taxonomic units in microbial communities is a key trait, giving rise to important ecological functions. In the rhizosphere, these functions include disease suppression and pathogen inhibition. However, limited effort has been given to exploring intragenus microdiversity in an increasingly homogenous agricultural system. Through an integrative approach combining culture-dependent and -independent methods, we explore the rhizosphere Pseudomonas pangenome and demonstrate cultivar-dependent taxonomic and functional microdiversity between two closely related modern winter wheat cultivars. A Fusarium-resistant cultivar demonstrated increased Pseudomonas taxonomic diversity but not biosynthetic diversity when compared to the susceptible cultivar, coinciding with a thinner root diameter of the resistant cultivar. We found enrichment of Pseudomonas isolates capable of antagonizing Fusarium as well as chitinase-encoding genes and pyoverdine gene clusters in the resistant cultivar. Across closely related Pseudomonas isolates from the two cultures, there were differences in genomic content and biosynthetic gene clusters. Ultimately, we highlight the need for fine-scale analysis to uncover the hidden microdiversity within rhizosphere Pseudomonas.

microbiology↗

bioRxiv2022

Exploitation of neighbouring subsoil for nutrient acquisition under annual-perennial strip intercropping systems

Little is known of how the deep root systems of perennial crops contribute to deeper and better resource use when intercropped with annuals in arable fields. Therefore, we aimed at measuring the capacity of perennial deep roots, alfalfa (Medicago sativa L.) and curly dock (Rumex crispus L.) to access the nutrient source located under the neighboring annuals at 1.0 and 2.5 m of soil depth. Alfalfa and curly dock were able to access the tracer-labelled source placed at a distance under the annual crop strips. As a result, the reliance on deeper soil layer for nutrient uptake under intercroppings became greater compared with sole-croppings. Combination of an annual cereal (winter rye) and a perennial legume (alfalfa) with contrasting root systems exhibited higher resource complementarity compared with intercroppings having similar root systems or absence of legumes. Our results demonstrated that the deep-rooted perennials when intercropped with annuals can induce vertical niche complementarity, especially at deeper soil layers. This was assumed to be due to the vertically stratified root activity between the crop components, however, the magnitude of the effects depended on choice of crop combinations, and on types of tracers. Future studies should include estimates such as relative yield total and land equivalent ratio to quantitatively determine the effects of resource acquisition under annual-perennial intercropping in arable fields.

plant biology↗

bioRxiv2020

RootPainter: Deep Learning Segmentation of Biological Images with Corrective Annotation

We present RootPainter, a GUI-based software tool for the rapid training of deep neural networks for use in biological image analysis. RootPainter facilitates both fully-automatic and semi-automatic image segmentation. We investigate the effectiveness of RootPainter using three plant image datasets, evaluating its potential for root length extraction from chicory roots in soil, biopore counting and root nodule counting from scanned roots. We also use RootPainter to compare dense annotations to corrective ones which are added during the training based on the weaknesses of the current model.

plant biology↗

bioRxiv2018

Chicory demonstrates substantial water uptake from below 2 m, but still did not escape topsoil drought

AimsDeep-rooted agricultural crops can potentially utilize deep water pools and thus reduce periods where growth is water limited. Chicory (Cichorium intybus L.) is known to be deep-rooted, but the contribution of deep roots to water uptake under well-watered and drought conditions by the deep root system has not been studied. The aim of this study was to investigate whether chicory could reach 3 m depth within a growing season and demonstrate significant water uptake from the deeper part of the root zone. MethodsWe tested if chicory exposed to either topsoil drought or resource competition from the shallow-rooted species ryegrass (Lolium perenne L.) and black medic (Medicago lupulina L.) would increase deep water uptake in compensation for reduced topsoil water uptake. We grew chicory in 4 m deep soil filled rhizotrons and found that the roots reached 3 m depth within a growing season. ResultsWater uptake from below 1.7 m depth in 2016 and 2.3 m depth in 2017 contributed significantly to chicory water use. However, neither drought nor intercropping increased the deep water uptake. ConclusionChicory benefits from being deep-rooted during drought events, yet deep water uptake cannot compensate for the reduced topsoil water uptake during drought.

plant biology↗