Unraveling root and rhizosphere traits in temperate maize landraces and modern cultivars: Implications for soil resource acquisition and drought adaptation.

A holistic understanding of plant strategies to acquire soil resources is pivotal in achieving sustainable food security. However, we lack knowledge about variety-specific root and rhizosphere traits for resource acquisition, their plasticity and adaptation to drought. We conducted a greenhouse experiment to phenotype root and rhizosphere traits (mean root diameter [Root D], specific root length [SRL], root tissue density, root nitrogen content, specific rhizosheath mass [SRM], arbuscular mycorrhizal fungi [AMF] colonization) of 16 landraces and 22 modern cultivars of temperate maize (Zea mays L.). Our results demonstrate that landraces and modern cultivars diverge in their root and rhizosphere traits. Although landraces follow a 'do-it-yourself' strategy with high SRLs, modern cultivars exhibit an 'outsourcing' strategy with increased mean Root Ds and a tendency towards increased root colonization by AMF. We further identified that SRM indicates an 'outsourcing' strategy. Additionally, landraces were more drought-responsive compared to modern cultivars based on multitrait response indices. We suggest that breeding leads to distinct resource acquisition strategies between temperate maize varieties. Future breeding efforts should increasingly target root and rhizosphere economics, with SRM serving as a valuable proxy for identifying varieties employing an outsourcing resource acquisition strategy.

Rhizosheath drought responsiveness is variety-specific and a key component of belowground plant adaptation.

Biophysicochemical rhizosheath properties play a vital role in plant drought adaptation. However, their integration into the framework of plant drought response is hampered by incomplete mechanistic understanding of their drought responsiveness and unknown linkage to intraspecific plant-soil drought reactions. Thirty-eight Zea mays varieties were grown under well-watered and drought conditions to assess the drought responsiveness of rhizosheath properties, such as soil aggregation, rhizosheath mass, net-rhizodeposition, and soil organic carbon distribution. Additionally, explanatory traits, including functional plant trait adaptations and changes in soil enzyme activities, were measured. Drought restricted soil structure formation in the rhizosheath and shifted plant-carbon from litter-derived organic matter in macroaggregates to microbially processed compounds in microaggregates. Variety-specific functional trait modifications determined variations in rhizosheath drought responsiveness. Drought responses of the plant-soil system ranged among varieties from maintaining plant-microbial interactions in the rhizosheath through accumulation of rhizodeposits, to preserving rhizosheath soil structure while increasing soil exploration through enhanced root elongation. Drought-induced alterations at the root-soil interface may hold crucial implications for ecosystem resilience in a changing climate. Our findings highlight that rhizosheath soil properties are an intrinsic component of plant drought response, emphasizing the need for a holistic concept of plant-soil systems in future research on plant drought adaptation.

Manually annotated and curated Dataset of diverse Weed Species in Maize and Sorghum for Computer Vision.

Sustainable weed management strategies are critical to feeding the world's population while preserving ecosystems and biodiversity. Therefore, site-specific weed control strategies based on automation are needed to reduce the additional time and effort required for weeding. Machine vision-based methods appear to be a promising approach for weed detection, but require high quality data on the species in a specific agricultural area. Here we present a dataset, the Moving Fields Weed Dataset (MFWD), which captures the growth of 28 weed species commonly found in sorghum and maize fields in Germany. A total of 94,321 images were acquired in a fully automated, high-throughput phenotyping facility to track over 5,000 individual plants at high spatial and temporal resolution. A rich set of manually curated ground truth information is also provided, which can be used not only for plant species classification, object detection and instance segmentation tasks, but also for multiple object tracking.

Above and belowground traits impacting transpiration decline during soil drying in 48 maize (Zea mays) genotypes.

BACKGROUND AND AIMS: Stomatal regulation allows plants to promptly respond to water stress. However, our understanding of the impact of above and belowground hydraulic traits on stomatal regulation remains incomplete. The objective of this study was to investigate how key plant hydraulic traits impact transpiration of maize during soil drying. We hypothesize that the stomatal response to soil drying is related to a loss in soil hydraulic conductivity at the root-soil interface, which in turn depends on plant hydraulic traits. METHODS: We investigate the response of 48 contrasting maize (Zea mays) genotypes to soil drying, utilizing a novel phenotyping facility. In this context, we measure the relationship between leaf water potential, soil water potential, soil water content and transpiration, as well as root, rhizosphere and aboveground plant traits. KEY RESULTS: Genotypes differed in their responsiveness to soil drying. The critical soil water potential at which plants started decreasing transpiration was related to a combination of above and belowground traits: genotypes with a higher maximum transpiration and plant hydraulic conductance as well as a smaller root and rhizosphere system closed stomata at less negative soil water potentials. CONCLUSIONS: Our results demonstrate the importance of belowground hydraulics for stomatal regulation and hence drought responsiveness during soil drying. Furthermore, this finding supports the hypothesis that stomata start to close when soil hydraulic conductivity drops at the root-soil interface.

Host Genotype and Weather Effects on Fusarium Head Blight Severity and Mycotoxin Load in Spring Barley.

Epidemiology of Fusarium Head Blight (FHB) of spring barley is relatively little understood. In a five-year study, we assessed quantitative resistance to FHB in an assortment of 17 spring barley genotypes in the field in southern Germany. To this end, we used soil and spray inoculation of plants with F. culmorum and F. avenaceum. This increased disease pressure and provoked genotypic differentiation. To normalize effects of variable weather conditions across consecutive seasons, we used a disease ranking of the genotypes based on quantification of fungal DNA contents and multiple Fusarium toxins in harvested grain. Together, this allowed for assessment of stable quantitative FHB resistance of barley in several genotypes. Fungal DNA contents were positively associated with species-specific Fusarium toxins in single years and over several years in plots with soil inoculation. In those plots, plant height limited FHB; however, this was not observed after spray inoculation. A multiple linear regression model of recorded weather parameter and fungal DNA contents over five years identified time periods during the reproductive phase of barley, in which weather strongly influenced fungal colonization measured in mature barley grain. Environmental conditions before heading and late after anthesis showed strongest associations with F. culmorum DNA in all genotypes, whereas for F. avenaceum, this was less consistent where we observed weather-dependent associations, depending on the genotype. Based on this study, we discuss aspects of practical resistance breeding in barley relevant to improve quantitative resistance to FHB and associated mycotoxin contaminations.

A model for estimating hearing aid coverage world-wide using historical data on hearing aid sales.

OBJECTIVE: To estimate the hearing aid coverage for people with disabling hearing loss using data on hearing aid sales. DESIGN: Data on prevalence of disabling hearing loss from WHO and on hearing loss from moderate to severe from the Global Burden of Disease enterprise are used to estimate the number of people with hearing loss. Data on hearing aid sales from the European Hearing Instrument Manufacturers Association (EHIMA) are used to estimate the number of people using hearing aids. STUDY SAMPLE: From 2009 to 2018, the worldwide sales of hearing aids by the EHIMA members were 124 million units. RESULTS: The world-wide hearing aid coverage is 10-11% depending on the prevalence of data source. For all low- to middle-income regions that make up 85% of the world population, the coverage ranges from 1.5% to 12%. In the group of high-income countries as defined by WHO, the coverage is 57%. CONCLUSIONS: Data on hearing aid sales can be used to estimate hearing aid coverage regionally, and world-wide. Globally, there is a huge unmet need for hearing instruments since less than 11% of people with a disabling hearing loss are hearing aid users.

Increasing the Effectiveness of Hearing Aid Directional Microphones.

Directionality is the only hearing aid technology - in addition to amplification - proven to help hearing aid users hear better in noise. Hearing aid directionality has been documented to improve speech intelligibility in multiple laboratory studies. In contrast, real-world studies have shown a disconnect between the potential of the technology and what hearing aid users experience in their daily life. This article describes the real-world studies that inspired ReSound to take a different approach to applying directional microphone technology. This approach is based on the idea that hearing aid directionality can leverage natural binaural hearing and inherent listening strategies. The directional strategy includes three listening modes that will be explained. These are the Spatial Cue Preservation mode, the Binaural Listening mode, and the Speech Intelligibility mode. The strategy and the advantages it provides in terms of sound quality, spatial hearing, and improved signal-to-noise ratio with maintained awareness of surroundings are explained.

A Smartphone App to Facilitate Remote Patient-Provider Communication in Hearing Health Care: Usability and Effect on Hearing Aid Outcomes.

Background: Patients often need multiple fine-tuning appointments with their hearing health care provider to achieve satisfactory hearing aid outcomes. A smartphone app that enables patients to remotely request and receive new hearing aid settings could improve hearing health care access and efficiency. Introduction: We assessed the usability of ReSound Assist™, (ReSound America, Bloomington, MN) the remote communication feature of a hearing aid app, and investigated whether hearing aid outcomes are influenced by app-based versus in-person patient-provider communication. Materials and Methods: Thirty adults were fit bilaterally with hearing aids and randomized to intervention and control groups. During a 6-week field trial, participants reported hearing aid problems via ReSound Assist (intervention) or at a scheduled face-to-face follow-up appointment (control). Usability of ReSound Assist was assessed with a questionnaire and interview. Hearing aid performance, benefit, satisfaction, and daily usage were compared for both groups. Results: ReSound Assist was rated as highly usable. Participants identified specific aspects of effectiveness and efficiency that could be improved. Similar problems were reported by intervention and control participants regardless of communication mode (app-based vs. in-person). However, almost half the requests received via ReSound Assist were for problems that required advice from the provider or physical modifications to the hearing aids rather than fine-tuning, highlighting the continued importance of in-person hearing health care. There was no significant difference in hearing aid outcomes between intervention and control participants. Conclusions: Apps enabling remote patient-provider communication are a viable method for hearing aid users to seek and receive help with hearing aid problems that can be addressed through fine-tuning.

Deciphering the genetic basis for vitamin E accumulation in leaves and grains of different barley accessions.

Tocopherols and tocotrienols, commonly referred to as vitamin E, are essential compounds in food and feed. Due to their lipophilic nature they protect biomembranes by preventing the propagation of lipid-peroxidation especially during oxidative stress. Since their synthesis is restricted to photosynthetic organisms, plant-derived products are the major source of natural vitamin E. In the present study the genetic basis for high vitamin E accumulation in leaves and grains of different barley (Hordeum vulgare L.) accessions was uncovered. A genome wide association study (GWAS) allowed the identification of two genes located on chromosome 7H, homogentisate phytyltransferase (HPT-7H) and homogentisate geranylgeranyltransferase (HGGT) that code for key enzymes controlling the accumulation of tocopherols in leaves and tocotrienols in grains, respectively. Transcript profiling showed a correlation between HPT-7H expression and vitamin E content in leaves. Allele sequencing allowed to decipher the allelic variation of HPT-7H and HGGT genes corresponding to high and low vitamin E contents in the respective tissues. Using the obtained sequence information molecular markers have been developed which can be used to assist smart breeding of high vitamin E barley varieties. This will facilitate the selection of genotypes more tolerant to oxidative stress and producing high-quality grains.

Molecular characterisation of resistance against potato wart races 1, 2, 6 and 18 in a tetraploid population of potato (Solanum tuberosum subsp. tuberosum).

Potato wart is caused by the obligate biotrophic fungus Synchytrium endobioticum, which is subject to quarantine regulations due to the production of long persisting spores in the soil and the lack of effective fungicides. The objective of this study was to identify quantitative trait loci (QTL) for resistance against potato wart races (R) 1, 2, 6 and 18 in a tetraploid potato population developed by crossing cv. Saturna (resistant to R1) with cv. Panda (resistant to R1, R2, R6, R18). A total of 92 progenies were used for phenotyping and genotyping. Resistance tests were performed for races 1 and 18 in 2 years and for races 2 and 6 in 1 year on 10 to 20 eyepieces per genotype. Based on amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers, linkage maps were established for the female and male parent, respectively. Single marker analysis followed by a multiple regression analysis revealed initial marker-trait associations. The interval mapping routine of TetraploidMap was applied for QTL analysis. A major QTL for resistance against race 1 explaining between 46 % and 56 % of the phenotypic variation was identified near Sen1, a known resistance locus for potato wart race 1 on chromosome XI. Other resistance QTL were detected on chromosomes I (to R2), II (to R6, 18), VI (to R1, 2, 6, 18), VII (to R2, 6, 18), VIII (to R1, 2, 6, 18), X (to R2, 6, 18), XI (to R2, 6, 18) and on an unknown linkage group (to R18) explaining minor to moderate effects of the phenotypic variation. Resistance QTL against different potato wart races often overlapped, particularly concerning races 2, 6 and 18. Overall, this study gives a valuable insight into the complex inheritance of resistance against potato wart.

The occlusion effect in unilateral versus bilateral hearing aids.

The benefit of bilateral hearing aids is well documented, but many hearing-aid users still wear only one aid. It is plausible that the occlusion effect is part of the reason for some hearing-aid users not wearing both hearing aids. In this study we quantified the subjective occlusion effect by asking ten experienced users of bilateral hearing aids and a reference group of ten normal-hearing individuals to rate the naturalness of their own voice while reading a text sample aloud. The subjective occlusion effect was evaluated in the unilateral versus bilateral condition for a variety of vent designs in earmolds and in a custom hearing aid. The subjective occlusion effect was significantly higher for bilateral hearing aids with all vent designs with the exception of a non-occluding eartip option. The subjective occlusion effect was reduced with the more open vent designs in both the unilateral and bilateral conditions. Assuming that the occlusion effect is a barrier to bilateral hearing aid use, these results indicate that open-hearing-aid fittings can help promote the use of two aids.

Occlusion effect of earmolds with different venting systems.

In this study the occlusion effect was quantified for five types of earmolds with different venting. Nine normal-hearing listeners and ten experienced hearing aid users were provided with conventional earmolds with 1.6 and 2.4 mm circular venting, shell type earmolds with a novel vent design with equivalent cross-sectional vent areas, and nonoccluding soft silicone eartips of a commercial hearing instrument. For all venting systems, the occlusion effect was measured using a probe microphone system and subjectively rated in test and retest sessions. The results for both normal-hearing subjects and hearing aid users showed that the novel vents caused significantly less occlusion than the traditional vents. Occlusion effect associated with the soft silicone eartip was comparable to the nonoccluded ear. Test-retest reproducibility was higher for the subjective occlusion rating than for the objectively measured occlusion. Perceived occlusion revealed a closer relationship to measured occlusion in the ear in which the measured occlusion effect was higher ("high OE" ear) than in the "low OE" ear. As our results suggest that subjective judgment of occlusion is directly related to the acoustic mass of the air column in the vent, the amount of perceived occlusion may be predicted by the vent dimensions.

Disturbance caused by varying propagation delay in non-occluding hearing aid fittings.

The disturbance caused by various short propagation delays to the perception of external sounds and own voice for a non-occluding hearing aid was investigated. Ten normal-hearing and 10 mildly hearing-impaired individuals listened to external sounds and their own voice while wearing non-occluding devices providing 10dB of linear gain. Participants rated the disturbance caused by delays of 2, 4 and 10ms to music, running speech, and their own voices. The results indicated greater disturbance for the longest delay for both subject groups when judging own voice, with the ratings of the hearing-impaired participants being lowest. Normal-hearing participants also judged the 10-ms delay as more disturbing for the external sounds. Owing to the listening conditions with constant gain from 800Hz and above, the results apply directly only to this experiment. Disturbance ratings for all delays were low, which suggests that any of those tested would be acceptable for this application.