Response Traits Research Articles

Accounting for nonlinear responses to traits improves range shift predictions

AbstractAccurately predicting species' range shifts in response to environmental change is paramount for understanding ecological processes and global change. In synthetic analyses, traits emerge as significant but weak predictors of species' range shifts across recent climate change. These studies assume linear responses to traits, while detailed empirical work often reveals trait responses that are unimodal and contain thresholds or other nonlinearities. We hypothesize that the use of linear modeling approaches fails to capture these nonlinearities and, therefore, may be under‐powering traits to predict range shifts. We evaluate the predictive performance of approaches that can capture nonlinear relationships (ridge‐regularized linear regression, support vector regression with linear and nonlinear kernels, and random forests). We apply our models using six multidecadal range shift datasets for plants, moths, marine fish, birds, and small mammals. We show that nonlinear approaches can perform better than least‐squares linear modeling in reproducing historical range shifts. Consistent with expectations, we identify dispersal and climatic niche traits as primary determinants of distribution shifts. Traits identified as important predictors and the direction of trait effects are generally consistent across models, but there are notable exceptions. Among important predictors, there are more consistent responses to climatic niches than dispersal ability. Modest improvements in predictability when accounting for nonlinearities and interactions, and the overall low amount of variance accounted for by trait predictors suggest limits to trait‐based statistical predictive frameworks.

Phytoplankton species and traits response to a gradient of urbanization in subtropical lowland streams

AbstractLotic environments are among the most vulnerable aquatic ecosystems, and changes occurring in them happen faster than our capacity to measure the impacts, with the choice of community attributes that best reflect these disturbances still unclear. In this study, we evaluated the response of phytoplankton species and species traits along a gradient of urbanization in lowland streams. To do this, we sampled nine streams in three areas classified as densely populated (DP), low populated (LP), and rural areas (RA) during the four seasons (n = 108), considering relevant limnological variables (including metals, herbicides, and inorganic nutrients) and phytoplankton. Phytoplankton was analysed using taxonomic and morpho‐functional traits approaches. We used several multivariate analyses to assess phytoplankton species and trait distribution among stream groups (DP, LP, RA) and identify their environmental drivers. We found that phytoplankton responded to the urbanization gradient at both taxonomic and functional levels. However, this response was mediated by the land use (urban vs. rural) rather than its intensity. The main stressors detected were eutrophic conditions and organic matter contamination, which differed among groups (DP‐LP and RA). Both approximations indicated eutrophic, organically enriched conditions, but the situation varied among seasons and stream groups. The response of the taxonomic approach was clearer than the traits‐based approach, showing differences in density only between stream groups in the summer and the spring. Phytoplankton was responding to the gradient of urbanization in these subtropical lowland streams, but the seasonality, especially temperature and changes in the water column mixing also mediate the effect.

Trait variation and performance across varying levels of drought stress in cultivated sunflower (Helianthus annuus L.).

Drought is a major agricultural challenge that is expected to worsen with climate change. A better understanding of drought responses has the potential to inform efforts to breed more tolerant plants. We assessed leaf trait variation and covariation in cultivated sunflower (Helianthus annuus L.) in response to water limitation. Plants were grown under four levels of water availability and assessed for environmentally induced plasticity in leaf stomatal and vein traits as well as biomass (performance indicator), mass fractions, leaf area, leaf mass per area, and chlorophyll content. Overall, biomass declined in response to stress; these changes were accompanied by responses in leaf-level traits including decreased leaf area and stomatal size, and increased stomatal and vein density. The magnitude of trait responses increased with stress severity and relative plasticity of smaller-scale leaf anatomical traits was less than that of larger-scale traits related to construction and growth. Across treatments, where phenotypic plasticity was observed, stomatal density was negatively correlated with stomatal size and positively correlated with minor vein density, but the correlations did not hold up within treatments. Four leaf traits previously shown to reflect major axes of variation in a large sunflower diversity panel under well-watered conditions (i.e. stomatal density, stomatal pore length, vein density, and leaf mass per area) predicted a surprisingly large amount of the variation in biomass across treatments, but trait associations with biomass differed within treatments. Additionally, the importance of these traits in predicting variation in biomass is mediated, at least in part, through leaf size. Our results demonstrate the importance of leaf anatomical traits in mediating drought responses in sunflower, and highlight the role that phenotypic plasticity and multi-trait phenotypes can play in predicting productivity under complex abiotic stresses like drought.

Drought effects on trait space of winter wheat are independent of land management.

Investigating plant responses to climate change is key to develop suitable adaptation strategies. However, whether changes in land management can alleviate increasing drought threats to crops in the future is still unclear. We conducted a management × drought experiment with winter wheat (Triticum aestivum L.) to study plant water and vegetative traits in response to drought and management (conventional vs organic farming, with intensive vs conservation tillage). Water traits (root water uptake pattern, stem metaxylem area, leaf water potential, stomatal conductance) and vegetative traits (plant height, leaf area, leaf Chl content) were considered simultaneously tocharacterise the variability of multiple traits in a trait space, using principal component analysis. Management could not alleviate the drought impacts on plant water traits as it mainly affected vegetative traits, with yields ultimately being affected by both management and drought. Trait spaces were clearly separated between organic and conventional management as well as between drought and control conditions. Moreover, changes in trait space triggered by management and drought were independent from each other. Neither organic management nor conservation tillage eased drought impacts on winter wheat. Thus, our study raised concerns about the effectiveness of these management options as adaptation strategies to climate change.

Identification of chili varieties (Capsicum annum) tolerance to root cutting based on stress selection indices and morphological traits planted in lowland area

Abstract. Kusumaningrum S, Sulistyaningsih E, Harimurti R, Dewi K. 2024. Identification of chili varieties (Capsicum annum) tolerance to root cutting based on stress selection indices and morphological traits planted in lowland area. Biodiversitas 25: 2063-2073. Root cutting is a potential technique for inducing root growth to increase chili yield. A set of four lowland chili varieties were evaluated under root cutting to identify tolerant variety. Stress selection indices such as stress tolerant level (TOL), Stress Susceptible Index (SSI), Stress Tolerance Index (STI), Yield Stability Index (YSI) and morphological traits responses were employed in screening of the variety. The research was arranged in randomized complete block design factorial, where the first factor was the lowland chili varieties ('Tanjung', 'Lembang-1', 'Tanjung-2', 'Ungara'), and the second factor was period of root cutting (0, 8, and 0 + 8 weeks after transplanting and no root cutting). The results showed that 'Kencana', 'Lembang-1', 'Ungara' were identified as the tolerant group under root cutting treatment and 'Tanjung-2' was identified as the intolerant group based on chili yield and stress selection indices. The tolerant group had chili yield increment under root cutting (0, and 8 WAT), which related to high root morphological traits (root diameter, root length, root surface area, and root dry weight density). Root cutting at 8 WAT gave the highest chili yield in tolerant group. The increased root growth in the tolerant group was contributed to promote shoot morphological traits (leaf number, leaf area, and plant height). Root cutting treatment in the intolerant group caused chili yield decrement, which was related to no increment of the root and shoot morphological traits. It was concluded that root cutting treatment at 8 WAT on tolerant group ('Kencana', 'Lembang-1', 'Ungara') can be used to increase chili yield in lowland areas.

Contrasting response of root traits of arbuscular mycorrhizal and ectomycorrhizal trees to phosphorus availability in subtropical forests

Contrasting response of root traits of arbuscular mycorrhizal and ectomycorrhizal trees to phosphorus availability in subtropical forests

The predicted benefits of genomic selection on pig breeding objectives.

The premise was tested that the additional genetic gain was achieved in the overall breeding objective in a pig breeding program using genomic selection (GS) compared to a conventional breeding program, however, some traits achieved larger gain than other traits. GS scenarios based on different reference population sizes were evaluated. The scenarios were compared using a deterministic simulation model to predict genetic gain in scenarios with and without using genomic information as an additional information source. All scenarios were compared based on selection accuracy and predicted genetic gain per round of selection for objective traits in both sire and dam lines. The results showed that GS scenarios increased overall response in the breeding objectives by 9% to 56% and 3.5% to 27% in the dam and sire lines, respectively. The difference in response resulted from differences in the size of the reference population. Although all traits achieved higher selection accuracy in GS, traits with limited phenotypic information at the time of selection or with low heritability, such as sow longevity, number of piglets born alive, pre- and post-weaning survival, as well as meat and carcass quality traits achieved the largest additional response. This additional response came at the expense of smaller responses for traits that are easy to measure, such as back fat and average daily gain in GS compared to the conventional breeding program. Sow longevity and drip loss percentage did not change in a favourable direction in GS with a reference population of 500 pigs. With a reference population of 1000 pigs or onwards, sow longevity and drip loss percentage began to change in a favourable direction. Despite the smaller responses for average daily gain and back fat thickness in GS, the overall breeding objective achieved additional gain in GS.

Genetic control of root architectural traits under drought stress in spring barley (Hordeum vulgare L.).

Root architectural traits play pivotal roles in plant adaptation to drought stress, and hence they are considered promising targets in breeding programs. Here, we phenotyped eight root architecture traits in response to well-watered and drought stress conditions in 200 spring barley (Hordeum vulgare L.) inbred lines over two consecutive field seasons. Root architecture traits were less developed under drought in both seasons when compared with control treatments. Genetic variation in root architectural traits was dissected employing a genome-wide association study (GWAS) coupled with linkage disequilibrium mapping. GWAS uncovered a total of 186 significant single nucleotide polymorphism-trait associations for eight root traits under control, drought, and drought-related indices. Of these, a few loci for root traits were detected on chromosomes 3 and 5, which co-located with QTL identified in previous studies. Interestingly, 13 loci showed simultaneou associations with multiple root traits under drought and drought-related indices. These loci harbored candidate genes, which included a wide range of drought-responsive components such as transcription factors, binding proteins, protein kinases, nutrient and ion transporters, and stress signaling factors. For instance, two candidate genes, HORVU7Hr3G0713160 and HORVU6H r3G0626550, are orthologous to AtACX3 and AtVAMPs, which have reported functions in root length-mediated drought tolerance and as a key protein in abiotic stress tolerance, respectively. Interestingly, one of these loci underlying a high-confidence candidate gene NEW ENHANCER OF ROOT DWARFISM1 (NERD1) showed involvement with root development. An allelic variation of this locus in non-coding region was significantly associated with increased root length under drought. Collectively, these results offer promising multi-trait affecting loci and candidate genes underlying root phenotypic responses to drought stress, which may provide valuable resources for genetic improvement of drought tolerance in barley.

Hydrogen sulfide-mitigated salinity stress impact in sunflower seedlings was associated with improved photosynthesis performance and osmoregulation

BackgroundSalinity is one major abiotic stress affecting photosynthesis, plant growth, and development, resulting in low-input crops. Although photosynthesis underlies the substantial productivity and biomass storage of crop yield, the response of the sunflower photosynthetic machinery to salinity imposition and how H2S mitigates the salinity-induced photosynthetic injury remains largely unclear. Seed priming with 0.5 mM NaHS, as a donor of H2S, was adopted to analyze this issue under NaCl stress. Primed and nonprime seeds were established in nonsaline soil irrigated with tape water for 14 d, and then the seedlings were exposed to 150 mM NaCl for 7 d under controlled growth conditions.ResultsSalinity stress significantly harmed plant growth, photosynthetic parameters, the structural integrity of chloroplasts, and mesophyll cells. H2S priming improved the growth parameters, relative water content, stomatal density and aperture, photosynthetic pigments, photochemical efficiency of PSII, photosynthetic performance, soluble sugar as well as soluble protein contents while reducing proline and ABA under salinity. H2S also boosted the transcriptional level of ribulose 1,5-bisphosphate carboxylase small subunit gene (HaRBCS). Further, the transmission electron microscope showed that under H2S priming and salinity stress, mesophyll cells maintained their cell membrane integrity and integrated chloroplasts with well-developed thylakoid membranes.ConclusionThe results underscore the importance of H2S priming in maintaining photochemical efficiency, Rubisco activity, and preserving the chloroplast structure which participates in salinity stress adaptation, and possibly sunflower productivity under salinity imposition. This underpins retaining and minimizing the injury to the photosynthetic machinery to be a crucial trait in response of sunflower to salinity stress.

The seasonal dynamics of cross-sectional tissue characteristics of Corylus mandshurica twig, petiole, and leaf vein are inconsistent

This study aims to explore how the environment affects the variation and trade-offs of anatomical traits in shrub plants, contributing to a deeper understanding of plant survival strategies and mechanisms of adaptation to the environment. The dominant shrub species Corylus mandshurica in the broad-leaved Korean pine (Pinus koraiensis) forest was selected as the research subject. Current-year twigs and leaves of C. mandshurica were collected in spring (May), summer (July), and autumn (September). Anatomical traits, including non-vascular column proportion (NVP), vascular column proportion (VP), phloem proportion (PP), and xylem proportion (XP), were measured for twigs, lower part of petioles, upper part of petioles, and leaf veins. We found that (1) Compared with seasons, organ type explained most of the variation in the four traits (NVP = 96 %, VP = 87 %, PP = 81 %, XP = 76 %). Lower part of petioles served as the turning point in the variation trend of tissue proportions in cross-sectional structure along the sequence of twigs, lower part of petioles, upper part of petioles, and leaf veins. (2) In spring, C. mandshurica exhibits higher NVP but lower VP and PP, while the results in summer and autumn are opposite to those in spring. Among different organs, twigs show lower NVP but higher VP and XP; whereas petioles and leaf veins show the opposite pattern. (3) Both hydrothermal conditions (monthly precipitation and mean monthly temperature) and light (canopy openness and total transmitted radiation) were the dominant environmental factors influencing anatomical trait variation. In different seasons, the response of NVP and VP in C. mandshurica twigs to dominant environmental factors was opposite to that of lower part of petioles, upper part of petioles, and leaf veins. The response of cross-sectional anatomical traits of current-year twigs, petioles, and leaf veins in C. mandshurica to seasonal changes exhibits distinct characteristics. Furthermore, twigs, petioles, and leaf veins demonstrate distinct survival strategies. Future research should focus on the variation of traits in different plant organs and their connecting parts.

Quantifying innate immune response of an insect host challenged by non‐replicative immune inducers

AbstractNon‐linear immune response is one of the causes of multi‐stability of infection outcomes. In order to avoid the uncertainty caused by multi‐stability in experiments, one needs to quantitatively measure immune response and other traits as well. Here, we took a quantitative approach, which combines mathematical model and time‐series data, to measure the immune response of the Tenebrio moliter challenged by non‐replicative immune inducers. The results showed that the host immunity that characterized by in‐vitro bacterial killing rapidly mounted after immune challenging, then slowly declined to an undetectable level within 100 h. We then quantified the immunity at 15 h after challenging. The results showed that immune response was non‐linearly correlated with the titter of inducer, which fits well to a Hill‐like function. Our results have verified the non‐linear immune response with respect to amount of invading pathogens and may also help to rigorously test the concepts and theories in host–pathogen interaction, such as resistance and tolerance.

Comparing combined application of biochar and nitrogen fertilizer in paddy and upland soils: Processes, enhancement strategies, and agricultural implications

Recently, biochar and N fertilizers have been used to tackle low N use efficiency (NUE) in crops across diverse environmental conditions. The coupling of biochar and N fertilizer may impact crop N utilization through different pathways in various soil types. However, there is currently a lack of comprehensive assessment of how coupling effects specifically influence N utilization in paddy and upland crops. We conducted a meta-analysis of 175 peer-reviewed studies to assess the responses of soil properties and crop traits in paddy and upland fields under coupling effects. The results indicate that NUE (+26.1 %) and N uptake (+15.0 %) in paddy fields increase more than in upland fields (+23.7 % and +8.0 %, respectively), with the coupling effect providing NH4+ predominantly for rice and NO3− for upland crops. NH4+ increases in paddy fields (+6.9 %) but decreases in upland fields (−0.7 %), while microbial biomass carbon (MBC) decreases in paddy fields (−2.9 %) and increases in upland fields (+36.0 %). These findings suggest that coupling effects supply soil inorganic nutrients in paddies and affect microbes in uplands, thereby positively affecting crop N utilization. Specifically, the greatest increase in paddy crop yield and N use efficiency occurs when the ratio of N fertilizer to biochar exceeds 1.5 %, and in uplands, it manifests when applying 10–20 t·ha−1 of biochar and <150 kg·ha−1 N fertilizer. In conclusion, this meta-analysis explores the differential effects of biochar and N fertilizer coupling in different arable land types, offering novel insights into the utilization strategies of biochar in agricultural fields.

Nutrition addition alleviates negative drought effects on Quercus acutissima seedlings

Changing precipitation patterns have exacerbated severe drought events, causing tree die-off and forest mortality. Nutrition addition, as a critical method for forest management, may alleviate negative drought effects. Therefore, we set up a two-factor orthogonal experiment to study the responses of the leaf structural traits of Quercus acutissima to nutrition addition under drought stress. Leaf structural traits, including leaf morphological traits, leaf mass, and leaf nutrition traits, were measured under nine water and nutrition addition treatments. Two-way analysis of variance was used to detect the main effect and interaction of water and nutrition addition on leaf structural traits, principal component analysis was used to screen key traits. Our results show that drought had a unique and decisive effect on leaf length, leaf width, and leaf center, while leaf thickness only depended on nutrition addition. Conversely, no treatments changed the leaf length-width ratio and leaf nitrogen-phosphorus ratio. Besides, nutrition addition alleviated negative drought effects on leaf area, leaf saturated mass, leaf dry mass, leaf nitrogen content, leaf phosphorus content, leaf volume, specific leaf area, and leaf dry-matter content. According to the principal component 1 (54.83%), we screened seven key traits from leaf structural traits, including leaf area, leaf saturated mass, leaf dry mass, leaf nitrogen content, leaf volume, specific leaf area, and leaf dry-matter content, to effectively capture changes in leaf structural traits. Our results demonstrate that under drought stress, nutrition addition enhanced soil nutrition availability, increased leaf nitrogen and leaf phosphorus content, and finally alleviated negative drought effects. Thus, nutrition addition is crucial for plants to get through drought and for forest ecological restoration under global climate change.

Trait-environment interactions of saproxylic beetles as a guide to biodiversity conservation strategies

Conservation of biodiversity requires in-depth knowledge of trait-environment interactions to understand the influence the environment has on species assemblages. Saproxylic beetles exhibit a wide range of traits and functions in the forest ecosystems. Understanding their responses to surrounding environment thus improves our capacity to identify habitats that should be restored or protected. We investigated potential interactions between ecological traits in saproxylic beetles (feeding guilds and habitat preferences) and environmental variables (deadwood, type and age of surrounding forest). We sampled beetles from 78 plots containing newly created high stumps of Scots pine and Silver birch in boreal forest landscapes in Sweden for three consecutive years. Using a model based approach, our aim was to explore potential interactions between ecological traits and the surrounding environment at close and distant scale (20 m and 500 m radius). We found that broadleaf-preferring beetle species are positively associated with the local broadleaf-originated deadwood and broadleaf-rich forests in the surrounding landscapes. Conifer-preferring species are positively associated with the local amount of coniferous deadwood and young and old forests in the surrounding landscape. Fungivorous and predatory beetles are positively associated with old forests in the surrounding landscapes. Our results indicate that both local amounts of deadwood and types of forests in the landscape are important in shaping saproxylic beetle communities. We particularly highlight the need to increase deadwood amounts of various qualities in the landscape, exempt older forests from production and to increase broadleaf-rich habitats in order to meet different beetle species’ habitat requirements. Trait responses among saproxylic beetles provide insights into the significance of broadleaf forest and dead wood as essential attributes in boreal forest restoration, which helps conservation planning and management in forest landscapes.

Short-term responses of growth and leaf physiology of the sclerophyllous Cryptocarya alba (Molina) seed sources to water restriction

ABSTRACT There are concerns about the vulnerability of some dominant sclerophyllous species in Mediterranean zones to water restriction, especially at outplanting, and much of the efforts for active restoration are on identifying proper seed sources. This study aimed to determine the short-term responses of growth, biomass partitioning, and leaf-physiological traits of Cryptocarya alba provenances to water restriction in nursery conditions. Three seed sources from xeric sites (northern distribution) and one from a more mesic site (southern distribution) were subjected to water restriction for three months and then evaluated in increments in root collar diameter and height, biomass components (leaves, shoots, roots), gas-exchange and fluorescence parameters, and carbon (Δ13) and oxygen (δ18O) isotopic ratios. Water restriction decreased growth and leaf biomass as a short-term response, but this effect was not expressed in stem and root biomass. Similarly, water restriction decreased the photosynthetic rate (Asat), stomatal conductance (gs), and maximum efficiency of PSII. Moreover, water restriction also increased the intrinsic water use efficiency (WUEint), but it had no effect on Δ13 or δ18O. Seed sources did not differ in any traits except in stem and total biomass. The results did not confirm a better performance of seed sources from xeric than mesic origin sites to water restriction.

Response of Functional Traits of Aquatic Plants to Water Depth Changes under Short-Term Eutrophic Clear-Water Conditions: A Mesocosm Study.

Aquatic plants play a key role in the structuring and functioning of shallow lake ecosystems. However, eutrophication often triggers shifts in plant communities and species diversity, especially in the early stages when the water is still clear. Additionally, water depth is an important factor regulating aquatic plant communities. We conducted a 50-day mesocosm study to investigate how water depth (50 cm and 100 cm) affected the functional traits (vertical expansion versus horizontal colonisation) of 20 aquatic plants under eutrophic clear-water conditions. Among the selected species, the submerged plants Hydrocotyle vulgaris and Limnophila indica exhibited higher plant height or biomass in deeper water, while the emergent plants Myriophyllum aquaticum showed the opposite trend. Additionally, Ludwigia peploides subsp. stipulacea exhibited better vertical growth than the remaining species, and the submerged species Vallisneria denseserrulata had better horizontal colonisation. There was a positive correlation between plant height and rhizome length, indicating the absence of a trade-off between vertical growth and horizontal expansion. Our findings suggest an overall resilience of aquatic plants to varying water depths within our study range and highlight the importance of analysing functional traits when selecting appropriate species in freshwater ecosystem restoration, particularly in the face of climate change-induced water depth fluctuations.

Nectar and floral morphology differ in evolutionary potential in novel pollination environments.

Plants can evolve rapidly after pollinator changes, but the response of different floral traits to novel selection can vary. Floral morphology is often expected to show high integration to maintain pollination accuracy, while nectar traits can be more environmentally sensitive. The relative role of genetic correlations and phenotypic plasticity (PP) in floral evolution remains unclear, particularly for nectar traits, and can be studied in the context of recent pollinator changes. Digitalis purpurea shows rapid recent evolution of corolla morphology but not nectar traits following a range expansion with hummingbirds added as pollinators. We use this species to compare PP, heritability, evolvability and integration of floral morphology and nectar in a common garden. Morphological traits showed higher heritability than nectar traits, and the proximal section of the corolla, which regulates access to nectar and underwent rapid change in introduced populations, presented lower integration than the rest of the floral phenotype. Nectar was more plastic than morphology, driven by highly plastic sugar concentration. Nectar production rate showed high potential to respond to selection. These results explain the differential rapid evolution of floral traits previously observed in this species and show how intrafloral modularity determines variable evolutionary potential in morphological and nectar traits.

Physiology Evolves Convergently but Lags Behind Warming inCities.

Cities, through the generation of urban heat islands, provide a venue for exploring contemporary convergent evolution to climatic warming. We quantified how repeatable the evolution of heat tolerance, cold tolerance, and body size was among diverse lineages in response to urban heat islands. Our study revealed significant shifts toward higher heat tolerance and diminished cold tolerance among urban populations. We further found that the magnitude of trait divergence was significantly and positively associated with the magnitude of the urban heat island, suggesting that temperature played a major role in the observed divergence in thermal tolerance. Despite these trends, the magnitude of trait responses lagged behind environmental warming. Heat tolerance responses exhibited a deficit of 0.84°C for every 1°C increase in warming, suggesting limits on adaptive evolution and consequent adaptational lags. Other moderators were predictive of greater divergence in heat tolerance, including lower baseline tolerance and greater divergence in body size. Although terrestrial species did not exhibit systematic shifts toward larger or smaller body size, aquatic species exhibited significant shifts toward smaller body size in urban habitats. Our study demonstrates how cities can be used to address long-standing questions in evolutionary biology regarding the repeatability of evolution. Importantly, this work also shows how cities can be used as forecasting tools by quantifying adaptational lags and by developing trait-based associations with responses to contemporary warming.

98 Adding parasite resistance to the breeding objective in hair sheep

Abstract Economic selection indexes provide the best method to achieve genetic gain for multiple traits simultaneously. Hair sheep enterprises, particularly in environments with substantial gastrointestinal nematode challenge, may benefit from incorporating parasite resistance in a selection index. However, obtaining the relative economic value (REV) for parasite resistance is challenging; information on its impact on productivity is incomplete, as are the costs of treatment given anthelmintic resistance. The National Sheep Improvement Program (NSIP) currently provides producers with an index designed to increase total weight of lamb weaned per ewe lambing (TW). Our objective was to assess the effects of including fecal egg count, an indicator of parasite resistance, as an additional goal trait. Including the benchmark scenario with TW as its sole objective, 10 indexes were constructed using standard index theory. Post-weaning fecal egg count (PFEC) was added to this breeding objective with a REV of -1 and the REV for TW was varied from +1 to +5 at +0.5 increments. Weaning weight, number of lambs born and weaned, and PFEC were the selection criteria, modelled as either phenotypes or estimated breeding values (EBV). Phenotypes and EBV were simulated for 1,000 lambs by Cholesky decomposition and used to generate index scores. Ten replicates were run and the top 3% of males and 26% of females were retained on index scores. Annual responses in the goal traits were estimated. Responses in PFEC were expressed as a percentage, assuming a mean PFEC of 2,089 eggs/g as in NSIP. Concordances with those selected in the benchmark scenario were determined. Using EBV as selection criteria, TW increased by 1.7 kg/yr in the benchmark scenario (Table 1). However, unfavorably, PFEC increased by 2.3%/yr. When phenotypic criteria were used, TW increased by 0.5 kg/yr, and PFEC by 0.3%/yr. Once added to the breeding objective, PFEC decreased regardless of the REV of TW. However, response in TW also reduced, although less so as its REV increased. With EBV as the criteria, the REV of +3 for TW appeared preferable: PFEC reduced by 7.1%/yr with 98% of the response in TW retained. With phenotypic selection criteria, PFEC reduced by 5.2%/yr with 94% of the response in TW retained. With +3 REV for TW and EBV as the selection criteria, on average 65% and 82% of males and females, respectively, were chosen in common with the benchmark. When phenotypic criteria were used, those percentages were 60% and 80%, respectively. Implementing a more holistic index with REV of +3 for TW and -1 for PFEC would result in reasonable responses in both traits. However, producers will need to decide if reduced gains in TW is acceptable to improve parasite resistance in a hair sheep breeding program.

When talk matters: the role of negative supervisor gossip and employee agreeableness in feedback seeking and job performance

PurposeThis study aims to understand the impact of negative supervisor gossip on job performance among South Indian hotel employees. The focus is not just on the direct influence, but also on the mediating role of feedback-seeking behaviour (FSB) and the moderating effects of the agreeableness trait.Design/methodology/approachThrough purposive sampling, data was garnered from South Indian hotel employees. Comprehensive analyses were performed using partial least squares structural equation modelling.FindingsThe analysis shows that FSB plays a mediating role in the positive relationship between negative supervisor gossip and job performance. In addition, the influence of gossip on FSB and subsequent job performance was more pronounced for employees with high agreeableness.Research limitations/implicationsThis research underscores the complex interplay between negative supervisor gossip and job performance, revealing that such gossip can catalyze FSB process in employees. It suggests that under certain conditions, negative gossip can be transformed into a constructive force that enhances job performance, challenging traditional perceptions of gossip in the workplace.Practical implicationsThe findings underscore the importance of understanding the effects of workplace dynamics, like supervisor gossip, on employee behaviour and performance. Recognizing the influence of individual personality traits, such as agreeableness, can guide management strategies for fostering a productive work environment.Originality/valueThis research sheds light on the intricate interplay between negative supervisor gossip, FSB and agreeableness, offering a novel perspective on their combined impact on job performance. It not only enriches the existing literature on workplace communication but also broadens the understanding of the role of personality traits in shaping employee responses and outcomes.