Search Results (17)

The improvement in yield in cultivar mixtures has been well established. Despite increasing knowledge of the improvement involving within-species diversification and resource use efficiency, little is known about the benefits arising from relatedness-mediated intraspecific interactions in cultivar mixtures. This study used a relatedness gradient of rice cultivars to test whether neighbor relatedness contributes to improvements in grain yields in cultivar mixtures. We experimentally demonstrated the grain yield of rice cultivar mixtures with varying genetic relatedness under both field and controlled conditions. As a result, a closely related cultivar mixture had increased grain yield compared to monoculture and distantly related mixtures by optimizing the root-to-shoot ratio and accelerating flowering. The benefits over monoculture were most pronounced when compared to the significant yield reductions observed in distantly related mixtures. The relatedness-mediated improvement in yields depended on soil volume and nitrogen use level, with effects attenuating under larger soil volumes or nitrogen deficiency. Furthermore, neighbor relatedness enhanced the richness and diversity of both bacterial and fungal communities in the rhizosphere soil, leading to a significant restructuring of the microbial community composition. These findings suggest that neighbor relatedness may improve the grain yield of rice cultivar mixtures. Beneficial plant–plant interactions may be generated by manipulating cultivar kinship within a crop species. A thorough understanding of kinship strategies in cultivar mixtures offers promising prospects for increasing crop production. Full article

Filial cannibalism is the consumption of one’s own viable progeny. It occurs in a range of taxa but is particularly well-documented in fish species. Since parental care in fishes is typically male-biased, it is usually assumed that filial cannibalism is predominantly performed by the parental male while he is providing care to offspring. Filial cannibalism by females is less studied in fish. Video-recorded observations of ten pairs of adults housed in captivity revealed the first documentation of female filial cannibalism in the redhead goby (Elacatinus puncticulatus). Females were observed consuming both their own eggs and larvae. We discuss non-adaptive and adaptive explanations for female filial cannibalism in the redhead goby, including confinement due to captivity, nutritional or energetic need, and a possible lack of kin recognition. Understanding the evolutionary significance of filial cannibalism exhibited by females is an important biological inquiry. Since the redhead goby is a species used in the aquarium trade, understanding the conditions that influence female filial cannibalism in captivity may yield practical implications. Full article

Conspecific plants exhibit morphological and biochemical plasticity in response to genetic relatedness in varying environments. However, the response strategies and factors influencing kin recognition in plants remain unclear. Meta-analysis is an approach to synthesize the effect size of plant–plant and plant–environment interactions. Here, we present the first case of a meta-analysis for response strategies and interfering factors in relatedness-mediated plant–plant interactions. We synthesized the effect of kin recognition on plant performance and environmental factors, based on 104 studies with 4045 cases. As a result, we found that kin recognition reduces root biomass, root length, root–shoot ratio, and lateral root number, lowering belowground competition. Furthermore, kin cooperation enhances aboveground light acquisition by increasing leaf area and boosts reproductive success by increasing seed biomass. The kinship effects are significantly influenced by both biotic (e.g., root interactions, kinship coefficient r, sex systems, recognition level) and abiotic factors (e.g., nutrient levels, experiment types, stress type, planting spacing and duration). Our meta-analysis highlights the response strategies and interfering factors of kin recognition in plant performance and environment dynamics, laying the foundation for further research on its ecological evolution and agricultural applications. Full article

It is hardly surprising that in the chronicles of the First Crusade (1096–1099) and in the Chronicon of William of Tyre, accounts propagating Christian warfare, impressiveness, authority and command stem from military actions blessed by God. In the depictions, the position of being a leader is constructed and maintained by a public display of martial ability, by deeds rather than by words. The sources certainly describe aristocratic warriors influencing their peers or larger mixed audiences by speech, but in these cases too, to be successful, the grasp on command normally requires that physical effort follows the communications. The narratives equate physical action with the motives, values and beliefs of the first crusaders. The initiative aimed at achieving leadership is often described approvingly, but the sources also criticize the leaders for manipulative behaviour and unwillingness to cooperate with each other. The judgement of the sources depends on authorial agenda and dynastic rivalries: the leaders of the First Crusade, here especially Bohemond of Taranto (c. 1054–1111), Tancred of Hauteville (c. 1078–1112) and the successors of Godfrey of Bouillon (c. 1060–1100), understood the relation between written history and the claim on power and actively contributed to the production of the heroic image of the first crusaders, that is, the highlighting of their own alleged excellence as leaders. For these three leaders, a cultural legacy, whether initiated during their lifetime or posthumously, was crucial to creating a lasting image of effective leadership. The case of Peter the Hermit, a preacher from Amiens with a supposedly low social background, is different. The fact that chroniclers and composers of chansons included a figure without military expertise and verifiable support from kin and allies among the leaders of the First Crusade, albeit in a controversial manner, bears evidence in itself of his recognition by medieval audiences. Leadership is a gendered talent in the twelfth-century chronicles. The close relation between command and military action on the one hand, and the categorical exclusion of women from the field of battle on the other, discouraged depictions of female leadership in the crusading context. As a result, women were excluded from the leadership of the First Crusade, and references to female authority did not appear in the sources until several decades later in an altered context, with Queen Melisende of Jerusalem (c. 1105–1161) being the clearest example. In her case, too, gender formed a barrier to action and leadership. William of Tyre’s description of her reign is ambivalent, while her sister Alice’s (c. 1110—after 1151) claim to the regency of Antioch is portrayed negatively. This article compares the models and qualities of the leaders of the First Crusade in medieval sources. The first section considers modern definitions of imposing (charismatic) authority and ties the discussion to the overarching theme of exploring medieval crusader leadership. The second part examines the examples of the leaders of Antioch and Jerusalem and their cultural legacy in the chronicles. Full article

Communication through airborne volatile organic compounds (VOCs) and root exudates plays a vital role in the multifarious interactions of plants. Common ragweed (Ambrosia artemesiifolia L.) is one of the most troublesome invasive alien species in agriculture. Below- and aboveground chemical interactions of ragweed with crops might be an important factor in the invasive species’ success in agriculture. In laboratory experiments, we investigated the contribution of intra- and interspecific airborne VOCs and root exudates of ragweed to its competitiveness. Wheat, soybean, and maize were exposed to VOCs emitted from ragweed and vice versa, and the adaptation response was measured through plant morphological and physiological traits. We observed significant changes in plant traits of crops in response to ragweed VOCs, characterized by lower biomass production, lower specific leaf area, or higher chlorophyll contents. After exposure to ragweed VOCs, soybean and wheat produced significantly less aboveground dry mass, whereas maize did not. Ragweed remained unaffected when exposed to VOCs from the crops or a conspecific. All crops and ragweed significantly avoided root growth toward the root exudates of ragweed. The study shows that the plant response to either above- or belowground chemical cues is highly dependent on the identity of the neighbor, pointing out the complexity of plant–plant communication in plant communities. Full article

Plants exhibit differential behaviours through changes in biomass development and distribution in response to environmental cues, which may impact crops uniquely. We conducted a mesocosm experiment in pots to determine the root and shoot behavioural responses of wheat, T. aestivum. Plants were grown in homogeneous or heterogeneous and heavily or lightly fertilized soil, and alone or with a neighbour of the same or different genetic identity (cultivars: CDC Titanium, Carberry, Glenn, Go Early, and Lillian). Contrary to predictions, wheat did not alter relative reproductive effort in the presence of neighbours, more nutrients, or homogenous soil. Above and below ground, the plants’ tendency to use potentially shared space exhibited high levels of plasticity. Above ground, they generally avoided shared, central aerial space when grown with neighbours. Unexpectedly, nutrient amount and distribution also impacted shoots; plants that grew in fertile or homogenous environments increased shared space use. Below ground, plants grown with related neighbours indicated no difference in neighbour avoidance. Those in homogenous soil produced relatively even roots, and plants in heterogeneous treatments produced more roots in nutrient patches. Additionally, less fertile soil resulted in pot-level decreases in root foraging precision. Our findings illustrate that explicit coordination between above- and belowground biomass in wheat may not exist. Full article

Despite increasing evidence of kin recognition in natural and crop plants, there is a lack of knowledge of kin recognition in herbicide-resistant weeds that are escalating in cropping systems. Here, we identified a penoxsulam-resistant barnyardgrass biotype with the ability for kin recognition from two biotypes of penoxsulam-susceptible barnyardgrass and normal barnyardgrass at different levels of relatedness. When grown with closely related penoxsulam-susceptible barnyardgrass, penoxsulam-resistant barnyardgrass reduced root growth and distribution, lowering belowground competition, and advanced flowering and increased seed production, enhancing reproductive effectiveness. However, such kin recognition responses were not occurred in the presence of distantly related normal barnyardgrass. Root segregation, soil activated carbon amendment, and root exudates incubation indicated chemically-mediated kin recognition among barnyardgrass biotypes. Interestingly, penoxsulam-resistant barnyardgrass significantly reduced a putative signaling (–)-loliolide production in the presence of closely related biotype but increased production when growing with distantly related biotype and more distantly related interspecific allelopathic rice cultivar. Importantly, genetically identical penoxsulam-resistant and -susceptible barnyardgrass biotypes synergistically interact to influence the action of allelopathic rice cultivar. Therefore, kin recognition in plants could also occur at the herbicide-resistant barnyardgrass biotype level, and intraspecific kin recognition may facilitate cooperation between genetically related biotypes to compete with interspecific rice, offering many potential implications and applications in paddy systems. Full article

In captivity, intact male horses, due to their sexual drive, are usually socially isolated from other horses. This lifestyle strongly contrasts with that experienced by horses living in free-roaming, feral, or semi-feral conditions, where adult stallions have several roles in their social group, with successful reproduction being their primary drive. Reproductive skew in wild populations is high; many stallions will fail to reproduce at all, while others achieve high levels of reproductive success, siring a large number of foals. Successful stallions are those with particular characteristics and abilities that facilitate harem formation and tenure, allowing them to successfully take over a harem or establish a new one, protect mares from rival stallions, employ appropriate social behaviour to maintain group cohesion, and avoid kin-mating, for example through kin recognition mechanisms. Whilst the life of free-living stallions is far from stress-free, they retain ancestral adaptations to selection pressures (such as predation and competition) exhibited by their natural environment over thousands of years. Here, we discuss the challenges faced by free-living horse stallions, the roles they play in social groups, and their resulting social needs. By understanding these pressures and how stallions react to them, we highlighted the importance of the social environment for the stallion. It is hoped that a better understanding of wild stallions’ lives will lead to their needs being more clearly met in captivity, reducing stereotypical behaviour and improving welfare. Full article

Chemical cues and pheromones mediate fish reproduction, aggregation, risk assessment, and kin recognition. To better understand the chemical communication of conspecific fish, the behavioral responses to bile acids (BAs), their source, and reception investigated in large yellow croaker (Larimichthys crocea). Behavioral experimental results indicated that juvenile fish were attracted to intestinal contents (ICs) emanating from conspecifics, regardless of whether the fish were feeding. IC BA-targeted metabolomics revealed that cholic acid (CA), taurocholic acid (TCA), taurochenodeoxycholic acid (TCDCA), chenodeoxycholic acid (CDCA), and taurodeoxycholic acid (TDCA) were the top five categories. Tests with and without fasting yielded similar categories and proportions of BAs, indicating that the intestinal BA profiles were generally stable. At the nanomolar level, CA led to significant preference behavior (p < 0.01). The electrophysiological results supported the hypothesis that the top five BAs were potent odorants in L. crocea. Moreover, inhibition of adenylate cyclase–cyclic adenosine monophosphate (AC–cAMP) signaling and phospholipase C (PLC) signaling reduced the electro-olfactogram (EOG) responses to CA and CDCA. Collectively, the findings of this study indicate that conspecific individuals could be attracted by ICs unrelated to feeding. As a key intestinal BA, CA led to fish preference behaviors and olfactory responses relying on cAMP and PLC transduction cascades. Full article

Olfaction is essential in some behaviors of honeybee, such as nursing, foraging, attracting a mate, social communication, and kin recognition. OBPs (odorant binding proteins) play a key role in the first step of olfactory perception. Here, we focused on a classic OBP with a PBP-GOBP domain from the Asian honeybee, Apis cerana cerana. Beyond that, the mRNA expression profiles and the binding affinity of AcerOBP6 were researched. According to qRT-PCR analysis, AcerOBP6 transcripts were mainly expressed in the antennae of forager bees. In addition, we found that the expression level of AcerOBP6 was higher than that of AmelOBP6. The fluorescence competitive binding assay indicated that the AcerOBP6 protein had binding affinity with most of the tested odors, including queen pheromone, worker pheromone, and floral volatiles, among which the strongest one was linolenic acid (with a Ki value of 1.67). However, AcerOBP6 was not sensitive to the brood pheromones. A further study based on EAG assay revealed that the antennae had the strongest response to 2-heptanone. The EAG recording values of the selected ligands were all reduced after AcerOBP6 was silenced, with 8 of 14 declining significantly (p < 0.01) given that these odors could specifically bind to AcerOBP6. As revealed in our current study, AcerOBP6 might be a crucial protein involved in olfactory recognition for foraging. Overall, the research provides a foundation for exploring the olfactory mechanism of A. cerana cerana. Full article

Mixtures of species in natural or agricultural systems can increase the performance of individuals or groups relative to monocultures, often through facilitative mechanisms. Mechanisms include root communication by which plants can interrogate the identity of adjacent plants and respond negatively or positively. Alternatively, mixtures of species can ameliorate the harmful effects of soil biota that are pronounced in monocultures, thereby improving plant productivity. Limited investments into roots by shade-grown Serianthes plants in nurseries have been correlated with reduced survival after transplantation to forested habitats. We used companion container cultures in two studies to determine if heterospecific neighbor, or “stranger” roots could experimentally increase the root growth of Serianthes grandiflora plants used as surrogates for the critically endangered Serianthes nelsonii. In one study, native sympatric eudicot and pteridophyte companions increased relative root growth and conspecific companions decreased root growth in comparison to control plants that were grown with no companions. In a second study, the phylogeny of companion plants elicited different root growth responses following the order of congeneric < eudicot = monocot < gymnosperm < pteridophyte. We propose the use of stranger roots that are experimentally maintained in production containers as a passive protocol to improve relative and absolute root growth, leading to improved post-transplant growth and survival of container-grown Serianthes plants. Full article

Body odours and their importance for human chemical communication, e.g., in the mother–child relationship, are an increasing focus of recent research. Precise examination of sampling methods considering physiology and feasibility aspects in order to obtain robust and informative odour samples is therefore necessary. Studies comparing body odour sampling at different body sites are still pending. Therefore, we sampled axilla, breast, and head odour from 28 mother–infant dyads and examined whether odour perception differs with regard to the body site. The participating mothers were asked to evaluate their own and their infant’s body odour samples, as well as odours of two unfamiliar mother–infant dyads. We tested whether maternal pleasantness and intensity evaluation, as well as recognition ability of the odours differed between the body sites. In infants, the head odour exhibited slightly lower pleasantness ratings than axilla and breast, and intensity ratings did not differ between body sites. In mothers, body site affected intensity ratings but not pleasantness ratings, as the breast odour was rated as less intense compared with head and axilla. Across all body sites, mothers rated the own and their infant’s odour as less intense when compared with unfamiliar samples. Recognition ability did not differ between body sites, and in line with previous studies, mothers were able to recognize their own and their own infant’s odour above chance. In sum, our study extends the previous methodological repertoire of body odour sampling and indicates that the axilla, breast, and head of adults as well as infants serve as informative odour sources. Full article

Studies on crop response to light quality (red (R) to far-red (FR) light ratio) often recommend early weed removal to reduce the effects of shade avoidance responses on crop yield. However, it is unclear whether crops are able to distinguish reflected light quality of kin from that of nonkin. We evaluated the response of sugar beet (Beta vulgaris L.) to reflected FR light from sugar beet, common lambsquarters (Chenopodium album L.), Kentucky bluegrass (Poa pratensis L.), alfalfa (Medicago sativa L.), and bare soil (control) under outdoor conditions in 2016 and 2017. Treatments were completely randomized with 10 replications per treatment. The study methods ensured there was no direct resource competition. The reflected R:FR of plant species ranged from 0.06 (common lambsquarters) to 0.24 (sugar beet) compared to 0.7 for the bare soil. In 2016 and 2017, there were 2 to 4 more leaves in the sugar beet surrounded by soil compared to sugar beet surrounded by neighboring species. There was up to 47, 57, 43, and 23% reduction in sugar beet leaf area, shoot dry weight, root diameter, and root dry weight, respectively, due to reflected R:FR light from neighboring species. Sugar beet did not respond differently to reflected light quality of kin compared to nonkin. Full article

Human kin recognition activates substrates of the extended facial processing network, notably the right-hemisphere structures involved in self-face recognition and posterior medial cortical substrates. To understand the mechanisms underlying prosociality toward kin faces in comparison to other familiar faces, we investigated the neural correlates of implicit trustworthiness ratings to faces of actual kin and personal friends, controlling for activation to distracter faces. When controlling for activation associated with unknown faces, trustworthiness ratings of faces of kin, compared to friends, were associated with increased activation in the dorsal anterior cingulate cortex, posterior cingulate, and precuneous. On the other hand, trustworthiness ratings of friend faces, relative to kin faces, were associated with the lateral occipital gyrus and insular cortex. Trustworthiness ratings for unknown faces were only associated with activation in the fusiform gyrus. These findings suggest that we should employ medial cortical substrates known to be part of the self-other network when making implicit social judgements about kin, but not other classes of facial stimuli. Full article

According to a prophecy told in a small, Muskogee-identified community in the US South, the seeds of Indigenous ways of knowing and relating to more-than-human kin will once again flourish in the ruins of colonial orders. Even settlers will be forced to turn to Indigenous knowledges because “they have destroyed everything else”. Following this visionary history-future, this article asks how Indigenous diplomacies and temporalities animate resurgent possibilities for making life within the fractures (and apocalyptic ruins) of settler states. This demands a rethinking of the global and the international from the perspective of deep Indigenous histories. I draw on research visiting ancestral landscapes with community members, discussing a trip to an ancient shell mound and a contemporary cemetery in which shells are laid atop grave plots. These stories evoke a long-term history of shifting and multivalient shell use across religious and temporal differences. They speak to practices of acknowledgement that exceed liberal settler regimes of state recognition and extend from much older diplomatic practices. Full article