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Sequoia and Sequoiadendron: Two paleoendemic megatrees with markedly different adaptive responses to recent high-severity fires 红杉和红杉:两种古特有的巨树,对最近的高严重性火灾有明显不同的适应反应。
IF 2.7 2区 生物学 Q2 PLANT SCIENCES Pub Date : 2025-09-24 DOI: 10.1002/ajb2.70089
Jon E. Keeley, Juli G. Pausas

Premise

Coast redwood (Sequoia sempervirens) and giant sequoia (Sequoiadendron giganteum) are two iconic paleoendemic species with limited distributions, well known for their spectacular size. Recently, they have been exposed to high-severity crown fires, with starkly contrasting responses.

Methods

We used all available published literature and field observations to understand the responses to fire in an evolutionary context.

Results

Coast redwoods, found in California's coastal rainforests, were highly resilient to high-severity fires, with most trees surviving due to their ability to resprout from the base and trunk, though seedling regeneration was largely lacking. In contrast, giant sequoias, native to the Sierra Nevada, do not resprout, leading to significant tree mortality after very high-severity fires; they released seeds only in patches where some trees survived moderately high-severity fires.

Conclusions

These high-severity fires were novel events for giant sequoias, but not for coast redwoods. Fire suppression has disrupted the natural fire regime in the giant sequoia ecosystem by preventing frequent lightning-caused surface fires, resulting in high-severity fires that killed a substantial number of these giants. In coast redwood forests, infrequent but high-severity crown fires were the norm before burning by Native Americans. Frequent, low-severity burning by Native Americans over the past few hundred years was localized and 20th-century fire suppression has returned the natural fire regime to these forests. The recent crown fires do not represent a threat to redwood conservation; however, other management goals may require emulating Native American burning practices and in some cases may be best termed cultural restoration.

前提:海岸红杉(Sequoia sempervirens)和巨红杉(Sequoiadendron giganteum)是两个标志性的古特有物种,分布有限,以其壮观的体型而闻名。最近,它们遭遇了严重程度很高的树冠火灾,反应截然不同。方法:我们利用所有可用的已发表的文献和实地观察来了解在进化背景下对火灾的反应。结果:在加利福尼亚沿海雨林中发现的海岸红杉对高度严重的火灾具有高度的弹性,大多数树木存活下来,因为它们能够从基部和树干上重新发芽,尽管幼苗再生在很大程度上缺乏。相比之下,原生于内华达山脉的巨型红杉不会重新发芽,导致在非常严重的火灾后树木大量死亡;他们只在一些树木在中度严重火灾中幸存下来的地方释放种子。结论:这些高度严重的火灾对巨红杉来说是新的事件,但对海岸红杉来说不是。灭火通过阻止频繁的闪电引起的地面火灾,破坏了巨红杉生态系统的自然火灾制度,导致大量巨红杉死亡的高严重性火灾。在海岸红杉林中,在印第安人燃烧之前,很少发生但严重程度很高的树冠火灾是常态。在过去的几百年里,印第安人频繁的、低强度的燃烧是局部的,20世纪的灭火使这些森林恢复了自然的火灾状态。最近的林冠火灾并不代表红木保护的威胁;然而,其他管理目标可能需要模仿美洲土著的焚烧做法,在某些情况下,最好被称为文化恢复。
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引用次数: 0
Insect visitation patterns in diploid Centaurea aspera and its related allotetraploid and triploid hybrids: Similar rates but distinct assemblages 二倍体半人马及其相关的异源四倍体和三倍体杂交种的昆虫访问模式:相似的比率但不同的组合。
IF 2.7 2区 生物学 Q2 PLANT SCIENCES Pub Date : 2025-09-23 DOI: 10.1002/ajb2.70103
Alfonso Garmendia, Hugo Merle, Pau Lucio-Puig, María Ferriol

Premise

Polyploidy is key to plant evolution by contributing to speciation, diversification, and adaptability. However, the minority cytotype exclusion effect can limit the persistence of polyploids, which can be mitigated by reproductive barriers such as distinct insect visitation between cytotypes. In eastern Spain, the diploid C. aspera, its related allotetraploid C. seridis, and their sterile triploid hybrid C. ×subdecurrens coexist in contact zones. Here we assessed the diversity and behavior of insects visiting these Centaurea taxa, identified factors influencing insect visitation, and explored potential changes in visitor composition and frequency across taxa in the contact zone of El Saler (Valencia, Spain).

Methods

Five natural blocks (25–50 m2) on sand dunes, each with all three plant taxa in proximity, were monitored weekly when their flowering periods overlapped. Insect visitors were identified, and number of visits and of capitula were recorded. Linear modelling was used to identify factors predicting visit frequency and differences in insect composition among plant taxa.

Results

Seventeen flying insect species visited Centaurea plants. The number of florets and the number of capitula were the strongest predictors of visit frequency, showing similar outcomes, rather than plant taxon or date. Although overall visitation rates did not significantly differ among plant taxa, insect assemblages varied. Centaurea seridis attracted a distinct set of insects compared to C. aspera and C. ×subdecurrens, with some insects displaying visitation biases at particular times.

Conclusions

Differences in insect assemblages suggest potential prezygotic barriers that could help C. seridis overcome minority exclusion, supporting its long-term establishment.

前提:多倍体是植物进化的关键,有助于物种形成、多样化和适应性。然而,少数细胞型排斥效应可以限制多倍体的持久性,这可以通过生殖障碍如不同细胞型之间不同的昆虫访问来缓解。在西班牙东部,二倍体C. aspera及其相关的异源四倍体C. seridis和它们不育的三倍体杂交C. ×subdecurrens共存于接触带。在此基础上,对西班牙El Saler接触带半人马花昆虫访花的多样性和行为进行了分析,确定了昆虫访花的影响因素,并探讨了昆虫访花的组成和频率的潜在变化。方法:在沙丘上设置5个自然块(25 ~ 50 m2),每个块附近均有3种植物类群,在其花期重叠时进行每周监测。鉴定了访虫者,记录了访虫次数和头状花序。利用线性模型分析了影响昆虫访花频率和昆虫组成差异的因子。结果:17种飞虫访问了半人马属植物。小花数和头状花序数对访花频率的预测效果较好,而植物分类群和日期对访花频率的预测效果相似。虽然各植物类群的总体访视率没有显著差异,但昆虫的组合却存在差异。与C. aspera和C. ×subdecurrens相比,半人马座的seridis吸引了一组不同的昆虫,一些昆虫在特定的时间表现出访问偏见。结论:昆虫组合的差异表明潜在的合子前屏障可以帮助C. seridis克服少数排斥,支持其长期建立。
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引用次数: 0
Sources of variation in plant chemical diversity: Lessons from Malagasy Ficus 植物化学多样性变异的来源:以马达加斯加榕属植物为例。
IF 2.7 2区 生物学 Q2 PLANT SCIENCES Pub Date : 2025-09-22 DOI: 10.1002/ajb2.70102
Linh M. N. Nguyen, Jana Ebersbach, Diary Razafimandimby, Jean-Yves Rasplus, Henriette Uthe, Radoniaina R. Rafaliarison, Stefanie Döll, Yvonne Poeschl, Kim Valenta, Nicole M. van Dam, Omer Nevo

Premise

Plants produce a tremendous variety of secondary compounds that are crucial to interspecific and intraspecific interactions and for adaptation to environmental changes. This chemical diversity has been attributed to multiple factors, including interactions with herbivores or pollinators, tissue-specific needs, and evolutionary constraints. The interplay between a vast array of factors driving plant chemodiversity remains unclear, mainly because most studies have focused on a single organ—mostly leaves—or, when comparing different organs, have been limited to single taxa. Thus, the relationship between functional and phylogenetic factors remains unresolved. We use a model system of Ficus from Madagascar to examine the extent to which phytochemical diversity is shaped by tissue-specific function and the degree to which phylogenetic relatedness explains variation in fruit and leaf chemodiversity.

Methods

We applied an untargeted metabolomics approach to unripe fruits (the syconium, a hollow structure containing numerous small flowers) and leaves from eight species of wild figs (Ficus spp.) sampled in a tropical rainforest in Madagascar. We characterized their chemical profiles using ultra-performance liquid chromatography–mass spectrometry and reconstructed their phylogeny using six genetic markers to understand the patterns of chemodiversity.

Results

Fruit and leaf metabolomes were more similar to the same organ in other species than to the other organs within the same species. There was a significant but moderate phylogenetic correlation in fruit and leaf chemodiversity.

Conclusions

Although phylogenetic relatedness influences plant chemodiversity in Malagasy figs, functional convergence of tissue-specific metabolites may be a major evolutionary driver.

前提:植物产生各种各样的次生化合物,这些化合物对种间和种内的相互作用以及对环境变化的适应至关重要。这种化学多样性归因于多种因素,包括与食草动物或传粉者的相互作用、组织特异性需求和进化限制。驱动植物化学多样性的大量因素之间的相互作用仍然不清楚,主要是因为大多数研究都集中在单个器官上——主要是叶子——或者,当比较不同的器官时,仅限于单个分类群。因此,功能因素和系统发育因素之间的关系仍未得到解决。我们使用来自马达加斯加的无花果模型系统来研究植物化学多样性在多大程度上由组织特异性功能形成,以及系统发育相关性在多大程度上解释果实和叶片化学多样性的变化。方法:我们采用非靶向代谢组学方法对马达加斯加热带雨林中8种野生无花果(Ficus spp.)的未成熟果实(sycon花序,一种含有许多小花的中空结构)和叶子进行了取样。我们利用超高效液相色谱-质谱法对它们的化学特征进行了表征,并利用6个遗传标记重建了它们的系统发育,以了解它们的化学多样性模式。结果:果实和叶片代谢组在其他物种中比在同一物种中更接近同一器官。果实和叶片的化学多样性存在显著但中等的系统发育相关性。结论:尽管系统发育相关性影响马达加斯加无花果的植物化学多样性,但组织特异性代谢物的功能趋同可能是主要的进化驱动因素。
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引用次数: 0
Aboveground-belowground microbial interactions in plants: A call to recognize the complexity within multispecies microbial communities 植物的地上-地下微生物相互作用:呼吁认识到多物种微生物群落的复杂性。
IF 2.7 2区 生物学 Q2 PLANT SCIENCES Pub Date : 2025-09-18 DOI: 10.1002/ajb2.70100
Connor N. Morozumi, Allison M. Reitman, Katy D. Heath, Posy E. Busby, Natalie Christian

Understanding and predicting plant responses to biotic and abiotic environments necessitates grappling with thousands of microbial interactions occurring within aboveground and belowground plant tissues. These distinct microbial communities are indirectly connected through their plant hosts, and aboveground-belowground (AGBG) microbial interactions could play large roles in plant health and drive plant community and ecosystem-level responses. In this review and synthesis, we first discuss mechanisms through which focal microbes directly and indirectly affect other microbes in distal plant compartments. We then add in a layer of complexity: How might microbial community interactions within aboveground plant organs affect root-associated microbiomes, and vice versa? We point to gaps in our knowledge that should drive future research agendas on how “discrete” microbial communities within plants influence one another—a key feature currently missing in plant microbiome research. We also discuss the utility of applying existing ecological theory to enhance the predictive power of plant microbiome research, particularly regarding the outcomes of AGBG microbial interactions across diverse environmental and ecological contexts. These efforts will be especially important within fields such as sustainable agriculture that seek to harness plant-microbiome interactions within a changed and ever-changing world.

理解和预测植物对生物和非生物环境的反应需要与地上和地下植物组织中发生的数千种微生物相互作用进行斗争。这些不同的微生物群落通过它们的植物寄主间接联系在一起,地上-地下(AGBG)微生物相互作用可能在植物健康中发挥重要作用,并驱动植物群落和生态系统水平的响应。在这篇综述和综述中,我们首先讨论了焦点微生物直接和间接影响远端植物室中其他微生物的机制。然后我们增加了一层复杂性:地上植物器官内的微生物群落相互作用如何影响与根相关的微生物群,反之亦然?我们指出了我们知识上的差距,这些差距应该推动未来的研究议程,即植物中“离散”的微生物群落如何相互影响——这是目前植物微生物组研究中缺失的一个关键特征。我们还讨论了应用现有生态学理论来提高植物微生物组研究的预测能力的效用,特别是关于AGBG微生物在不同环境和生态背景下相互作用的结果。这些努力在可持续农业等领域尤其重要,因为可持续农业寻求在不断变化的世界中利用植物-微生物组的相互作用。
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引用次数: 0
Nitrogen enrichment reduces parasitism in an annual hemiparasite 氮的富集减少了一年生半寄生虫的寄生。
IF 2.7 2区 生物学 Q2 PLANT SCIENCES Pub Date : 2025-09-18 DOI: 10.1002/ajb2.70101
Jasmine Taite, Paul D. Nabity

Premise

Anthropogenic activities such as fossil fuel combustion and synthetic fertilizer synthesis have resulted in nitrogen (N) deposition and elevated N availability in ecosystems. Many parasitic plants are adapted to low N environments and have evolved mechanisms to sequester water, N, and other limiting nutrients from hosts. Anthropogenic N deposition may perturb these host–parasite interactions, thereby altering nutrient cycling and ultimately reducing biodiversity.

Methods

To test how N enrichment affects the incidence and degree of plant parasitism, we assayed host–parasite performance and in vitro root growth under supplemental N levels representative of urban areas experiencing N deposition. We focused on the annual hemiparasite Castilleja exserta and two co-occurring host species, Nasella lepida and N. pulchra.

Results

Elevated N decreased haustoria formation and host-seeking behavior by roots but did not affect growth, suggesting N enrichment may reduce parasitism without associated loss of parasite biomass. We confirmed that parasitism decreased host performance and that the degree of parasitism was positively related to host biomass and earlier flowering. We also found N. lepida may be preferred over N. pulchra as a host.

Conclusions

These results indicate that N pollution altered parasitism in C. exserta and highlight the far-reaching ecological effects of N pollution on host–parasite interactions within plant communities.

前提:化石燃料燃烧和合成肥料等人为活动导致生态系统中氮(N)沉积和氮有效性升高。许多寄生植物适应低氮环境,并进化出了从寄主那里隔离水、氮和其他限制性营养物质的机制。人为氮沉降可能扰乱这些宿主与寄生虫的相互作用,从而改变养分循环,最终降低生物多样性。方法:为了研究富氮如何影响植物寄生的发生率和程度,我们在具有代表性的城市地区的补氮水平下,测定了寄主-寄主性能和离体根系生长。我们主要研究了年生半寄生虫Castilleja exserta和两种共存的寄主物种:lepida Nasella和N. pulchra。结果:氮的增加减少了吸器的形成和根系寻找寄主的行为,但不影响生长,表明富氮可能会减少寄主的寄生,而不会导致寄主生物量的损失。寄生降低了寄主的生产性能,寄生程度与寄主生物量和开花时间的提前呈正相关。我们还发现,作为寄主,瘦毛蛛可能比粗毛蛛更受青睐。结论:这些结果表明,氮污染改变了外植草的寄生行为,并突出了氮污染对植物群落内寄主-寄生虫相互作用的深远生态影响。
{"title":"Nitrogen enrichment reduces parasitism in an annual hemiparasite","authors":"Jasmine Taite,&nbsp;Paul D. Nabity","doi":"10.1002/ajb2.70101","DOIUrl":"10.1002/ajb2.70101","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Anthropogenic activities such as fossil fuel combustion and synthetic fertilizer synthesis have resulted in nitrogen (N) deposition and elevated N availability in ecosystems. Many parasitic plants are adapted to low N environments and have evolved mechanisms to sequester water, N, and other limiting nutrients from hosts. Anthropogenic N deposition may perturb these host–parasite interactions, thereby altering nutrient cycling and ultimately reducing biodiversity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>To test how N enrichment affects the incidence and degree of plant parasitism, we assayed host–parasite performance and in vitro root growth under supplemental N levels representative of urban areas experiencing N deposition. We focused on the annual hemiparasite <i>Castilleja exserta</i> and two co-occurring host species, <i>Nasella lepida</i> and <i>N. pulchra</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Elevated N decreased haustoria formation and host-seeking behavior by roots but did not affect growth, suggesting N enrichment may reduce parasitism without associated loss of parasite biomass. We confirmed that parasitism decreased host performance and that the degree of parasitism was positively related to host biomass and earlier flowering. We also found <i>N. lepida</i> may be preferred over <i>N. pulchra</i> as a host.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These results indicate that N pollution altered parasitism in <i>C. exserta</i> and highlight the far-reaching ecological effects of N pollution on host–parasite interactions within plant communities.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"112 9","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bsapubs.onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.70101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
New evidence of Miocene forest grasses (Poaceae: Pharoideae L.G. Clark & Judz.) from Ethiopia and Kenya: Implications for biogeography, evolution, and paleoecology 埃塞俄比亚和肯尼亚中新世森林草(禾本科:禾本科L.G. Clark & Judz.)的新证据:生物地理学、进化和古生态学意义。
IF 2.7 2区 生物学 Q2 PLANT SCIENCES Pub Date : 2025-09-17 DOI: 10.1002/ajb2.70099
Bonnie F. Jacobs, Alice Novello, Caroline A. E. Strömberg, Ellen D. Currano, Christine H. S. Kabuye, E. J. Judziewicz, Aaron D. Pan

Premise

Grasses support critically important ecosystems, occupy a large portion of Earth's land surface, and provide essential resources, including maize, other cereal crops, and bamboo. Their radiation and global spread have been documented primarily by microfossils and paleosol isotopic studies, whereas reconstruction of phylogenetic relationships has relied primarily on living species. However, hypothetical dates associated with evolutionary events can be tested only by fossils. We report new, dated Pharoideae phytoliths from Ethiopia (21.73 Ma), pushing back the first occurrence of that subfamily in the Old World by 10 million years. We also formally describe a rare Pharoideae leaf impression reported from Kenya (12.6 Ma). We discuss the relevance of the fossils to phylogenetics, paleobiogeography, and paleoecology.

Methods

Phytoliths and the macrofossil were prepared using standard techniques. Fossils were identified by comparison with online, herbarium, and research collections.

Results

The phytoliths possess characters exclusive to living Pharoideae. The fossil leaf compares favorably to one species in each of the two living Paleotropical Pharoideae genera, Leptaspis and Scrotochloa. Thus, the subfamily was present in Africa by the early Miocene, improving on previous middle Miocene estimates used to date the Neotropical-Paleotropical crown group split. The fossil sites were forests, indicating that Pharoideae occupied the same niche as today; the broad leaf of the macrofossil is consistent with that of living C3 forest grasses.

Conclusions

Early Miocene (21.73 Ma) Pharoideae phytoliths from Ethiopia provide a new, earlier, first occurrence datum for Poaceae trees. The subfamily occupied a forest niche as it does today.

前提:草类支撑着至关重要的生态系统,占据了地球陆地表面的很大一部分,并提供必要的资源,包括玉米、其他谷类作物和竹子。它们的辐射和全球传播主要是通过微化石和古土壤同位素研究来记录的,而系统发育关系的重建主要依赖于现存物种。然而,与进化事件有关的假设日期只能通过化石来检验。我们在埃塞俄比亚(21.73 Ma)报道了新的、定年的Pharoideae植物岩,将该亚科在旧大陆的首次出现时间推迟了1000万年。我们还正式描述了肯尼亚(12.6 Ma)报道的一种罕见的鹭科叶片印象。我们讨论了化石与系统发育、古生物地理学和古生态学的相关性。方法:采用标准工艺制备植物岩和大化石。化石是通过与网上、植物标本馆和研究藏品的比较来确定的。结果:该植物岩具有现存蕨科植物所特有的特征。在现存的两个古热带鞘翅目属(Leptaspis和Scrotochloa)中,这片化石叶子与每一个物种相比都有优势。因此,该亚科早在中新世就出现在非洲,这比之前用于确定新热带-古热带冠群分裂日期的中新世中期估计有所改善。化石地点是森林,这表明Pharoideae与今天占据了相同的生态位;大化石的阔叶与C3森林草的阔叶一致。结论:埃塞俄比亚早中新世(21.73 Ma)菊科植物岩为禾科树木提供了一个新的、更早的首次出现的资料。这个亚科像今天一样占据了一个森林生态位。
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引用次数: 0
The origin and diversification of Amaryllidaceae: A phylogenetic and biogeographic analysis amarylliedaceae的起源和多样性:系统发育和生物地理分析。
IF 2.7 2区 生物学 Q2 PLANT SCIENCES Pub Date : 2025-09-11 DOI: 10.1002/ajb2.70092
Zoë H. Dennehy-Carr, Kálmán Könyves, Chris Yesson, John C. David, Alastair Culham

Premise

Previous angiosperm-wide studies estimated that the geophytic family Amaryllidaceae diverged in Africa 87.00–46.77 million years ago (mya), spanning the Cretaceous and Palaeogene periods, including multiple important climatic and geological events. Greater precision on when and where this divergence occurred is lacking due to limited sampling of Amaryllidaceae and the paucity of the monocot fossil record. A robust phylogeny is required to estimate the age and origin of suprageneric groups; however, the evolutionary relationships within Amaryllidaceae are unclear.

Methods

We used 78 plastome protein-coding genes to infer the phylogenetic relationships of Amaryllidaceae and estimated the age of the family using four fossils and five secondary calibration points from across the Asparagales. We conducted a new biogeographic analysis to determine the ancestral origins of Amaryllidaceae and suprageneric groups, providing insights into the drivers of diversification.

Results

Our phylogenetic analyses recovered Amaryllidaceae as monophyletic, with Agapanthoideae sister to Amaryllidoideae and Allioideae. We estimate that Amaryllidaceae diverged in southern Africa 48.6 mya (50.3–46.6 mya) during the early Eocene, a period of elevated global temperatures with increasing seasonal aridity. Our biogeographic analyses indicate that taxa migrated from Africa via the Arabian Peninsula to temperate Asia and beyond during the Miocene.

Conclusions

The comprehensive taxon sampling across Amaryllidaceae, the greater number of genes, and the placement of fossils has made it possible to substantially refine estimates of lineage divergence. Establishing a robust age estimate and reconstructing the biogeographic history has led to a better understanding of evolution within the family, of present-day distributions, and of possible drivers of diversification.

前提:以往的被子植物研究估计,地球植物Amaryllidaceae科在8700 - 4677万年前(mya)在非洲分化,跨越白垩纪和古近纪,包括多个重要的气候和地质事件。由于Amaryllidaceae的有限采样和单子叶化石记录的缺乏,对这种分化发生的时间和地点缺乏更精确的认识。需要一个可靠的系统发育来估计超属群的年龄和起源;然而,菊科植物的进化关系尚不清楚。方法:利用78个质体组蛋白编码基因推测Amaryllidaceae的系统发育关系,并利用4块化石和5个二级校准点估算Amaryllidaceae的年龄。通过生物地理分析,确定了Amaryllidaceae和超属类群的祖先起源,为多样性的驱动因素提供了新的见解。结果:我们的系统发育分析恢复了amaryllidae为单系,与amaryllidae和alliodae有亲缘关系。我们估计,在始新世早期,全球气温升高,季节性干旱加剧的时期,Amaryllidaceae在非洲南部48.6亿年前(50.3-46.6亿年前)开始分化。我们的生物地理分析表明,在中新世,类群从非洲经阿拉伯半岛迁移到温带亚洲或更远的地方。结论:通过对Amaryllidaceae的综合分类单元采样,更多的基因数量和化石的放置,可以大大改进谱系分化的估计。建立一个可靠的年龄估计和重建生物地理历史,可以更好地理解家庭内部的进化,当今的分布,以及多样化的可能驱动因素。
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引用次数: 0
Selection maintains floral color polymorphism in scarlet paintbrush, Castilleja coccinea, reflecting combined ecological factors. 选择维持了红漆刷Castilleja coccinea花色的多态性,反映了综合生态因素。
IF 2.7 2区 生物学 Q2 PLANT SCIENCES Pub Date : 2025-09-11 DOI: 10.1002/ajb2.70094
Emma Fetterly, Anna S Braum, Chloe Eun Sun Kim, Katherine E Wenzell, Mary V Ashley, Laura Steger, Jeremie B Fant

Premise: Evolutionary theory predicts polymorphism should be rare; however, intraspecific variation in floral color is common and can be attributed to genetic drift, plasticity, or variable selection. Examining floral color polymorphism both within contact zones and across a species' range can reveal the mechanisms maintaining this variation. Here, we used a multistep approach to investigate spatially heterogeneous variation in floral bract color in Castilleja coccinea.

Methods: We compared frequencies of color morphs, floral morphology, fitness, and genetic structure in regional populations and in a common garden. Next, we examined habitat differences, including edaphic factors, as potential drivers of variation. Lastly, we leveraged herbarium and iNaturalist occurrence data to investigate whether patterns were consistent at the landscape scale.

Results: Bract color in C. coccinea is genetically heritable, with yellow dominant over red, and is under selection. Populations are predominantly monomorphic, with color distance showing no correlation to genetic or geographic distance, despite significant genetic isolation by distance. Yellow morphs were associated with open wetlands, while red morphs occurred at drier sites with nearby tree cover. Red morphs demonstrated lower fitness in a common garden, suggesting trade-offs associated with pleiotropic effects of floral color.

Conclusions: Differences in floral color between morphs are consistent with diversification associated with a shift in ecological niche. We identified variation in edaphic and habitat conditions as probable drivers of divergence in floral color. Additionally, variation in other floral traits suggests a combined role of pollinators and habitat differences acting in concert to maintain distinct floral color morphs.

前提:进化论预测多态性应该是罕见的;然而,花颜色的种内变异是常见的,可归因于遗传漂变、可塑性或变量选择。在接触区和物种范围内检查花的颜色多态性可以揭示维持这种变化的机制。本研究采用多步骤方法研究了卡斯蒂莱花苞片颜色的空间异质性。方法:比较了区域种群和普通园林的颜色变异频率、花形态、适合度和遗传结构。接下来,我们研究了生境差异,包括土壤因素,作为变异的潜在驱动因素。最后,我们利用植物标本馆和iNaturalist的发生数据来调查景观尺度上的模式是否一致。结果:葡萄球菌苞片的颜色具有遗传遗传性,黄色优势于红色,是一种选择。种群主要是单态的,尽管距离造成了显著的遗传隔离,但颜色距离与遗传或地理距离没有相关性。黄色变种与开放湿地有关,而红色变种发生在附近有树木覆盖的干燥地区。红色变种在普通花园中表现出较低的适应性,这表明花的颜色与多效性效应有关。结论:不同花型间的花色差异与生态位变化相关的多样性是一致的。我们确定了土壤和生境条件的变化可能是花色差异的驱动因素。此外,其他花性状的变化表明,传粉者和栖息地的差异共同作用,维持了不同的花的颜色变化。
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引用次数: 0
Heat drastically alters floral color and pigment composition without affecting flower conspicuousness. 热量会剧烈地改变花的颜色和色素成分,但不会影响花的显著性。
IF 2.7 2区 生物学 Q2 PLANT SCIENCES Pub Date : 2025-09-09 DOI: 10.1002/ajb2.70096
Eduardo Narbona, Francisco Perfectti, Adela González-Megías, Luis Navarro, José C Del Valle, Cristina Armas, José M Gómez

Premise: Floral pigments primarily serve to attract pollinators through color display and also contribute to protection against environmental stress. Although pigment composition can be plastically altered under stress, its impact on pollinator color perception remains poorly understood. Moricandia arvensis (Brassicaceae) exhibits seasonal floral dimorphism, with lilac spring flowers and white summer flowers. This study examines how heat-driven shifts in floral pigments alter flower color and its perception by pollinators.

Methods: We conducted a comparative analysis of spring and summer floral morphs in a natural population by measuring petal spectral reflectance, analyzing absorption spectra of petal extracts, and modeling floral color in the visual systems of major pollinator functional groups. Additionally, UHPLC-ESI-MS/MS analysis was conducted under controlled conditions to characterize differences in phenolic profiles.

Results: Spring flowers exhibited strong UV reflectance and a reduction in reflectance in the green spectrum, whereas summer flowers showed no UV reflectance and high reflectance in the visible range. Anthocyanins were detected only in spring flowers, while summer flowers accumulated high levels of UV-absorbing flavonoids. Despite these differences, both floral morphs remained visually conspicuous to hymenopterans, dipterans, lepidopterans, and coleopterans. Summer flowers produced twice as many phenolic compounds and accumulated higher concentrations, with ferulic acid and kaempferol derivatives the most prominent.

Conclusions: White summer flowers of Moricandia arvensis are not merely anthocyanin-deficient but exhibit a distinct profile of UV-absorbing phenolics that may confer heat tolerance while preserving floral conspicuousness to pollinators. These findings highlight the role of multifunctional traits in the evolution of flower color.

前提:花色素的主要作用是通过颜色展示吸引传粉者,同时也有助于保护植物免受环境胁迫。虽然色素组成可以在压力下发生可塑性改变,但其对传粉媒介颜色感知的影响仍然知之甚少。Moricandia arvensis(芸苔科)表现出季节性的花二态性,春天的花是淡紫色的,夏天的花是白色的。本研究探讨了热驱动的花色素变化如何改变花的颜色和传粉者对它的感知。方法:通过测量花瓣光谱反射率,分析花瓣提取物的吸收光谱,并在主要传粉昆虫功能群的视觉系统中建立花的颜色模型,对自然种群春夏花的形态进行对比分析。此外,在控制条件下进行UHPLC-ESI-MS/MS分析以表征酚类特征的差异。结果:春花紫外反射率强,绿光谱反射率降低,夏花紫外反射率不强,可见光谱反射率高。花青素仅在春季花中检测到,而夏季花积累了高水平的吸收紫外线的类黄酮。尽管存在这些差异,但在膜翅目、双翅目、鳞翅目和鞘翅目中,这两种花的形态在视觉上仍然很明显。夏花产生的酚类化合物是夏花的两倍,且积累的浓度更高,其中阿魏酸和山奈酚衍生物最为突出。结论:Moricandia arvensis的白色夏季花不仅缺乏花青素,而且表现出独特的吸收紫外线的酚类物质,这可能赋予耐热性,同时保持花对传粉者的显著性。这些发现强调了多功能性状在花色进化中的作用。
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引用次数: 0
Elevated ozone promotes the dominance of invasive plant species in low-diversity native plant communities 臭氧浓度升高促进了入侵植物在低多样性本地植物群落中的优势地位。
IF 2.7 2区 生物学 Q2 PLANT SCIENCES Pub Date : 2025-09-08 DOI: 10.1002/ajb2.70098
Yan Li, Ayub M. O. Oduor

Premise

The diversity–invasibility hypothesis suggests that native plant communities with high species diversity are more resistant to invasions by exotic species compared to those with fewer species. This resistance stems from more complete resource use and stronger biotic interactions in diverse communities, which limit opportunities for invaders to establish. However, this resistance could potentially be weakened by environmental stressors, including elevated tropospheric ozone. Ozone levels have increased globally from 10 ppb in pre-industrial times to around 50 ppb today. Elevated ozone affects plant species differently, depending on their functional traits and physiological tolerances. Yet, no prior study has tested how elevated ozone affects the link between native plant community diversity and invasion resistance. We thus set up an open-top chamber experiment to assess the impact of ozone enrichment on invasive plant growth in native communities of differing species richness.

Methods

We established 16 native plant communities: eight low-diversity and eight high-diversity. Each community was invaded by a single individual from one of nine exotic species and grown in either ambient (40.72 ppb) or elevated (83.10 ppb) ozone.

Results

Elevated ozone reduced the mean aboveground biomass of invasive species by 9.64% overall. The decline was greater in low-diversity communities (–18.46%) than in high-diversity ones (–12.54%). Elevated ozone enhanced the mean proportional aboveground biomass of invasive species in low-diversity communities (11.24%), but not in high-diversity communities.

Conclusions

These findings support the diversity–invasibility hypothesis and suggest that species-rich communities maintain stronger resistance to invasion even in elevated ozone.

前提:物种多样性-入侵假说认为物种多样性高的本土植物群落比物种较少的本土植物群落更能抵御外来物种的入侵。这种抗性源于更完整的资源利用和不同群落中更强的生物相互作用,这限制了入侵者建立的机会。然而,这种抗性可能会被环境压力因素削弱,包括对流层臭氧升高。全球臭氧水平已从工业化前的10 ppb增加到今天的50 ppb左右。臭氧升高对植物的影响是不同的,这取决于它们的功能特性和生理耐受性。然而,之前没有研究测试臭氧升高如何影响本地植物群落多样性和入侵抵抗之间的联系。在不同物种丰富度的原生群落中,通过开顶室实验研究臭氧富集对入侵植物生长的影响。方法:建立了16个本地植物群落:8个低多样性和8个高多样性。每个群落都被来自9种外来物种之一的单个个体入侵,并在环境臭氧(40.72 ppb)或升高臭氧(83.10 ppb)中生长。结果:臭氧浓度升高使入侵物种地上平均生物量总体减少9.64%。低多样性群落的下降幅度(-18.46%)大于高多样性群落(-12.54%)。臭氧浓度升高使低多样性群落的平均地上生物量增加(11.24%),而在高多样性群落中则没有增加。结论:这些发现支持了物种多样性入侵假说,并表明物种丰富的群落即使在高臭氧水平下也能保持更强的入侵抵抗力。
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引用次数: 0
期刊
American Journal of Botany
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