Annals of botany最新文献

{"title":"Hydraulic architecture, height-related changes in photosynthesis, and seasonal positive pressure declines in bamboo: Implications for top dieback.","authors":"Wen Guo, Jing-Qiu Feng, Jiao-Lin Zhang, Ze-Xin Fan, Pei-Li Fu, Hervé Cochard, Yong-Jiang Zhang, Shi-Jian Yang","doi":"10.1093/aob/mcaf102","DOIUrl":"https://doi.org/10.1093/aob/mcaf102","url":null,"abstract":"<p><strong>Background and aims: </strong>Bamboos, arborescent monocotyledons without secondary growth, often show top dieback during the dry season. The potential mechanism underlying bamboo top dieback and its association with culm hydraulic architecture and positive pressure dynamics remain unclear. We investigated how the axial scaling of anatomical traits influenced physiological performances of the culm top under drought conditions, as well as how seasonal changes in positive pressure were related to top dieback and culm height.</p><p><strong>Methods: </strong>Variations in culm anatomical and physiological characteristics (hydraulic traits, leaf photosynthetic gas exchange, and water potentials) along the longitudinal axis of a bamboo (Dendrocalamus membranaceus) were investigated and seasonal changes in positive pressure were monitored to reveal potential factors associated with top dieback.</p><p><strong>Key results: </strong>The hydraulically-weighted mean vessel diameters (Dh) exhibited a widening pattern from the culm apex with a scaling exponent in the range reported for trees. However, Dh did not increase continuously and instead declined noticeably near the culm base. Theoretical hydraulic conductivity decreased to a low level near the culm top, where most of the resistance was located. The lower water potentials, maximum quantum yield of photosystem II, stomatal conductance, and photosynthetic rate indicated that culm top was subjected to severer water stress than the base part. Height supported by the maximum positive pressure declined from the wet season to the dry season, which was close to the measured culm height after top dieback.</p><p><strong>Conclusions: </strong>This study implies the potential impact of vessel widening pattern on water supply along the culm height, and the association of seasonal changes in positive pressure with culm height, which offers novel insights into understanding bamboo top dieback.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144141252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How do the principal megabiases in the fossil record affect the discovery of past bryophyte diversity?","authors":"Candela Blanco-Moreno, Alexander C Bippus, Alexandru M F Tomescu","doi":"10.1093/aob/mcaf070","DOIUrl":"https://doi.org/10.1093/aob/mcaf070","url":null,"abstract":"<p><strong>Background and aims: </strong>The bryophyte fossil record is less abundant and diverse than predicted by the age of the group and as compared to the fossil record of younger plant groups. Taphonomic biases explain only partially its scarcity. Here, we investigate whether and how recently recognized megabiases that have the potential to affect the fossil record, in general, determine the structure of the bryophyte fossil record.</p><p><strong>Methods: </strong>We update the pre-Miocene bryophyte fossil record with a ~30% increase since its latest review (in 2018) and examine fossil bryophyte diversity against the temporal and spatial distribution of the rock record, and economic geography, to document patterns in potential presence, discovery and study of bryophyte fossils.</p><p><strong>Key results: </strong>Fossil bryophyte abundance is not correlated with the area of rocks exposed around the planet for different geologic ages. More fossil bryophytes are known from younger rocks due to overall richer fossil content of those rocks. More fossil bryophytes have been documented from the Northern hemisphere, from developed countries, from countries where English is the official language and from countries where more specialists are exploring the fossil record.</p><p><strong>Conclusions: </strong>Discovery and documentation of bryophyte fossils are biased by socio-economic and language factors, which affect significantly the structure of the fossil record of the group, at least in terms of taxonomic diversity. \"Parachute science\" did not and does not significantly influence the documentation of fossil bryophytes.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144118615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mitoplastomic discordance in Brassicaceae phylogenomics confirms the complex evolutionary history of the family.","authors":"Lisa J M A Dominicus, Ihsan A Al-Shehbaz, Dmitry A German, Klaus Mummenhoff, Nikolai M Hay, Martin A Lysak, Marcus A Koch, Frederic Lens, Kasper P Hendriks","doi":"10.1093/aob/mcaf084","DOIUrl":"https://doi.org/10.1093/aob/mcaf084","url":null,"abstract":"<p><strong>Background and aims: </strong>The phylogeny of the Brassicaceae family has traditionally been inferred from plastid and nuclear DNA. However, early studies were limited by the availability of genetic markers and incomplete taxon sampling. Recent phylogenomic studies, leveraging more densely sampled nuclear and plastid datasets, have resolved many taxonomic uncertainties. These studies either targeted complete plastomes or provided extensive representation of the nuclear genome. Nevertheless, substantial cytonuclear discordance, poorly resolved backbone relationships, and challenges placing 'rogue taxa' have left unresolved questions about deeper relationships, notably of the family's five supertribes. In this context, we performed the first phylogenomic analysis of the slower-evolving, maternally inherited mitogenome, which presents a promising avenue for resolving deeper phylogenetic nodes.</p><p><strong>Methods: </strong>Using published mitogenomes from nine Brassicaceae species, we generated a mitogenomic reference file to recover mitogenomic sequencing read data from Hendriks et al. (2023). Subsequently, we reconstructed a codon-aware mitogenomic supermatrix, alongside updated nuclear (281 genes) and plastome (76 genes) supermatrices, and inferred family-wide maximum likelihood phylogenies from each of these three genomes. Congruence among the resulting phylogenies was thoroughly assessed.</p><p><strong>Key results: </strong>We present the first densely sampled family-wide mitogenomic Brassicaceae phylogeny, including 167 species, 145 genera (40% of the family), and 40 tribes (69% of the family), and the first family-wide phylogenomic comparison based on all three plant genomes. While cytonuclear discordance was evident, we also uncovered strong phylogenomic discordance between the two organellar genomes-mitogenome and plastome-coined here as 'mitoplastomic discordance'. Our findings offer new insights into placing several rogue and previously unplaced taxa.</p><p><strong>Conclusions: </strong>Phylogenomic discordance in Brassicaceae was more pervasive than expected. While bifurcating phylogenies offer clear evolutionary hypotheses, they do not fully capture evolutionary complexities. Our results have implications for understanding Brassicaceae evolution, taxonomy, and systematics, shedding light on processes like hybridisation and genome duplication, commonly resulting in evolutionary reticulation.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144109520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A genomic perspective on adaptation to heterogeneous environments for Cycas segmentifida (Cycadaceae), an endemic cycad in southwest China.","authors":"Yi-Qing Wang, Jian Liu, Si-Yue Xiao, Hui-Hui Xi, Xun Gong, Xiu-Yan Feng","doi":"10.1093/aob/mcaf067","DOIUrl":"https://doi.org/10.1093/aob/mcaf067","url":null,"abstract":"<p><strong>Background and aims: </strong>Exploring the interplay of environmental variability and adaptation of an endemic species is essential to unravel its evolutionary history and lays the groundwork for assessing how it may react to the accelerating pace of climate change. Employing a population genomics method, this research sought to investigate the adaptation of a cycad species, Cycas segmentifida, to heterogeneous environments and how this fosters population differentiation, guiding its conservation efforts.</p><p><strong>Methods: </strong>We used double digest restriction-site associated DNA-sequencing (ddRAD-seq) to elucidate the pattern of genetic diversity and divergence, and then analyze how geographical and environmental factors contribute to population divergence in C. segmentifida. We further investigate the genetic basis of adaptation to heterogeneous environments and their implications for predicting its genomic vulnerability under future climate conditions.</p><p><strong>Key results: </strong>Cycas segmentifida can be geographically categorized into two genetic groups: the Northwest (NW) and the Southeast (SE) group, with the genetic diversity of the SE group significantly higher than the NW group. Both geographical distance and environment factors could explain this genetic structure. These two groups exhibited similar demographic histories from late Pliocene to middle Pleistocene, experiencing recent population contraction events. The Genotype-environment association analysis revealed significant differences in environmental variables between two habitats of C. segmentifida, suggesting the possible existence of adaptation. The genomic vulnerability of C. segmentifida is relatively low throughout its distribution range, suggesting its potential to cope with future climate changes.</p><p><strong>Conclusions: </strong>Our results unveil environmental heterogeneity profoundly influences the genetic structure of C. segmentifida, and provide understanding of its sensitivity to climate change and capacity for adaptive responses, guiding future conservation endeavors.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144101045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leaf senescence-associated genes and transcriptional changes under dark conditions.","authors":"Antonio Ferrante, Petronia Carillo","doi":"10.1093/aob/mcaf063","DOIUrl":"https://doi.org/10.1093/aob/mcaf063","url":null,"abstract":"<p><strong>Background: </strong>Leaf senescence is a high regulated and complex process that can be trigged by dark conditions, as demonstrated in various studies. Dark-induced leaf senescence resembles natural senescence by triggering typical symptoms such as protein degradation and chlorophyll loss. Transcription factors have been recognized as key modulators of dark-induced senescence and are associated with plant hormones such as cytokinins, ethylene, gibberellins, and jasmonic acid. Treatments with cytokinins and gibberellins can delay leaf senescence caused by darkness.</p><p><strong>Scope: </strong>This review aimed to collect information regarding the biochemical, physiological, and molecular mechanisms underlying senescence induced by dark incubation. The main variations that occur during leaf senescence are highlighted and discussed. Specific genes associated with dark-induced senescence and related metabolic pathways have been described.</p><p><strong>Conclusions: </strong>This study highlights the intricate nature of the senescence process and explores how genetic and environmental factors can be manipulated to slow down or prevent senescence. These insights have significant implications for improving crop productivity, extending product shelf life, and enhancing vase life of cut flowers.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144075461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modern wheat has deeper roots than ancient wheats, is this an adaptation to higher productivity?","authors":"Arnesta Odone, Kristian Thorup-Kristensen","doi":"10.1093/aob/mcaf065","DOIUrl":"https://doi.org/10.1093/aob/mcaf065","url":null,"abstract":"<p><strong>Background and aims: </strong>There is growing interest in production of ancient grains including emmer, einkorn and spelt, particularly in low input systems. Differences in their root systems and how these affect water and nitrogen uptake are not well known, but can offer important insights into the effects of plant breeding on resource use and root physiology, which can inform breeding of future crops.</p><p><strong>Methods: </strong>In this study, we used imaging in minirhizotron tubes to evaluate root development in emmer, einkorn, spelt and modern wheat growing under field conditions, taking images to 2.2m soil depth. We evaluated water stress in the different species using carbon isotope discrimination and used a nitrogen tracer to compare N uptake over time.</p><p><strong>Key results: </strong>The results show that modern wheats have deeper and more efficient root systems. Modern wheats showed less water stress in late developmental stages due to their deeper roots which allow access to deep soil water, and can therefore sustain high grain yields. They were also able to translocate N more efficiently to the grain. The results contradict previous hypotheses that modern wheat has shallow rooting systems due to high inputs, showing that where more nutrient resources are available, deeper roots have become important for water uptake to support higher yields.</p><p><strong>Conclusions: </strong>This is the first field study of roots of ancient and modern wheats, where we clearly see that there are substantial differences between the root systems. These results help to explain how past selection for yield has affected belowground crop physiology.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144075463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How to be a big genus? Ficus L. as an emerging model.","authors":"Nicole Mitidieri-Rivera, Elliot Gardner, Julianne Phipps, Nyree Zerega, Leandro C Pederneiras, Alexander Damián-Parizaca, Kenneth J Sytsma","doi":"10.1093/aob/mcaf101","DOIUrl":"https://doi.org/10.1093/aob/mcaf101","url":null,"abstract":"<p><strong>Background and aims: </strong>If we replayed the tape of life, would large lineages evolve into the same dazzling diversity observed today? While the macroevolutionary drivers underlying plant diversification have been investigated for some large genera, many clades remain understudied. Ficus L., with 876 species, one of the largest and most ecologically important genera in Moraceae, is renowned for its iconic inflorescence, intricate pollination mutualism, and broad ecological adaptability. As the sole member of the monotypic tribe Ficeae, Ficus occupies a unique evolutionary position within a family that also includes major crop plants such as common fig, breadfruit, breadnut, cempedak, jackfruit, che, and mulberries.</p><p><strong>Methods: </strong>We used a well-sampled, dated phylogenomic backbone of Moraceae to investigate diversification patterns and their associated drivers in Ficus and allied genera using Maximum-Likelihood and Bayesian process-based methods. We assembled a morphological matrix of 508 species in Moraceae to investigate patterns of trait evolution based on stochastic mapping.</p><p><strong>Key results: </strong>Our results indicate that diversification within Moraceae is closely associated with shifts in global paleoclimate. The emergence of key clades of pollen and seed dispersers during periods of global warming following the Cretaceous-Paleogene (K-Pg) boundary approximately 66 Mya appears to have significantly shaped the complex diversification patterns observed in Ficus. Evolutionary transitions in floral traits within Moraceae are linked to changes in pollinator guilds; however, HiSSE (Hidden State Speciation and Extinction) models suggest that these shifts alone may not fully account for the diversification dyanmics of the genus.</p><p><strong>Conclusions: </strong>This study advances our understanding of the drivers of diversification in big pantropical genera, emphasizing the need to integrate multiple lines of evidence to holistically reconstruct the evolutionary history of ecologically and morphologically diverse plant taxa.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144075457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Giant mitogenomes in Rhynchospora are a result of nuclear gene and retrotransposon insertions in intergenic spaces.","authors":"Cicero Almeida, André Marques","doi":"10.1093/aob/mcaf098","DOIUrl":"https://doi.org/10.1093/aob/mcaf098","url":null,"abstract":"<p><strong>Background and aims: </strong>The mitochondrial genomes of plants are large, with the majority ranging between 500 and 800 kb. However, the mitochondrial genomes of Cyperaceae (sedges) species were found to be much larger, exceeding 1 Mb in size. Here, we aimed to investigate the gigantism of the mitochondrial genomes of three Rhynchospora (beak-sedges) species and one related species of the sister family Juncaceae, the common rush (Juncus effusus).</p><p><strong>Methods: </strong>Long PacBio HiFi reads were sequenced and assembled using Hifiasm software. The mitochondrial genomes were annotated using Geneious and Mitofy software. Transposable elements were annotated using DANTE and RepeatModeler pipelines, and gene prediction in intergenic regions was conducted using Augustus. The predicted genes were annotated using BLAST and gene ontology terms.</p><p><strong>Key results: </strong>The mitogenome of R. breviuscula was 2,222,920 bp, that of R. pubera was 2,064,773 bp, that of R. tenuis was 1,678,054 bp, and that of the species of J. effusus was 553,985 bp. The results revealed giant intergenic spaces in all Rhynchospora, containing predicted nuclear genes and LTR retrotransposons. BLASTn revealed a high migration of DNA from the nucleus to the mitogenome.</p><p><strong>Conclusions: </strong>Our findings show that the Rhynchospora mitogenome is the largest among the monocotyledons. These mitogenomes feature giant intergenic spaces, incorporation of chloroplast DNA and numerous rearrangements. Gigantism of the intergenic spaces is associated with the movement of nuclear DNA segments, suggesting a mechanism of DNA transfer from the nuclear genome to the mitochondrial genome.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144075453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Node of origin matters: comparative analysis of soil water limitation effects on nodal root anatomy in maize (Zea mays L.).","authors":"Tina Koehler, Yunhee Kim, Shu-Yin Tung, Adrien Heymans, Nicolas Tyborski, Franziska Steiner, Andreas J Wild, Johanna Pausch, Mutez A Ahmed, Hannah M Schneider","doi":"10.1093/aob/mcaf075","DOIUrl":"https://doi.org/10.1093/aob/mcaf075","url":null,"abstract":"<p><strong>Background and aim: </strong>Root anatomy, determining the composition and organization of root tissues, has implications for water uptake and transport, and potential for enhancing crop resilience amid changing environmental conditions and erratic water supply. While our understanding of the functional relationship between root anatomical traits and soil resource acquisition continues to improve, anatomical traits are commonly investigated on adventitious roots emerging from a single node or averaged across nodes. We test the hypothesis that drought adaptations of anatomical and hydraulic phenes are specific to the nodal origin of the root.</p><p><strong>Methods: </strong>We grew four maize (Zea mays L.) genotypes in the field under control and drought conditions, imposed by rainout shelters. Subsequently, we investigated the effect of soil drought on crown root anatomical phenes between consecutive shoot nodes. Based on these phenotypes, we inferred root cross-sectional hydraulic properties by integrating simulations of root anatomical networks via the GRANAR model and translating the outputs into hydraulic properties using the MECHA model.</p><p><strong>Key results: </strong>At the individual node level, drought-induced changes in root anatomical and hydraulic phenes were neither consistently significant nor unidirectional across nodes or genotypes. Notably, only second node crown roots consistently exhibited significant changes in response to drought. However, we observed distinct treatment differences in the development of phenes between consecutive shoot nodes. Most root anatomical and hydraulic phenes showed a (hyper)allometric relationship with increasing root cross-sectional area from older to younger roots. However, under drought, those allometric trajectories shifted. Specifically, the root cross-sectional area and the areas of stele, cortex, metaxylem, and aerenchyma, as well as cortical cell size and the axial hydraulic conductance increased more strongly from older to younger roots under drought. In contrast, metaxylem number increased more strongly under controlled conditions.</p><p><strong>Conclusion: </strong>Our findings suggest that examining the drought response of root anatomical phenes at a single node may not provide a comprehensive understanding of root system responses to the environment.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144075466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mycoheterotrophic continuum in rhizoctonia associations: Genetic divergence and carbon acquisition variation among Odontochilus orchids.","authors":"Kenji Suetsugu, Hidehito Okada, Shun K Hirota, Yoshihisa Suyama","doi":"10.1093/aob/mcaf100","DOIUrl":"https://doi.org/10.1093/aob/mcaf100","url":null,"abstract":"<p><strong>Background and aims: </strong>Mycoheterotrophy is a nutritional strategy in which plants obtain carbon and essential nutrients from fungal partners. Comparative studies of closely related taxa differing in mycoheterotrophic dependency offer important insights into the evolutionary transitions underlying this lifestyle.</p><p><strong>Methods: </strong>We integrated stable isotope (δ¹³C and δ15N) analyses, MIG-seq-based phylogenetics, and fungal metabarcoding to investigate the physiological ecology and evolutionary history of three Odontochilus taxa: the large-leaved O. fissus, the small-leaved O. nakaianus (including albino, chlorophyll-deficient variants), and the very small-leaved O. aff. fissus. Morphologically, O. aff. fissus differs from O. fissus in having reduced, often reddish scale leaves and coralloid rhizomes, which are traits commonly observed in fully mycoheterotrophic orchids or mixotrophic orchids with high heterotrophy.</p><p><strong>Key results: </strong>Albino individuals and protocorms of O. nakaianus exhibited isotope signatures characteristic of full mycoheterotrophy, whereas normal individuals of O. fissus, O. nakaianus, and O. aff. fissus displayed isotopic patterns indicative of partial mycoheterotrophy, with fungal dependence likely inversely correlated with leaf size. Metabarcoding revealed that all taxa consistently associated with Ceratobasidiaceae OTUs, suggesting that similar rhizoctonia fungi support varying degrees of mycoheterotrophy. MIG-seq analysis confirmed that O. aff. fissus, O. fissus, and O. nakaianus form distinct genetic clusters, while albino O. nakaianus individuals were genetically indistinguishable from their green counterparts.</p><p><strong>Conclusions: </strong>These findings provide evidence of both genetic and nutritional divergence between O. fissus and O. aff. fissus. The results expand our understanding of the mycoheterotrophic continuum in Odontochilus species associated with rhizoctonia fungi.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143960157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}