{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T12:16:18Z","timestamp":1789992978296,"version":"4.0.1"},"reference-count":28,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T00:00:00Z","timestamp":1789948800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Precise Identification and Innovative Utilization of Forest and Grass Germplasm Resources","award":["2024LZGC003"],"award-info":[{"award-number":["2024LZGC003"]}]},{"name":"Youth Innovation Team of Shandong Provincial HigherEducation Institutions","award":["2025KJI010"],"award-info":[{"award-number":["2025KJI010"]}]},{"name":"Shandong Province High level Natural Resources Science and Technology Innovation Talent Team Precious Tree Species GermplasmConservation and Utilization Innovation Team"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Plants"],"abstract":"<jats:p>In this study, the rare and endangered tree species Tilia taishanensis S. B. Liang was selected as the research material, and its embryonic developmental characteristics and abortion mechanism were systematically observed using scanning electron microscopy and resin semi-thin sectioning techniques. The results showed that its pollen was bicellular, the anther wall belonged to the dicotyledonous type with a secretory tapetum, and asynchronous meiosis occurred during microsporogenesis. The pistil possessed a pentalocular ovary and anatropous ovules, and the embryo sac exhibited a typical seven-celled, eight-nucleate structure of the Polygonum type. Male gametophyte development initiated 1\u20132 weeks earlier than female gametophyte development, although both gametophytes matured synchronously in late June, and the embryo and endosperm developed following the Solanad type and nuclear type, respectively. Multiple reproductive barriers existed in this species: the pollen viability was only approximately 10%, and abnormal tapetal degeneration interrupted nutrient supply for microspores; continuous embryo sac degeneration may contribute to a hollow seed rate of 90%; developmental asynchrony between male and female gametophytes further reduced fertilization efficiency. This study explores the embryonic developmental characteristics and abortion mechanism of T. taishanensis, providing cytological evidence for elucidating its endangered causes and germplasm conservation.<\/jats:p>","DOI":"10.3390\/plants15182882","type":"journal-article","created":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T11:05:53Z","timestamp":1789988753000},"page":"2882","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Embryonic Development and Potential Causes of Reproductive Failure in Tilia taishanensis S. B. Liang"],"prefix":"10.3390","volume":"15","author":[{"given":"Hanlin","family":"Liu","sequence":"first","affiliation":[{"name":"Key Laboratory of National Forestry and Grassland Administration for Warm Temperate Forest Ecosystem Conservation and Restoration, Forestry College of Shandong Agricultural University, Tai\u2019an 271018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Meixuan","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of National Forestry and Grassland Administration for Warm Temperate Forest Ecosystem Conservation and Restoration, Forestry College of Shandong Agricultural University, Tai\u2019an 271018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weihao","family":"Song","sequence":"additional","affiliation":[{"name":"Key Laboratory of National Forestry and Grassland Administration for Warm Temperate Forest Ecosystem Conservation and Restoration, Forestry College of Shandong Agricultural University, Tai\u2019an 271018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaoshuo","family":"Jiang","sequence":"additional","affiliation":[{"name":"Key Laboratory of National Forestry and Grassland Administration for Warm Temperate Forest Ecosystem Conservation and Restoration, Forestry College of Shandong Agricultural University, Tai\u2019an 271018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yaxuan","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of National Forestry and Grassland Administration for Warm Temperate Forest Ecosystem Conservation and Restoration, Forestry College of Shandong Agricultural University, Tai\u2019an 271018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruichen","family":"Shan","sequence":"additional","affiliation":[{"name":"Key Laboratory of National Forestry and Grassland Administration for Warm Temperate Forest Ecosystem Conservation and Restoration, Forestry College of Shandong Agricultural University, Tai\u2019an 271018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qian","family":"Zhang","sequence":"additional","affiliation":[{"name":"Shandong Academy of Forestry, Jinan 250014, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruixue","family":"Wang","sequence":"additional","affiliation":[{"name":"Shandong Provincial Forestry Protection and Development Service Center, Jinan 250014, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8527-3838","authenticated-orcid":false,"given":"Limin","family":"Sun","sequence":"additional","affiliation":[{"name":"Key Laboratory of National Forestry and Grassland Administration for Warm Temperate Forest Ecosystem Conservation and Restoration, Forestry College of Shandong Agricultural University, Tai\u2019an 271018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,21]]},"reference":[{"key":"ref_1","first-page":"70","article-title":"Two New Species of Tilia from Shandong Province","volume":"2","author":"Liang","year":"1985","journal-title":"Shandong For. Sci. Technol."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Jurk\u0161ien\u0117, G., Danusevi\u010dius, D., and Kembryt\u0117-Il\u010diukien\u0117, R. (2023). Dendrological Secrets of the Pazaislis Monastery in Central Lithuania: DNA Markers and Morphology Reveal Tilia \u00d7 europaea L. Hybrids of an Impressive Age. Plants, 12.","DOI":"10.3390\/plants12203567"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1176","DOI":"10.1002\/j.1537-2197.1994.tb15612.x","article-title":"Inflorescence bracts of fossil and extant Tilia in North America, Europe, and Asia: Patterns of morphologic divergence and biogeographic history","volume":"81","author":"Manchester","year":"1994","journal-title":"Am. J. Bot."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"012025","DOI":"10.1088\/1757-899X\/1208\/1\/012025","article-title":"Mechanical properties changes in fir wood (Abies sp.), linden wood (Tilia sp.), and beech wood (Fagus sp.) subjected to various thermal modification process conditions","volume":"1208","author":"Ganguly","year":"2021","journal-title":"IOP Conf. Ser. Mater. Sci. Eng."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1630","DOI":"10.1080\/23802359.2021.1926358","article-title":"Characterization of the complete chloroplast genome of basswood (Tilia mongolica maxim.)","volume":"6","author":"Zheng","year":"2021","journal-title":"Mitochondrial DNA B Resour."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"102368","DOI":"10.1016\/j.fochx.2025.102368","article-title":"Amur linden honey and its principal polyphenols alleviate obesity and regulate gut microbiota in high-fat diet-induced mice","volume":"27","author":"Chen","year":"2025","journal-title":"Food Chem. X"},{"key":"ref_7","first-page":"24","article-title":"Deciphering aroma formation during flowering in nectar tree (Tilia amurensis): Insights from integrated metabolome and transcriptome analysis","volume":"3","author":"Cai","year":"2023","journal-title":"For. Res."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Bao, W., Shen, Y., and Verdonk, J.C. (2024). Dynamic Changes in Flavonoids\u2019 Accumulation Pattern in Tilia miqueliana Flowers at Different Developmental Stages Based on Widely Targeted Metabolomic Analysis. Forests, 15.","DOI":"10.3390\/f15101795"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1086\/706781","article-title":"Morphological Variation in North American Tilia and Its Value in Species Delineation","volume":"181","author":"McCarthy","year":"2019","journal-title":"Int. J. Plant Sci."},{"key":"ref_10","first-page":"44","article-title":"Study on Grafting Propagation Technology of Tilia spp","volume":"8","author":"Li","year":"2018","journal-title":"J. Agron."},{"key":"ref_11","first-page":"3639","article-title":"First Report of Leaf Spot Disease Caused by Alternaria alternata in Tilia miqueliana in Jiangsu Province, China","volume":"107","author":"Ming","year":"2023","journal-title":"Plant Dis."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Shi, F., Cao, Y., Gao, Y., Qiu, Y., Lu, Y., Han, B., and Shen, Y. (2024). The Impact of Magnetic Field and Gibberellin Treatment on the Release of Dormancy and Internal Nutrient Transformation in Tilia miqueliana Maxim. Seeds. Forests, 15.","DOI":"10.3390\/f15020311"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"551","DOI":"10.1093\/oxfordjournals.jmicro.a023843","article-title":"A new method for detecting and localizing cell markers endocytosed by fibroblasts in epoxy resin semi-thin sections using scanning electron microscopy combined with energy dispersive X-ray microanalysis after ion-etching","volume":"49","author":"Fujiwara","year":"2000","journal-title":"J. Electron Microsc."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1093\/jmicro\/50.1.51","article-title":"Three-dimensional reconstruction by scanning electron microscopy from serial epoxy resin semi-thin sections after ion-etching","volume":"50","author":"Shimizu","year":"2001","journal-title":"J. Electron Microsc."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Wang, X., Chen, J., Hu, L., Zhang, J., Xiao, F., Zhang, S., Shao, F., and Huang, L. (2023). Embryological Observations on Seed Abortion in Hibiscus syriacus L. and Physiological Studies on Nutrients, Enzyme Activity and Endogenous Hormones. BMC Plant Biol., 23.","DOI":"10.1186\/s12870-023-04669-y"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e18711","DOI":"10.7717\/peerj.18711","article-title":"Basis of single-seed formation in chestnut: Cytomorphological observations reveal ovule developmental patterns of Castanea henryi","volume":"13","author":"Qiu","year":"2025","journal-title":"PeerJ"},{"key":"ref_17","first-page":"22","article-title":"Megasporogenesis, Microsporogenesis and Development of Male and Female Gametophytes in Tilia miqueliana","volume":"24","author":"Gao","year":"2010","journal-title":"China For. Sci. Technol."},{"key":"ref_18","first-page":"1249","article-title":"Studies on Pollen Viability and Fertilization of Clivia miniata Regel","volume":"34","author":"Shen","year":"2007","journal-title":"Acta Hortic. Sin."},{"key":"ref_19","first-page":"265","article-title":"Cytological observation of pollen development in \u2018Ougan\u2019(Citrus suavissima Hort. ex Tanaka) and its seedless mutant","volume":"31","author":"Zhang","year":"2014","journal-title":"J. Fruit Sci."},{"key":"ref_20","first-page":"64","article-title":"Cytological study of male sterility and pollen abortion in pear (Pyrus spp.) variety \u201cXinli 7\u201d","volume":"26","author":"Han","year":"2004","journal-title":"J. Southwest Agric. Univ."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1076","DOI":"10.3724\/SP.J.1006.2020.94159","article-title":"Biological characteristics and cytological studies on anther abortion of male sterile Camellia crassocolumna","volume":"46","author":"Jiang","year":"2020","journal-title":"Acta Agron. Sin."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"41","DOI":"10.36253\/caryologia-2965","article-title":"Anther structure and pollen development in Jurinea kilaea Azn. (Asteraceae)","volume":"78","author":"Ekici","year":"2025","journal-title":"Caryologia"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"166","DOI":"10.1093\/botlinnean\/boac081","article-title":"Gynoecium structure and pollen tube pathway in the cactus family with emphasis on tribe Trichocereeae (Cactaceae: Cactoideae)","volume":"202","author":"Zini","year":"2023","journal-title":"Bot. J. Linn. Soc."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1146\/annurev-arplant-080620-102159","article-title":"Pollen-Pistil Interactions as Reproductive Barriers","volume":"72","author":"Broz","year":"2021","journal-title":"Annu. Rev. Plant Biol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"747","DOI":"10.21273\/JASHS.130.5.747","article-title":"Embryo Development of Cypripedium formosanum in Relation to Seed Germination In Vitro","volume":"130","author":"Lee","year":"2005","journal-title":"J. Am. Soc. Hortic. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1911","DOI":"10.1093\/genetics\/162.4.1911","article-title":"Embryo and Endosperm Development Is Disrupted in the Female Gametophytic capulet Mutants of Arabidopsis","volume":"162","author":"Grini","year":"2002","journal-title":"Genetics"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1000","DOI":"10.1111\/nph.12954","article-title":"Emergence of apospory and bypass of meiosis via apomixis after sexual hybridisation and polyploidisation","volume":"204","author":"Hojsgaard","year":"2014","journal-title":"New Phytol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1387\/ijdb.052023lb","article-title":"Gametophyte interaction and sexual reproduction: How plants make a zygote","volume":"49","author":"Boavida","year":"2005","journal-title":"Int. J. Dev. Biol."}],"container-title":["Plants"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2223-7747\/15\/18\/2882\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T11:56:43Z","timestamp":1789991803000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2223-7747\/15\/18\/2882"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,21]]},"references-count":28,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["plants15182882"],"URL":"https:\/\/doi.org\/10.3390\/plants15182882","relation":{},"ISSN":["2223-7747"],"issn-type":[{"value":"2223-7747","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,21]]}}}