Türkiye'nin Güncel (Thurya capitata ve Nephelochloa orientalis) ve Eski (Aegokeras caespitosa) Monotipik Endemik Taksonlarının Polen Morfolojisi ve Taksonomik Önemi

Abstract

Bu çalışma, monotipik veya tarihsel olarak monotipik kabul edilen soy hatlarıyla ilişkili üç endemik Türk taksonunun, yani *Thurya capitata* (Caryophyllaceae), *Nephelochloa orientalis* (Poaceae) ve *Aegokeras caespitosa* (Apiaceae)’nın polen morfolojisini ilk kez ayrıntılı olarak incelemeyi ve polen karakterlerinin taksonomik önemini değerlendirmeyi amaçlamaktadır. Wodehouse yöntemi kullanılarak hazırlanan polen örnekleri üzerinde gerçekleştirilen incelemelerde, her bir türe özgü nitel ve nicel palinolojik özellikler ortaya konulmuştur. Caryophyllaceae familyasına ait *Thurya capitata*, 6–9 por taşıyan polipantoporat yapıda, monad ve prolat-sferoidal (P/E: 1.01) polen tanelerine sahiptir. Ekzin ornamentasyonu mikroekinli-perforat olup operkulum yüzeyi spinulat ve granulat süslenme göstermektedir. Türde polar eksen 35.83–43.68 (39.75 ± 2.38) µm, ekvatoral eksen 34.74–43.73 (39.29 ± 2.44) µm, ekzin kalınlığı ise 1.13–2.13 (1.43 ± 0.33) µm arasında değişmektedir. Porlar arası mesafe 8.01–14.61 (11.54 ± 1.89) µm olup por oranı (plg/plt) 1.08 olarak belirlenmiştir. Apiaceae familyasının bir üyesi olan *Aegokeras caespitosa*, rugulat yüzey ornamentasyonuna sahip, monad, prolat (P/E: 1.90) ve trikolporat polenlerle karakterizedir. Türün en dikkat çekici özelliği, 24.45’lik Clg/Clt oranıyla ifade edilen oldukça uzun ve dar kolpuslarıdır. Polenlerde polar eksen 21.34–25.46 (24.00 ± 0.94) µm, ekvatoral eksen 11.61–13.40 (12.57 ± 0.48) µm olarak ölçülmüş; ekzin ve intin kalınlıkları sırasıyla 0.75 ± 0.08 µm ve 0.40 ± 0.07 µm olarak belirlenmiştir. Poaceae familyasına ait *Nephelochloa orientalis* ise mikroekinli-areolat ekzin ornamentasyonuna sahip, annulat-monoporat ve prolat-sferoidal (P/E: 1.01) polen taneleri üretmektedir. Bununla birlikte, bazı örneklerde diporat polenlerin gözlenmesi dikkat çekici bir bulgu olarak değerlendirilmiştir. Bu durum Poaceae için tipik kabul edilen monoporat yapıdan farklılık göstermekte olup, türün palinolojik çeşitliliğine ilişkin yeni veriler sunmaktadır. Sonuç olarak, incelenen taksonlar için elde edilen ayrıntılı polen verileri, her türün kendine özgü morfolojik özellikler taşıdığını ortaya koymuş ve bu özelliklerin ilgili familyalar içerisindeki sistematik konumlarının daha iyi anlaşılmasına katkı sağlamıştır. Elde edilen bulgular, Türkiye'nin endemik ve taksonomik açıdan dikkat çekici bitki taksonlarının palinolojik çeşitliliğinin ortaya konulmasına yönelik önemli veriler sunmaktadır.

Keywords

• Aegokeras caespitosa
• monotipik tür
• Nephelochloa orientalis
• palinoloji
• Thurya capitata

Pollen Morphology and Taxonomic Significance of Current (Thurya capitata and Nephelochloa orientalis) and Former (Aegokeras caespitosa) Monotypic Endemic Taxa of Türkiye

Abstract

This study investigates, for the first time, the detailed pollen morphology of three endemic taxa of Türkiye associated with monotypic or historically monotypic lineages: Thurya capitata Boiss. & Balansa (Caryophyllaceae), Nephelochloa orientalis Boiss. (Poaceae), and Aegokeras caespitosa (Sibth. & Sm.) Raf. (Apiaceae), and evaluates the taxonomic significance of their pollen characters. Pollen grains prepared using the Wodehouse method were examined by light and scanning electron microscopy. Thurya capitata has monad, prolate-spheroidal (polar axis/equatorial axis ratio, P/E = 1.01), polypantoporate pollen with 6–9 pores and microechinate-perforate exine ornamentation. Aegokeras caespitosa has monad, prolate (P/E = 1.9), tricolporate pollen with rugulate ornamentation; its most distinctive feature is the very long and narrow colpus. Nephelochloa orientalis has prolate-spheroidal (P/E = 1.01), annulate-monoporate pollen with microechinate-areolate ornamentation, while occasional diporate forms were also observed. Quantitative measurements further differentiated the taxa in pollen size, aperture dimensions, and wall thickness. Among the examined taxa, T. capitata had the largest pollen grains, whereas A. caespitosa showed the most elongated pollen form. The observed characters are consistent with the general pollen features of their respective families while also revealing diagnostic differences among the taxa. These data provide useful palynological information for evaluating their taxonomic and systematic relationships within their respective families and may contribute to future comparative studies of endemic taxa of Türkiye.

Keywords

• Aegokeras caespitosa
• Monotypic species
• Nephelochloa orientalis
• Palynology
• Thurya capitata

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