前胡族花粉外壁超微结构及其系统学意义

报道了前胡族(Peucedaneae Drude)当归亚族(Angelicinae Drude)、阿魏亚族(Ferulinae Drude)和环翅芹亚族(TordyliinaeDrude)等3亚族18属18种植物的花粉外壁表面和内部的超微结构.根据花粉外壁超微结构资料,论述了18种及其所在属的系统位置.对现时尚存疑的问题,诸如当归亚族中的山芹属(Ostericum Hoffm.)等7属(种),经分析认为统归于当归属(Angelica L.)不恰当;阿魏亚族中的球根阿魏(Schumannia turcomanica Kuntze)、伊犁芹(Talassiatransiliensis(Herd.)Korov.)、胀果芹(Phlojodicarpus villosus(Turcz.ex Fisch.et Mey.)Turcz.ex Ledeb.)等属的代表种显示其外壁演化程度相差甚大,应以与阿魏属(Ferula L.)分别独立为宜;环翅芹亚族(Tordyliinae Drude)中大瓣芹属(Semenovia Regel et Herd.)与独活属(Heracleum L.)的代表种其外壁演化程度相距甚远,也以分立为宜.

Ultrastructure of Pollen Exine in Peucedaneae Drude with Reference to Its Systematic Significance

Transmission electron microscopy (TEM) observation of pollen grains of 18 species belonging to 18 respective genera of the tribe Peucedaneae Drude revealed distinct ultrastructural difference in the pollen exine, including the thickness and features of tectum, columnar layer, foot layer and endexine. The systematic position of those 18 species are re-evaluated based on their ultrastructural characteristics of pollen exine observed in this study. Seven genera related to Angelica L. in Angelicinae Drude have been deduced to genus Angelica L. For example, Ostericum grosseserratum (Maxim.) Kitagawa was changed to Angelica L. by some authors, but it differs from Angelica sinensis (Oliv.) Diels in having well developed tectum which is thicker than the columnar layer and foot layer. Its columnar layer is quite well-developed with long and branched columellae. Besides its surface is tuberculated. Evidently, its development exceeds that of Angelica sinensis. However, it is only a moderate evolutional species in its genus, and the Angelica sinensis accounts as the most advanced species in Angelica Diels, thus, placing genus Ostericum Hoffm. in Angelica L. is not suitable, it may be more appropriate to keep its original position. In addition, Ferula akitschkensis B. Fedtsch. ex K.-Pol. differs greatly from those of Talassia transiliensis (Herd.) Korov. and Schumannia turcomnnia Kuntze, because of its very well-developed columnar layer, being about four to five times thicker than the total of tectum and foot layer, tuberculated tectum surface and complicated structure of columnellae. As another species Heracleum forrestii Wolff also differs from Semenovia rubtzovii (Schischk.) Monden. in having an even thickness of exine and well-developed columnar layer, it seems suitable that they should also be treated as two independent genera.