中国酸模属植物花粉形态研究

STUDY ON THE POLLEN MORPHOLOGY OF THE GENUS RUMEX IN CHINA

利用光学显微镜、扫描电镜对１５种，透射电镜对２种国产酸模属植物的花粉进行观察与研究。本属花粉为球形或近球形，大小为１５～４０×１８～４０μｍ。具３孔沟、４斜孔沟、散孔沟、散沟等；沟或外沟狭长，几达两极，内陷或不内陷，内孔圆形、稍横长或纵长；表面具皱波状纹饰；外壁厚１．０～３．５μｍ，外层明显厚于内层。在透射电镜下，花粉外壁分３层：覆盖层最厚，具穴状或穿孔，颗粒状或刺状纹饰，内面均匀；柱状层明显，厚，小柱为钝圆锥体或圆柱状，基层和内层不分，最薄，但在萌发孔处明显增厚。根据花粉形态，本属花粉可以分成７个组，它们是：小酸模组、滨海酸模组、酸模组、土大黄组、荒地酸模组、巴天酸模组和钝叶酸模组。对萌发孔分布规律的研究，基本支持Ｗｏｄｅｈｏｕｓｅ（１９３１）的观点，同时据花粉萌发孔演化的规律，认为本属花粉可能是蓼科花粉由少数萌发孔向多数萌发孔演化的过渡类型。

Pollen morphology of 15 species in the genus Rumex(Polygonaceae) from China was examined by means of LM, SEM and TEM. Pollen grains are spheroidal,subspheroidal,tricolporate,4-loxocolporate,pantocolporate(hexacolporate mainly),pantocolpate. The ornamentation of exine is microgranulate-perforate, rugulate under SEM. Sexine is thicker than nexine,nexine and intine are united as a foot layer-endexine unit. According to the characteristics of aperture and ornamentation of exine, pollen grains of Rumex show a fewer difference than those of Polygonum.But 7 pollen groups are recognized, i.e. R. acetosella-group, R. maritimus-group, R. acetosa group, R. madaio-group, R. conglomeratus-group, R, patientia-group and R. Obtuslfolius-group. The authors agree with wodehouse's(1931) explanation about the distribution of apertures, and consider that the characteristics of pollen grains of Rumex may be a transitional type in Polygonaceae.