中国沙参属花粉形态的研究

STUDY ON THE POLLEN MORPHOLOGY OF ADENOPHORA FROM CHINA

对分布于我国的沙参属(Adenophora Frisch.)32种(亚种、变种)植物的花粉形态进行了光学显微镜和扫描电镜的观察,研究结果表明:(1)沙参属植物花粉形态较相似,但其外壁纹饰,厚度、小刺密度、萌发孔情况在种、亚种、变种鉴别上有一定的意义。(2)本属花粉粒演化趋势为:表面条网状,条脊窄,小刺多,网孔类圆形→表面条状,脑纹状,条脊宽,小刺少,网孔不规则形。(3)花粉形态结合植物形态和染色体演化趋势,推断本属各组的演化关系为:基生叶组(Sect.BasiphyllusP.F.Tu et G.J.Xu)→沙参组(Sect.Ovatifolius P.F.Tu et G.J.Xu)→有柄组(Sect.Remotiflorae (Fed.)P.F.Tu et G.J,Xu)→筒花组(Sect.Adenophora)。

Pollen grains of 32 species in the genus Adenophora from China were examined under the light microscope (LM)and scanning electron microscope (SEM). The results are as follows: (1)Nearly all species of the genus Adenophora possess simliar type of spiny porotic pollen grains. Species, sub-species and varieties, however can be indetified by their different exine ornamentation, breadth of lirae, thickness of exine, density of spinule and condition of trema. (2) The evolution trends of the pollen grain in genus Adenophora are: from striate-reticulate, narrow lirae, roundish scrobiculus and dense spinules to striate, brain-gyrus, broad lirae, irregular scrobiculus and sparse spinules in the exine ornamentation. (3) According to this pollen study, conformed with the plant morphology and chromosome studies, the evolutionary tendency of the sections on the genus Adenophora is suggested as: Sect. Basiphyllus P. F. Tu et G. J. Xu→Sect. Ovatifolius P. F. Tu et G. J. Xu→ Sect. Remotiflorae (Fed.) P. F. Tu et G. J. Xu→ Sect. Adenophora.