何首乌不同种质花粉形态及进化趋势研究

采用电镜扫描法,对48份何首乌种质的花粉形态进行了观察和分析。结果表明:何首乌花粉形状主要为椭球形,少量为长椭球形和近球形,部分种质花粉形状正处于椭球形向长椭球形进化的阶段;极面观主要为三裂圆形,部分种质的变异为半球状、四边形、凹陷状或平三角形;赤道面观主要为椭圆形,部分种质为三角形或四边形;萌发沟3条,狭长,几达两极,部分种质的1条或2条萌发沟中部或近极端处隆起,2条或3条萌发沟在极端处相交;表面纹饰为穴状,部分种质的穴中出现小孔。研究结果表明,何首乌物种正处于活跃进化阶段且因区域及生境的差异其进化速度不一致,低纬度地区的种质进化程度较高纬度地区的高,其最初的起源中心可能位于高纬度地区,在向低纬度地区迁移过程中其花粉形态发生了不同程度的变异。

Pollen Morphology and Evolutionary Trend in Polygonum multiflorum Thunb.Germplasms

Pollen morphology of 48 Polygonum multiflorum Thunb.germplasms was observed and analyzed with scanning electron microscopy.The observed results showed that pollen morphology of P.multiflorum Thunb.was mainly spheroidicity,a few long spheroidicity and subglobose and pollen shape of part germplasms was verging on phase from spheroidicity to long spheroidicity;mainly 3-labed-rounded with a few hemispheric,quadrangular,caved or plane triangle in part germplasms in polar views and mainly ellipse in equatorial views with a few triangle or quadrangular in part germplasms;with 3 germinal furrows which shape is long and narrow,almost reaching the poles.1 or 2 germinal furrows upheaved in the middle or near the poles,2 or 3 germinal furrows intersecting in the poles in part germplasms;the surface emblazonry was cave-shaped,with 1 ostiole in it in a few germplasms.The studied results showed that the species of P.multiflorum Thunb.is being at the active evolutionary stage and the rate of evolution is not synchro because of different regions and habitats.The evolutionary degree of low-latitude germplasms is higher than that of high-latitude germplasms.The primal center of origin of P.multiflorum Thunb.might be in the high-latitude,whose pollen morphology varied in different degrees in the migrating process from high-latitude to low-latitude.