中国苎麻属组群分类及演化研究

Classification and Evolution of Groups on the Boehmeria in China

在同地种植条件下,对中国苎麻属5组13种的植物形态学和4组10种的花粉形态学进行比较研究表明:根系有分枝根型、萝卜根型和浅直根型;茎有直立茎型和匍匐茎型;花序为簇生花序组成穗状花序或复穗状花序或分枝型花序,或单个腋生;花粉萌孔有具内陷孔膜、具稍隆孔膜和无孔膜。不同组的根型、茎型、花序、花粉萌孔有明显不同,据此完善和修正了中国苎麻属组群的分类标准。分析了该属植物主要分类性状的演化趋势,建立了新的组间演化亲缘关系模型。

Botanical morphology of 13 species was examined in cultigen. Pollen morphol ogy of 10 species was examined by means of light microscope and scanning electron microscope. Root system could be classified as branched root, storage root and shallow stright root. Stem could be classified creeping stem and erect stem. The inflorescence was spike or compound spike or branched vulgaris or indiridual, Which made fascicled inflorescence. The inflorescence was transition type from 'leaflet' to 'bracteate'. Pollen grains of the Boehmeria was subglobular or suboblate,miniature-sized(11.20~20.85 um), P/E 0.8~1.0 ratio, 2~8 porate, membrana fenestrata leviter prominulis or invagination or no, and microgranulate. There are obvious differ ent in root type, stem type, inflorescence and pollen grains among groups of the Boehmeria. The mainly evolutionary trend of the Boehmeria is; branched root →torage root or shallow stright root, erect stem→creeping stem. 5 or 6 stamen, pedicellate 3~8 mm longa→3 or 4 stamen, pedicellate no or brevissima. membrana fenestrata invagination→membrana fenestrata leviter prominulis or no. The present anthor revision classification system of group of the Boehmeria. A new Y type evolutionary affinity of five groups of the Boehmeria is proposed.