摘要
根据幼苗形态特征 ,把双子叶植物幼苗划分为 1 8个类型 9个亚型 ,用图解释了幼苗类型之间的进化关系。双子叶植物幼苗类型进化的主线是 :暗罗型 (子叶具吸收功能 ,留土 )→紫玉盘型 (子叶具吸收功能 ,留于种壳中 ,下胚轴伸长 )→木兰型 (子叶具吸收兼光合功能 )→蜡梅型 (子叶具光合功能 )→樱型 (子叶具光合兼贮藏功能 )→樟型 (子叶具贮藏功能 ) ,其他类型或亚型则为进化的旁支或盲支。根据幼苗类型来判断 ,现存被子植物最古老的科应为番荔枝科。
Eighteen types and nine subtypes of the seedlings in dicots are recognized based on a long-term investigation on the seedlings of 1251 species in 740 genera of 157 families. They are: I Polyalthia Type; 2. Earyale Type; 3. Uvaria Type; 4. Magnolia Type; 5. Peperomia Type; 6. Cyclamen Type; 7. Corydalis Type; 8. Sterculia Type; 9. Rhizophora Type; 10. Loranthas Type; 11. Cuscuta Type; 12. Pyrola Type; 13. Ceratophyllum Type (including Ceratophyllum Subtype, Nelumbo Subtype and Trapa Subtype); 14. Chimonanthus Type; 15. Cerasus Type; 16. Cinnamomum Type (including Cinnamomum Subtype and Cassytha Subtype); 17. Garcinia Type (including Garcinia Subtype and Terstroemia Subtype); 18. Sechium Type (including Sechium Subtype and Hodgsonia Subtype). The possible evolutionary relationships of these types are discussed. Six of the 18 types are considered to constitute an evolutionary line, evolving from the Polyalthia Type (in which the cotyledons perform absorptive function) to Uvaria Type (in which the cotyledons perform absorptive function, and the hypocotyls are elongated), then to Magnolia Type (in which the cotyledons perform both absorptive and photosynthetic functions) I Chimonanthus Type (in which the cotyledons perform photosynthetic function), Cerasus Type (in which the cotyledons perform both photosynthetic and storing functions), and the Cinnamomum Type (in which the cotyledons perform storing function). The remaining types seem to be side lines or dead ends in evolution. Ten seedling types are distributed in the Magnoliidae sensu Cronquist, and among them the Magnolia Type appears to be of the highest evolutionary potential. This type seems to be adaptable to different niches. From it many side lines of evolution may have been derived. Most importantly, the Chimonanthus Type, which may have continued to give rise to several other types, may have been directly derived from the Magnolia Type. From the perspective of the evolutionary trends of the seedling types, therefore, it is considered that the basal subclas
出处
《植物分类学报》
CSCD
北大核心
2003年第5期447-464,共18页
Acta Phytotaxonomica Sinica
关键词
双子叶植物
幼苗
演化
形态特征
dicots
seedling type
evolutionary relationship
