Morphology,distribution,and chromosome counts of two varieties of Hedychium villosum(Zingiberaceae)  

作　　者：Fei YU W. John KRESS Jiang-Yun GAO 

机构地区：[1]Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China [2]Graduate School of the Chinese Academy of Sciences, Beijing 100049, China [3]Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington DC 20013-7012, USA

出　　处：《Journal of Systematics and Evolution》2010年第5期344-349,共6页植物分类学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.30970440);the West Light Foundation of the Chinese Academy of Sciences to Jiang-Yun GAO;the Natural Science Foundation of Yunnan Province of China(Grant No.2007C108M)

摘　　要：Polyploidy is a major mechanism of adaptation and speciation in plants. Two varieties of Hedychium villosum, var. villosum and var. tenuiflorum, primarily differ in plant and flower size. Chromosome number suggests that vat. tenuiflorum is diploid （2n = 34） and var. villosum is tetraploid （2n = 68）. Although the flowers of the two varieties do not have any difference in floral shape, each can be easily distinguished morphologically because the shoots, leaves, and flowers of the tetraploid var. villosum are consistently larger than the diploid var. tenuiflorum. The two varieties each possess distinct geographic ranges and habitats, and no sympatric distribution has been found. The tetraploid var. villosum has a broader geographic distribution range and more diverse ecological habitats than the diploid var. tenuiflorum. The two varieties are also completely reproductively isolated due to the non-overlap of their flowering times. The two varieties should be recognized as two distinct species as they fulfill the requirements of various species concepts. Thus, we suggested that the tetraploid var. villosum should be kept as Hedychium villosum and the diploid var. tenuiflorum should be renewed to Hedychium tenuiflorum.Polyploidy is a major mechanism of adaptation and speciation in plants. Two varieties of Hedychium villosum, var. villosum and var. tenuiflorum, primarily differ in plant and flower size. Chromosome number suggests that vat. tenuiflorum is diploid （2n = 34） and var. villosum is tetraploid （2n = 68）. Although the flowers of the two varieties do not have any difference in floral shape, each can be easily distinguished morphologically because the shoots, leaves, and flowers of the tetraploid var. villosum are consistently larger than the diploid var. tenuiflorum. The two varieties each possess distinct geographic ranges and habitats, and no sympatric distribution has been found. The tetraploid var. villosum has a broader geographic distribution range and more diverse ecological habitats than the diploid var. tenuiflorum. The two varieties are also completely reproductively isolated due to the non-overlap of their flowering times. The two varieties should be recognized as two distinct species as they fulfill the requirements of various species concepts. Thus, we suggested that the tetraploid var. villosum should be kept as Hedychium villosum and the diploid var. tenuiflorum should be renewed to Hedychium tenuiflorum.

关 键 词：DISTRIBUTION Hedychium villosum MORPHOLOGY POLYPLOIDY Zingiberaceae. 

分 类 号：Q949.718.3[生物学—植物学] TB47[一般工业技术—工业设计]