Morphometric delimitation of Gnetum species in Africa
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- 作者：Elvire H. Biye ; Glynis V. Cron ; Kevin Balkwill
- 关键词：Africa ; Gnetaceae ; Morphological characterization ; Phenetics ; Taxonomy
- 刊名：Plant Systematics and Evolution
- 出版年：2016
- 出版时间：October 2016
- 年：2016
- 卷：302
- 期：8
- 页码：1067-1082
- 全文大小：1,769 KB
- 刊物类别：Biomedical and Life Sciences
- 刊物主题：Life Sciences
Plant Sciences
Plant Ecology
Plant Anatomy and Development
Plant Systematics/Taxonomy/ Biogeography - 出版者：Springer Wien
- ISSN：1615-6110
- 卷排序：302
文摘
The economically important gymnosperm Gnetum L. is distributed in humid tropical forests of Africa. Its leaves are used as commercialized vegetables and greatly alleviate poverty for local people. Previously, the number of species recognized in Africa was uncertain, and Gnetum africanum Welw. and G. buchholzianum Engl. had been variously, and erroneously, applied to specimens. Based on recent morphological studies, species limits were clarified and two new African species, Gnetum interruptum E.H.Biye and G. latispicum E.H.Biye, were described. The purpose of this study was to determine species limits, to investigate potential infraspecific variation in wild African Gnetum species and to determine which features distinguish them in order to assess the validity of four species recognized by Biye et al. (Pl Syst Evol 300(2):263–272, 2014). Sixty-seven morphological characters were scored for a total of 175 (56 male and 119 female) specimens and analysed using cluster, principal components and principal coordinates analyses. Four distinct clusters of Gnetum specimens were recognized that correspond to the species now described as G. africanum, G. buchholzianum, G. interuptum and G. latispicum. A lack of geographical correlation with subclusters as well as their structure suggests there is no justification for recognizing infraspecific taxa. Characters that describe features of the spikes should be used to differentiate between and identify the species in Africa. In view of the high levels of utilization of two species and rarity of a third, it is urgent to assess the threat status of Gnetum species in Africa and to design appropriate conservation strategies to conserve these economically valuable plants.