Genetic variation within the endangered quillwort Isoe ¨tes hypsophila (Isoetaceae) in China as evidenced by ISSR analysis Jin-Ming Chen a , Xing Liu a , Jing-Yuan Wang a , Gituru Wahiti Robert b , Qing-Feng Wang a, * a Laboratory of Plant Systematics and Evolutionary Biology, College of Life Sciences, Wuhan University, Wuhan 430072, Hubei, PR China b Botany Department, Kenyatta University, P. O. Box 43844, Nairobi, Kenya Received 1 March 2004; received in revised form 18 January 2005; accepted 15 February 2005 Abstract The genetic diversity of 56 individuals of Isoe ¨tes hypsophila Hand.-Mazz. from China was investigated by ISSR. Twelve primers were screened from 65 primers, and a total of 119 DNA fragments were scored, of these, 82% were polymorphic bands, which indicated that high levels of genetic variation existed in the natural populations. Genetic diversity varied greatly among popula- tions with the percentage of polymorphic band (PPB) values ranging from 8 to 35%. An analysis of molecular variance (AMOVA) was used to apportion the variation between regions, among populations within regions, and within populations. Results indicated that most of the variance (85%) occurred between Yunnan and Sichuan. The variances among populations within regions and within populations, however, were only 5 and 10%, respectively. In the among-population analysis, the larger part of genetic variation (77%) resided among populations, and less (23%) presented differences within populations. UPGMA cluster analysis showed that there was no distinct genetic differentiation between populations from Sichuan province. A number of causes including limited gene flow, genetic drift and inbreeding might have led to these observed genetic profiles of I. hypsophila. # 2005 Elsevier B.V. All rights reserved. Keywords: Conservation; Endangered; Genetic variation; Isoe ¨tes hypsophila; ISSR www.elsevier.com/locate/aquabot Aquatic Botany 82 (2005) 89–98 * Corresponding author. Tel.: +86 27 68752869; fax: +86 27 68752869. E-mail address: wangqf97@public.wh.hb.cn (Q.-F. Wang). 0304-3770/$ – see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.aquabot.2005.02.007