Full Length Research Paper

Genetic diversity in three morphological types of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao as revealed by inter simple sequence repeat markers

Xiaolong Xie^1,2,3, Yanping Hu^1,2, Li Wang^1,2, Jian Yang^1,2, Yi Li¹* and Min Peng¹*

¹Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, Qinghai, P.R. China.

²Graduate University of Chinese Academy of Sciences, Beijing 100049, P.R. China.

³Henan University of Traditional Chinese Medicine, Zhengzhou 450008, P.R. China.

*Corresponding authors. E-mail: liyi@nwipb.ac.cn (Yi Li), pengm@nwipb.ac.cn (Min Peng). Tel.: +86971-6101454. Fax: +86971-6143282.

Abbreviations: AMOVA, analysis of molecular variance; CTAB, cetyltrimethylammonium bromide; ISSR, inter simple sequence repeat; PCR, polymerase chain reaction; UPGMA, unweighed pair-group method using arithmetic average.

Accepted 20 July, 2009

   Abstract

Inter simple sequence repeat (ISSR) markers were used to detect the genetic diversity in three morphological types of cultivated Astragalus membranaceus Bge. var. mongholicus (Bge.) Hsiao discovered in Gansu province of China. Eight primers used for analysis generated 165 scorable bands of which 162 (98.18%) were polymorphic. The percentage polymorphic bands (PPB), Shannon’s information index (I) and Nei’s gene diversity (h) for 3 types ranged from 59.39%, 0.2912, 0.1901 to 78.18%, 0.3411, 0.2238 respectively, indicating each type had a high genetic diversity. Analysis of molecular variance (AMOVA) showed 90.41% of the total genetic diversity existed within the 3 morphological types, whereas only 9.59% occurred among them. The UPGMA tree based on SM similarity coefficients implied that the 3 types had genetically differentiated though not obviously. The high genetic diversity suggested that each type had a potential to develop new strains or cultivars and ISSR was a potentially useful tool in the process of selective breeding of A. membranaceus var. mongholicus.

Key words: Astragalus membranaceus var. mongholicus, morphological type, genetic diversity, ISSR, Radix astragali.