Genetic diversity of Indigofera kirilowii Maxim. ex Palibin using AFLP makers

The present studies were conducted to assess the genetic diversity and to infer population structure of 220 individuals of Indigofera kirilowii from 8 natural populations of Shandong province, north China, using amplified fragment length polymorphism (AFLP) markers. A total of 1589 AFLP bands were produced, of which 99.87% were polymorphic. High genetic diversity was considered (H = 0.1401; I = 0.2346), with high genetic differentiation (GST = 0.1058), while estimates of gene flow (Nm) were high in all analysis. No correlations were observed between geographic location and genetic diversity (r = –0.0901; p = 0.3293). Based on the results, here a strategy for the conservation of I. kirilowii germplasm was proposed. Indigofera kirilowii Maxim. ex Palibin is one of the native tree species with important medicinal and landscaping value, which mainly distributes in the northeast and north China. Previous studies on I. kirilowii are only limited in chromosome (Wang and Xu 1994), chemical constituents (Su et al. 2006, Lv et al. 2009, seedling cultivation (Deng et al. 2008), seeds germination (Zhao et al. 2013), urban landscaping (Ji 2011) and comprehensive utilization (Xu et al. 2016). However, no research about the genetic diversity and population structure of I. Kirilowii has been reported. Assessment of genetic diversity and population structure of the species is of the great necessity for utilization and protect I. kirilowii resources. Because of environmental destruction by human disturbance and over development caused a sharp decline in natural populations of I. kirilowii. Therefore, it is very necessary to take some adoption of effective conservation strategy for this species. Amplified fragment length polymorphism (AFLP) is a kind of quite effective molecular marker technique, which has been widely applied in assessing the genetic diversity and population structure among endangered species (Vos et al. 1995, Cires et al. 2013). AFLP markers were applied in this study to assess the genetic diversity and population structure of 220 I. kirilowii germplasms from 8 different populations to provide certain theoretical evidences for utilization and conservation of natural I. kirilowii resources. Young leaves were collected from 220 I. kirilowii individuals from 8 different populations of Shandong province, north China. The geographic locations of sampling sites are shown in Fig.1, and the details are presented in Table1. The number of samples per populations varied from 8 to 54. The collected leaves were stored with silica gel in zip-lock bags until DNA extraction. Total genomic DNA was extracted from dried leaf tissues following the modified Doyle (1987) CTAB method. All the experimental operations were carried out in key laboratory of silviculture in Shandong province, Tai'an. * Author for correspondence: . Collaborative Innovation Centre of Sustainable Forestry in Southern China, College of Forest Science, Nanjing Forestry University, Nanjing-210037, China. College of Horticulture Science and Engineering, Shandong Agriculture University, Tai'an-271000, China.