Genetic diversity of Miyamasukashi‐yuri ( <i>Lilium maculatum</i> Thunb. var. <i>bukosanense</i> ), an endemic and endangered species at Mount Buko, Saitama, Japan

Abstract

Abstract Lilium maculatum var. bukosanense , Miyamasukashi‐yuri in Japanese, grows endemically in Saitama Prefecture, Japan, and is listed in the Saitama Prefecture Red Data Book as a critically endangered plant. Articles about its genetic diversity and population genetic structure have not been reported. Before it is lost, population genetic studies can provide information for efficient in situ conservation as well as for possible future use in breeding programs. Therefore, we carried out a population genetic study of natural L. maculatum var. bukosanense using chloroplast DNA (cpDNA) and inter‐simple sequence repeat (ISSR) markers. In this study, fresh leaves of 46 L. maculatum var. bukosanense individuals were collected from two populations in Mount Buko. By polymerase chain reaction (PCR)‐restriction fragment length polymorphism analysis of cpDNA, we estimated the maternal origin of individuals sampled. Sixteen cpDNA primer pairs were tested, and only four of them produced clear bands. Twenty‐four combinations from these PCR fragments combined with six restriction enzymes were assayed; however, only 18 of them could be digested, producing two to four fragments. All individuals of L. maculatum var bukosanense analyzed were virtually identical for all primer–enzyme combinations. These findings suggest that the maternal origin of the 46 individuals analyzed is close. In addition, we analyzed ISSR markers to provide mainly biparental inheritance. PCR products of five anchored simple sequence repeat primers showed polymorphism, indicating that the individuals sampled were not clones, and thus it appears that they could have been reproduced from seeds. The primers yielded a total of 30 polymorphic bands (i.e. an average of six polymorphic bands per primer). The mean genetic distance and genetic identity values between the populations were 0.032 and 0.97, respectively. These findings suggest that all individuals from both populations are genetically similar. The individuals growing at 1000 m have greater genetic variation than those individuals from 650 m and this could possibly be attributed to altitude. A significant correlation between gene diversity and population size is also reported. From the results presented here some strategies for its in situ and ex situ conservation might be considered.