GENETIC DIVERSITY OF NATURALLY DISTRIBUTED Rhododendron moulmainense Hook. f. POPULATIONS IN LAM VIEN PLATEAU, VIETNAM REVEALED BY ISSR AND SCoT MARKERS

Abstract

Genetic diversity and variation of three naturally distributed Rhododendron moulmainense populations in the Lam Vien Plateau of Vietnam were analyzed using ISSR and SCoT markers separately and data from the two types of markers were then combined to show the overall results. Based on combined data, the genetic diversity parameters of the Tuyen Lam population were percentage of polymorphic bands (PPB) = 28.79%; genetic heterozygosity (He) = 0.1041; Shannon index (I) = 0.1552. The corresponding parameters were PPB = 37.88%; He = 0.1434; I = 0.2131 in the Hon Nga population, and PPB = 46.21%; He = 0.1857; I = 0.2709 in the Bidoup population. At the species level in Lam Dong province, the corresponding parameters were PPB = 62.12%; He = 0.1747; I = 0.2756. The average of pairwise genetic similarity coefficients among investigated individuals of Tuyen Lam population was 0.973, of Hon Nga population was 0.911, and of Bidoup population was 0.895. The genetic differentiation and the number of migrants per generation among investigated populations were GSTS = 0.1735 and Nm = 2.3824 individuals, respectively. Genetic distance between Tuyen Lam and Hon Nga populations was 0.0399, between Tuyen Lam and Bidoup populations were 0.0621, and Bidoup and Hon Nga populations were 0.0670. Data generated by both marker types and the combined revealed similar trends of genetic diversity levels among the studied populations. The SCoT data showed higher values of genetic diversity and population gene differentiation than did the ISSR data, but the latter showed higher gene differentiation among sampled individuals in the study populations. Comparing the values of Polymorphism Information Content (PIC) for discriminatory ability; Effective Multiplex Ratio (EMR) for several revealed loci and/or efficiency of the primer-marker system; Marker Index (MI) for the efficiency of used method; and Resolving Power (Rp) between used techniques indicated that discriminatory ability, efficiency, and ability of the ISSR primer combinations were higher but using SCoT marker system was more efficient than ISSR marker system for evaluating genetic diversity.

Conservation Genetics of the Only Honeysuckle Azalea (Rhododendron luteum) Population Present in Greece

“…accessions [29] (Table 1). The expected heterozygosity (Nei's gene diversity) was also lower compared to all studies in other Rhododendron species (Table 1), except one study in natural populations of R. moulmainense [39] that also used ISSR markers (Table 1); however, this study reported the use of populations declining in size [39].…”

“…The Shannon diversity index (I) found in this study was lower than the values reported in the majority (75%) of other studies in Rhododendron using dominant molecular markers and different genetic entries (Table 1). Moreover, the only studies that presented lower Shannon index values were the ISSR study on the declining R. moulmainense natural populations [39] discussed above and the AFLP study of the endangered R. protistum var. giganteum that used only two known endemic populations present in a restricted geographical area [40].…”

“…The only study with a sample size similar to ours can be considered as the study of Wu et al [40] (n = 28), which employed AFLP markers (Table 1) where genetic diversity was lower (I = 0.358, whereas in our study I = 0.410). When considering natural population studies using ISSRs, the most similar to our sample size was the study of Trung et al [39], which used a population sample size almost half that of ours (n = 20). In this study, genetic diversity was also found to be lower (I = 0.256; Table 1) than in the present study.…”