Study on the Genetic Variation of Triadica sebifera (Linnaeus) Small Populations Based on SSR Markers

Abstract

Triadica sebifera (Linnaeus) Small is a tree species native to China. The seeds of T. sebifera are rich in oil and are widely used in industrial fields. To explore the genetic diversity and genetic differentiation of T. sebifera germplasm resources, 10 pairs of microsatellite markers were applied to 203 samples collected from eight populations. Forty-three alleles were detected. The average expected heterozygosity (He = 0.491) revealed a low level of genetic diversity. The genetic differentiation among T. sebifera populations was low (Fst = 0.026), which might be related to high gene flow (average Nm = 11.151). Genetic distance and structure results further confirmed that the genetic compositions of the eight populations were quite similar. One of the possible reasons for this phenomenon is that the early introduction and cultivation of T. sebifera were common, so gene exchange was frequent among populations. However, UPGMA clustering results indicated that the eight T. sebifera populations could still be divided into three categories. The classification was related to their geographical location: the southwestern group (ZY), central group (HG and XY) and eastern group (LS, HS, LX, XZ and LY). The reason for this differentiation might be severe deforestation following the decline in T. sebifera economic status. In addition, the central XY population had the largest number of rare alleles (4). In conclusion, although T. sebifera germplasm resources had a low level of genetic diversity, several rare alleles were detected in the central populations, which are valuable for breeding. These resources should be conserved to maintain genetic diversity in the T. sebifera populations. Moreover, geographical distances were important reasons for the limited genetic variations among the populations.

Genetic Analysis and Construction of a Fingerprint for Licensed Triadica sebifera Cultivars Using SSR Markers

“…The wild Ipomoea batatas individuals have a higher degree of genetic diversity than the cultivars [38]. However, the genetic diversity of widespread T. sebifera populations (He = 0.491) is much lower than that of T. sebifera cultivars [1]. The main reason may be that a wide range of T. sebifera trees have been destroyed or transplanted, which may lead to a loss of both germplasm and genetic diversity.…”

“…Triadica sebifera is a native tree species of China and is mainly distributed in areas south of the Qinling Mountains and Huaihe River [1]. The seeds have been used for candles, heating oils, and cocoa butter equivalents since the late 1980s [2][3][4].…”

“…To date, studies on T. sebifera have focused mainly on phylogenetic relationships, chemical components, and biological activity [2,23,24]. In terms of molecular markers, several SSR markers have been developed and applied in the genetic analysis of T. sebifera populations [1,[25][26][27]. Hence, SSR markers may be an effective method to study the genetic relationship and fingerprinting of T. sebifera cultivars.…”

Biodiversity and Conservation of Forests

“…They recommend the adoption of appropriate management measures to maintain the diversity in the high-diversity populations and increase the gene exchange in the low-diversity populations to restore genetic diversity. Limited genetic variations among studied populations of Triadica sebifera are reported by Zhou et al [18], along with a relatively low within-population genetic diversity. However, the existence of some rare alleles in some populations may prove extremely important in maintaining the level of genetic diversity.…”

Development of Microsatellite Markers to Determine Genetic Diversity of Indonesian Betel Nut (Areca catechu L.)

“…Differences in the performance of areca nut are not only caused by genetics, but differences in altitude and agro-climate make the diversity of areca nut even greater. Genetic diversity in a population between regions is caused by humans and nature over time (Zhou et al, 2020). The existence of genetic diversity is the main capital in the management of germplasm more effectively and efficiently.…”