Genetic diversity and population structure of Prunus mira (Koehne) from the Tibet plateau in China and recommended conservation strategies

Abstract

Prunus mira Koehne, an important economic fruit crop with high breeding and medicinal values, and an ancestral species of many cultivated peach species, has recently been declared an endangered species. However, basic information about genetic diversity, population structure, and morphological variation is still limited for this species. In this study, we sampled 420 P. mira individuals from 21 wild populations in the Tibet plateau to conduct a comprehensive analysis of genetic and morphological characteristics. The results of molecular analyses based on simple sequence repeat (SSR) markers indicated moderate genetic diversity and inbreeding (A = 3.8, Ae = 2.5, He = 0.52, Ho = 0.44, I = 0.95, FIS = 0.17) within P. mira populations. STRUCTURE, GENELAND, and phylogenetic analyses assigned the 21 populations to three genetic clusters that were moderately correlated with geographic altitudes, and this may have resulted from significantly different climatic and environmental factors at different altitudinal ranges. Significant isolation-by-distance was detected across the entire distribution of P. mira populations, but geographic altitude might have more significant effects on genetic structure than geographic distance in partial small-scale areas. Furthermore, clear genetic structure, high genetic differentiation, and restricted gene flow were detected between pairwise populations from different geographic groups, indicating that geographic barriers and genetic drift have significant effects on P. mira populations. Analyses of molecular variance based on the SSR markers indicated high variation (83.7% and 81.7%), whereas morphological analyses revealed low variation (1.30%–36.17%) within the populations. Large and heavy fruits were better adapted than light fruits and nutlets to poor climate and environmental conditions at high altitudes. Based on the results of molecular and morphological analyses, we classified the area into three conservation units and proposed several conservation strategies for wild P. mira populations in the Tibet plateau.

Evaluation of the genetic diversity in the feijoa accessions maintained at Santa Catarina, Brazil

“…Similar studies performed with other species revealed quite similar results. Bao et al (2017) found that in Prunus mira (Koehne), geographic distance is not a crucial factor for genetic composition in small areas, and an altitude gradient can have more significant effects on population structure than geographical distance. In addition, Tang et al (2014), observed in Lilium pumilum DC that altitude, mean annual temperature, and mean annual rainfall contribute 9.5, 11.5, and 14.0% of the total variance among the populations, respectively.…”

Assessing Genetic Diversity and Population Structure of Kalmia latifolia L. in the Eastern United States: An Essential Step towards Breeding for Adaptability to Southeastern Environmental Conditions

“…For instance, K. latifolia populations at the southernmost range usually have a flowering time one month earlier than populations in Massachusetts according to our investigation. This gap in blooming period, coupled with the large geographic distance, could prevent insect pollination [37]. Therefore, a relatively higher level of among-population differentiation was observed on K. latifolia than other out-crossing species.…”

“…Frequent gene flow led to low level of genetic differentiation and small genetic distance between them [38]. By contrast, gene flow between populations inhabiting different geographic regions was reduced because of different phenological phases (e.g., blooming time) caused by different environmental conditions [37]. In addition to limited gene flow, the result of plants' adaptations to different growing conditions might also account for the higher level of genetic differentiation and larger genetic distance between populations that distribute in different geographic regions.…”

Male Sterility is linked to the Flavonoid Biosynthesis Pathways in Prunus mira

“…In a previous field survey, Zeng [7] observed that many wild P. mira trees in the Tibet region were male sterile. The high proportion of male sterility trait may have contributed to the high genetic variation observed in P. mira [8,9].…”