Phylogeography of Chinese cherry (Prunus pseudocerasus Lindl.) inferred from chloroplast and nuclear DNA: insights into evolutionary patterns and demographic history.

Chinese cherry (Prunus pseudocerasus Lindl.) is a commercially valuable fruit crop in China. In order to obtain new insights into its evolutionary history and provide valuable recommendations for resource conservation, phylogeographic patterns of 26 natural populations (305 total individuals) from six geographic regions were analyzed using chloroplast and nuclear DNA fragments. Low levels of haplotype and nucleotide diversity were found in these populations, especially in landrace populations. It is likely that a combined effect of botanical characteristics impact the effective population size, such as inbreeding mating system, long life span, as well as vegetative reproduction. In addition, strong bottleneck effect caused by domestication, together with founder effect after dispersal and subsequent demographic expansion, might also accelerate the reduction of the genetic variation in landrace populations. Interestingly, populations from Longmen Mountain (LMM) and Daliangshan Mountain (DLSM) exhibited relatively higher levels of genetic diversity, inferring the two historical genetic diversity centers of the species. Moreover, moderate population subdivision was also detected by both chloroplast DNA (GST = 0.215; NST = 0.256) and nuclear DNA (GST = 0.146; NST = 0.342), respectively. We inferred that the episodes of efficient gene flow through seed dispersal, together with features of long generation cycle and inbreeding mating system, were likely the main contributors causing the observed phylogeographic patterns. Finally, factors that led to the present demographic patterns of populations from these regions and taxonomic varieties were also discussed.

[The determination sorbitol and carbohydrates in nane fruit by high performance liquid chromatography].

A high performance liquid chromatographic method for the determination of carbohydrates and sorbitol in Nane fruit is described. The chromatography was carried out on a mu-Spherogel carbohydrate column(4.6 mm i.d. x 300 mm) (at 85 degrees C) using water as mobile phase and refractive index detector. The average recovery of carbohydrates were 75.00%-88.37% and correlation coefficients were 0.9709-0.9999. The relative standard deviations for intra-day were 5.10% for sucrose, 3.15% for glucose, 3.03% for fructose and 4.84% for sorbitol respectively (n = 5). The accumulations of soluble carbohydrates(including fructose, glucose, sorbitol and sucrose) in flesh showed their characteristic patterns in different special phase of fruit growth.