RESUMEN
BACKGROUND: Picea brachytyla is a unique tree species in China. Due to being extensively exploited in the past, it is listed as Vulnerable in the IUCN Red List. It is mainly distributed across the Hengduan and Daba-Qinglin mountains and has been found in other areas including Sichuan Province and Qinghai Province, China. Microsatellites, or simple sequence repeats (SSRs), are widely used in correlational studies of genetic protection. Few markers have been developed for P. brachytyla because of the small number of trees and scholarly resources available for study. METHODS AND RESULTS: The genomic DNA of P. brachytyla was sequenced using the DNBSEQ platform, and unigenes were obtained after assembly and deredundancy. Of the 100 primer pairs screened, we isolated 10 useful microsatellite loci from P. brachytyla genes. The observed and expected heterozygosity values ranged from 0.173 (P24) to 0.788 (P79; mean 0.469) and 0.199 (P87) to 0.911 (P79; mean 0.700), respectively. Polymorphism-information content (PIC) ranged from 0.190 (P84) to 0.904 (P79; mean 0.666). Only P84 and P72 were in a Hardy-Weinberg equilibrium (P > 0.05) in the different P. brachytyla populations. All the levels of linkage disequilibrium (LD) were high for the 10 SSR loci indicating that there were no autocorrelations among the 10 SSR loci. CONCLUSIONS: The novel polymorphic microsatellite markers showed high polymorphism for P. brachytyla. These polymorphic microsatellites can provide a basis for future conservation and genetic research on this rare plant species.
Asunto(s)
Picea , China , Desequilibrio de Ligamiento/genética , Repeticiones de Microsatélite/genética , Picea/genética , Polimorfismo Genético/genéticaRESUMEN
Koji-making is a key process for production of high quality soy sauce. The microbial composition during koji-making was investigated by culture-dependent and culture-independent methods to determine predominant bacterial and fungal populations. The culture-dependent methods used were direct culture and colony morphology observation, and PCR amplification of 16S/26S rDNA fragments followed by sequencing analysis. The culture-independent method was based on the analysis of 16S/26S rDNA clone libraries. There were differences between the results obtained by different methods. However, sufficient overlap existed between the different methods to identify potentially significant microbial groups. 16 and 20 different bacterial species were identified using culture-dependent and culture-independent methods, respectively. 7 species could be identified by both methods. The most predominant bacterial genera were Weissella and Staphylococcus. Both 6 different fungal species were identified using culture-dependent and culture-independent methods, respectively. Only 3 species could be identified by both sets of methods. The most predominant fungi were Aspergillus and Candida species. This work illustrated the importance of a comprehensive polyphasic approach in the analysis of microbial composition during soy sauce koji-making, the knowledge of which will enable further optimization of microbial composition and quality control of koji to upgrade Chinese traditional soy sauce product.