RESUMEN
A total of 178 Chinese wolfberry individuals from 17 populations were detected by 7 pairs of SSR primers to evaluate genetic diversity and structure, using software GenALEx 6.5,NTSYS,STRUCTURE, the effects of cultivation on genetic diversity and structure were clarified aiming to find the strategies for genetic management and sustainable use. The results showed that the genetic diversity of cultivated Chinese wolfberry was low. The average number of alleles N_A, expected heterozygosity H_E, observed heterozygosity H_O, and Shannon's information index H' was 3.9, 0.443 7, 0.556 6, 0.788 1, respectively. STRUCTURE, UPGMA clustering and PCA test indicated that Chinese wolfberry varieties were severely intermixed but no differentiation among varieties. Mantel test showed no significant correlation between genetic distance and geographic distance. AMOVA analysis showed that genetic variation mainly occurred among individuals within the population(84.58%, P<0.001), and there was almost no genetic differentiation between varieties(3.63%, P<0.001) and between populations(11.79%, P<0.001). The cultivation has caused a significant decline in the genetic diversity of Chinese wolfberry, which may cause inbreeding decline. New germplasm resources should be sought from the wild to improve the existing cultivars. On the other hand, there are obvious homogenization and germplasm intermixing between cultivated varieties and populations. Meanwhile, Chinese wolfberry cultivars should be purified and prevented from flowing into the wild population, in case of causing pollution of the wild germplasm.
Asunto(s)
Variación Genética , Genética de Población , Lycium/genética , Repeticiones de Microsatélite , Alelos , FitomejoramientoRESUMEN
Dioscorea L., the largest genus of the family Dioscoreaceae with over 600 species, is not only an important food but also a medicinal plant. The identification and classification of Dioscorea L. is a rather difficult task. In this study, we sequenced five Dioscorea chloroplast genomes, and analyzed with four other chloroplast genomes of Dioscorea species from GenBank. The Dioscorea chloroplast genomes displayed the typical quadripartite structure of angiosperms, which consisted of a pair of inverted repeats separated by a large single-copy region, and a small single-copy region. The location and distribution of repeat sequences and microsatellites were determined, and the rapidly evolving chloroplast genome regions (trnK-trnQ, trnS-trnG, trnC-petN, trnE-trnT, petG-trnW-trnP, ndhF, trnL-rpl32, and ycf1) were detected. Phylogenetic relationships of Dioscorea inferred from chloroplast genomes obtained high support even in shortest internodes. Thus, chloroplast genome sequences provide potential molecular markers and genomic resources for phylogeny and species identification.
RESUMEN
Chinese yam has been used both as a food and in traditional herbal medicine. Developing more effective genetic markers in this species is necessary to assess its genetic diversity and perform cultivar identification. In this study, new chloroplast genomic resources were developed using whole chloroplast genomes from six genotypes originating from different geographical locations. The Dioscorea polystachya chloroplast genome is a circular molecule consisting of two single-copy regions separated by a pair of inverted repeats. Comparative analyses of six D. polystachya chloroplast genomes revealed 141 single nucleotide polymorphisms (SNPs). Seventy simple sequence repeats (SSRs) were found in the six genotypes, including 24 polymorphic SSRs. Forty-three common indels and five small inversions were detected. Phylogenetic analysis based on the complete chloroplast genome provided the best resolution among the genotypes. Our evaluation of chloroplast genome resources among these genotypes led us to consider the complete chloroplast genome sequence of D. polystachya as a source of reliable and valuable molecular markers for revealing biogeographical structure and the extent of genetic variation in wild populations and for identifying different cultivars.
Asunto(s)
Cloroplastos/genética , ADN de Cloroplastos/genética , Dioscorea/genética , Genoma del Cloroplasto/genética , Genoma de Planta/genética , Marcadores Genéticos/genética , Genómica/métodos , Genotipo , Repeticiones de Microsatélite/genética , Filogenia , Polimorfismo de Nucleótido Simple/genética , Análisis de Secuencia de ADN/métodosRESUMEN
Scutellaria baicalensis Georgi (Lamiaceae) is the source of the well-known traditional Chinese medicine "HuangQin" (Radix Scutellariae). Natural sources of S. baicalensis are rapidly declining due to high market demand and overexploitation. Moreover, the commercial products of Radix Scutellariae have often been found to contain adulterants in recent years, which may give rise to issues regarding drug efficacy and safety. In this study, we developed valuable chloroplast molecular resources by comparing intraspecific and interspecific chloroplast genome. The S. baicalensis chloroplast genome is a circular molecule consisting of two single-copy regions separated by a pair of inverted repeats. Comparative analyses of three Scutellaria chloroplast genomes revealed six variable regions (trnH-psbA, trnK-rps16, petN-psbM, trnT-trnL, petA-psbJ, and ycf1) that could be used as DNA barcodes. There were 25 single nucleotide polymorphisms(SNPs) and 29 indels between the two S. baicalensis genotypes. All of the indels occurred within non-coding regions. Phylogenetic analysis suggested that Scutellarioideae is a sister taxon to Lamioideae. These resources could be used to explore the variation present in Scutellaria populations and for further evolutionary, phylogenetic, barcoding and genetic engineering studies, in addition to effective exploration and conservation of S. baicalensis.