A Rapid PCR-RFLP Method for Assessing Heterozygosity of Murraya paniculata Germplasm / 中国实验方剂学杂志

ObjectiveTo establish a rapid method for evaluating the heterozygosity of Murraya paniculata germplasm materials and provide as a foundation for developing germplasm breeding and innovation measures for M. paniculata. MethodSingle nucleotide polymorphisms （SNPs） were screened from the genome resequencing data of 65 plants of M. paniculata. A self-written script was used to transform 20 SNPs into restriction fragment length polymorphism （RFLP） markers. Polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） was employed to detect the 20 RFLP markers in 12 M. paniculata germplasm accessions， and the heterozygosity of M. paniculata germplasm accessions was calculated based on the number of enzyme-cutting bands at the 20 RFLP marker sites. Plink was used to calculate the whole genome heterozygosity of 12 M. paniculata germplasm accessions， and the results obtained with different methods were compared. ResultThere was no significant difference in the heterozygosity calculated by the PCR-RFLP method and the genome resequencing method. The PCR-RFLP and genome resequencing methods identified 8 and 9 germplasm accessions， respectively， with a heterozygosity level less than 30%. Seven germplasm accessions with heterozygosity less than 30.00% were calculated by both methods. ConclusionThe PCR-RFLP method established in this study for evaluating the heterozygosity of M. paniculata germplasm demonstrates the precision of 87.5% and the accuracy of 77.8%. This method serves as a reference for developing heterozygosity evaluation methods in other medicinal plant germplasm resources.

Specific PCR Identification of Hibisci Cortex and Its Adulterants Based on DNA Signature Sequence Tags / 中国实验方剂学杂志

ObjectiveUncommon medicinal herbs are valuable medicinal resources， but their identification is a difficult problem in Chinese medicine due to their particularity and complexity. It is， therefore， urgent to establish a method for the identification of uncommon medicinal herbs. In this study， DNA signature sequence （DSS） tags were used to establish a specific polymerase chain reaction （PCR） identification method for Hibisci Cortex， the origin plant of Hibisci Cortex， and its adulterants. MethodThe candidate DSS tags were obtained from the chloroplast genome sequence analysis， and the DSS tags were verified by DNA sequencing. The specific identification primers for H. syriacus were designed based on the obtained reliable DSS tags. The PCR reaction conditions were optimized， and the tolerance and feasibility were investigated. ResultA DSS tag for identification of H. syriacus was obtained from the comparison of sequencing results of the amplified products with DSS， which revealed the distinguishing characteristics of Hibisci Cortex and its adulterants. A pair of specific primers for H. syriacus was designed according to the DSS tag. After PCR amplification and gel electrophoresis with the primers， a single bright band of about 270 bp was observed from H. syriacus， which did not appear in the four adulterants. ConclusionA DSS tag obtained in this study can be used to identify H. syriacus. The specific primers designed based on this DSS tag can accurately and simply identify the original plant of Hibisci Cortex and its adulterants， which provides a new method and idea for the molecular identification of genuine and counterfeit products of Hibisci Cortex.

Rapid Screening of Gastrodia elata with High Purity by PCR-RFLP Identification / 中国实验方剂学杂志

ObjectiveTo establish a rapid screening method for germplasm materials of Gastrodia elata with high purity， and lay a foundation for pure line breeding and cross breeding. MethodBased on the whole genome sequencing and population resequencing of G. elata， 20 restriction fragment length polymorphism (RFLP) markers were developed by single nucleotide polymorphism (SNP) sites. The polymerase chain reaction (PCR)-RFLP method was used to carry out restriction endonuclease experiments on 20 RFLP markers of 15 G. elata germplasms. According to the number of enzymatic bands at 20 RFLP marker sites, the purity of 15 germplasms was calculated and evaluated. On this basis, genome resequencing technology was used to verify the assessment results. ResultTen germplasm materials with purity greater than 95% were screened out by PCR-RFLP method， 3 of which had 95% purity and 7 had 100% purity. Nine germplasm materials with purity greater than 95% were screened out by genome resequencing methods, and 8 of them were consistent with the results of PCR-RFLP. ConclusionThe PCR-RFLP method established in this study for screening G. elata germplasms with high purity precision of RFLP markers has 80% precision and 89% accuracy. The method is simple， efficient， and significantly less expensive than genome resequencing method, which provides technical support for pure line breeding of G. elata and references for breeding of other Chinese medicinal materials.