Patent Application
20210198756
The present application is based upon and claims priority to Chinese Application No. 2020106089828, filed on Jun. 30, 2020, and entitled “DNA barcode for species identification of Lychium chinensis and identification method therefor”, and Chinese Application No. 2020103478862, filed on Apr. 28, 2020, and entitled “method for rapid identification of Lychium chinensis based on DNA barcode”, the entire contents of which are incorporated herein by reference.
The contents of the electronic sequence listing (Sequence-Listing-2021-03-19; Size: 81,000 bytes; and Date of Creation: Mar. 19, 2021) is herein incorporated by reference in its entirety
The present disclosure relates to the technical field of identification of Wolfberry species, especially relates to DNA barcodes for species identification of wolfberry and identification method therefor.
Wolfberry (Lycium chinensis) belongs to Lyciinae wettst in Solaneae reichb. of Solanaceae, it is a kind of plant, in particular to a deciduous shrub with perennial rootstock, whose fruit, root bark and leaves have high medicinal and health care value. There are 80 species of wolfberries, distributed all around the world. And in China, they are mainly distributed in Ningxia, Xinjiang, Gansu and Qinghai. Traditional morphological identification methods hardly work for species identification of Lycium chinensis, as they may have same origin or are close sib in one species, and they are similar in development morphology, the tissue structure and the chemical composition. DNA barcoding (DNA barcode) can be used to recognize and identify target varieties using one or a few DNA fragments. It is characterized by simple operation, high accuracy, and rapid identification, etc. Presently, it has become a new research area and hotspot of interest in modern biological taxonomy. In recent years, researchers at home and abroad have carried out active exploration and studies on DNA barcode gene sequences suitable for plant identification.
A patent application CN110229927A with title “method for identifying wolfberry based on DNA barcoding and an application thereof”, provides a method for identifying wolfberry based on DNA barcoding, wherein the gene sequence of a Lycium ruthenicum Murr. Identifyed DNA barcoding is LRITS2 (the sand internal transcribed spacer)/LrpsbA-trnH (a non-coding region between chloroplast genes psbA and trnH); the sequence LRITS2/LrpsbA-trnH of the Lycium ruthenicum Murr. Identified by DNA barcoding may be used together or one of them is used separately. The invention can efficiently and accurately distinguish the Lycium ruthenicum Murr. from other counterfeit products; it can be used for the identification in fruit powder, fruit shreds and others.
An article titled “Early Screening of intraspecies Hybrids of Lycium barbarum based on ITS barcode sequence”, discloses early screening of intraspecies hybrid varieties of wolfberries by using a barcode sequence in ribosome internal transcribed spacer (ITS), wherein an improved cetyltrimethylammonium bromide (CTAB) method is used to extract DNA of wolfberry leaves, and a synthetic specific primers is used to amplify and clone the nrDNA ITS region, and then the target fragments are sequenced and analyzed. The results show, a group of Ningxia wolfberry including L. barbarum Linn (Ningqi Ningqi 2# and white-flowered wolfberry are used as parents for selective breeding and hybrid matching, and a cluster analysis of the hybrid offspring produced by the intraspecies crossbreeding based on the ITS barcode sequence to analyze the genetic relationship and differences between the hybrid offspring and their parents so as to conduct early screening of their hybrid offspring; as can be seen from the results, that the sequence based on ITS barcode can be used for early screening of hybrid progenies for breeding. However, the barcode database of wolfberries is deficient in both richness and number, and a lot of research is further needed.
The present disclosure provides DNA barcodes for species identification of Wolfberry (Lycium chinensis) and a method using them to identy Lycium chinensis, overcomes the problems in the prior art of delayed excavation and utilization of excellent wolfberry resources, unclear genetic background of species resources of wolfberries, unknown inter-species relationship, and deficiency in species richness and quantity in the barcode database of wolfberries. The present invention provides a method of quickly identifying molecular markers of wolfberries including Lycium ruthenicum Murr., Huangguo wolfberry, Lycium barbarum Yuanguo, Lycium dasystemum, local wolfberry species of Ningxia, the northern, Xinjiang, Yunnan and Hebei, and representative wolfberry species of different sources such as hybrid population, space mutation population and ploidy population on the basis of China's only Lycium barbarum germplasm resources nursery and the breeding materials Obtained from the long-term development of new species of wolfberry, which can be applied to identification of wolfberry species.
The present invention provides a method of identifying Lycium chinensis species and distinguishing the interspecies relationship of Lychium chinensis by DNA barcoding. The invention also provides a trnG-trnS barcode database. The identification is completed by the following steps: aligning the trnG-trnS sequence of a sample to be identified with the sequence in the trnG-trnS barcode database, to identify the species of the wolfberry and determine the interspecies relationship of the wolfberry. This provides an effective basis for the species identification of wolfberry.
The technical solutions of the present invention are described as below. For one purpose, the present disclosure provides a method for species identification of Lychium chinensis based on DNA barcode, the said DNA barcode is a trnG-trnS barcode,
The group of species to be identified includes: L. barbarum Linn (Ningqi 1#), Ningqi 2#, Ningqi 3#, Ningqi 4#, Ningqi 5#, Ningqi 6#, Ningqi 74 and Ningnongqi 9#, L. barbarum Linn. var. auranticarpum K.F.Ching var. nov., Lycium barbarum Bianguo, Lycium ruthenicum Murr., L. barbarum Linn 5#, Lycium chinense MilL. var. potaninii (Pojark,) A. M. Liu, Damaye (L. barbarum Linn), Baihua (L. barbarum),), L. chinense Mill. Var., Lycium yunnanenseKuang et A. M. Lu, Manshenggouqi (L. barbarum), Ziguogouqi (L. barbarum), Lycium dasystemum, Xiaomaye (L. barbarum Linn), Lycium chinense, Lycium dasystemumPojark, Mengqi 1#, Ningqicai 1#, black half-bred wolfberry variant by space mutation, wolfberry variant by space mutation, Lycium barbarum Yuanguo, 9001# wolfberry, Lycium barbarum Huangguo, Changji wolfberry, Hebei wolfberry and others.
Preferably, the said method for species identification of Lychium chinensis based on DNA barcoding, comprising the following steps:
The present disclosure provides a trnG-trnS DNA barcoding database consisting of SEQ ID NO.1-36.
The trnG-trnS DNA barcoding obtained by the present invention is used to build a phylogenetic tree, to perform homology ratio comparison to analyze and calculate base composition of the target sequence, the base variation frequency between sequences and the conversion frequency between sequences and their ratios, and the distribution difference of intra- and inter-species in sequences, thereby establishing a trnG-trnS DNA barcode identification technology system for identification of wolfberry species.
Preferably, in step 1), a DNA of the sample is extracted by a kit.
Preferably, in step 1), the kit is a DNA secure Plant Kit.
Preferably, extraction of DNA using a kit has the following steps:
1.1 Extraction of DNA
Taking fresh and tender leaves of wolfberry plants as sample, washing up and stored at −80° C. Extracting total DNA using an extraction kit for new plant genomic DNA (DNA sure Plant Kit). The derailed extraction method is as follows:
1.1.1 Taking 100 g sample to a multifunctional high-efficiency biological sample preparation instrument and grind it for 2 minutes by 22 times/seconds; immediately adding 400 μl buffer solution LP1 and 6 ul RNase A (10 mg/ml)), oscillating it by a vortex method for 1 min, and staying it at a room temperature for 10 min.
1.1.2 Adding 130 ul buffer LP2, mixing well and oscillating by a vortex method for 1 min. 1.1.3 Centrifuging at 12000 rpm for 5 minutes, and transferring the supernatant to a new centrifugal tube.
1.1.4 Adding 1.5 times volume of buffer LP3 into the supernatant (checking if absolute ethanol is added before using), and fully oscillating the solution for 15 sec to mix it evenly; at this time, a flocculent precipitate may appear.
1.1.5 Adding the solution and flocculent precipitate obtained in the previous step into an adsorption column CB3 (which is placed in a collection tube), centrifuging the mixture at 12000 rpm for 30 s, discarding the waste fluid, and putting the adsorption column CB3 into the collection tube.
1.1.6 Adding 600 ul rinse solution PW to the adsorption column CB3 (checking if the absolute ethanol is added before using), centrifuging the solution at 12000 rpm for 30 s, discarding the waste fluid, and putting the adsorption column CBS into the collection tube. (Note: If the adsorption column membrane is green, adding 500 ul absolute ethanol to the adsorption column CB3, centrifuging at 12000 rpm for 30 s, discarding the waste fluid, and putting the adsorption column CB3 into the collection tube)
1.1.7 Repeating the step 1.1.6.
1.1.8 Putting the adsorption column CB3 into the collection tube, centrifuging at 12000 rpm for 2 minutes, and discarding the waste fluid; placing the adsorption column CB3 at a room temperature for 15 minutes to remove the remaining rinse solution in the adsorption material thoroughly.
1.1.9 Transferring the adsorption column CB3 into a clean centrifugal tube, and dropping 100 ul elution buffer TE in the air into the middle of the adsorption membrane, staying at room temperature for 2 minutes, centrifuging at 12000 rpm for 2 minutes, and collecting the solution into the centrifugal tube.
1.1.10 Repeating the step 1.19. Keeping the DNA product at −80° C. to prevent DNA degradation.
1.2 DNA concentration and purity detection
1.2.1 Agarose gel electrophoresis detection
Preparing 1.2% agarose gel with 1.2 g agarose and 100 ml 1*TAE buffer, adding a detection system of 4 ul ddH2O+1 ul DNA sample (undiluted)+1 ul 6*loading buffer into a PCR tube for agarose gel electrophoresis, and observing the test results under a IN gel imaging system.
1.2.2 UV spectrophotometer detection
Preheating a UV spectrophotometer, and adding 99 ul ddH2O +1 ul DNA sample (undiluted) into the PCR tube for detection. The test results show the sample concentration and OD260/OD280 ratio, OD260/OD280 ratio should be within 1.7-1.9; if an elution buffer is not used in eluting, but ddH2O is used, the ratio will be lower, because the PH value and the presence of ions could affect the light absorption value, but it does not mean that the purity is low.
Preferably, in the above step 2), the PCR amplification reaction system includes: 2.1 pre-denaturation at 94° C. for 2 min; 2.2 denaturation at 94° C. for 30s, annealing at 55° C. for 30s (annealing temperature is adjustable within 58-60° C.), extension at 72° C. for 2 min, with 35 cycles; 2.3 incubation at 72° C. for 10 min; 2.4 storage at 4° C. After the PCR product is subjected to 1.0% agarose gel electrophoresis, observing the amplification result under a UV gel imaging system.
Preferably, in the above step 3), the sequencing is performed by the following steps:
3.1 PCR product cloning:
Taking a AxyPrep DNA gel extraction kit to recover a target band, and taking 1.2% agarose gel electrophoresis to perform recovery detection, and taking the purified target DNA as a sequencing template; use a pLB zero background fast cloning kit (Lethal Based Simple Fast Cloning Kit) to attach the recovered product to a T vector (pGEM-T) and then transfer it to a Escherichia coli DH5 α for culturing; screen the positive colonies by Blue-White Screening and conduct PCR detection for the colonies. Observing amplification results under a UV gel imaging system.
3.2 Sequence sequencing and analysis:
Performing sequencing of the DNA sequences of positive clones, and performing homology alignment with the sequences published in NCBI to analyze the sequences. Refer to specific operations below:
In the present invention, after PCR detection of positive bacterial colonies, the colonies containing target fragments are cultured in a LB fluid medium, and 3 colonies of each group are taken and sent to perform Sanger sequencing, thus to obtain the trnG-trnS sequence.
A homology alignment is made by Use DNAMAN on the DNA barcoding gene sequences obtained and the sequences published in NCBI database, and the DNA barcoding gene sequences of wolfberries are aligned by a Clustal X program, phylogenetic analysis software MEGA7.0 is applied to calculate the base composition of the target sequence, the base variation frequency between sequences and the conversion frequency between sequences and their ratios, the distribution difference of intra- and inter-species in sequences is compared to build a phylogenetic tree, thereby establishing a trnG-trnS DNA barcode identification technology system for identification of wolfberry species.
Another purpose of the present invention is to provide a trnG-trnS barcode database for wolfberry samples established according to the above methods, comprising 36 groups of trnG-trnS barcode, indicated by nucleotide sequence SEQ ID NO.1-36.
Another purpose of the present invention is to provide an application of the trnG-trnS barcode database for wolfberry samples in identification of wolfberry species.
Preferably, based on the application of the trnG-trnS barcode database for wolfberry samples in identification of a wolfberry species, the steps are given as below:
Aligning the trnG-trnS sequence of a sample to be identified with the sequence in the trnG-trnS barcode database, and then performing species identification of the sample.
Aligning the trnG-trnS sequence of a sample to be identified with the sequence in the trnG-trnS barcode database, effectively identify the species of the wolfberry and determine the interspecies relationship of the wolfberry, and further determine the interspecies relationship between the wolfberry to be identified and the wolfberry in the barcoding database, thereby providing an effective basis for classification and identification of wolfberry species.
Preferably, the trnG-trnS sequence of the sample to be identified is also obtained by the steps of genomic DNA extraction, PCR amplification and sequencing of PCR amplification products. The operation steps are the same as those in steps 1), 2) and 3) described in above.
The present invention has the following advantages compared to the prior art:
(1) An identification method of wolfberry species is established based on a trnG-trnS barcode gene for the first time, and it can be applied for identification of L. barbarum Linn, L. barbarum Linn. var. auranticarpum K.F.Ching var. nov., Lycium ruthenicum Murr., Lycium chinense MilL. var. potaninii (Pojark.) A.M.Lu, Damaye (L. barbarum Linn), L. chinense Mill. Var., Lycium yunnanenseKuang et A. M. Lu, Manshenggouqi (L. barbarum) Ziguogouqi (L. barbarum), Lycium dasystemum and other species.
(2) The DNA barcode provided by the present invention can be applied to building a wolfberry phylogenetic tree to be used for studying intra-species and inter-species phylogeny of wolfberries, and it reveals the genetic diversity and relationship of wolfberries based on trnG-trnS genes, thereby providing an effective basis for identification, classification and phylogenetic study of wolfberry species;
(3) Accurate identification of wolfberry species based on trnG-trnS gene.
(4) A trnG-trnS barcode database is provided, which can be used to rapidly identity wolfberry species. The group of wolfberry species comprises Ningxia, the northern, Xinjiang, Yunnan, Hebei and Sichuan, and representative wolfberry species of different sources, such as hybrid population, space mutation population and ploidy population, such as Lycium ruthenicum Murr., Huangguo wolfberry, Lycium barbarum Yuanguo, Lycium dasystemum, which are all known as China's representative species, hence, it provides an effective bases for classification and identification of wolfberry species.
Align the trnG-trnS sequence of a sample to be identified with the sequence in the trnG-trnS barcode database, effectively identify the species of the wolfberry and determine the interspecies relationship of the wolfberry, thereby providing an effective basis for classification and identification of wolfberry species.
The present invention is described in details below by referencing specific embodiments, unless otherwise stated, the technical means used in the present invention are methods known to those skilled in the art, and the embodiments are understood as illustrative without limiting the scope of the invention. The scope of the present invention are defined only by the Claims. For those skilled in the art, any change or alteration of the material composition and dosage in these embodiments shall also fall within the scope of protection of the invention as long as it does not deviates from the nature and scope of the invention. As below, the present invention is further explained in combination with the following specific embodiments.
Embodiment 1 Identification of Wolfberry Samples and Construction of trnG-trnS Barcode Database
The following gives detailed description of the solutions of the present invention in combination with specific embodiments.
1. trnG-trnS Barcode Database of Wolfberry Samples
A total of 36 wolfberry samples with partial similar morphology from different regions are collected, the trnG-trnS barcode database of wolfberry samples is constructed. See Table 1 for details:
L.
barbarum
L.
barbarum Linn
L.
barbarum
L.
barbarum
Lycium
barbarum
Lycium
barbarum
Lycium
ruthenicum
Lycium
ruthenicum
L.
barbarum Linn
Lycium
chinense
Lycium
chinense
Lycium
barbarum
Lycium
barbarum
Lycrum
chinense
Lycium
chinense
L.
Chinense
L.
Chinense
2. Identification of Wolfberry Samples and Construction Method of trnG-trnS Barcode Database
1) Extraction of DNA
Collecting 36 samples of fresh and tender leaves of the said 36 wolfberry plants from the base of Wolfberry Engineering Technology Institute, Ningxia Academy of Agriculture and Forestry Sciences, putting them in a 5 ml cryogenic tube separately, make a mark on the tubes and add liquid nitrogen to store the sample at −80° C. Sampling time: June 2018, place of sampling: Wolfberry National Forest Tree Germplasm Resources Repository in Yinchuan City, Ningxia. See Table 1 for sample details.
Extract the total DNA using an extraction kit for new plant genomic DNA (DNA sure Plant Kit), and following the extraction method as follows:
(1) Taking 100 g sample to a multifunctional high-efficiency biological sample preparation instrument and grind it for 2 minutes (22 times/s); immediately adding 400 ul buffer solution LP1 and 6 ul RNase A (10 mg/ml), oscillating it by a vortex method for 1 min, and staying it at a room temperature for 10 min.
(2) Adding 130 ul buffer LP2, mixing it well and oscillating it by a vortex method for 1 min.
(3) Centrifuging it at 12000 rpm for 5 minutes, and transferring the supernatant to a new centrifugal tube.
(4) Adding 1.5 × volume buffer LP3 (please check if absolute ethanol is added before using), and fully oscillating the solution to mix it evenly for 15 s; at this time, a flocculent precipitate may appear.
(5) Adding the solution and flocculent precipitate obtained in the previous step into an adsorption column CB3 (which is placed in a collection tube), centrifuging the mixture at 12000 rpm for 30 s, discarding the waste fluid, and putting the adsorption column CB3 into the collection tube.
(6) Adding 600 ul rinse solution PW to the adsorption column CB3 (please check if the absolute ethanol is added before using), centrifuging the solution at 12.000 rpm for 30 s, discarding the waste fluid, and putting the adsorption column CB3 into the collection tube. (Note: If the adsorption column membrane is green, add 500 ul absolute ethanol to the adsorption column CB3, centrifuge it at 12,000 rpm for 30s, discard the waste fluid, and put the adsorption column CBS into the collection tube)
(7) Repeating step 6.
(8) Putting the adsorption column CBS back to the collection tube, centrifuging at 12,000 rpm for 2 minutes, and discarding the waste fluid; putting the adsorption column CBS at a room temperature for 15 minutes to dry the remaining rinse solution in the adsorption material thoroughly.
(9) Transferring the adsorption column CB3 into a clean centrifugal tube, and dropping 100 ul elution buffer TE into the middle of the adsorption membrane, staying it at room temperature for 2 minutes, centrifuging at 12,000 rpm for 2 minutes, and collecting the solution into the centrifugal tube.
(10) Repeating step 9. Store the DNA product at −80° C. to prevent DNA degradation.
2) DNA Concentration and Purity Detection
{circle around (1)} Agarose Gel Electrophoresis Detection
Preparing 1.2% agarose gel with 1.2 g agarose and 100 ml 1*TAE buffer, adding a detection system of 4 ul ddH2O+1 ul DNA sample (undiluted)+1 ul 6*loading buffer into a PCR tube for agarose Gel electrophoresis, and observing the test results under a UV gel imaging system, as shown in
{circle around (2)} UV Spectrophotometer Detection
Preheating a UV spectrophotometer, and adding 99 ul ddH2O+1 ul DNA sample (undiluted) into the PCR tube for detection. The test results show the sample concentration and OD260/OD280 ratio, OD260/OD280 should be 1.7-1.9; if an elution buffer is not used in eluting, but ddH2O is used, the ratio will be lower, because the pH value and the presence of ions could affect the light absorption value, but it does not mean that the purity is low.
3) PCR Amplification Taking the DNA obtained in step 1) as a template, adding a reagent required for amplification such as a primer for PCR amplification. The specific primer and amplification system are shown in Table 2 and Table 3,
(1) The design primers are as follows:
2) PCR Amplification System:
Conduct PCR amplification for the genomic DNA of the test material using the above primers. The amplification system is shown in Table 3:
The PCR reaction includes: 1) pre-denaturation at 94° C. for 2 min; 2) denaturation at 94° C. for 30 s, annealing at 55° C. for 30 s (annealing temperature is adjustable between 58-60° C.), extension at 72° C. for 2 min, with 35 cycles; 3) incubation at 72° C. for 10 min; 4) storage at 4° C. After the PCR product is subjected to 1.0% agarose gel electrophoresis, observing the amplification result under a UV gel imaging system (
4) PCR Product Cloning:
Use a AxyPrep DNA gel recovery kit to recover a target band, and use 1.2% agarose gel electrophoresis for recovery detection, and take the purified target DNA as a sequencing template; use a pLB zero background fast cloning kit to attach the recovered product to a T vector (pGEM-T) and then transfer it to a Escherichia coli DH5 α for culturing; note to observe the amplification result under a UV gel imaging system (
5) Sequence Sequencing and Analysis
In the present invention, after PCR detection of positive bacterial colonies, the colonies containing target fragments are cultured in a LB fluid medium, and 3 colonies of each material are taken and sent to Sangon Biotech (Shanghai) Co., Ltd. for sequencing, thus to obtain the trnG-trnS sequences of 36 samples.
The DNA barcode gene sequences obtained are aligned with the sequence published in the NCBI database by DNAMAN, and the DNA barcode gene sequences of 36 wolfberry samples are aligned using a Clustal X program; with the help of phylogenetic analysis software MEGA7.0, the relevant data of the trnG-trnG sequence are obtained as below: the total length is 1673bp, there are 1617 conservative sites, accounting for 96.6%; 30 variant sites, accounting for 1.8%, including 10 information sites and 20 descendant sites; and the base conversion value is 0.7, and the average GC content accounts for 32.3%.
After sequence alignment and analysis, the result indicates, 10 germplasms of L. barbarum Linn. var. auranticarpum K.F.Ching var. nov., Lycium ruthenicum Murr., L. barbarum Linn, HZ-13-01, ZH-13-08, W-12-27, W-11-15, W-13-26, W-42-26, Changji wolfberry has a base A missing at 256 bp; has a transversion at 526 bp, 592 bp, 1029 bp; a conversion at 1365 bp; a conversion from CT to AA at 1592 bp; a conversion from TA to AG at 1612 bp; wherein, germplasms of L. barbarum Linn. var. auranticarpum K.F.Ching var. nov., Lycium ruthenicum Murr. and Changji wolfberry are transposed at 935 bp; L. barbarum Linn. var. auranticarpum K.F.Ching var. nov. has 2 base TTs inserted at 1410 bp; Lycium ruthenicum Murr. has a base T inserted at 1410 bp; Changji wolfberry has 1 base A missing at 72 bp, and a transversion at 1051 bp, and the remaining 7 germplasms are converted at 1074 bp; HZ-13-01 has a conversion at 11.062 bp; W-12-27 has a conversion at 1582 bp; W-13-26 bp has 1 base A missing at 529 by and a conversion at 1093 bp; W-12-26 has a conversion at 1036 bp and has a base T missing at 1409 bp.
Ningqi 4, Lycium chinense MilL. var. potaninii (Pojark.) A. M. Lu, Lycium barbarum Yitanguo, Lycium dasystemum, Hebei wolfberry and Lycium dasystemumPojark have a base A missing at 72 bp; are converted at 1365 bp; wherein L. barbarum Linn 4 is inserted with 2 bases TT at 1410 bp; Lycium chinense MilL. var. potaninii (Pojark.) A. M, Lu has a conversion at 55 bp and a transversion at 935 bp; Lycium dasystemum has a conversion at 423, 708 bp, and have 1 base T missing at 1409 bp, a 22 bp sequence (i.e. CATTTTAATAGTTGTAATATTT) inserted at 501 bp; Hebei wolfberry has a conversion at 241 bp and 964 bp, and a transversion at 935 bp.
L. chinense Mill. var, and Lycium yunnanenseKuang et A.M.Lu have 2 base AA missing at 72 bp; 1 base A missing at 252 bp; have a transversion at 935 bp and 1029 bp; L. chinense Mill. Var. has a base T inserted at 1811 bp; has 6 by sequence (i.e. TTTGAA) at 464 bp; and has 3 base AAA inserted at 592 bp; Lycium yunnanenseKuang et A. M. Lu has a conversion at 381 bp and a transversion at 592 bp.
L. barbarum Linn 2 has a conversion at 1471 bp, Lycium barbarum Huangguo has a conversion at 1097 by and 1252 bp; Manshenggouqi (L. barbarum) has a conversion at 664 bp, 935 by and 1365 bp; and a base T inserted at 1410 bp; and has a transversion at 744 by and 1603 bp.
A phylogenetic tree is constructed by comparing the distribution of intraspecies and interspecies differences (
The above proves that the DNA barcode provided by the present invention can be applied to building a wolfberry phylogenetic tree to be used for studying intra-species and inter-species phylogeny of wolfberries, and further proves the DNA barcode provided by the present invention is effective and feasible in identification, classification and phylogenetic study of wolfberry species;
In addition, the embodiment of the present invention constructs a trnG-trnS barcode database based on barcode trnG-trnS sequence, which includes Lycium ruthenicum Murr., Huangguo wolfberry, Lycium barbarum Yuanguo, Lycium dasystemum, also local wolfberry species of Ningxia, the northern, Xinjiang, Yunnan and Hebei, and representative wolfberry species of different sources, such as hybrid population, space mutation population and ploidy population, which are all known as China's representative species, hence, it provides an effective bases for classification and identification of wolfberry species.
Align the trnG-trnS sequence of a sample to be identified with the sequence in the trNg-TRNS barcode database, effectively identify the species of the wolfberry and determine the interspecies relationship of the wolfberry, and further determine the interspecies relationship between the wolfberry to be identified and the wolfberry in the barcoding database, thereby providing an effective basis for classification and identification of wolfberry species.
1. Sampling
Taking ten wolfberry samples numbered SD 18-01, SD 18-02, ZJ 18-03, ZJ 18-04, No.1 Huang, Dayezihuang, P1806, 16-23-8-10, 16-18-16-15 and *2-184 to align with barcode in trnG-trnS barcode database of a part of wolfberry samples in embodiment 1. As this wolfberry species can not be identified by a morphological method, DNA barcoding is used in this experiment.
2. DNA Extraction and Concentration Detection, PCR Amplification, PCR Product Cloning, Sequence Sequencing and Analysis are Consistent with that Described in Embodiment 1.
3. Analysis of Sequence Results
Software MEGA7.0 is applied to conduct sequence alignment and cluster analysis, and NJ (Neighbor-joining) method is used to construct a phylogenetic tree as shown in
The test samples P1806, 16-23-8-10, 16-18-16-15 and *2-184, and L. barbarum Linn(Ningqi 1) (number 1 in the barcode database), as well as Lycium barbarum Huangguo (number 24 in the barcode database) are clustered into one branch, with the closest generic relationship and the bootstrap rate is 90; wherein *2-184 and 16-23-8-10 are clustered into one sub-branch, they have the closest generic relationship and the bootstrap rate is 66. The above 4 test samples (1806, 16-23-8-10, 16-18-16-15 and *2-184) are obtained by hybridization of different varieties of Lycium barbarum L. (Ningxia wolfberry) or hybridization of the hybridized offsprings. From both Genetic distance and cluster analysis, it can be concluded that the 4 test samples have the closest generic relationship with Lycium barbarum L. (Ningxia wolfberry).
The 4 test samples No.1 Huang and Dayezihuang are in one branch, which are the closest generic relationship, and the bootstrap rate is 100, so the confidence level is high. SD 18-01, SD 18-02, ZJ 18-03 and ZJ 18-04 are clustered in one branch, they have the closest generic relationship, with the bootstrap rate of 96, and the confidence level is high. No.1 Huang is the stage of L. barbarum Linn(Ningqi 1) when it is under bud mutation and the fruits are in yellow color; SD 18-01, SD 18-02, ZJ 18-03 and ZJ 18-04 are Chinese wolfberries in Shandong and Zhejiang regions, so the branch of the test sample No.1 Huang is close to the branch of Lycium barbarum L. (Ningxia wolfberry), having the closest generic relationship; while it has a poor relationship with the branch of SD 18-01, SD 18-02, ZJ 18-03 and ZJ 18-04; the bootstrap rate of each branch is higher than 60, and the confidence level is high. This indicates that trnG-trnS barcode sequence and the barcode database constructed by the method of the invention are helpful in classification and species identification for wolfberry samples from different regions.
The genetic distance is calculated by using the K2P model (Kimura 2-parameter Model) and software MEGA7.0, as shown in Table 5. The genetic distance between L. barbarum Linn. var. auranticarpum K.F.Ching var. nov., Lycium ruthenicum Murr., L. barbarum Linn(Ningqi 1) and P1806 is 0.00000, it's a minimum. And the genetic distance between No. 1 Huang and ZJ-18-04 is 0.009192, it's a maximum.
L.
barbarum
L.
barbarum
Lycium
Lycium
ruthenicum
barbarum
L.
barbarian
L.
barbarian
Lycium
ruthenicum
Lycium
barbarum
1. Sampling
8 wolfberry samples numbered B1, B3, B5, B8, B9-1, HB, HB5 and 15-1 are taken. They cannot be identied by morphological method. The method of the present invention based on DNA barcode database is used to perform species identification. DNA barcode alignments of the 8 samples with barcode in trnG-trnS barcode database in embodiment 1.
2. DNA Extraction and Concentration Detection, PCR Amplification, PCR Product Cloning, Sequence Sequencing and Analysis are Consistent with that Described in Embodiment 1.
3. Analysis of Sequence Results
MEGA7.0 software is applied to conduct sequence alignment and cluster analysis, and NJ method is used to construct a phylogenetic tree as shown in
8 Lycium ruthenicum Murr. test samples and Lycium ruthenicum Murr. (number 12 in the barcode database) are clustered into one branch, with the bootstrap rate of 77, and the confidence level is high. Wherein the test sample B3 and 151 can clustered into one sub-branch, the both have the closest generic relationship, with the bootstrap rate of 55. Sample B8, B1 and H5 are clustered into one branch, they have the closest generic relationship, with the bootstrap rate of 92, and the confidence level is high. This indicates that trnG-trnS barcode sequence and the barcode database constructed by the method of the invention are helpful in classification and identification of Lycium ruthenicum Murr. samples from different regions that cannot be identified by morphological method.
The genetic distance is calculated by using the K2P model (Kimura 2-parameter Model) and software MEGA7.0, as shown in Table 7. The genetic distance between B9-1 and Lycium ruthenicum Murr. is 0.000608, it's a minimum. They have the closest generic relationship. The genetic distance between B8 and Lycium barbarum Huangguo is 0.011048, it's a maximum. It's a distant genetic relationship between them.
L. barbarum
Lycium
Lycium
L.
ruthenicum
barbarum
Chinense
L. barbarum
Lycium
ruthenicum Murr.
Lycium barbarum
L. Chinense
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020103478862 | Apr 2020 | CN | national |
| 2020106089828 | Jun 2020 | CN | national |
