Abstract:The ultrastructure of the pollen in the Glycyrrhiza uralensis F., Glycyrrhiza glabra L., and Glycyrrhiza inflata Batal. was observed by the scanning electron microscope (SEM). The pollination way, the pollen viability and the stigma activity, the fertilization time ascertainment after pollination were observed by the fluorescence microscope. The results showed that the study on the ultrastructure of pollen offered certain morphology basis for the discrimination of the liquorice. The pollination way of the liquorice was cleistogamy. The pollen viability was the highest at 12:00 in daytime, and the stigma had no ability to accept the pollen exceeding four days after artificial emasculation. The pollen tube entered into the ovule to fertilize 6h after pollination when the fixed pistils were observed different time after pollination. In order to establish the correct strategy of seed selection and breeding of the liquorice in the future, the sexual reproduction properties of the liquorice was studied in the study.
Abstract:The present report summarized the progress on the collecting work of wild soybean genetic resources and on the general situations of studies in wild soybean resources during the recent decade （2001-2010）in China. There were 5939 wild soybean accessions collected during 1979-1982 and 600 accessions collected during 1979-1982 in the China Genebank. In recent ten years (2001-2010), a total of 1979 accessions were collected across 17 provinces, distributed in 318 counties and 930 towns. Of which 178 counties were newly-collected areas. Wild soybean accessions increased by 33.3 percent in the Chinese wild soybean collection.
Abstract:Abstract: The characteristic of starch RVA, dough mixing and protein of 698 germplasm including 412 landraces, 154 improved varieties and 132 introduced varieties were studied in detail in two years, and the quality characteristic of different wheat ecological types was also analyzed. The results are as follows: 1) Different source germplasm showed different quality characteristic. Long dough mixing development time and high Zeleny sedimentation were found in improved variety and introduced variety. There were 10 and 16 germplasm with long mixing development time over 3.5min, 32 and 25 germplasm with high sedimentation over 40.0 ml of this two type variety respectively, and the maximum development time was 5.2min , maximum Zeleny sedimentation was 61.8 and 68.8 ml respectively. Good starch RVA characteristic and high protein content were showed in landrace. There were 24 landraces with high peak viscosity over 2900cP, and the maximum was 4099cP.The 48.8% landrace showed the sedimentation over 40.0ml, and the maximum was high to 58.8ml. 2) Different characteristic was found in landraces belonging to different ecological types. Good starch RVA characteristic and high protein content were showed in landrace in Yantai and Qingdao belonging to Jiaodong hilly land, the variety belonging to winterness late-maturing type. Good starch RVA characteristic was found in landrace in Binzhou,Weifang and Dezhou belonging to plain in northwestern Shandong province, and the variety belonging to winterness/semiwinterness late-maturation type. High protein content was found in landrace in Linyin and Taian belonging to hillyland and mountain in mid-Shandong province, and the variety belonging to semiwinterness/winterness type. 3) Some germplasm with outstanding quality characteristic were selected, including improved varieties Jinan17, Jinning16, Jimai20, Zhouyuan9369 and Taimai1 with Zeleny sedimentation over 50.0ml and development time over 4.5min, induced varieties Gaocheng9415, Ji5099, Linfen6410 and Linfen6510 with Zeleny sedimentation over 60.0ml, landraces Banjiemang, Baitutou, Sanbamai, Xiaobaimang and Banjiesui with high peak viscosity over 3100cP, and landrace Mazhatou, Baidu, Baiqisiwu, Yisuishou, Silengbai, Baisuihong and Banjiehongsui with high Zeleny sedimentation over 50.0ml. All these germplasm could be used as the preferred option parent in screening quality wheat.
Abstract:Under three level stress treatment of P supplies, shoot and root acid phosphatase activities, Crown-root ratio, amount of dry matter, the phosphate content and P efficiency of 23 soybean breeds were studied by determination, contrast and analysis. The result showed that there were significantly variance among shoot or root acid phosphatase activities，relative value of shoot and root acid phosphatase activities，Crown-root ratio， P efficiency，and relative value of P efficiency（P
Abstract:Yunnan is the center of tea origination with abundant in tea germplasm resources enriching the genetic diversity, which plays in an important role in tea research. In this paper, the research achievements and progress of Yunnan tea germplasm resource in past sixty years are systematically reviewed from the following aspects: exploration, collecting, conservation, protection, identification, evaluation and shared utilization. Simultaneously, the current problems and the suggestions about subsequent development of tea germplasm resources in Yunnan were discussed, including superior and rare germplasm collection, tea genetic diversity research, biotechnology utilization in tea germplasm innovation, super gene exploration and function, the construction of utilization platform, biological base of species and population conservation.
Abstract:The southern of Xinjiang has experienced the Replacement of 5 times, the breeding of high yield varieties has played an important role, compared with the early vareties,new varieties are increasing with the velocity of 12.1kg/ha per year,. To production ,the Contribution of Improved varieties is 43.9%.The total tedency of evolve in lint percentage, per plant boll number and weight is increasing In agriculture Characteristic , the per plant height drop , width increase , the reproduction quantity of self-breeding varieties was lower, loss rate is higher, the composite quality in southern of Xinjiang has less change, especially the producing quality of cotton has not undergo a Fundamental change.There are larger selecting potential of southern Xinjiang's cotton in these facets : per plant ball numbers , increase flowers , cut down the falling rate , plant width,first branch , selection of high photosynthesis varieties and fiber strength . In the early ripening cotton variety breeding process in South Xinjiang cotton varieties in the early history of development, high-quality, big ball, adaptability of superiority and rational utilization of introduced varieties of disease resistance, high yield, plant type, grade, loose culture is strong wait for an advantage to expand the genetic basis of cotton varieties in Xinjiang.
Abstract:The genetic diversity and relationship of taro (Colocasia esculenta Schott) resources were analyzed at the molecular level provide the base for the classification, protection and effective utilization of these resources and breeding new varieties. The genetic diversity and relationship of 65 taro accessions were analyzed by Sequence-related Amplified Polymorphism (SRAP) markers. The data was analyzed by NT-SYS 2.1 software. Dendrogram was generated by UPGMA cluster. 341 DNA bands were amplified by 28 different primer combinations, 251 of which were polymorphic. The accessions were separated into 5 main groups based on the UPGMA cluster, the classification was basically consistent with the classification based on the growth styles of corm and cormel，basically concordant to the morphological description of 4 traits, including spot color of leaf center, petiole color (mid and base), sprout color of corm and flesh color of corm. There is rich genetic diversity in taro germplasms of different styles which were collected form different area and ecological environment. The classification based on the SRAP markers was consistent with the classification based on some primary morphological traits，and also explain possible evolutionary relationship in the cultivated taros.
Abstract:Totally，72 sweet sorghum germplasm in XinJiang were used to analyze their genetic diversity and genetic relationship using 50 SSR primers. The result indicated that a total of 20 SSR primers performed polymorphism and 91 alleles loci were detected. The average number of alleles per SSR was 3.45 with a range from 2 to 5.The value of allelic polymorphic information content (PIC) ranged from 0.2859 to 0.6652,on an average of 0.5057 per SSR marker. The genetic similarity coefficient ranged from 0.2001 to 1.000 with a average of 0.5599. The cluster analysis grouped the 72 sweet sorghum cultivars and lines into 2 main groups.Group A included 69 accessions and group B included only 3 accessions. Group A was again sub-divided into sub-groups I through XI. The accessions of sweet sorghum with similar agronomic trait was mostly clustered one group.
Abstract:Genetic diversity of 13 cannabis populations from different sources was analyzed by POPGENE 3.2 Software. AFLP analysis showed that the Yunnan population had the highest level of genetic diversity (PPB = 88.82%，h = 0.3011，I = 0.4571)，and then the Heilongjiang population (PPB = 75.66%，h = 0.2572，I = 0.3897). The percentage of polymorphic loci (PPB) of 13 Cannabis populations was 92.11%. Nei's total genetic diversity (Ht) was 0.3837，the genetic diversity (Hs) was 0.1640. Coefficient of genetic differentiation among populations (Gst) was 0.5725，it means that 57.25% of the total genetic variation occurred among populations，and 42.75% genetic variation in different populations. To further analyze the genetic differentiation among populations, the genetic distance and genetic identity of Cannabis were calculated according to Nei's (1978) method. The results showed that the genetic identity among populations was from 0.6556 to 0.9258，the highest degree of consensus between Guangxi population and Sichuan population was 0.9258. Genetic identity between Yunnan population and Guizhou population or Sichuan population were 0.9196 and 0.9173. Gansu and Shanxi population with lowest genetic identity in all populations was 0.6556. The results indicated that rich genetic diversity among 13 cannabis populations. This study analyzed genetic diversity of cannabis populations in molecular level，provided scientific evidence for the protection of seeds, breeding, evolution study of industrial hemp.
Abstract:Herbicide resistance of seedling and combining ability of 10 main agronomic traits have been analyzed for 30 hybrids mated by NCⅡ designation using 6 herbicide-resistant indica restorer lines as male and 5 wide-utilized sterile lines as female. The resistance results showed that restorer lines and three-line hybrids had mostly complete resistance of herbicide, and two-line hybrids had more than 90% resistance level. The combination analysis showed the difference of GCA between female parents reached the significant level for all traits but PN, all for male parents. Four traits (YP, SSR, KGW, and DS) showed the significant difference among SCA effects of combinations. Among the sterile lines, Jinke 1A had the highest GCA effect in such traits as YP, SSR, and so on, but VSCA was the lowest; Guangzhan 63-4S had the highest GCA and VSCA of KGW, most negatively effect of GCA in DS; C815S had the most negative effect of GCA and higher VSCA in PH. Among the restorer lines, Huakanghui 101 had the highest GCA and VSCA in PN; Huakanghui 104 had the highest GCA in PL, the highest negative effect in DS; Huakanghui 105 had the highest GCA in YP, SSR and so on, and negative GCA effect in PH; Huakanghui 106 had the highest GCA and VSCA in KGW. Some herbicide-resistant hybrids with strong heterosis could be obtained using herbicide-resistant restorer lines as male through comprehensive mating of parents with high GCA and VSCA.
Abstract:The resistance to pear scab of 197 pear cultivars in National Germplasm Resources Garden was evaluated by artificial inoculation of Venturia inaequalis. The results showed that the morbidity of different pear varieties varied widely. Chinese white pear cultivars（P. bretschneideri Rehd.）and sand pear cultivars〔P. pyrifolia （Burm.f.）Nakai〕were the most susceptible to scab, Ussurian cultivars（P. ussuriensis Maxim.）and Pyrus hybrid cultivars were the second most susceptible to scab, Xinjiang pear cultivars（P. sinkiangensis Yü）were resistant to scab, common pear cultivars（ P. communis L.）were the most resistant to scab. The disease index in pear variety distribution was analyzed. Huangjitui, Shuaili, Suanli, Jinxiang, and a number of resistant resources were screened and the disease susceptibility results between natural occurrence and artificial inoculation was compared.
Abstract:Stripe rust and powdery mildew, caused respectively by Puccinia striiformis f. sp. tritici (Pst) and Blumeria graminis f. sp. tritici (Bgt), are globally important diseases of wheat. Genes transferred to wheat from wild species are often associated with deleterious traits. In this study, a wheat-Thinopyrum intermedium germplasm line CH7124 was characterized by a combination of resistance evaluation, cytological observation and genomic in situ hybridization (GISH). Disease screening demonstrated this line was highly resistant to both Pst races CYR29, CYR31, CYR32 and CYR33 and Bgt isolates E09, E20, E21 and E26, which are the most widely virulent pathotypes in China and virulent to most of the known resistance genes, and the resistance derived from Th. intermedium. Genetic analysis of the F1, F2, F3 and BC1 populations from resistant line CH7124 revealed that the resistance to powdery mildew and stripe rust was controlled by a single dominant allele. Mitotic observation showed that CH7124 had 42 chromosomes, and the chromosomes in most pollen mother cells of its F1s involved wheat genotypes Chinese Spring and Mianyang 11 at PMC MI formed 21 bivalents, averaging, respectively, 20.73 in 102 cells and 20.74 in 87 cells, suggesting stability of CH7124 in cytology and regular pairing with common wheat. As no signal could be detected when using genomic Th. intermedium DNA as a probe in the GISH experiment, the introgressed alien chromatin in this line was very small and cytologically undetectable, further indicating that CH7124 is a cryptic wheat-alien introgression line. This study showed that CH7124 appears to serve as a novel resistance source for wheat breeding.
Abstract:This paper reviewed the systematic position, current problems in classification, and distribution of the neem species in Azadirachta. And then the worldwide distribution map of origination and introduction of Azadirachta species was drawn based on their geographic regions of plantation.
Abstract:This article provides an overview of domestic and foreign progress of several aspects of tissue culture including micropropagation ,anther culture, protoplast culture, embryogenesis, organogenesis, and transformation of kenaf bast fiber crops . Problems and prospects on tissue culture and transformation were also discussed in this paper, raised some opinions of further research, in order to provide the scientific basis for promoting the hemp crops tissue culture and genetic transformation study.
Abstract:It is very useful to detect bar gene in transgenic and non-transgenic wheat by a method with convenience, swiftness, and reliability for the screening of stable transgenic lines, the development of marker-free transgenic plants, inspection of commercial wheat varieties and products. Three identification methods of leaf painting, plant spraying, and mature embryos in vitro culture with the herbicides corresponding to bar gene were compared and evaluated in this study. Results indicated that transgenic or non-transgenic wheat plants and seeds with or without bar gene could be distinguished well by the three methods mentioned above. Application of leaf painting with 0.1% Liberty for the confirmation of the herbicide transgenic plants was better than PCR analysis in accuracy. The optimal concentrations for plant spraying were 100ppm for Basta and 150ppm for Liberty, and the available amount of bialaphos in medium for the intro mature embryos is 5-8 mg L-1. However, the first two methods were influenced in some extent by environmental conditions such as temperature, light, and nutrition in practice, which often led to an unclear observation in symptom for detecting the bar plants. In comparison, mature embryo in vitro culture on the medium with herbicide was less dependant on environment, and showed some advantages including clear observation, easy manipulation, and short time expense. Therefore, mature embryo in vitro culture identification was strongly suggested to be used in the detection and inspection of bar gene in transgenic and commercial wheat.
Abstract:The promoter fragments of 1298bp and 838bp upstream from the 5’ upper of Chimonanthus praecox non-specific lipid transfer protein(nsLTP) gene family member CpLTP3 and CpLTP4 were isolated from the genomic DNA of Chimonanthus praecox by hiTAIL-PCR technique respectively. Bioinformatics analysis revealed that the two sequences contained basic cis-elements，such as TATA-box and CAAT-box and many elements involved in the plant abiotic stress. The result of transient expression indicated that all the sequences had the function to drive reporter gene GUS in tobacco.
Abstract:It will provide useful information for germplasm DNA fingerprint identification, phylogeny by using ITS sequences analysis of Elymus sibiricus and E.nutans. The results show length of ITS, ITS1, 5.8S and ITS2 are identity, and they are 604bp, 222bp, 164bp and 218bp in order, and G C content are 62.25-63.08%, 62.16-63.06%, 59.76%, 64.22-65.60% in order. Except for 5.8S, base sites have some vary, some variable sites are species-specific and can be used as DNA molecular markers of Elymus sibiricus and E.nutans. Percent identity of the seven ITS squences is 98.7%-99.8%, divergence is 0.2-1.3, they have conservation, and not recent differentiated groups. Phylogenetic analysis indicates that different sources of the same species, speed of DNA changes and the number of base subsititue are different, but the same species belongs to group together, and reflects the intraspecific genetic stability in further.
Abstract:The yield and earliness-related traits of the sea-island cotton were identified to provide DNA molecular markers for using in cotton improvement in the future. A genetic linkage map of sea-island cotton was constructed by using 190 F2: 3 family lines derived from two sea-island cotton cultivers (Xinhai 3 and Jiza 82) with 107 polymorphic primer pairs obtained by screening among 5000 SSR primer pairs. The linkage map covered 20.12% of the whole cotton genome which including 22 linkage groups, 74 markers, a whole length of 893 cM with an average interval of 12.06 cM between two markers by Joinmap3.0 software. Based on composite interval mapping. 21 QTLs related with yield and earliness traits of the sea-island cotton were detected. 12 QTLs associated with earliness traits were respectively located on linkage groups LG1 LG3 LG5 LG6、LG11、LG17, LG22 , and 9 QTLs associated with yield traits were respectively located on linkage groups LG4、LG5、LG6、LG16、LG22. This research could provide valuable information for the molecular design breeding of yield and earliness in sea-island cotton.
Abstract:662 accessions of rice germplasm, including 120 wild rice and 542 cultivars, were collected from Southeast Asia mainly through field surveys and collection. Information database of all germplasm resources was constructed after quarantine, propagation and phenotype identification. Based on evaluation for 300 accessions of cultivated rice, some germplasm resources were found to have good characteristics including 58 accessions resistant to brown planthopper, 9 accessions resistant to rice blast, 11 accessions resistant to bacterial blight and 12 accessions with salt-tolerance. The results indicated that the germplasm resources of rice in Southeast Asia are abundant of superior characteristics which are important for widening rice genetic background, enriching rice gene pool and improving rice varieties in China.
Abstract:The stomatal density, stomatal area, size of stoma and stomatal apparatus of 25 Chinese bayberry(Myrica rubra Sieb.et Zucc)leaves in southeast of Zhejiang province Taizhou.,Wenzhou.,Ningbo and Shaoxing The stomatal density, stomatal area, size of stoma and stomatal apparatus of 25 Chinese bayberry(Myrica rubra Sieb.et Zucc)leaves in southeast of Zhejiang province Taizhou.,Wenzhou.,Ningbo and Shaoxing were examined by optical microscope. The results showed that stomata of all varieties were of parallel type; stomatal density ranged from 500-1200 No./ mm2, and major cultivars, such as Dongkui, Biqi and Ding’aomei presented a low density level; size of stomatal area concentrated in 50μm2 at a range of 40-80μm2; Weizhi No.1 had the largest major and minor axis of stomatal apparatus size, while Wenzhoutumei had the smallest; the major axis were bigger than the minor axis of all stoma size. Cluster analysis of stomatal density, stomatal area, size of stoma and stomatal apparatus by center of gravity method, classification from a distance of 0.5, it can be divided into five categories A cluster analysis showed that it was, to a certain extent, practicable to distinguish the varieties by using stomatal similarity. However, molecular biology and morphology methods were also needed for precise study of the genetic relationships. Keywords: Chinese bayberry; sStomatal characters; mMicro observation; cCluster analysis
Abstract:To select suit parents was the key work of hybridization in Brassica napus L. The genetic diversity of 180 parental germplasm of yellow-seeded B. napus provided by the Chongqing Rapeseed Engineering Research Center of Southwest University were analyzed. 308 alleles were detected via 60 SSR primer pairs which were selected from the different linked groups in Brasicca napus, , among them 207 polymorphic bands were obtained, accounting for 67.2% of the total bands. The UPGMA cluster analysis based on SSR data showed that 180 parental lines could be classified into three groups at the threshold 0.566 of genetic distance, which agrees with the pedigree analysis. 20 samples were chosen as core collection by the pedigree, genetic distance and five quality traits of germplasm characteristics. The results showed that the SSR markers could be explained the genetic diversity B. napus accessions appropriately. It was an effective method to develop a core collection of the crop by SSR markers and germplasm characteristics. It could also provide the theoretical basis for the hybridization and breeding of yellow-seeded Brassica napus.
Abstract:Abstract There have been the lack of certainly and integrity in sprout characteristics evaluation of grasspea and breed quality identification for a long time. In this case, 29 resources of grasspea from diffident locations of china were collected as the materials. They were cultivated as the method described by ZNLG institute. An preliminary study has been performed by basis statistics analysis, K-means clustering analysis and correlation analysis on the eight traits of grasspea and grasspea sprouts. The results showed that variation coefficient of bean sprouts output reached 24.42% that is larger than other traits. Twenty-nine copies of grasspea species were divided into 5 groups. Character of one group is small grain, high seedling production, high soluble protein content, and high VC content. Length of grasspea sprouts was significantly correlated with bean sprouts output（p<0.01）,and was significantly correlated with smoothness of seed skin（p<0.01）.Bean sprouts output was significantly correlated with smoothness of seed skin（p<0.01）, and was negatively correlated with kernel weight（p<0.01）. To screen and evaluate resources of grasspea for sprouts, sprouts output should take more importance than other traits, and the value of them should be larger than 1.01g/g. In this study, grasspea of Gansu Zhangye, White fragrant grasspea, A za grasspea -2 were selected as excellent resources for further study.
Abstract:Sequence related amplified polymorphism (SRAP) markers were used to evaluate the genetic diversities of 13 pummelo (C.maxima) germplasms collected from southern Zhejiang province and Guanxi miyou pummelo and its bud mutant from Fujian province. Fourteen SRAP primer combinations were thus selected and a total of 220 PCR fragments with an average of 15.7 bands per primer combination were obtained. Among these bands, 122 (55.4%) were polymorphic，showing a relatively low level of genetic diversity among the analyzed germplasms. Eleven genotypes were uniquely identified in the 15 germplasms by SRAP markers. UPGMA Clustering analysis of the SRAP banding patterns showed that the 15 pummelos could be divided into 8 major groups at the similarity coefficient level of 0.97. The first group included the 7 Sijipao varieties. The second group included Guanxi miyou and its bud mutant hongrou miyou. Each of the rest pummelos, i.e., Pingyang pummelo, Zaoxiang pummelo, Chuhong pummelo, Hongxin 1 pummelo, Hongxin2 pummelo and Sour pummelo, was clustered as a separate group. It showed that slight change occurred at DNA level in Wucheng1, Wucheng3, Mazhanhongxin pummelo based on genetic diversities.
Abstract:In the present study, the genetic diversity of microsatellite sequence (CT)n and intron 1 G/T in Wx Gene were determined for 90 individuals in the natural population of O.rufipogon from Yunjiang of Yunnan Province , 9 wild rice lines of O.rufipogon, and O.longistaminata from Dongxiang of China ,India, Indonesia, Cameroon and Cote Divoire. In the loci of the microsatellite sequence (CT)n and intron 1st G/T in Wx gene, all of individuals from the natural population of wild rice in Yuanjiang were homogenetic, whose intron 1 G/T were base G the band type of microsatellite sequence (CT)n wassimilar to one of the local indica cultivars from Yunnan.
Abstract:The chromosome number and karyotype of three Zantedeschia Cultivars were studied using squash method. The results showed that the chromosome number of all tested cultivars was 32. Karyotypes among them were not distinct with mostly metacentric or submetacentric chromosomes. The karyotype formula of three Zantedeschia hybrid cultivars as follows：‘Allure’ was 2n= 2x= 32= 14m（2SAT） 2sm；‘Cupdio’ was 2n= 2x= 32= 14m 2sm； ‘Odessa’ was 2n= 2x= 32= 1M 15m（1SAT）. All cultivars belonged to 1A type and its asymmetry index were 72.96%, 77.39%, 75.93% respectively.
Abstract:Abstract: In this study, 75 germplasm resources in the primary core collection of Cornus officinalis were collected from three provinces in China. Many quantitative traits, including leaf length, leaf breadth, fruit length, fruit broad, fresh fruit 100-seed weight, seed 1000-seed weight, seed moisture content, ash content of date bark, moisture content of date bark, water soluble extractives and content of Loganin, were analyzed on coefficient of variability and correlation. The core collections were sampled by Euclidean hierarchical clustering method from the primary core collection, and then the construction of the core collection of C. officinalis was evaluated. The results showed that the coefficient of variability in leaf length, leaf breadth, fresh fruit 100-seed weight, seed 1000-seed weight, ash content of date bark and content of Loganin were higher than 10%. It indicated that there were large changes and it was not instability in these characteristics between individuals. The coefficient of variability in fruit length, fruit broad, seed moisture content, moisture content of date bark and water soluble extractives were less than 10%, which indicated that there were less variation and these traits were relatively stable between individual. Correlation analysis results showed that there was a relationship in these traits. The fruit length and fruit breadth had a significant correlation to fresh fruit 100-seed weight (0.396b and 0.312b), which suggested that it was a key reason that the fruit of length and breadth affected the fresh fruit 100-seeds weight. There was significant correlation between the fruit length, the fruit breadth, the content of Loganin and water-soluble extractives, respectively (0.481b, 0.280a and 0.372b). It meaned that the characteristic of water-soluble extractives contents closely related to the fruit size, the fruit shape and content of Loganin. These results will provide a parameter for screening and evaluating the germplasm resources of C. officinalis in the future. There were only 22 samples (29.33% in total) after the core collection was constructed from primary core collection by least distance stepwise sampling (LDSS). The results of T verification and the poor compliance rate (CR%=90.63 > 80%) showed there was no significance between core collection and the primary core collection of C. officinalis. The results showed that the core collection was a better representative sample of the primary collection with minimum repetitiveness and maximum genetic diversity of C. officinalis. The methods of construction and the core collection will provide a reference and research basis for construction of the core collection to C. officinalis or the other medicinal plant resources.