Chemical Diversity and Antimicrobial Activity of Salvia multicaulis Vahl Essential Oils

The chemical compositions and antimicrobial activities of the essential oils (EOs) of aerial parts of Salvia multicaulis Vahl , collected during the same week from two different Lebanese regions, were investigated. The EOs were obtained by hydrodistillation using a Clevenger‐type apparatus and characterized by GC and GC/MS analyses. The minimum inhibitory concentrations of these EOs were determined against one Gram‐negative and two Gram‐positive bacteria, one yeast, and five dermatophytes using the broth microdilution technique. One EO was notably active against Staphylococcus aureus, methicillin‐resistant S. aureus, and all of the Trichophyton species tested. Nerolidol was found to be the major compound in the active oil; nerolidol was also absent from the inactive oil. This study demonstrated that nerolidol shows antimicrobial activity and therefore significantly contributes to the antimicrobial potential of the oil. The chemical diversity of worldwide S. multicaulis EOs was analyzed, revealing that the EOs of this study belong to two different chemotypes found in the literature. The nerolidol chemotype appears to be restricted to Lebanon, and it can be used as antimicrobial agent against external bacterial and fungal infections.     

Genetic diversity and structure of the noxious alien grass Praxelis clematidea in southern China

Praxelis clematidea (Asteraceae), a plant species native to South America, is a noxious weed in southern China. We examined the genetic variation and population structure of 12 populations (76 individuals) of P. clematidea from Fujian, Guangdong, and Hainan Provinces in China using inter-simple sequence repeat (ISSR) analysis. From an initial set of 69 ISSR primers, 10 were selected which yielded 80 reproducible bands. Polymorphic bands (P) were 100%, Shannon's information index (I) was 0.4226, and Nei's gene diversity (H) was 0.2791. We infer that the high levels of genetic diversity exhibited by P. clematidea may have contributed to its invasiveness. Gene flow among populations was 2.4930, which has led to homogenization. The coefficient of population differentiation (Gst = 0.1671) indicated low levels of genetic variation among populations and high levels of genetic polymorphism within populations. There was a negative correlation between population elevation and genetic diversity, while there was a significant positive correlation between genetic distance and geographic distance based on a Mantel test (r = 0.5820, P < 0.01). Some populations from different provinces clustered together in principal coordinate and UPGMA analyses indicating that human-mediated events may have contributed to the dispersal of the species.     

Genetic diversity and relationships among wild and cultivated Stenocereus queretaroensis populations in western Mexico

Stenocereus queretaroensis is an endemic, chiropterophilous, columnar cactus of economic importance in Mexico. To investigate the effect of artificial selection on genetic diversity, inter-simple sequence repeat (ISSR) markers were used to estimate the genetic variation of wild, orchard, and backyard populations of S. queretaroensis from two regions in western Mexico. Six primers were used to generate 62 bands, of which 39 were polymorphic (62.9%). The total genetic diversity was similar in the wild (H_T = 0.296) and orchard (H_T = 0.291) groups, and slightly lower in the backyard group (H_T = 0.281). Wild populations (F_ST = 0.13) were less differentiated than backyard (F_ST = 0.17) and orchard (F_ST = 0.21) populations. The wild and backyard groups were genetically closer (0.015) than the wild and orchard (0.018) groups. A Mantel test revealed a positive correlation between genetic and geographic distances (r = 0.433, p = 0.002). In conclusion, gene flow and the prevailing management system have efficiently maintained genetic diversity and facilitated inter-population differentiation in S. queretaroensis.     

江西主要山脉春兰野生居群遗传结构与分化

利用ISSR分子标记对江西省主要山脉的21个春兰(Cymbidium goeringii(Rchb.f.)Rchb.f.)居群进行居群遗传结构研究。结果显示,利用14个筛选的引物共扩增出139条条带,其中多态性条带118条,多态性条带百分率(PPL)为84.89%。21个居群的Nei s基因多样性(He)为0.2292,Shannon指数(I)为0.3613。AMOVA分析表明,春兰居群间变异占50.79%,居群内变异占49.21%,居群间的遗传分化大于居群内的分化。STRUCTURE群体遗传结构和UPGMA聚类分析均表明,江西主要山脉的春兰居群存在地理隔离和生境片断化。推测江西春兰曾广泛分布于罗霄山脉和武夷山脉,受第四纪冰期影响,春兰群体因气候剧烈变化而骤减,仅在山脉间适宜的环境中得以保存并繁衍至今,罗霄山脉和武夷山脉是春兰最主要的两个冰期避难所。综合遗传多样性与居群遗传结构特点,建议在遗传多样性较高的石城(SC)、宜丰(YF)、贵溪(GX)居群设点进行就地保护;对资源破坏严重的大余(DY)和井冈山(JGS)居群实行迁地保护。     

Genetic diversity and structure among natural populations of Sindora glabra in Hainan Island,China as revealed by ISSR markers

Sindora glabra, one of the second-class national protective plants in China, has important ecological and commercial values. To understand the genetic diversity and structure of S. glabra, eleven natural populations from four areas of Hainan Island in China were analyzed by inter-simple sequence repeat (ISSR) markers. Thirteen primers were screened out and used to amplify 157 DNA samples. A total of 122 bands were obtained, among which 114 (93.4%) bands were polymorphic. Genetic parameters including average number of effective alleles (1.547), Nei's gene diversity (0.321), Shannon's information index (0.482), and gene differentiation coefficient (0.1944) revealed a high level of genetic diversity maintained in S. glabra populations. The variation within populations accounted for 85.6% of total variation based on analysis of molecular variance. Genetic distance analysis showed that 11 populations could be divided into three groups and populations from the same areas were classified as one group, suggesting that high genetic diversity of S. glabra was attributable to geographic isolation. Together, introduction of germplasm from distant natural distribution areas would be a sound strategy for germplasm resource conservation of S. glabra and selection of elite individuals from populations of far relationship for hybridization is of great importance for breeding improvement programs in future.     

Population structure and diversity in cultivated and wild Luffa species

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Evaluation of genetic diversity in wild populations of Peganum harmala L., a medicinal plant

Peganum harmala L. is a perennial herbaceous plant and can be a future drug due to its wide medicinal purposes. Despite its economic importance, the molecular genetics of P. harmal have not yet been studied in detail. Genetic diversity of 12 P. harmala genotypes were investigated by using Inter-Simple Sequence Repeats (ISSR), PCR-RFLP of rDNA-ITS, PCR-SSCP of rDNA-ITS and Simple Sequence Repeat (SSR) markers. The level of polymorphism revealed by ITS-SSCP is the lowest, followed by ITS-RFLP then ISSR and the highest polymorphism level was reported for SSR marker. The AMOVA analysis implied that most of the variation occurred within the Populations. A value of inbreeding coefficient F_is estimated by the three co-dominant markers was nearly equal and offer an indication of the partial out-crossing reproductive system of P. harmala. Principal Coordinate Analysis (PCOA) plot revealed a clear pattern of clustering based on the locations of collected plants which coincide with the isolation by distance. The study revealed that ITS-SSCP and ISSR markers respectively were more informative than the other used markers in the assessment of genetic diversity of P. harmala. The results reflect the great diversity of P. harmala and data obtained from this study can be used for future collecting missions.     

Genetic diversity assessment of a germplasm collection of Salvia miltiorrhiza Bunge. based on morphology,ISSR and SRAP markers

Salvia miltiorrhiza is one of the most important traditional Chinese medicinal plants for its therapeutic effects. In the present study, morphological traits, ISSR (inter-simple sequence related) and SRAP (sequence-related amplified polymorphism) markers were used to analyze the genetic diversity of 59 S. miltiorrhiza phenotypes. Out of the 100 ISSR primers and 100 SRAP primer combinations screened, 13 ISSRs and 7 SRAPs were exploited to evaluate the level of polymorphism and discriminating capacity. The results showed that the 13 ISSRs generated 190 repeatable amplified bands, of which 177 (93.2%) were polymorphic, with an average of 13.6 polymorphic fragments per primer. The 7 SRAPs produced 286 repeatable amplified bands, of which 266 (93.4%) were polymorphic, with an average of 38.1 polymorphic fragments per primer. Cluster analysis readily separated different morphological accessions, wild and cultivated controls based on morphological traits, ISSR and SRAP markers. The study indicated that morphological traits, ISSR and SRAP markers were reliable and effective for assessing the genetic diversity of phenotypic S. miltiorrhiza accessions. The overall results suggested that the introduction of genetic variation from morphology-based germplasms enlarged the genetic base for the collection, conservation and further breeding program of S. miltiorrhiza germplasm.     

大连沿海鼠尾藻野生种群遗传结构的ISSR分析

为了解大连沿海鼠尾藻野生种群的遗传结构,采用ISSR分子标记技术对5个采自辽宁大连和1个采自山东蓬莱的野生鼠尾藻种群进行遗传多样性和亲缘关系分析。利用筛选出的14个ISSR引物共扩增得到160个位点,其中多态性位点145个,多态位点个数占90.62%。6个种群的多态位点百分率(PPB)分布为41.25%～64.38%,基因多样性指数(H)为0.2321～0.3464,而Shannon信息指数(I)则为0.1585～0.2333,大连沿海鼠尾藻种群的遗传多样性水平高于蓬莱种群。分子变异分析(AMOVA)结果表明:在总的遗传变异中,种群内部变异为5.66%,种群之间为64.34%。基因流Nm=0.7837,各种群间存在有限的基因交流。UPGMA聚类结果显示,大长山(DC)、董坨子(DT)和将军石种群(JJ)聚为一支,亲缘关系较近,再与石城岛(SC)和盐场种群(YC)聚类,最后与蓬莱种群(PL)聚类在一起。鼠尾藻的生殖方式以及生长环境的差别可能是其种群遗传分化的主要原因。     

山东丹参(Salvia miltiorrhiza)不同地理居群的遗传多样性

以山东泰安、临沂、莱芜、菏泽和潍坊5个居群的72份丹参株系为材料,利用ISSR引物进行群体遗传结构的研究。结果表明：8个ISSR引物在5个居群中共扩增出219个位点,平均可扩增出27条带,在种级水平及泰安、临沂、莱芜、菏泽和潍坊5个居群水平多态性位点百分比分别为98.63%、81.28%、66.67%、66.21%、51.14%和50.68%,种级水平的Nei基因多样性和Shannon信息指数大于各居群;5个居群Nei基因多样性和Shannon信息指数相比较,泰安〉临沂〉莱芜〉菏泽〉潍坊;根据基因分化系数,测得的基因流值Nm为4.2352;UPGMA聚类分析结果表明,莱芜居群和临沂居群遗传一致度最大,遗传关系最近,泰安居群与其它4个居群遗传关系最远;分析发现菏泽居群、泰安居群是相对独立的群体,但5个居群间存在部分基因交流。所有参数分析表明,泰安居群遗传多样性最丰富,故在制定原位种质保护计划时应优先考虑泰山周边地区的丹参。     

基于ISSR标记的南方红豆杉野生种群和迁地保护种群的遗传多样性和遗传结构分析

采用ISSR标记方法,对南方红豆杉〔Taxus chinensis(Pilger)Rehd.var.mairei(Lemée et Lévl.)Cheng et L.K.Fu〕3个野生种群(包括江西黄港和黄沙种群以及福建枫溪种群)、2个迁地保护栽培种群及2个迁地保护衍生种群(均位于江苏南京中山植物园和江西庐山植物园)的遗传多样性和遗传结构进行了分析和比较。结果显示:用8个引物从南方红豆杉的基因组总DNA中共扩增出73条带,其中多态性条带62条。2个迁地保护衍生种群的多态性条带百分率(PPB)、Nei’s多样性指数(h)和Shannon信息指数(I)较高,3个野生种群的PPB、h和I值总体上居中,而2个迁地保护栽培种群的PPB、h和I值较低。合并后的迁地保护衍生种群以及野生种群均有较高的遗传多样性,二者的PPB、h和I值相近,分别为78.08%和82.19%、0.207 6和0.205 8、0.322 9和0.325 9;但二者的遗传结构存在差异,迁地保护衍生种群的遗传分化系数(GST)为0.068 9,明显低于野生种群(0.168 5)。合并后的迁地保护栽培种群的遗传多样性相对较低,PPB、h和I值分别为60...     

Genetic diversity analysis of Perinereis aibuhitensis based on ISSR and SRAP markers of Chinese coast populations

The objective of this study was to obtain an overview of the genetic relationships within Perinereis aibuhitensis using Inter-Simple Sequence Repeat (ISSR) and Sequence-Related Amplified Polymorphism (SRAP) markers that were derived from related populations residing in the Chinese coasts. The percentage of polymorphic bands, Nei's gene diversity and Shannon's information index revealed a high level of genetic diversity at the species level. The analysis of molecular variance revealed that 81.22% (ISSR) and 76.29% (SRAP) of variability were partitioned among individuals within populations, which indicated the coherent trend by Nei's genetic differentiation (Gst) (0.2568/0.2876). The gene flow number (Nm) was 1.4470/1.2385, which indicated that there was limited gene exchange between populations. The phylogenetic tree of the ten P. aibuhitensis populations was separated into four major clusters using the neighbor-joining (NJ) method. These results provide a simple and useful basis for P. aibuhitensis germplasm research and aquaculture breeding.     

Genetic diversity and genome size variability in Linum austriacum (Lineaceae) populations

Genetic diversity and genome size variability were studied in 16 geographical populations of Linum austriacum (Lineaceae). Genetic diversity parameters were determined in each population based on ISSR molecular markers. AMOVA test, Gst value and Hickory test revealed significant molecular difference among the studied populations. Mantel test showed correlation between genetic distance and geographical distance in these populations. NJ tree and NeighborNet network grouped the studied plant specimens in 3 major clusters. STRUCTURE analysis identified 12 allelic combinations in agreement with K-Means clustering result. These analyses revealed the presence of genetic variability both among and within studied population. The plant specimens of these geographical populations also differed significantly in their genome size.     

Genetic diversity of yacon (Smallanthus sonchifolius (Poepp. & Endl.) H. Robinson) and its wild relatives as revealed by ISSR markers

Set of 29 accessions of Smallanthus sonchifolius, an important tuber crop from South America, and its three wild relatives were analysed using the Inter Simple Sequence Repeats (ISSR) markers. Seven primers out of 30 primers screened gave clear and reproducible spectra. The range of amplified bands was from 2500 bp to 300 bp. These seven primers generated in total 77 bands, from which 75 (97.4%) were polymorphic. Nei's genetic distances between samples varied from 0.01 to 0.24. The Shannon's index (I) was estimated as 0.0392. The UPGMA dendrogram created using the Neighbour joining method and based on the Dice's dissimilarity coefficient separated clearly the wild accessions from all S. sonchifolius samples, which remained close to each other, confirming the clonal origin and thus a very low genetic variability within the genus.     

不同生态区罂粟种质的遗传多样性ISSR分析

为了揭示罂粟种质的遗传多样性,利用ISSR分子标记进行遗传多样性研究,从100条随机引物中筛选出9条多态性引物对所有样品扩增,共检测到109个等位变异位点,引物等位位点数在9～16之间,平均每条引物有12个等位变异,其中,引物807的等位位点最多,为16个。引物等位位点多态性信息量PIC值为0.77～0.92。其中引物807的PIC值最大(0.92),引物847的PIC值最小(0.77),遗传相似系数在-0.452～0.981之间,且明显聚为2个类群;亲缘关系和地理分布呈一定的相关性,但没有形成明显的地理变异模式;本研究将为罂粟种质资源科学有效利用提供理论依据。     

Genetic diversity of wild populations of Rheum tanguticum endemic to China as revealed by ISSR analysis

Rheum tanguticum is an important but endangered traditional Chinese medicine endemic to China. The wild resources have been declining. Establishing the genetic diversity of the species would assist in its conservation and breeding program. Inter-simple sequence repeats (ISSR) markers were used to assess the genetic diversity and population genetic structure in 13 wild populations of R. tanguticum from Qinghai Province. Thirteen selected primers produced 329 discernible bands, with 326 (92.94%) being polymorphic, indicating high genetic diversity at the species level. The Nei's gene diversity (He) was estimated to be 0.1724 within populations (range 0.1026–0.2104), and 0.2689 at the species level. Analysis of molecular variance (AMOVA) showed that the genetic variation was found mainly within populations (71.02%), but variance among populations was only 28.98%. In addition, Nei's differentiation coefficients (G_st) was found to be high (0.3585), confirming the relatively high level of genetic differentiation among populations. Mantel test revealed a significant correlation between genetic and geographic distances (r = 0.573, P = 0.002), and the unweighted pair-group method using arithmetic average (UPGMA) clustering and Principal coordinates analysis (PCoA) demonstrated similar results. Meanwhile, the genetic diversity of R. tanguticum positively correlated with altitude and annual mean precipitation, but negatively correlated with latitude and annual mean temperature. This result might be an explanation that the natural distribution of R. tanguticum is limited to alpine cold areas. We propose conservation strategy and breeding program for this plant.     

Genetic diversity within and among the wild populations of Murraya koenigii (L.) Spreng., as revealed by ISSR analysis

Murraya koenigii (L.) Spreng., commonly known as curry leaf plant, is found in the different hilly regions of India. In the present study, fifty-nine accessions representing eight wild populations of M. koenigii were analyzed using thirteen ISSR primers. A total of 152 bands were amplified, out of which, 136 were polymorphic corresponding to 89.47% polymorphism across the accessions. The pairwise population genetic distances were calculated for all the populations that varied from 0.05 to 0.13 between the populations of M. koenigii. AMOVA and Nei’s genetic diversity analysis revealed higher genetic variations within populations than among the populations. The clustering of populations in the dendrogram was not in congruence with geographical affiliations. The results indicate that the ISSR method is sufficiently informative and powerful to estimate the genetic diversity in M. koenigii populations. As M. koenigii is an important wild plant genetic resource, therefore, information on genetic variability might be a potential source as breeding material for development of commercially valuable traits in M. koenigii plants.     

Genetic diversity and variation in wild populations of dark sleeper (Odontobutis potamophila) in China inferred with microsatellite markers

Twenty-one highly variable microsatellite loci were used to investigate the genetic diversity and variation of Odontobutis potamophila in China. A total of 160 samples from five wild populations (Dangtu, Sheyang, Yuyao, Minjiang and Donxishan) were genotyped. All of the 21 microsatellite loci tested in this study showed polymorphism. The number of allele per locus ranged from 5.05 to 9.90. Locus 87a of Minjiang population had a 259-bp characteristic allele. The average observed heterozygosity and expected heterozygosity ranged from 0.33 to 0.62 and from 0.40 to 0.70, respectively. The pair-wise F_ST tests and NJ trees of the five O. potamophlia populations revealed that Dangtu, Sheyang, Yuyao and Dongxishan were genetically close to one another and distinct from Minjiang. Far genetic distances were observed among populations from distant geographical areas. This result provided guide for the use of O. potamophila breeds and the protection of the species.     

白皮松天然群体遗传结构的地理变异分析

为探讨白皮松天然群体遗传结构在地理分布上的差异,利用7对SSR引物对5个白皮松分布区域的遗传结构进行了分析。结果表明：7对SSR引物在5个区域内476个单株中共检测到14个多态性位点。各区域间观测等位基因数（Na）、有效等位基因数（Ne）、Shannon’s 信息指数（I）、观测杂合度（Ho）、期望杂合度（He）、Nei’s期望杂合度（Nei’s）分别介于1.7143~2.1429、1.1942~1.571、0.1948~0.4954、0.1726~0.3116、0.1178~0.3325、0.1172~0.3307之间。白皮松遗传多样性水平总体较低,区域间差异较大;遗传多样性水平最高的区域为秦岭西侧群体,其次为大巴山区群体;太行山与吕梁山群体多样性水平相对较低。区域间的遗传分化系数Fst介于0.0138~0.2242之间,基因流Nm介于0.865~17.8646之间。遗传分化较大、基因流水平较低的区域均发生在秦岭西侧及其与其他区域之间。各区域间遗传相似系数在0.8416~0.9964之间,遗传相似度最高的群体为太行山与吕梁山区域,遗传距离最大的为太行山与秦岭西侧区域。白皮松多样性分布的中心主要存在于秦岭西侧和大巴山区域,因此应对该区域进行重点保护。     

Genetic variability and population structure of Bergenia ciliata (Saxifragaceae) in the Western Himalaya inferred from DAMD and ISSR markers

Genetic variability and population structure of Bergenia ciliata (Haw.) Sternb., commonly known as “Pashanbheda” (Stone-breaker), collected from the Western Himalayan region of India were estimated using two DNA fingerprinting methods viz., directed amplification of minisatellite DNA (DAMD) and inter simple sequence repeats (ISSR). The cumulative data analysis of DAMD and ISSR markers for 74 accessions from eight populations showed 86.1% polymorphism. Analysis of molecular variance (AMOVA) showed highest percentage of variation within individuals of populations (73.6%) and 21.7% among populations. STRUCTURE and PCoA analyses on the hierarchical partitioning of genetic diversity showed strong admixture of individuals among the eight assumed geographical populations of B. ciliata. The data suggests that high genetic flow is one of the major factors responsible for low genetic differentiation. Preservation of genetic diversity of B. ciliata is important, both to promote adaptability of the populations to changing environment as well as to preserve a large gene pool for future prospection. The present study using DAMD and ISSR markers, therefore, provide the means of rapid characterization of accessions within the populations, and thus enable the selection of appropriate accessions for further utilization in conservation and prospection programmes.