Assessment of diversity among populations of Rauvolfia serpentina Benth. Ex. Kurtz. from Southern Western Ghats of India,based on chemical profiling,horticultural traits and RAPD analysis

Genetic, morphological and chemical variations of ten natural populations of Rauvolfia serpentina Benth. Ex. Kurtz. from Southern Western Ghats of India were assessed using RAPD markers reserpine content and morphological traits. An estimate of genetic diversity and differentiation between genotypes of breeding germplasm is of key importance for its improvement. Populations were collected from different geographical regions. Data obtained through three different methods were compared and the correlation among them was estimated. Statistical analysis showed significant differences for all horticultural characteristics among the accessions suggesting that selection for relevant characteristics could be possible. Variation in the content of Reserpine ranges from 0.192 g/100 g (population from Tusharagiri) to 1.312 g/100 g (population from Aryankavu). A high diversity within population and high genetic differentiation among them based on RAPDs were revealed caused both by habitat fragmentation of the low size of most populations and the low level of gene flow among them. The UPGMA dendrogram and PCA analysis based on reserpine content yielded higher separation among populations indicated specific adaptation of populations into clusters each of them including populations closed to their geographical origin. Genetic, chemical and morphological data were correlated based on Mantel test. Given the high differentiation among populations conservation strategies should take into account genetic diversity and chemical variation levels in relation to bioclimatic and geographic location of populations. Our results also indicate that RAPD approach along with horticultural analysis seemed to be best suited for assessing with high accuracy the genetic relationships among distinct R. serpentina accessions.     

Molecular characterization and genetic relationships among most common identified morphotypes of critically endangered rare Moroccan species Argania spinosa (Sapotaceae) using RAPD and SSR markers

? The objective of this work is the molecular characterization of most common identified morphotypes of critically endangered rare Moroccan species Argania spinosa.

? Eighteen RAPD markers and twenty SSR markers have been assayed in 38 argan tree accessions from the three most commonly identified morphotypes: oval, spherical and spindle fruit types.

? A total of 140 polymorphic RAPD bands were detected out of 146 bands. The number of presumed alleles revealed by the SSR analysis ranged from 1 to 5 alleles per locus with a total number of 32 alleles identified. Results demonstrated an extensive genetic variability within the tested argan accessions. RAPDs presented a high level of polymorphism and greater information content than SSRs.

? Our results could indicate that Vitellaria paradoxa is genetically closer to argan than Manilkara huberi. In addition, the correlation between the clustering based on RAPD and SSR markers were in general low. The observed clustering could be better explained according to geographic proximity than morphotype. For this reason the traditional morphological characterization of the argan accessions in morphotypes (according to fruit phenotype) seem not to be in correlation to the real genetic background (genotype) of this specie. The implications of these results in the creation of effective germplasm core collection in argan have been also discussed.

     

Molecular characterization and marker based chemotaxonomic studies of Podophyllum hexandrum Royle

Detailed chemical studies and RAPD analysis were done in different populations of Podophyllum hexandrum collected from high altitude regions of North Western Himalayas. Random amplified polymorphic DNA (RAPD) analysis revealed a high degree of genetic diversity among the 12 collected accessions, attributed to their geographical and climatic conditions. HPLC analysis also revealed variation in the concentration of two major marker compounds which lead to the identification of a chemotype. The study demonstrated that RAPD and chemical markers are very useful tools to compare the genetic relationship and pattern of variation among such prioritized and endangered medicinal plants.     

分子标记技术在槭树种质资源研究中的应用

中国是槭树种质资源丰富且分布集中的国家。为了更科学地开发和利用兼具观赏、药用、经济等多种珍贵价值的槭树种质资源,文中综述了国内分子生物学研究前期对槭树DNA和RNA提取的方法,以及RAPD、AFLP、ISSR、ITS和SRAP等分子标记技术在槭树植物研究中的应用,主要包括种质资源鉴定、种群遗传结构与遗传多样性、濒危植物保护、物种谱系地理分析等方面的研究;针对槭树类植物的分子生物学研究中存在的问题,提出了今后研究的重点和发展方向,以期为槭树植物的种质资源开发和深入研究提供参考。     

Variation in seed production of <Emphasis Type="Italic">Jatropha curcas</Emphasis> L. accessions under tropical dry forest conditions in Ecuador

The Ecuadorian Government has, since the end of 2011, promoted an initiative for using pure jatropha oil, derived from the seeds of Jatropha curcas L., to generate electricity to supply Floreana Island (one of the Galapagos Islands). In the present study, nine elite accessions of J. curcas from tropical dry forests in Ecuador were cultivated for the purpose of evaluating seed production in relation to the propagation method used (seed, cutting). A split-plot design with three replicates was applied. Seed production, measured over a period of 7 years (2009–2015) showed a large year-to-year variation. However, seed production varied significantly among accessions and depended on the propagation method (seeds or cuttings). Propagation by stem cuttings stabilized the variability in the vegetative and seed production components measured, increasing the strength of their relationships with seed yield. The three highest yielding accessions produced 0.28–0.30 kg of seeds tree^?1 year^?1. As seed yield was not correlated with annual precipitation, the year-to-year variation in production of accessions indicates the effect of other factors not considered here, such as agronomic practices. The study findings suggest that agroforestry practices could be developed that would enable J. curcas to play a predominant role in a strategy for tropical dry forests aimed at reducing poverty (also known as pro-poor growth strategy).     

麻疯树对土壤性状的影响研究进展

麻疯树是公认的生物燃料植物之一,也是一种具有修复土壤重金属污染潜力的物种。近年来,基于麻疯树速生和各器官含有毒物质,麻疯树对土壤产生的影响越来越受到关注。文中综述了麻疯树对土壤物理性状、化学性状、微生物数量、微生物群落组成及土壤酶活性变化的影响,展望了未来的研究方向。研究表明,在不同种植条件下麻疯树引起土壤水分含量、pH值、主要养分含量及微生物多样性变化的趋势不同,麻疯树对土壤性状影响的研究存在一定局限性。建议深入研究麻疯树种植及其凋落物对土壤性状的影响,以期为麻疯树种植与调控提供科学参考。     

Success of three soil restoration techniques on seedling survival and growth of three plant species in the Sahel of Burkina Faso (West Africa)

In the Sahel of Africa, where 90 % of the population depends on natural resources for their livelihood, a large part of the soils are structurally unstable,prone to crusting and hard setting, and have low water holding capacity, which hamper vegetation establishment.The effect of soil restoration techniques on survival and growth of seedlings of Acacia nilotica, Acacia tortilis and Jatropha curcas was tested in completely barren, degraded land in a Sahelian ecosystem in Burkina Faso. A total of522 seedlings(174 plants of each plant species) were planted in a randomized complete block design with three replicates combining three soil preparation techniques:half-moon, za¨? and standard plantation. Survival and growth rates evaluated over 20 months were significantly higher using the half-moon technique compared with the other two techniques. Survival rates of plant species planted using half-moon technique were 62.5, 28.57 and10.71 % for A. nilotica, A. tortilis and J. curcas respectively, but in za¨? and standard planting, seedling survival was zero. The low survival rate of J. curcas using the half-moon technique may indicate that J. curcas is unsuitable for barren and degraded land, whereas A. nilotica and A. tortilis appear to be promising tree species for rehabilitation of degraded land.     

柽柳属植物遗传改良研究进展

柽柳属植物具有抗旱、抗寒、抗盐碱、耐水湿等特性,作为干旱区、半干旱区大面积沙荒地和盐碱化土地上广泛分布的一类重要灌木植物,以其独特的生物、生态学特征和重要的生态、社会经济价值成为学者的研究热点。文中综述了柽柳属植物种质资源遗传多样性、相关抗逆基因研究、育种技术以及良种繁育等方面的研究进展,指出在柽柳属植物分子生物学研究和品种培育工作中存在的问题,并提出柽柳遗传资源开发利用的建议,旨在为包括柽柳在内的干旱区主要植物资源遗传育种研究提供参考。     

小桐子繁育系统与传粉生态学研究

在野外定位观测小桐子花朵的功能形态特征、开花动态、传粉方式,用杂交指数(OCI)、花粉/胚珠比(P/O)、去雄、套袋、人工授粉等方法分别测定小桐子的繁育系统.结果显示:(1)小桐子是单性花,雌雄同株同序.雄花单花期2 d,雌花单花期5～8 d,雌花直径略大于雄花.(2)雄花开花后9 h内花粉活力较高,24 h后花粉活力明显降低,48 h后花粉基本散失活力;雌花柱头可授性在开花后4 d内最强,5～8 d可授性开始降低,第9天基本失去可授性.(3)传粉方式以虫媒传粉为主,为虫媒植物.(4)繁育系统检测结果为部分自交亲和异交,需要传粉者活动才能完成授粉过程.     

Evaluation of genetic fidelity among micropropagated plants of Gloriosa superba L. using DNA-based markers — a potential medicinal plant

Malabar glory lily (Gloriosa superba L.) is a medicinally potent plant species used for the production of alkaloid colchicine. With ever increasing demand, there is a pressing need to conserve it through biotechnological approaches. A large number of complete plantlets were obtained by direct regeneration from the non-dormant tuber explants on Murashige and Skoog (MS) medium supplemented with 2.0 mg/l 6-benzylaminopurine (BAP) + 0.5 mg/l α-naphthalene acetic acid (NAA). Large number of plants can be produced in vitro under aseptic conditions, but there is always a danger of producing somaclonal variants by tissue culture technology. Thus, the genetic stability of micropropagated clones was evaluated using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) analysis. During the study a total of 80 (50 RAPD and 30 ISSR) primers were screened, out of which 10 RAPD and 7 ISSR primers produced a total of 98 (49 RAPD and 49 ISSR) clear, distinct and reproducible amplicons. The amplification products of the regenerated plants showed similar banding patterns to that of the mother plant thus demonstrating the homogeneity of the micropropagated plants. This is the first report that evaluates the use of genetic markers to establish genetic fidelity of micropropagated G. superba using RAPD and ISSR, which can be successfully applied for the mass multiplication, germplasm conservation and further genetic transformation assays for colchicine production to meet the ever increasing demand of this medicinally potent plant for industrial and pharmaceutical uses.     

Genetic diversity and phylogenetic relationships between and within wild Pistacia species populations and implications for its conservation

Although cultivation and utilization of Pistacia are fully exploited, the evolutionary history of the Pistacia genus and the relationships among the species and accessions is still not well understood. The aim of this study was to analyze random amplified polymorphic DNA(RAPD) in a total of 50 accessions of wild pistachio species, which included five populations Pistacia vera, Pistacia khinjuk,Pistacia atlantica, Pistacia mutica, and Pistacia eurycarpa.High levels of genetic diversity were detected within wild pistachio accessions, as revealed by using the unweighted pair-group method with arithmetic averaging and supported via analysis of molecular variance. The objectives of this investigation were to estimate marker indices, polymorphic information contents(PICs), and genetic similarities(GS)for RAPD markers; assess the genetic diversity of Pistacia species, using GS estimated from RAPD fingerprints and molecular characterization; and facilitate the use of markers in inter-specific introgression and cultivar improvement.Out of the 149 polymerase chain reaction fragments that were scored, 146(97.98 %) were polymorphic. Genetic similarities ranged from 0.3 to 0.86 %, marker indices ranged from 2.98 to 17.74 %, and PICs ranged from 0.80 to0.99 %. Our results provided great molecular identification of all assayed genotypes, which have shown that there is large quantity of genetic diversity among the pistachio accessions. This finding might render striking information in breeding management strategies for genetic conservation and cultivar development.     

Population genetic structure of <Emphasis Type="Italic">Juniperus phoenicea</Emphasis> (Cupressaceae) in the western Mediterranean Basin: gradient of diversity on a broad geographical scale

• Introduction, Material and Methods  

The genetic structure and diversity of ten natural populations of Juniperus phoenicea L. from the western part of the species range have been studied using random amplified polymorphic DNA (RAPD) markers.     

分子标记在竹类植物遗传多样性保护中的应用

竹类植物与人类的生存和生活密切相关,对其在DNA水平上的遗传多样性研究具有重要的理论和实践意义。分子标记是基因型的特殊的易于识别的表现形式,它是生物分类学、育种学、遗传学和物种起源与进化等研究的主要技术指标之一。本文综述了几种常用的DNA分子标记(RFLP、RAPD、AFLP等)在竹类植物种质资源鉴定、分类、亲缘关系、遗传多样性和起源进化等方面的研究进展,同时进一步展望了分子标记在濒危竹种保护和研究中的应用前景。     

RAPD技术在林木遗传育种中的应用

RAPD是用以检测种一级水平基因多样性的分子遗传标记技术。该文对RAPD标记的基本原理进行了介绍 ,并综述了近年来RAPD分子标记在林木种质资源研究 ,分子遗传图谱的构建 ,数量性状位点定位 ,分子标记辅助育种 ,群体遗传结构及多样性等方面的应用 ,最后指出了存在的问题与展望     

Molecular characterization of a collection of the tropical multipurpose shrub legume Flemingia macrophylla

Random amplified polymorphic DNA (RAPD) markers were used for assessing genetic diversity and its structure in a collection of the drought-tolerant, tropical multipurpose shrub legume Flemingia macrophylla (Willd.) Merrill. The species is especially suited to low-input smallholder production systems and is used as dry season forage supplement, live soil cover, mulch and living barrier, among others. Genetic groups identified by RAPD analysis related closely to four morphotypes revealed by multivariate analysis of morphological, agronomic and forage quality characteristics. Overall genetic diversity in the collection was moderate (H _T = 0.241), with 79% differentiation among and high genetic similarity (GS) within groups (0.672–0.965). Results indicate a closer relationship of the semi-erect morphotypes M3 and M4 with F. stricta rather than with the erect morphotype M1. The latter was genetically the most depauperate, followed by morphotypes M2 and M4. New evidence is provided that non-Asian accessions collected in Africa and South America are derived from introduced Southeast Asian material. Furthermore, RAPD data suggest the presence of duplicates in the collection, especially in the overrepresented erect morphotype M1.     

Genetic variation in relation to adaptability of three mangrove species from the Indian Sundarbans assessed with RAPD and ISSR markers

Rich genetic polymorphism is important for plants to adapt to changes because it enables the plant to make anatomical, physiological and biochemical changes in response to abiotic stress. Geomorphologic characteristics, demographic interference and a cumulative decrease in freshwater influx in the Indian Sundarbans region have proved detrimental to some economically important plants. In this study, genetic polymorphism of three mangrove species, Xylocarpus granatum, Excoecaria agallocha, and Phoenix paludosa, was assessed using RAPD and ISSR molecular markers. X. granatum, already in distress in the Sundarbans, had the least genetic polymorphism, 14.56% in the RAPD analysis and 12.92% in the ISSR. Relatively higher genetic polymorphism was recorded for the profusely growing E. agallocha and P. paludosa: 24.66 and 26.4% in RAPD; 24.87 and 20.32% in ISSR analysis respectively. A UPGMA dendrogram constructed using the similarity matrix from RAPD, ISSR and combined data showed that for X. granatum, the least and highest salinity zones clustered together, whereas for E. agallocha and P. paludosa, higher and lower salinity areas clustered in different clades. Nei’s genetic diversity, calculated from RAPD and ISSR data, was also in accordance with 0.0637 and 0.0583 for X. granatum, respectively, much lower than 0.0794 and 0.0818 for E. agallocha and 0.0799 and 0.0688 for P. paludosa. This opposing degree of polymorphism might be attributed to the profusely growing E. agallocha and P. paludosa and precarious status of X. granatum throughout the Indian Sundarbans.     

Genetic structure of Tunisian natural carob tree (Ceratonia siliqua L.) populations inferred from RAPD markers

? Seven RAPD markers were used to assess the genetic diversity and structure of ten Tunisian natural Ceratonia siliqua L. populations from different geographic and bioclimatic zones.

? The species maintain a high diversity within population as estimated by the percentage of polymorphic loci and Shannon’s index (P% = 76.31, $\bar H'_{pop} = 0.569$ ). The range of variation between populations was large. Populations from the upper semi-arid bioclimates, with more continuous distribution area showed the highest level of variation.

? A high genetic differentiation among populations (Φ_ST = 0.250 and $\bar G_{ST} = 0.347$ ), as a result of population isolation was revealed. Nevertheless, the genetic structure is in accordance with bioclimate indicating that ecological factors also should influence differentiation. Populations from the sub-humid, upper semi-arid and mean semi-arid zones clustered together and were distinct from those of the lower semi-arid ones.

? Conservation strategy should be made according to the level of polymorphism within population and bioclimate.

     

地理隔离对西南藏区山杨居群遗传结构影响的SRAP分析

采用SRAP分子标记技术,对分布于我国西南3个藏族地区山杨9个居群130个个体进行了遗传结构分析。结果表明,筛选出的7对引物组合共检测到多态性条带(AP)99条,多态性条带百分比(PPB)为59.28%。采用POPGENE软件分析,山杨9个居群平均多态位点百分率(PPB)为33.80%,Nei’s基因多样性指数(H)和Shannon’s信息指数(I)分别为0.130 9和0.213 7,较东北地区山杨具有偏低的遗传多样性。遗传分化系数Gst=0.325 5,表明遗传变异主要存在于居群内个体间。地理距离与遗传距离之间具有弱相关关系(r=0.349,P=94.5%),山脉阻隔效应是导致西南藏族地区山杨居群间遗传分化的主要因素。UPGMA聚类表明,甘孜地区4个居群与迪庆地区的维西居群具有较近的亲缘关系,迪庆地区的德钦、香格里拉居群和昌都地区2个居群的遗传相似度较高。基于西南藏族地区山杨遗传结构分析,建议实施就地保护的同时,建立山杨种质资源库,促进不同居群间的基因交流。     

Genetic variation of Tunisian Myrtus communis L. (Myrtaceae) populations assessed by isozymes and RAPDs

The genetic variation of six Tunisian Myrtus communis L. (Myrtaceae) populations was assessed using nine isozymes coding for 17 putative loci and 79 RAPD markers, amplified by five decamer random primers. The analysed populations belonged to three bioclimatic zones (lower humid, sub-humid and upper semi-arid). A high genetic diversity within populations was detected both by isozymes and RAPDs. The level of variation differed according to bioclimate. Populations collected from sub-humid bioclimate showed more polymorphism than those grown in the upper semi-arid zone. For all populations, the genetic diversity revealed by RAPDs was more pronounced than that detected with isozymes. A high differentiation among populations related to bioclimate and geographic distance was revealed by both methods. Population’s structure based on RAPD markers was more concordant with bioclimatic zones in comparison with isozymes. Differentiation between ecological groups was higher than that revealed within groups. Conservation programs should take into account the level of genetic diversity within population revealed by the two complementary classes of markers according to bioclimate.     

Low genetic diversity and high genetic differentiation among severely fragmented populations of the critically endangered tree Talbotiella gentii (Fabaceae)

The genetic diversity among 17 populations (including 10 newly discovered) of Talbotiella gentii (Fabaceae, Caesalpinioideae), a rare tree species endemic to Ghana, was assessed using random amplified polymorphic DNA (RAPD). A total of 80 polymorphic bands were generated from eight primers and analysed by cluster and correspondence analysis. This showed a clear distinction between populations, with two major groups associated with geographical origin. AMOVA analysis showed that 94.05% of the genetic variation was partitioned among populations, while only 5.95% was found within populations suggesting little gene flow between populations. Possible reasons for the high population genetic differentiation and the low levels of genetic variation within populations are inbreeding and genetic drift. Of a total of 26 known populations, 14 are now extinct, five during the course of this study. Action to prevent complete extinction of the species is therefore urgent.