Micropropagation of an endangered Indian sandalwood (Santalum album L.)

Santalum album is known as East Indian sandalwood. It is the most economically important tree harvested for heartwood oil, and India is among the chief exporters of sandalwood and its products. Multiple shoots were induced from nodal shoot segments derived from a 50- to 60-year-old candidate plus tree (CPT) on Murashige and Skoog (MS) medium supplemented with 0.53 μM α-naphthaleneacetic acid (NAA) and 11.09 μM 6-benzylaminopurine (BA). In vitro differentiated shoots were multiplied on MS medium with 0.53 μM NAA, 4.44 μM BA, and additives: 283.93 μM ascorbic acid, 118.10 μM citric acid, 104.04 μM cystine, 342.24 μM glutamine, and 10% (v/v) coconut milk. New shoots were harvested repeatedly for up to three subculture passages on fresh medium at 4-week intervals. Microshoots treated with 98.4 μM indole-3-butyric acid (IBA) for 48 h produced roots on growth-regulator-free, quarter-strength MS basal salts medium with vitamin B₅ and 2% sucrose. In vitro root induction was achieved from microshoots pulsed with 1230 μM IBA for 30 min in soilrite rooting medium. The percentage of rooting in soilrite was higher than that for agar medium, and in vitro raised plants were established in the field and showed normal growth.     

秃杉优选单株的离体培养技术研究

在选育12年生秃杉优良种源的优良母株上,取其枝条的顶芽为外植体,进行离体培养技术研究。结果表明,以改良WPM BA 1.0 mg/L ZT 0.5 mg/L NAA 0.05 mg/L CA 50 mg/L S 3%为最适宜芽苗增殖培养基;改良WPM BA 0.5 mg/L ZT 0.5 mg/L NAA 0.1 mg/L CA 50 mg/L S 3%为最适宜芽苗壮苗生长培养基;最适宜生根培养基为1/2MS IBA 0.5 mg/L NAA 0.3 mg/L CA 100 mg/L S 2%;将生根的试管苗移栽于蛭石、珍珠岩、泥炭体积比为5∶3∶2的混合基质,控制温度为20~30℃,相对湿度85%~90%,保湿20~25 d,其间适当遮荫,35 d后成活率达86%以上。研究成果为秃杉优良种质保存利用提供了扩繁实用技术。     

An efficient in vitro shoot regeneration through direct organogenesis from seedling-derived petiole and leaf segments and acclimatization of Ficus religiosa

Prolific and rapid in vitro plant organogenesis via direct regeneration has been obtained from axenic seedling-derived petiole and leaf explants of Ficus religiosa in Murashige and Skoog (MS) medium containing different concentrations of cytokinins in combination with indole-3-butyric acid (IBA). MS medium with 1.5 mg/l 6-benzylaminopurine plus 0.15 mg/l IBA produced the highest shoot induction frequency with an average of 6.26 and 10.13 shoots per leaf and petiole explants, respectively. After 4 weeks, the highest root formation frequency (96.7%), root number (5.73), and root length (4.76 cm) were with MS medium containing 2.0 mg/l IBA plus 0.1 mg/l α-naphthalene acetic acid. In addition, the effect of four sodium nitroprusside (SNP) treatments on acclimatization was also studied. Highest morphological traits such as survival rates, fresh and dry root weights as well as antioxidant enzymatic activities such as superoxide dismutase, peroxidase, and catalase was achieved with 125 ppm SNP. The α-amino acid, proline, content was highest with this treatment while the highest H2O2 (hydrogen peroxide) was in the controls. This study introduces a cost-effective, prolific, and efficient in vitro multiplication system to supply pharmaceutical and ornamental needs. It is the first report of an in vitro organogenesis protocol for F. religiosa by direct regeneration through axenic seedling-derived petiole and leaf explants, which can be efficiently employed for the utilization of active biomolecules.     

Plant communities, species diversity, richness, and regeneration of a traditionally managed coastal forest, Kenya

The Kenyan coastal forests make up one of the World 25 Biodiversity Hotspots. They consist of over 140 fragments (the majority with areas less than 0.5 km²) of the once extensive Zanzibar-Inhambane lowland moist forest. The over 60 known Mijikenda sacred Kaya forests and groves scattered along the coastal hinterland form the greater part of this ecosystem. The forests are of biological and cultural significance, and this has been recognized nationally and internationally, with some now listed as World Heritage Sites. The forests are protected by councils of Kaya elders who regulate use of their resources. Increasing human population and subsequent rise in demand for forest products and land for settlement has put a strain on these relic forests. Farm encroachment and extraction of forest products in different Kaya forests have affected the vegetation ecology at varying levels. This study investigated the spatial species distribution, association and regeneration potential of commonly utilized plants in one of these traditionally managed ecosystems. A modified nested plot method was used to collect data in the field.Using TWINSPAN multivariate, and indicator species analysis, two plant communities (Asteranthe and Bridelia) and an undifferentiated vegetation type were identified. Species association in Asteranthe consisted largely of forest dependant species, with a significant presence of woody climbers. It was comprised of two sub-communities namely Manilkara and Scorodophloeos. In contrast the second plant community, Bridelia, was dominated by light demanding species. It comprised one sub-community (Catunaregam) and a seral stage (Keetia). The species diversity and richness was higher in the Asteranthe community compared to Bridelia. Some of the forest species commonly utilized by the local people were observed to regenerate both in open and closed forest habitats while others had seedling recruitment confined to closed forest.Despite some coastal forests showing physiognomic similarity, detailed study shows intra-variation linked to topography, exposition, type and intensity of human perturbation both currently and in the distant past. Clearly, vegetation patterns of coastal forests of eastern Africa change at fairly short intervals.Recruitment of forest specialists is likely to decline if closed forests are opened up by farm encroachment, however their less specialized counterparts can pioneer in re-colonization of disturbed sites if conservation is strengthened. There is need to invigorate traditional management systems of forests with cultural significance by recognizing and giving increased legal mandates to the local custodians.     

群众杨组培体系的研究

以群众杨(Populus popularis 35-44)为材料建立组织培养再生系统。研究表明，外植体取材部位对不定芽的分化率有非常明显的影响，叶片的再生能力较弱，而幼茎的再生能力很强，叶柄的再生能力介于叶片及幼茎之间。因此，无菌苗幼茎是快繁和基因转化的理想外植体。在组培体系建立过程中发现再生不定芽中存在生长优于对照的个体，是否为体细胞无性系变异有待进一步研究。     

华富苹果离体叶片再生的主要影响因素研究

以花药培养选育的富士品种"华富"组培苗的叶片为试材,研究了离体叶片诱导再生不定芽过程中不同激素种类与组合、暗处理时间等因素对不定芽再生率的影响。结果表明:试管苗继代培养3～4代,取顶部嫩叶3～4片,剪除叶片边缘,叶片以近轴面接种到最佳诱导再生培养基MS+TDZ 2.0mg/L+IAA 0.75mg/L+蔗糖30g/L,pH值5.8,黑暗培养10～15d后,转入光照培养条件下,再生率达83.3%～86.7%。再生不定芽分化15～20d后转接到增殖培养基MS+BA 0.5mg/L+IBA 0.1mg/L上,当不定芽长度约2cm时再转接到生根培养基1/2MS+IAA 1.0mg/L+蔗糖2%,15d后,生根率可达95.0%以上。     

照白杜鹃离体快繁体系建立及种质试管保存

以照白杜鹃新生嫩芽为外植体,应用均匀设计法筛选其最适合的嫩芽基部直接再生芽苗、生根及种质试管保存的培养基,结果表明,最适合的基部直接再生芽苗诱导培养基为:DR ZT 3.00 mg.L-1,诱导率达96%以上;生根培养基:MS(改良) IAA0.50 mg.L-1 IBA 0.10 mg.L-1 KT 0.20 mg.L-1,生根率达98%以上;试管保存培养基:N-68 B92.30 mg.L-1 根皮苷1.50 mg.L-1,保存时间可达36个月以上.并对再生植株进行了快繁,35 d为一个周期,增殖倍数平均达60倍以上.常温条件下,采取"矮化延缓生长"的方法可在试管内保存种质资源.     

4个芦荟品种离体快繁技术研究

该文对库拉索、中华、木立和高尚4个芦荟品种离体快繁技术进行了研究。结果表明，库拉索和木立芦荟不定芽间接分化，库拉索主要是丛生芽＋愈伤组织方式，木立芦荟主要是愈伤组织的形式；中华芦荟和高尚芦荟主要是丛生芽方式直接分化。4个芦荟品种的最适继代增殖培养基库拉索为MS＋6-BA2．0mg／L＋NAA0．1mg／L，繁殖系数为7．29；中华芦荟为MS＋6-BA1．0mg／L＋NAA1．5mg／L，繁殖系数达6．64；木立芦荟为MS＋6-BA2．0mg／L＋NAA0．1mg／L，繁殖系数达14．0；高尚芦荟为MS＋6-BA1．0mg／L＋NAA0．1mg／L，繁殖系数达8．10。库拉索和中华芦荟的最适生根培养基为MS＋NAA0．5mg／L，生根率分别为86．5％和100％；木立和高尚芦荟为MS，生根率分别为99％和79％。最适移栽基质为珍珠岩：河沙：草炭土=1：1：1，成活率达92％。     

35杨微繁殖与叶片不定芽再生研究

以35杨茎段外植体为供试材料,对腋芽微繁殖、叶片不定芽再生、生根以及移植的离体培养技术体系进行了研究,结果表明：获得初始无菌苗的取材以4月取田间杨树新枝茎段外植体为最好;茎段外植体的启动培养基以附加NAA0．1mCL、0．5mg／L6-BA及GA,0．5mg／L的WPM培养基为优;腋芽微繁殖最快的培养基为WPM＋0．2mg／L6-BA＋0．1mg／LIAA＋0．1mg／LIBA;生根培养基以3／5WPM＋0．1mg／LIBA为好;叶片不定芽再生培养基以WPM＋0．2mg／L 6-BA＋0．1mg／LIAA＋0．1mg／LIBA再生频率最高,达92．86％;叶片不定芽在生根培养基上培养20d后获健壮生根苗,移栽成活率达100％。     

新疆杨不定芽短中期离体保存的研究

以新疆杨不定芽为材料,研究甘露醇、蔗糖和温度对其短中期离体保存的影响.不定芽在添加一定浓度甘露醇和蔗糖的1/2MS培养基上4℃保存225d发现,添加20g/L甘露醇或0g/L蔗糖的处理叶片变黄和茎变红数最少,而0g/L甘露醇和20g/L蔗糖的处理的芽恢复分化能力最强,达5.9个/芽,说明含20g/L蔗糖的1/2MS培养基更有益于新疆杨不定芽的保存.不添加任何激素的不定芽分别在4℃和25℃保存225d,存活率分别为100%和59%,将其连续转接3代,40℃保存苗可完全恢复分化率.增生率达6.1个/芽,而25℃保存苗第3代仍未恢复到原分化水平,表明4℃比25℃更有利于新疆杨芽的离体保存.     

An efficient micropropagation system for Celastrus paniculatus Willd.: a vulnerable medicinal plant

A micropropagation protocol was developed for Celastrus paniculatus, a vulnerable medicinal plant. Cultures were initiated from nodal explants collected from young shoots of a 12-year-old plant in MS basal medium. An average of five shoots were produced in MS medium supplemented with 1.5 mg l⁻¹ benzyl adenine (BA) and 0.1 mg l⁻¹ naphthalene acetic acid (NAA) after two subculture cycles with a 30-day interval. Continuous subculture in the same medium for three more cycles resulted in reduction of the number of multiple shoots (2 or 3 shoots), vitrification of the shoots, and callus formation. Vitrification of cultures could be overcome by the use of MS medium supplemented with lower concentrations of BA (0.05 mg l⁻¹) and NAA (0.01 mg l⁻¹). Among the various rooting trials, ex vitro rooting of shoots with simultaneous hardening was most efficient. The method standardized in the present study is simple, as it eliminated separate steps for in vitro rooting and hardening. Qualitative chemical similarity of the tissue culture regenerants with the mother plant was confirmed using high performance thin-layer chromatographic (HPTLC) profiling.     

Plant regeneration by somatic embryogenesis in Eucalyptus spp.: current status and future perspectives

Forest tree improvement programs benefit from the emergence of new biotechnological strategies that complement plant developmental biology and discovery of genes associated with complex multigenic traits. Recently, significant progress has been made in the area of plant regeneration via somatic embryogenesis (SE) for economically important tree species (e.g. pines). These advances have opened up new scenarios for deployment of new high-performance clonally replicated planting stock to forest plantations and may also be a valuable tool for the development of efficient gene transfer techniques. Although high rates of plant propagation from axillary shoot proliferation can be achieved easily in many Eucalyptus species, even higher multiplication rates through SE have been recorded in other tree species. If the clonal propagation of Eucalyptus through SE proves to be an effective propagation method, it has the potential to meet the increasing industrial demands for high-quality uniform materials and to rapidly capture the benefits of breeding programs. Since 2002 a reproducible protocol for SE induction from mature zygotic embryos of E. globulus has been available. However, for SE to be useful in E. globulus improvement programs, the frequency of SE initiation, maturation, germination and acclimatisation needs to be improved and controlled. If this technology could be extended to elite germplasm, it would become an economically feasible tool for large-scale production and delivery of improved planting stock. This is one of the greatest current challenges in Eucalyptus tissue culture. In this review we update the most important aspects of SE in Eucalyptus with particular emphasis on E. globulus. We highlight both genetic control and the influence of different environmental factors in the SE process (e.g. medium composition, antioxidants, light and plant growth regulators), from induction to plant acclimatisation in both primary and secondary SE.     

Multiplication of Elaeagnus angustifolia L. from a Single Shoot in Vitro

1INTRODUCTIONElaeagnusangusifoliaLisahighlytolerantnativewoodyspeciesinsouthernEuropeandAsia.Itmaybeusedinreforestationandsoil-waterconservationandforanexcellentwindbreaktoarrestwind(Bertrand,1985;LiShaozhong,etal,1997),materialsoffragranceandmedicineandnutritivefood(ChangZhaofeng,etal,1994;Goncharova,1997;Rasekh,1999;Ahmadiani2001;JiangFashou,etal,2002).Insomepreviousresearches,BA,2ip,KN(Bertrand,1985,Economou,1988)andBA(Iriondo1995;Mariella,1996)wereusedinshootmultiplicationofE…     

In vitro somatic embryogenesis in callus cultures of Azadirachta indica A. Juss.—a multipurpose tree

Plant regeneration via somatic embryogenesis was achieved in embryogenic callus cultures derived from immature zygotic embryos 40 days after anthesis of Azadirachta indica A. Juss. on semisolid basal Murashige and Skoog (MS) salts and vitamins supplemented with 1.11 µM 6-benzylaminopurine (BA) and 4.52–6.78 µM 2,4-dichlorophenoxyacetic acid (2,4-D). The globular-stage embryos were induced when the callus was transferred to medium with 1.11 µM BA and 0.45 µM 2,4-D. The highest average number of somatic embryos per 200 mg of callus was 152.8 after 8 weeks of culture on the medium. Maturation and germination of the somatic embryos were achieved on half-strength MS salts and vitamins supplemented 0.38–0.94 µM abscisic acid (ABA) and 2% (w/v) sucrose. The maximum percentage (64.2%) of germination was obtained with 0.94 µM ABA within 2 weeks of culture. Somatic embryo-derived plantlets were acclimatized in a greenhouse and subsequently showed normal growth. This efficient protocol will be helpful for propagating elite clones on a mass scale and will also be useful for genetic transformation study.     

Factors influencing in vivo and in vitro micrografting of sandalwood (Santalum album L.): an endangered tree species

In vivo micrografting of Santalum album was achieved (50%) by grafting 4- to 5-cm-long scions, collected from a candidate plus tree (CPT) of 50–60 years of age, onto 90-day-old nursery-grown rootstock. Scion size, rootstock age, and scion collection season were found to influence graft success. Grafted plants were incubated under greenhouse conditions for 6–8 weeks during the graft union process. In vitro micrografts were achieved by placing 1- to 2-cm-long scions derived from nodal shoot segments (collected from CPT) onto the hypocotyl of 45-day-old in vitro rootstocks. Use of in vitro grown shoots as a source of scion gave better graft success (60%) than scions collected directly from field-grown trees. In vitro grafting was also influenced by scion size and rootstock age. Under favorable conditions, scions and hypocotyls unite to form complete plants that produced two to four leaves after 6–8 weeks. This is the first report on in vivo and in vitro micrografting of S. album having potential for production of disease-free clonal plants for conservation and improvement targets.     

珍稀濒危植物珙桐初代培养研究

以珙桐芽体为试材,采用WPM、1/2 MS、B5三种基本培养基,附加6-BA、NAA、GA34因素3水平正交实验设计,同时研究了不同外植体消毒时间、剥离方式、芽体长度对珙桐初代培养的影响。结果表明:用75%酒精30 s+0.1%HgCl220 min消毒效果较好,外植体长度大于0.5 cm,剥离芽体至剩余鳞片叶1~2个的处理方式有利于降低污染率,最佳芽诱导的培养基配方为:WPM+6-BA 1.0 mg/L+NAA 0.05 mg/L+AC 0.5 g/L。     

Establishment of high frequency shoot regeneration system in Himalayan poplar (Populus ciliata Wall. ex Royle) from petiole explants using Thidiazuron cytokinin as plant growth regulator

Populus species are important resources for industry and in scientific study on biological and agricul-tural systems. Our objective was to enhance the frequency of plant regeneration in Himalayan popla...     

Natural regeneration of Pinus brutia Ten. in a recreational public forest in Zawita-Kurdistan region,Iraq

Zawita natural forest has recently has been subject to mass recreational activities during spring that have denuded large areas of the forest.It was thus essential to assess regeneration before designing optimizing strategies.To this end,we studied the overstory canopy and microhabitat conditions for recruitment of Pinus brutia Ten in 10 plots(20×25 m)on the southern aspects where the Zawita natural forest is still present.In total,1540 regenerating P.brutia were recorded,854 seedlings,597 saplings,and 89 trees.Seedlings and saplings were more frequent beyond the canopy than under the canopy of the parent trees.Regeneration requirements differed between seedlings and saplings.The probability of the occurrence of seedlings was negatively correlated with increasing litter depth and increasing soil compaction.The density of saplings only showed a positive significant correlation with increasing slope.The nearest neighbor index showed a trend toward a positive spatial association between understory shrubs with their neighboring seedlings at a mean distance of 1.6 m.Overall,the study highlighted the requirements for seedling regeneration as a relatively open canopy cover,a light understory litter layer,and noncompacted soils.These results are a step towards designing effective management and restoration programs.     

Effect of auxins on axillary and de novo shoot regeneration from in vitro shoot cultures derived from forced epicormic buds of teak (Tectona grandis L.)

In this presentation,we report on de novo and axillary shoot regeneration and rooting of shoots maintained over a long term,from cultures of Tectona grandis L.Shoot-tips of teak shoots forced from epicormic buds were used as the starting material for axenic shoot-culture establishment.Long term maintenance of such axenic shoot cultures was carried out by regular sub-culturing on MS media supplemented with N 6-benzyleadenine (BA,8.8 μmol L-1) and indole-3-butyric acid (IBA,2 μmol L-1) for 24 months.Vigorously growing shoot tips (2 3 cm long) were inoculated on the MS basal medium supplemented with different concentrations (0,1,2,4,6,8 or 10 μmol L-1) of either IBA or α-naphthaleneacetic acid (NAA) for rooting.Axillary and de novo shoots were developed from axillary and cut basal ends of shoots,respectively.Shoots growing on auxins were further sub-cultured (every 15 days) and maintained for 45 days.The greatest number of de novo (5.06) as well as axillary shoots (2.85) was observed on the MS medium supplemented with 10 μmol L-1 NAA or 8 μmol L-1 IBA,respectively,after 45 days.The combinations of both IBA (μmol L-1) + NAA (μmol L-1) were tested at different concentrations (4 + 4,6 + 6,8 + 8) supplemented to a half strength MS basal medium with 0.1% activated charcoal for rooting of decapitated and non-decapitated de novo and axillary shoots.Rooting from non-decapitated de novo shoots was highest (93.33%) with a mean number of roots of 4.61 on this medium,supplemented with 6 μmol L-1 IBA + 6 μmol L-1 NAA,after 36 days of initial culture.Individual auxin,however,was not effective for root induction.Rooted shoots were acclimatized in a green house and after four weeks plantlets were transferred to the field.     

枣疯病和泡桐丛枝病原植原体分离物的组织培养保藏和嫁接传染研究

分别从河北唐县赞皇大枣、辽宁凌源梨枣和河南濮阳扁核酸3个品种的枣疯病和来自山东、江西和北京的不同无性系的泡桐丛枝病树上采集丛枝枝条作为组织培养材料,获得的枣疯病和泡桐丛枝病组培苗皆表现典型的丛枝症状。其中感染植原体的赞皇大枣组培苗(Ft)和扁核酸组培苗(HPD)在未加任何激素的MS培养基和其它培养基交替继代培养1a以上仍能维持丛枝苗生长;而发病梨枣(LD)除产生丛枝外,还出现叶片黄化和植株矮化、枯梢等衰退症状。泡桐丛枝病植原体可在不同无性系组培苗上通过各种培养基交替和单纯的MS培养基继代培养,并已在实验室内连续保藏达10a,其引致丛枝症状的能力无明显的改变。用枣树Ft染病材料作接穗,以健康冬枣(DJ)和抗病婆枣(W14)砧木进行组培苗间嫁接传病试验,可使部分DJ和W14发病;而嫁接未发病的砧木多数像健苗一样正常生长。用感染山东泡桐丛枝病植原体ZD株系丛枝组培苗为接穗,嫁接健康泡桐无性系组培苗致使无性系MB33、TY2T和C125发病。用植原体16SrDNA通用引物进行PCR,确证了泡桐和枣树发病苗和嫁接发病组培苗体内存在植原体。用DAPI荧光显微镜技术比较组培苗韧皮部筛管中的植原体浓度,结果显示,Ft和嫁接发病冬枣(DJ-Ft)筛管中植原体浓度相对较高,但仍低于各泡桐无性系染病丛枝组培苗;HPD和LD浓度中等,而发病的W14砧木含有植原体的筛管数量较少、且浓度很低。在嫁接不成功或未发病的DJ和W14砧木组织及健康对照组织中皆检测不到植原体荧光。