Assessment of genetic fidelity of encapsulated microshoots of <Emphasis Type="Italic">Picrorhiza kurrooa</Emphasis>

In vitro grown microshoots of Picrrhiza kurrooa were encapsulated in the alginate beads. Regrowth of encapsulated microshoots, using alginate encapsulation, of P. kurrooa reached 89.33% following 3 months of storage. Amongst developing plantlets, 42.66% exhibited formation of multiple shoots at the onset of regrowth and 21.43% demonstrated simultaneous formation of shoots and roots. Healthy root formation was observed in plantlets following 2 weeks of their transfer to half-strength Murashige and Skoog medium containing 1 μM α-naphthalene acetic acid. Plants were transplanted to the greenhouse in three batches with 95% frequency of survival. The genetic fidelity of P. kurrooa plants growing out after storage in encapsulated form was ascertained by random amplified polymorphic DNA (RAPD) analysis. Molecular analysis of randomly selected plants from each batch was conducted using 45 random decamer primers. Of 45 primes tested, 14 produced scorable amplified products. Total 68 bands were observed amongst them 7.35% bands were polymorphic. Cluster analysis of the RAPD profile revealed an average similarity coefficient of 0.966 thus confirming genetic stability of plants derived from encapsulated microshoots following 3 months of storage.     

ISSR and RAPD Based Evaluation of Genetic Stability of Encapsulated Micro Shoots of Glycyrrhiza glabra Following 6?Months of Storage

In vitro grown axillary micro shoots of Glycyrrhiza glabra were encapsulated in alginate beads. Following 6?months of normal storage at 25?±?2°C the re growth of encapsulated G. glabra micro shoots, reached 98% within 30?days of incubation on MS medium supplemented with 0.1 mg/l IAA. Re growth was characterized by the development of both shoot and root from single encapsulated micro shoot. Healthy plants were established to glass house with 95% survival. The genetic fidelity of plants obtained after conversion of alginate beads was ascertained through 10 RAPD and 13 ISSR primers. Of the 10 RAPD primers tested, 6 of them produced 14 clear and reproducible amplicons with an average of 2.3 bands per primer out of which 28.57% were polymorphic generated by only two primers. Eight ISSR primers produced total 37 bands ranging between 300 and 3,500?bp length. Number of scorable bands for each primer varied from 3 to 8 with an average of 4.6 bands per primer. Cluster analysis from ISSR and RAPD showed that all the tested plants including the mother plant distributed in two major groups with similarity coefficient ranging from 0.91 to 0.96 for RAPD and 0.89 to 0.97 for ISSR.     

Adventitious bud regeneration from leaf explants of <Emphasis Type="Italic">Platanus occidentalis</Emphasis> L. and genetic stability assessment

The aim of this work is to develop a method of plant regeneration from leaf explants of Platanus occidentalis L. successfully. Woody plant medium (HortScience 16:453–459, 1981) and Murashige and Skoog (Physiol Plant 15:473–497, 1962) medium were used as induced and rooted basal medium, respectively. The effects of combinations of 6-BA, IBA, NAA and KT with different concentrations on adventitious bud regeneration from P. occidentalis leaf explants were compared. The results showed that the highest shoot regeneration frequency (90%) and maximum number (13.72 ± 0.44) of shoots per explant was recorded on WPM medium supplemented with 22.20 mmol l⁻¹ 6-BA and 0.49 mmol l⁻¹ IBA. A 40-day-old explants were much more productive for shoot formation than others in this study. The regenerated shoots were cultured on MS medium supplemented with 1.33 mmol l⁻¹ 6-BA, 0.16 mmol l⁻¹ NAA and 2% (w/v) adenine, after 2-week shoots were transferred to 1/2 MS medium supplemented with 0.49 mmol l⁻¹ IBA for rooting. Hardened plantlets via acclimatization were transferred to pots and transplanted to the soil finally. To ascertain whether tissue culture had effects on the genetic stability of plantlets regenerated, the genetic diversity was assessed using RAPD marker. A total of 96 bands ranging from 0.5 to 2.2 kb with an average of 6.4 bands per primer, were obtained using 15 primers. Amplified products exhibited few of polymorphic patterns across all the plants of P. occidentalis and the overall frequency of detection of somaclonal polymorphisms was lower than 0.0104%. Yuehua Sun, Yanling Zhao, and Xiaojuan Wang contributed equally to this work.     

In vitro propagation, genetic and secondary metabolite analysis of Aconitum violaceum Jacq.: a threatened medicinal herb

Aconitum violaceum Jacq. is an important medicinal species used for various health ailments including renal pain, rheumatism and high fever. In the present report, a reproducible in vitro regeneration system for Aconitum violaceum Jacq. has developed from the nodal segment of the plant. Induction of shoot buds was achieved on basal Murashige and Skoog (MS) medium. The shoots were elongated on MS medium supplemented with 0.5 μM 6-benzylaminopurine (BAP) and 0.1 μM α-napthaleneacetic acid (NAA) and subsequently transferred to rooting medium. In vitro grown microshoots of A. violaceum were encapsulated in the alginate beads. The success rate of their re-growth was found to be approximately 85.43 %. Of the encapsulated microshoots, 39.86 % exhibited formation of multiple shoots following re-growth on plant growth regulator free MS medium. Healthy root formation was observed in all microshoots following 2 weeks of transfer on half-strength MS medium containing 0.1 μM indole-3-acetic acid (IAA) and 1.0 μM α-naphthalene acetic acid (NAA). These plants were subsequently transferred to pots containing a mixture of soil, sand and compost (1:1:1 v/v), and same were then shifted in the greenhouse with 87 % survival rate. The molecular analysis was carried out using 35 random amplified polymorphic DNAs (RAPD) primers and 25 inter simple sequence repeats (ISSR) primers. Cluster analysis of the RAPD and ISSR profile revealed an average similarity coefficient of 0.966 and 0.974, respectively, confirming genetic stability of tissue culture-raised (TR) plants and synthetic seed-derived plants (SR). The phytochemical analysis of tissue culture-raised and synthetic seeds-derived plants showed higher aconitine content than control plant. The propagation protocol developed in this study provides a basis for germplasm conservation and harnessing the medicinally active compounds of A. violaceum.     

In vitro propagation of the endangered plant <Emphasis Type="Italic">Centaurea ultreiae</Emphasis>: assessment of genetic stability by cytological studies,flow cytometry and RAPD analysis

The effect of different cytokinins on multiple shoot regeneration from shoots of Centaurea ultreiae was studied. The culture system consisted of solid basal half-strength Murashige and Skoog medium supplemented with one of four cytokinins [6-benzyladenine (BA), zeatin, kinetin, or N⁶-(2-isopentyl) adenine (2-iP)] at each of five different concentrations. The highest multiplication rate (5.52 shoots per explant) was obtained in the medium supplemented with 4.44 μM BA. Shoots were successfully rooted (91% success) by dipping the basal end into a solution containing 10 M 1-naphthaleneacetic acid for 30 s. Genetic stability of the regenerated plants was assessed by random amplified polymorphic DNA (RAPD) analysis and flow cytometry. In the initial randomly selected plant material (control) and 20 of its regenerants, 2,688 bands were generated by RAPD with 12 different primers, and the same banding profiles were exhibited. Molecular and cytological analyses did not reveal genomic alterations in any of the regenerated plants obtained on medium containing 4.44 μM BA. The success of acclimatization to environmental conditions—100% of plants were successfully acclimatized—suggests that the micropropagation system described is a reliable method for propagation of C. ultreiae.     

Micropropagation of <Emphasis Type="Italic">Cotoneaster wilsonii</Emphasis> Nakai—a rare endemic ornamental plant

A simple and efficient micropropagation system was developed for Cotoneaster wilsonii through node and shoot tip explants obtained from mature field-grown plants. Of the two explants, node explants were found to be the most effective for axillary shoot proliferation. The highest frequency of shoot induction was achieved when nodal explants were incubated on Murashige and Skoog (MS) medium supplemented with 0.5 mg L⁻¹ thidiazuron (TDZ) and 0.1 mg L⁻¹ α- naphthaleneacetic acid (NAA) with an average of 34 shoots per explant. The microshoots were separated from the multiple shoots and subcultured on MS medium supplemented with 3% (w/v) sucrose and 0.8% (w/v) agar for further shoot growth. Maximum rooting was obtained on half-strength MS medium supplemented with 0.5 mg L⁻¹ indole-3-butyric acid (IBA). The in vitro-grown plantlets were successfully acclimatized in a glasshouse with 98% of survival. High concentrations of TDZ (1.5–2.0 mg L⁻¹) and repeated subcultures resulted hyperhydric shoots. Supplementation of the culture medium with silicon significantly reduced the induction of hyperhydric shoots. Increasing silicon concentration significantly decreased malondialdehyde content of the regenerated shoots. Data indicate that addition of silicon to the culture medium can effectively control hyperhydricity.     

Micropropagation of <Emphasis Type="Italic">Pinus massoniana</Emphasis> and mycorrhiza formation in vitro

A protocol was developed for the micropropagation of Pinus massoniana and mycorrhiza formation on rooted microshoots. Seedling explants were first cultured on Gresshoff and Doy (GD) medium supplemented with 6-benzyladenine (BA) alone or in combination with α-napthaleneacetic acid (NAA) to stimulate the formation of intercotyledonary axillary buds. The frequency of axillary bud induction was up to 97% on medium supplemented with 4.0 mg l⁻¹ BA and 0. 2 mg l⁻¹ NAA, and the average number of buds per explant reached up to 5.5 on medium with 4.0 mg l⁻¹ BA and 0.1 mg l⁻¹ NAA. Axillary buds elongated rapidly after being transferred to half-strength GD medium containing activated charcoal (0.1% w/v). Shoot proliferation was achieved by cutting elongated shoots into stem segments and subculturing on GD medium containing 2 mg l⁻¹ BA and 0.2 mg l⁻¹ NAA. Root primordia were induced in 82% of shoots when transferred to half-strength GD medium containing 0.2 mg l⁻¹ NAA. Root elongation was achieved in a hormone-free GD agar medium or a perlite substrate. Rooted plantlets were inoculated with the mycelium of ectomycorrhizal fungus Pisolithus tinctorius and the formation of ectomycorrhiza-like structures was achieved in vitro.     

RAPD based genetic stability analysis among micropropagated,synthetic seed derived and hardened plants of <Emphasis Type="Italic">Bacopa monnieri</Emphasis> (L.): a threatened Indian medicinal herb

Bacopa monnieri (L.), a highly endangered miracle medicinal herb with global interest, is one of the popular ancient Indian ayurvedic plants. With ever increasing demand for Bacopa based formulations in pharmaceutical industries, there is a need to preserve the stocks of the plant through biotechnological approaches. Randomly amplified polymorphic DNA (RAPD) fingerprinting approach was applied to analyze the genetic stability of 19 different B.monnieri plants randomly selected after micropropagation, regrowth from alginate encapsulated uninodal cuttings (before and after storage at 4°C) and hardening with the mother plant (wild type). 16 arbitrary decamer primers amplified a total of 334 reproducible distinct DNA fragments ranging from 180 to 1,500 bp, of which 262 (78.4%) were monomorphic and the rest (21.5%) were polymorphic with an average of 20.8 bands per primer. The extent of polymorphism was low to moderate. Primers OPAK 14, OPM 15 and OPD 13 generated 69, 46 and 42% polymorphic patterns. Primers OPA 04, OPU 13 and OPD 08 generated 100% monomorphic pattern. Similarity matrix based on Jaccard’s coefficient revealed that pair wise values between the wild type and its analyzed plants ranged from 0.00 to 0.92 and among the micropropagated, synthetic seed derived and hardened plants, the range of genetic distance is from 0.67 to 0.92. Unweighted pair group method with arithmetic averages cluster analysis resulted in one loose group of the wild type with three subgroups. The present study paves the way for the identification and maintenance of genetically uniform B. monnieri plants micropropagated in the lab, plants regrown from synthetic seeds and hardened in the field.     

High frequency plant regeneration following abnormal shoot organogenesis in the medicinal tree Hovenia dulcis

An efficient plant regeneration protocol for shoot organogenesis from Hovenia dulcis callus cultures was established. Induction of organogenic callus was achieved on Murashige and Skoog (MS) medium supplemented with 4.65 μM kinetin and 4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Further differentiation of organogenic callus into primordia, shoot-like structures, and plantlets was achieved on MS medium supplemented with 0.23 μM gibberellic acid (GA₃) and 0.46 μM kinetin. Numerous abnormal shoots developed upon transfer of callus to MS medium containing cytokinins, and these failed to grow further into whole plantlets. However, transfer of ‘abnormal’ shoots to a fresh MS medium lacking cytokinins resulted in growth of normal shoots. Elongated shoots subsequently were rooted in basal MS medium, and whole plantlets were established in a soil mix. Analysis of regenerated plants using random amplified polymorphic DNA (RAPD) confirmed the genetic stability of these regenerant plantlets.     

Shoot organogenesis in elite clones of <Emphasis Type="Italic">Eucalyptus tereticornis</Emphasis>

An efficient shoot organogenesis system has been developed from mature plants of selected elite clones of Eucalyptus tereticornis Sm. Cultures were established using nodal explants taken from freshly coppice shoots cultured on Murashige and Skoog medium containing 58 mM sucrose, 0.7% (w/v) agar (MS medium) and supplemented with 2.5 μM benzyladenine (BA) and 0.5 μM α-naphthaleneacetic acid (NAA). Shoot organogenesis was achieved from leaf segments taken from elongated microshoots on MS medium supplemented with 5.0 μM BA and 1.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D). The addition of cefotaxime to the medium promoted shoot differentiation, whereas carbenicillin and cephalexin inhibited shoot differentiation. Maximum shoot bud organogenesis (44.6%) occurred in explants cultured on MS medium supplemented with 5.0 μM BA, 1.0 μM 2,4-D and 500 mg/l cefotaxime. Leaf maturity influenced shoot regeneration, with maximum shoot organogeneisis (40.5%) occurring when the source of explants was the fifth leaf (14–16 days old) from the top of microshoot. Shoot organogenic potential also varied amongst the different clones of E. tereticornis. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analyses indicated clonal uniformity of the newly formed shoots/plants, and these were also found to be true-to-type.     

An assessment of genetic fidelity of micropropagated plants of Chlorophytum borivilianum using RAPD markers

Rapid micropropagation was achieved in Chlorophytum borivilianum Santapau and Fernandes using shoot base as explants. Multiple shoots were induced on Murashige and Skoog’s (MS) medium supplemented with 3.0 mg dm⁻³ 6-benzylaminopurine, 0.1 mg dm⁻³ 1-naphthaleneacetic acid, 150 mg dm⁻³ adenine sulphates and 3 % saccharose. Rooting was readily achieved upon transferring the shoots onto half strength MS medium supplemented with 0.1 mg dm⁻³ indolebutyric acid and 2 % saccharose. Micropropagated plantlets were hardened in the greenhouse and successfully established in soil. Random amplified polymorphic DNA (RAPD) markers were used to evaluate the genetic stability of the micropropagated plants. Thirty one arbitrary decamers were used to amplify genomic DNA from in vitro and in vivo plant material to assess the genetic stability. All RAPD profile analysis from micropropagated plants was genetically similar to mother plants.     

Evaluation of the genetic fidelity of in vitro-propagated gerbera (<Emphasis Type="Italic">Gerbera jamesonii</Emphasis> Bolus) using DNA-based markers

The genetic fidelity of in vitro-raised gerbera clones was assessed by using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. Out of 35 RAPD and 32 ISSR primers screened, only 12 RAPD and 10 ISSR primers produced clear, reproducible and scorable bands. The 12 RAPD primers produced 54 distinct and scorable bands, with an average of 4.5 bands per primer. The number of scorable bands for ISSR primers varied from 3 (ISSR-14) to 9 (ISSR-07), with an average of 5.5 bands per primer. The number of bands generated per primer was greater in ISSR than RAPD. All banding profiles from micropropagated plants were monomorphic and similar to those of the mother plant. A similarity matrix based on Jaccard’s coefficient revealed that the pair-wise value between the mother and the in vitro-raised plantlets was 1, indicating 100% similarity. This confirmed the true-to-type nature of the in vitro-raised clones.     

RAPD Fingerprint to Appraise the Genetic Fidelity of In Vitro Propagated <Emphasis Type="Italic">Araucaria excelsa</Emphasis> R. Br. var. glauca Plantlets

Randomly amplified polymorphic DNA (RAPD) was used as a tool to assess the genetic fidelity of in vitro propagated Araucaria excelsa R. Br. var. glauca with explants taken from orthotropic stem along with their related mother plants after treatment with kinetin, 2iP, BA (0.02–0.26 mg/l) and TDZ (0.001–1 mg/l) to produce axillary shoots. TDZ and kinetin induced more shoot and higher length per explant. Results showed a total of 1,676 fragments were generated with 12 RAPD primers in micropropagated plants and their donor mother plants. The number of loci ranged from 6 in OPB 12–18 in OPY 07 with a size ranging from 250 bp in OPH 19–3500 bp in OPH 11. Cluster analysis of RAPD data using UPGMA (unweighted pair group method with arithmetic average) revealed more than 92% genetic similarities between tissue cultured plants and their corresponding mother plant measured by the Jaccard’s similarity coefficient. Similarity matrix and PCoA (two dimensional principal coordinate analysis) resulted in the same affinity. Primers had shown 36% polymorphism. However, careful monitoring of tissue culture derived plants might be needed to determine that rooted shoots are adventitious in origin.     

High frequency in vitro propagation of <Emphasis Type="Italic">Trichopus zeylanicus</Emphasis> subsp. <Emphasis Type="Italic">travancoricus</Emphasis> using branch–petiole explants

Trichopus zeylanicus subsp. travancoricus (known as Arogyapacha), an endangered ethnomedicinal plant of the Western Ghats of South India, serves as the major source of the commercial drug Jeevani. The present study established a long-term high frequency in vitro propagation protocol for Arogyapacha. Callus obtained from the branch–petiole explants cultured on Murashige and Skoog (MS) medium with 4.5 μM 2,4-dichlorophenoxyacetic acid upon subculture to medium with different concentrations of 6-benzyladenine (BA) either alone or in combination with an auxin favoured shoot morphogenesis. Medium with 13.3 μM BA alone facilitated high frequency shoot bud (mean of 93.2) formation. Medium with lower concentrations of BA (4.4, 6.6 and 8.8 μM) alone or in combination with lower concentration of α-naphthaleneacetic acid (NAA) or indole-3-butyric acid (IBA) favoured better shoot growth than 13.3 μM BA containing medium, but with reduced number of shoot buds. Subsequent cultures on medium with lower concentrations of BA and also on MS basal media facilitated shoot formation as well as growth of shoots. The shoot regeneration potential showed no decline up to 5 years. Culture of the in vitro-derived whole branch–leaf explants on MS basal medium developed shoots directly from the node. On medium with 19.6 μM IBA, the whole branch–leaf explants induced nodular callus from the node, which developed shoots later. Subsequent cultures on medium with BA exhibited high frequency shoot formation. The transfer of shoots after 10–15 days culture on half-strength MS medium containing 2.7 μM NAA to half-strength basal medium induced a mean of 11.3 roots. Field survival of plantlets relied on the soil mix: a 1:4 ratio of sand and red-soil exhibited the highest plantlets survival (86.6%). RAPD profile of the source plant and plants regenerated from calli after 4 years showed no polymorphism. The established plantlets with morpho-floral features similar to that of the source plants flowered normally and set fruits.     

Medium,container and genotype all influence in vitro cold storage of apple germplasm

The goal of this study was to evaluate the in vitro storage of apple germplasm by screening a range of genotypes followed by more comprehensive testing of multiple parameters on two genotypes of differing species, Malus domestica cultivar Grushovka Vernenskaya and wild Malus sieversii selection TM-6. Stored plants were rated on a 6 point scale (0 low to 5 high) for plant appearance at 3 month intervals after storage at 4°C. Combinations of carbon source (sucrose and/or mannitol), nitrate nitrogen content (25, 50 or 100%) and plant growth regulators (ABA, BAP, IBA) were studied in three types of containers (tissue culture bags, test tubes or jars). An initial screen of 16 genotypes stored in tissue culture bags indicated that plantlets could be stored at 4°C for 9–14 months without subculture on standard 3% sucrose Murashige and Skoog (1962) (MS) medium with no plant growth regulators (PGRs). In subsequent in-depth studies on the two genotypes, ANOVA indicated highly significant interactions of medium, container and genotype. ‘Grushovka Vernenskaya’ shoots with no PGRs and 3% sucrose remained viable (ratings of ≥1) for 21 months of storage in bags. Storage on reduced nitrogen (MS with 25% nitrogen), PGRs, and 3% sucrose kept ‘Grushovka Vernenskaya’ shoot condition rated >2 at 21 months. Addition of 0.5 or 1 mg⁻¹ abscisic acid (ABA) also improved plant ratings at 21 months. The longest storage for ‘Grushovka Vernenskaya’ was 33–39 months with PGRs and 3% sucrose in either tubes or jars. Addition of abscisic acid (ABA) to the medium did not improve storage of plantlets in jars and tubes at 15 months. TM-6 stored best in tubes on 3% sucrose with PGRs or in jars on 2% mannitol and 2% sucrose. Overall it appears that cold storage of apple shoot cultures can be successful for 21 months in tissue culture bags with 25% MS nitrate nitrogen, 3% sucrose, and no PGRs or for 33 months in jars or tubes on MS with 3% sucrose and PGRs. Preliminary RAPD analysis found no significant differences between plants stored for 39 months and non-stored controls.     

In vitro propagation and assessment of clonal fidelity of Nepenthes khasiana Hook. f.: a medicinal insectivorous plant of India

An efficient in vitro protocol for large-scale multiplication of Nepenthes khasiana, a threatened insectivorous plant of India, has been developed from nodal stem segments. The highest shoot proliferation of 19.16 ± 0.23 shoots/explant was recorded in half-strength Murashige and Skoog (MS) medium supplemented with 2.5 mg/l kinetin, 2.0 mg/l 6-benzyl aminopurine, 3 % sucrose and 0.8 % agar. The best rooting was achieved in half-strength MS medium supplemented with 2.0 mg/l α-naphthalene acetic acid with an average of 9.04 ± 0.46 roots/shoot. The plantlets were successfully transferred to the greenhouse with survival rate of 92 %, exhibiting normal development. Cytological and random amplified polymorphic DNA (RAPD) analyses were carried out to assess the genetic integrity of the regenerated plantlets. Cytological analysis revealed no change in chromosome number with cells studied showing 2n = 80. Of the 80 primers screened for RAPD analysis, 14 primers resulted in clear and scorable bands. A total of 72 amplification products were obtained out of which only 4.1 % bands were polymorphic. Cluster analysis of the RAPD profile revealed an average similarity coefficient ranging from 0.98 to 1.0, thus suggesting genetic stability in the micropropagated plants of N. khasiana.     

Molecular analysis of genetic fidelity in Cannabis sativa L. plants grown from synthetic (encapsulated) seeds following in vitro storage

The increasing utilization of synthetic (encapsulated) seeds for germplasm conservation and propagation necessitates the assessment of genetic stability of conserved propagules following their plantlet conversion. We have assessed the genetic stability of synthetic seeds of Cannabis sativa L. during in vitro multiplication and storage for 6 months at different growth conditions using inter simple sequence repeat (ISSR) DNA fingerprinting. Molecular analysis of randomly selected plants from each batch was conducted using 14 ISSR markers. Of the 14 primers tested, nine produced 40 distinct and reproducible bands. All the ISSR profiles from in vitro stored plants were monomorphic and comparable to the mother plant which confirms the genetic stability among the clones. GC analysis of six major cannabinoids [Δ⁹-tetrahydrocannabinol, tetrahydrocannabivarin, cannabidiol, cannabichromene, cannabigerol and cannabinol] showed homogeneity in the re-grown clones and the mother plant with insignificant differences in cannabinoids content, thereby confirming the stability of plants derived from synthetic seeds following 6 months storage.     

Storage and conversion of Eclipta alba synseeds and RAPD analysis of the converted plantlets

The encapsulated shoot tips and nodal segments of Eclipta alba were stored at 4, 12 and 20 °C under irradiance of 1.5 gmmol m⁻² s⁻¹ and high conversion was observed in synseeds stored at 4 °C for 8 weeks. Duration of storage was extended up to 12 weeks by decreasing sucrose concentration in the alginate matrix from 3 to 1 or 2 % and conversion frequency was 71.2–76.1 %. Synseed-derived plantlets survived by 100 % in ex vitro conditions. RAPD analysis revealed uniform amplification profile in donor and synseed derived plantlets.     

Clonal micropropagation of <Emphasis Type="Italic">Crataeva adansonii</Emphasis> (DC.) Prodr.: A multipurpose tree

Summary A method of micropropagation through multiple shoot formation from axillary buds of mature tree and rootstock growths of Crataeva adansonii (DC.) Prodr. (a multipurpose tree) has been developed. Factors affecting multiplication rate included season, age of explant source, explant type, type of bud, position of bud on the foliage twig, type of medium, various additives, and explant implantation on the medium. The maximum number of buds was produced from the sixth to 10th axillary buds taken from foliage twigs of 40–50-d-old rootstock growth in the months of October to December. At this time of the year the contamination was minimum. Optimum response was recorded on Murashige and Skoog (MS) medium supplemented with 6-benzyladenine (BA; 3 mgl⁻¹, 13.3μM) and 1-naphthaleneacetic acid (NAA; 0.05 mgl⁻¹, 0.27 μM) after 21 d of culture. Shoot buds were further multiplied and maintained on BA (1–1.5 mgl⁻¹, 4.4–6.7 μM) while shoots elongated on BA (0.1–0.5 mgl⁻¹, 0.44–2.2 μM) supplemented medium. The number of shoots was further multiplied by using nodal segments of in vitro-regenerated shoots as microcuttings and repeated subculturing of stumps after excising the microshoots. In vitro rooting on growth regulator-free MS medium was possible with 70% of microshoots after 4 wk. From one nodal segment 150 plantlets were produced within 14 wk.     

Determination of genetic stability of long-term micropropagated plantlets of Platanus acerifolia using ISSR markers

Inter-simple sequence repeat (ISSR) markers were used to assess the genetic stability of long-term micropropagated plantlets of London plane tree (Platanus acerifolia Willd.). Twenty micropropagated plantlets were chosen from a clonal collection of shoots that originated from a single mother shoot. This clonal collection had been maintained under in vitro culture conditions for at least 8 years, as achieved by axillary branch multiplication. Out of 38 ISSR primers screened, 16 primers were found to produce clear reproducible bands resulting in a total of 103 distinct bands with an average of 6.44 scorable bands per primer. Of these 103 bands, 86 were monomorphic across all 20 of the plants tested and 17 showed polymorphisms (16.5 % polymorphism). Based on the ISSR band data, similarity indices between the plantlets ranged from 0.92 to 1.00. These similarity indices were used to construct an UPGMA dendrogram and demonstrated that all 20 micropropagated plants grouped together in one major cluster with a similarity level of 91 %. A total of 1771 scorable bands were obtained from the full combination of primers and plantlets and only 51 (2.88 %) were polymorphic across the plantlets which indicates that this micropropagated line of P. acerifolia is genetically stable.