Comparison of agar and gum karaya as gelling agent for in vitro regeneration of rough lemon (Citrus jambhiri Lush.) plantlets from nodal explants

In the present study, attempt was made to compare agar with gum karaya as gelling agent in micropropagation of rough lemon (Citrus jambhiri Lush.). Initially nodal segments were cultured on agar-gel MS medium containing benzyladenine (BA), kinetin (KN), zeatin (ZN) (1.0–2.5 mg L^?1) and malt extract (200–1,200 mg L^?1) to standardize the medium. Maximum shoot regeneration (66.66%) was observed with KN 2 mg L^?1 with an average shoot length of 0.73 cm. Gum karaya and agar was then evaluated at different concentration and combinations in same medium. The shoot regeneration response on media gelled with 30 g L^?1 gum karaya was 62.49% with an average shoot length of 0.80 cm. Regenerated shoots were rooted on MS medium gelled with agar and supplemented with different concentrations (0.5–2.5 mg L^?1) of indole-3-acetic acid (IAA), naphthalene acetic acid (NAA), and indole-3-butyric acid (IBA). Maximum response (52.77 %) was observed with IBA 2.0 mg L^?1 with an average number of 2.58 roots/shoot. A maximum of 53.47% cultures showed root regeneration with an average number of 2.91 roots/shoot in 30 g L^?1 gum karaya-gel medium. Texture measurements revealed that firmness of gum karaya-gel medium was nowhere near to that of agar. However, in their capability of supporting growth and differentiation of explants they are equal to agar medium. Gum karaya forms less adhesive and gummy medium as compared to agar. This study indicates that gum karaya can be used as gelling agent in place of agar.     

Clonal propagation of Acacia saligna by shoot tip culture

Summary Multiple shoots buds were obtained successfully from shoot tips of Acacia saligna by placing explants into solidified Murashighe & Skoog (1962) medium (MS medium) supplemented with 5.0 to 9.0 mg/L BAP. Sequential culture treatment was highly effective for shoot elongation using MS medium containing 0.3 mg/L BAP and 0.2 mg/L IAA. The shoots rooted best on MS medium supplemented with 2.0 mg/L IBA. Plantlet survival after transfer to soil was more than 90%. The shoot proliferation method described could be used for the mass clonal propagation of selected genotypes.     

The effect of plant growth regulators and natural supplements on in vitro propagation of Pogostemon cablin Benth.

The effect of plant growth regulators and natural supplements on the morphogenetic response of Pogostemon cablin Benth. was investigated. Murashige and Skoog (MS) media supplemented with 0.5 mg L^?1 benzyl-6-adenine and 0.5 mg L^?1 kinetin was effective in inducing multiple shoots (63.20 ± 0.15) with an average shoot length of 5.27 ± 0.15 cm and biomass of 5.20 ± 0.10 g shoot^?1. Among the natural supplements, 10% coconut water supplemented to MS media showed a better response in all the morphological parameters studied. The use of 10% tomato extract, 20% banana extract, 10% carrot extract, and 10% papaya extract in MS medium have efficiently increased multiple shoots, shoot length, and fresh weight of the shoots. The natural supplements also effectively increased the chlorophyll content, total protein, and total carbohydrate content in the plant. The frequency of rooting (93%) was highest when shoots were implanted on 1/2 strength MS media with 100 mg L^?1 activated charcoal. The in vitro rooted plants were successfully acclimatized and established in soil. Also, RAPD analysis showed no variation suggesting true-to-type nature of the micropropagated plants. Hence, this protocol can effectively reduce the cost of in vitro multiplication of plants.     

Effect of antiviral chemicals on in vitro regeneration response and production of PLRV-free plants of potato

Potato leaf roll virus (PLRV) is causing serious loss in yield and quality of potatoes. In the present study, the effect of seven antiviral chemicals viz. Acyclovir, 5-Azacytidine, Cytarabine, 5-Bromouracil, Ribavirin, 2-Thiouracil and Zidovudine on regeneration response and production of PLRV-free plants under in vitro conditions is reported. MS medium supplemented with 0.1 mg L^?1 GA₃, 0.1 mg L^?1 NAA and 500 mg L^?1 malt extract was used for regeneration of plantlets from nodal explants. DAS-ELISA and RT-PCR was used for virus indexing of the mother plant and in vitro-regenerated plantlets. Explants of PLRV positive potato plants were cultured on this medium containing different concentrations (5 – 30 mg L^?1) of antiviral chemicals. Shoot regeneration response varied between tested antiviral chemicals and was decreased with increase in concentration of antiviral chemicals from 5 to 30 mg L^?1. Antiviral chemicals at 30 mg L^?1 concentration showed strong inhibitory effect on regeneration response of shoots. In vitro regenerated plantlets tested negative in both ELISA and RT-PCR were only considered as virus free. When regeneration response and number of virus-free plants produced was compared, 2- thiouracil and ribavirin (25 mg L^?1) were found to be effective. 2- thiouracil (25 mg L^?1) gave 38.68% PLRV free plants with 30.55% cultures showing shoot regeneration and ribavirin (25 mg L^?1) gave 39.62% PLRV-free plants with 36.80% cultures showing shoot regeneration. Regeneration response of explants was better on 5-Bromouracil at 30 mg L^?1 concentrations but it was found least effective in production of PLRV-free potato plants.     

Actions for ex situ conservation of Gloriosa superba L. - an endangered ornamental cum medicinal plant

Factors affecting in vitro propagation and microtuberization were evaluated for Gloriosa superba L., an endangered ornamental cum medicinal plant having limited reproductive capacity. Surface sterilization of tuber explants with 0.1% mercuric chloride (HgCl₂) for 5 min eliminated the contamination effectively with highest survival rate. Among the various combinations used, Murashige and Skoog (MS) medium with 2.0 mg L^?1 6-benzylaminopurine (BAP) + 0.5 mg L^?1 α-naphthalene acetic acid (NAA) containing 3% sucrose with 16-h photoperiod exhibited the greatest in vitro tuberization (3.2) with the highest shoot regeneration frequency (90%). The longest tuber regeneration occurred on MS media containing 4% sucrose. Transfer of in vitro-regenerated shoots to half-strength MS medium with 1.0 mg L^?1 indole-3-butyric acid (IBA) + 0.5 mg L^?1 NAA showed maximum root induction (66.6%). The in vitro-grown plantlets were successfully acclimatized and transplanted to sterilized soil and sand mixture (3:1) in the glasshouse with 70% survival. The colchicine content was determined in the tubers of ex vitro plants by HPLC using the same retention time (1.5 min) as that of the standard colchicine. This revealed that the micropropagation protocol developed by us for rapid mass production could be used as raw material for colchicine extraction and provides a basis for germplasm conservation and genetic improvement of G. superba.     

High frequency plantlet regeneration from nodal segment culture of female <Emphasis Type="Italic">Momordica dioica</Emphasis> (Roxb.)

An in vitro propagation method for female plants of Momordica dioica (Roxb.) has been established. The nodal segments were harvested and the cut ends of the explants were sealed with wax and then surface sterilized and cultured. Bud breaking occurred on Murashige and Skoog’s (MS) agar-gelled medium + 2.0 mg L⁻¹ 6-Benzylaminopurine (BAP) + 0.1 mg L⁻¹ Indole-3 acetic acid (IAA). The cultures were amplified by passages on MS medium supplemented with 1.0 mg L⁻¹ BAP + 0.1 mg L⁻¹ IAA. Further, shoot amplification (29.2 shoots per vessel) was achieved by subculturing of in vitro regenerated shoot clump on MS medium + 0.5 mg L⁻¹ BAP + 0.1 mg L⁻¹ IAA. The micropropagated shoots were subsequently transferred for root formation on half-strength MS medium + 2.0 mg L⁻¹ Indole-3 butyric acid (IBA) with 89% success rate. The in vitro-regenerated shoots were also rooted ex vitro with 34% success. These plantlets were hardened in the greenhouse and transferred to the field. The established protocol is suitable for true to type cloning of mature female plant of M. dioica.     

Efficient Micropropagation Protocol for <Emphasis Type="Italic">Jatropha</Emphasis> Curcas Using Liquid Culture Medium

Although several studies have been made on the micropropagation of Jatropha curcas using agar base mediums, none of them have been by using liquid medium systems. The effects of explant type and temporary immersion system (test tube, jar with filter paper boat, and growtek bioreactor) on the micropropagation of J. curcas were studied. The explant type influenced shoot quality, multiplication coefficient (MC), and rooting. Leaf explant produced more and longer shoots than nodal explant. Use of filter paper (FB) boat prevented hyperhydricity and allowed proliferation of nodal explants cultured in liquid MS (Murashige and Skoog) medium supplemented 6-benzylaminopurine (BAP) and Kinetin (KN). The best shoot bud induction (92.1±3.1%) was achieved in liquid MS medium supplemented with 2.0 mg/L KN. Leaf regeneration efficiency was compared in growtek bioreactor and in jar containing liquid MS medium supplemented with 0.5 mg/L Thidiazuron (TDZ). The best shoot bud regeneration (78.7±2.1%) was obtained in growtek bioreactor. Shoot buds achieved from nodal segment and leaf were subcultured on filter paper boats in jar and bioreactor containing liquid MS medium supplemented with BAP, Indole butyric acid (IBA), Indole-3-acetic acid (IAA), and KN. Best shoot proliferation and elongation was obtained in filter paper boats containing liquid MS medium supplemented with 1.5 mg/L BAP, 0.5 mg/L IAA, and 0.2 mg/L KN. The number of multiple shoot buds was higher in leaf explants as compared to nodal explants and the highest number of multiple shoot buds was recorded from leaf explants. Up to 76.4% rooting efficiency was obtained when the shoots were ex vitro rooted. The generated plants well established in the nursery and grew normally in outdoor conditions. The protocol has good potential for application in large-scale propagation of J. curcas using liquid medium.     

Optimal protocol for mass propagation of Aloe vera

We established an advanced protocol for in vitro propagation of Aloe vera via comparison of basal media, sucrose contents, growth hormone combinations, and additional supplementation with various polyamines. The maximal number and growth of shoots after 5 weeks was obtained using MS media including 30 g L^?1 sucrose supplemented with 1.0 mg L^?1 BA and 0.1 mg L^?1 NAA. To improve shoot production, various concentrations of putrescine, spermidine, and spermine were added under optimal growth hormone conditions (MS media supplemented with 30 g L^?1 sucrose, 1.0 mg L^?1 BA, and 0.1 mg L^?1 NAA). Maximal shoot number and growth after 5 weeks were achieved with supplementation of 50 mg L^?1 spermidine. Regenerated plants were successfully acclimatized in soil with 100% efficiency. Cytogenetic inspection revealed that the regenerated plants maintained intact chromosomes identical to those of plants grown in field conditions. This protocol provides a valuable alternative for mass production of elite Aloe vera.     

Micropropagation of <Emphasis Type="Italic">Kaempferia angustifolia</Emphasis> Roscoe - An Aromatic,Essential Oil Yielding,Underutilized Medicinal Plant of Zingiberaceae Family

Kaempferia angustifolia is an aromatic, essential oil-yielding plant of the Zingiberaceae family with an ethno-medicinal repute. We standardized an effective system for micropropagation of K. angustifolia, and this is probably the very first report of in vitro culture of this species. Axillary buds were cultured on a Murashige and Skoog (MS) medium supplemented with various concentrations and combinations of plant growth regulators (PGRs) and spermidine. Highest multiplication occurred when the MS medium was supplemented with a combination of 2.0 mg L^?1 6-benzylaminopurine (BAP), 2.0 mg L^?1 kinetin (KIN) and 1.0 mg L^?1 α-naphthalene acetic acid (NAA). Addition of spermidine (2.0 mM) along with optimum PGRs had further improved the multiplication rate with a maximum of 6.6 ± 0.36 shoots per explant within 60 days of implantation. The number of multiplied shoots per explant increased with each subsequent regeneration cycle; and the shoots per explant increased from 6.6 ± 0.36 on the 1^st regeneration cycle to 10.3 ± 0.42 on the 2^nd regeneration cycle and further increased to 13.7 ± 0.37 on the 3^rd regeneration cycle on the same medium composition. The best result for in vitro root induction of multiplied shoot was achieved on a half-strength MS medium fortified with 2.0 mg L^?1 IBA, with a maximum of 18.5 ± 0.28 roots per shoot. Regenerated plantlets were acclimatized with 88.9 % survival rate. After 9 months of field-transfer, all these plants were harvested and rhizomes were collected. However, the present protocol can definitely be applied for large-scale propagation and commercial cultivation of K. angustifolia.     

Investigation of the efficiency of direct and indirect regeneration in evening primrose (Oenothera biennis)

As a medicinal plant, the importance of evening primrose (Oenothera biennis L.) is due to its unsaturated fatty acids in the seeds and roots, and also oenotherine and comfarol in the leaves. Low germination and difficulties in seed production are the main problems encountered with growing this plant in the field. As an alternative approach, an in vitro experiment was set up for the evaluation of evening primrose production via direct and indirect regeneration of the cultivars NC-1 and VNK. For callogenesis and direct regeneration, the explants from the apical bud and petiole were cultured on MS medium supplemented with 0.25, 0.75, and 1.25 mg L^?1 of both BAP and Kinetin (KIN). Indirect regeneration was performed by placing apical buds, petioles, and leaf explants on MS medium supplemented with 0.5 and 1 mg L^?1 2,4-D and 0.5, 1, and 1.25 mg L^?1 of both BAP and KIN. The highest shoot induction from direct regeneration was obtained with apical bud explants of VNK treated with 0.75 mg L^?1 BAP. The highest callus weight (3.17 g) obtained from indirect regeneration was with petiole explants treated with 1 mg L^?1 2, 4-D and 1 mg L^?1 BAP in VNK cultivars. The highest number of torpedo embryogenic clusters (23.8) was obtained from the VNK petiole explants treated with 0.5 mg L^?1 2, 4-D and 1.25 mg L^?1 BAP. BAP had higher positive effects on in vitro production of evening primrose than KIN in both direct and indirect regeneration. In general, results indicated that VNK was more potent for regeneration than NC-1 and concentrations of 0.75 mg L^?1 BAP for direct and 0.5 mg L^?1 2, 4-D and 1.25 mg L^?1of BAP for indirect regeneration had a higher efficiency for increasing in vitro production of evening primrose.     

Induction and development of adventitious shoots of Atropa baetica as a means of propagation

In vitro propagation of Atropa baetica was established employing axillary buds. Single buds were cultured through a multiple shoot induction phase, rooting phase, and then followed by acclimatization in soil. For multiple shoot induction, Murashige and Skoog (MS) medium with 3% sucrose, supplemented with either 0.75 or 1.25 mg l^-1 of BAP provided the best results with an average of 5.6 shoots per explant after 31 days of culture. Similar results were obtained with higher BAP concentrations (1.75–2.0 mg l^-1); however, these media had a negative effect on the subsequent root induction due to residual BAP effect. Medium containing only 0.25 mg l^-1 of BAP induced a significantly lower number of shoots. Root induction occurred spontaneously after transferring the shoots onto MS medium lacking any plant growth regulator. Moreover, root induction also occurred on media supplemented with 0.125 and 0.25 mg l^-1 of NAA. On these two rooting media, this response was more prominent and with a higher number of roots per explant. Nevertheless, after 28 days on root induction medium, the number of rooted plantlets was similar on the three media. Acclimatization of plantlets in soil was very successful (95.52%). However, all plantlets which died during acclimatization were rooted on medium containing 0.25 mg l^-1 NAA suggesting a negative carry over effect of this medium upon plantlet survival, irrespective of the initial BAP treatment used. On the other hand, karyological studies showed no variation in the number of chromosome (2n=72) in root tips of the plantlets produced. This revised version was published online in July 2006 with corrections to the Cover Date.     

Medium, Explant and Genotype Factors Influencing Shoot Regeneration in Oilseed Brassica spp.

The effects of culture media, explants and genotypes on shoot regeneration in oilseed Brassica species were examined in this study. The maximum shoot regeneration frequency was obtained in Murashige and Skoog medium supplemented with 3 mg l^?1 6‐benzylaminopurine and 0.15 mg l^?1 1‐naphthaleneacetic acid. The addition of 2.5 mg l^?1 AgNO₃ was very beneficial to shoot regeneration in B. napus and Ag₂S₂O₃ (10 mg l^?1) was even superior to AgNO₃ (2.5 mg l^?1). Explant age, explant type and carbon source also significantly affected shoot regeneration. Four‐day‐old seedlings of cotyledonary explants showed the maximum shoot regeneration frequency and number of shoots per explant. Of the four explants – peduncles, hypocotyls, cotyledons and leaf petioles – cotyledons produced the highest shoot regeneration frequency (56.67 %). Four carbon sources – glucose, maltose, starch and sucrose – were compared for their respective effects on shoot regeneration from cotyledonary explants. Sucrose appeared to be the best carbon source for shoot regeneration with the highest shoot regeneration frequency (76.00 %). Considerable variation in shoot regeneration from cotyledonary explants was observed both between and within Brassica species. The shoot regeneration frequency ranged from 10.00 % for cv. R5 (B. rapa) to 83.61 % for cv. N1 (B. napus). Two B. napus, one B. carinata and one B. juncea cultivars exhibited shoot regeneration frequency higher than 70 %. In terms of the number of shoots produced per explant, B. rapa showed the highest variation, ranging from 5.64 for cv. R3 to 1.33 for cv. R5. Normal plantlets were regenerated from all induced shoots and developed normally. The regenerated plants were fertile and identical with the source plants.     

In vitro callogenesis and detection of somaclonal variations in Plantago ovata L.

Planago ovata L. is an economically important species in the monotypic genus Plantago. It is a short-stemmed annual herb. The seed husk of this plant is commonly called psyllium or isabgol which is important in pharmaceutical formulation and food industry. In this study, callus induction was optimized using different explants of Plantago ovata. Callus DNA was utilized to access the somaclonal variations using the Random Amplification of Polymorphic DNA (RAPD) markers. The maximum callus growth was observed in Murashige and Skoog (MS) medium containing 4 mg L^?1 2,4-D concentration for shoots, 0.5 mg L^?1 for seeds and 2 mg L^?1 for roots. Moreover, the effect of culture age was considered in assessing genetic variability. Maximum genetic variability was observed in the DNA samples of callus at the concentration of 2 mg L^?1 2,4-D for all explants (roots, shoots, and seeds). Cluster analysis was performed based on 1) similarity coefficient between samples and 2) molecular data using the Numerical Taxonomy and Multivariate Analysis System (NTSYS) PC version 2.01; similarity index was generated by similarity for Quantitative Data (SIMQUAL). Our study indicated that Random Amplified Polymorphic DNAs can successfully be used to explore polymorphism among callus samples at different hormonal concentrations. This study can be useful for the production of callus from Plantago ovata and estimation of genetic variations due to tissue culture conditions. Evaluation of genetic variations can display novel features and manipulate genetic bottlenecks in Plantago ovata. New genetic variations in somaclones can bring vital insight for plant improvement.     

High frequency shoot proliferation from cotyledonary node of <Emphasis Type="Italic">Lawsonia inermis</Emphasis> L. and validation of their molecular finger printing

An efficient and reproducible protocol for in vitro plant regeneration was developed for Lawsonia inermis L. using cotyledonary node explant derived from axenic seedlings. Highest shoot proliferation frequency (ca 96.6%) was achieved on Murashige and Skoog’s, 1962 (MS) basal medium supplemented with 8.88 μM 6-Benzyladenine (BA) + 2.68 μM Napthalene acetic acid (NAA). Up-scaling of shoots was carried out using in vitro nodes on MS medium supplemented with 4.44 μM BA. So overall, an average of 238 shoots was produced at 75 days. Of the four different forms of cotyledonary node explants evaluated, highest shoot multiplication was observed in cotyledonary node explant with two whole cotyledons. In vitro regenerated shoots were best rooted (ca 34.3 roots / shoot) on ½ MS medium devoid of any growth regulator. The plantlets were successfully acclimated in sand:soil:: 1:1and established in the garden soil. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analysis revealed a homogeneous amplification profile for all micropropagated plants validating the genetic fidelity of the in vitro-regenerated plants and supporting the regeneration protocol for economic commercial exploitation.     

根癌农杆菌介导苎麻转绿色荧光蛋白（GFP）基因植株再生

以苎麻优良品系“5041-3”子叶作为受体,利用根癌农杆菌介导法进行了绿色荧光蛋白基因的遗传转化研究,农杆菌菌株为EHA105,重组质粒为pBIN m-GFP5-ER。经农杆菌浸染后的子叶外植体经过共培养、选择培养、伸长培养和生根培养后再生出抗性植株,对抗性植株的再生过程进行了GFP荧光检测,结果表明,GFP基因能在苎麻中强烈表达,证明GFP基因能够在苎麻遗传转化中得到应用。对抗性植株的Southern杂交检测证实外源基因已整合到苎麻基因组中。     

High frequency direct plant regeneration from leaf and petals of Cape Primrose (<Emphasis Type="Italic">Streptocarpus</Emphasis>)

High frequency direct plant regeneration from leaf and petal explants was accomplished for the first time in Streptocarpus varieties. The shoot induction frequency varied with respect to the benzylaminopurine (BAP) concentration added to the Murashige and Skoog (MS) medium. MS medium with 0.5 mg l⁻¹ BAP exhibited the highest (69.9%) plant regeneration frequency with an average of 186 shoots per explant. A higher concentration of BAP inhibited shoot bud induction and plant regeneration along with necrosis of explants. Petal explants derived from the varieties ‘Branwen’ (pink and white) and ‘Chorus Line’ (violet and white) displayed plant regeneration frequency of 22.2–47.4% (within a total of 12 weeks) on MS medium containing 2.0 mg l⁻¹ α-naphthaleneacetic acid and 0.5 mg l⁻¹ BAP for 8 weeks followed by 4 weeks on MS medium with 1.0 mg l⁻¹ BAP. Scanning electron microscopy confirmed direct plant regeneration without callus. Regenerated plants from leaf explants with well-developed leaves and roots were hardened and successfully transferred to pots in glasshouse exhibiting 86% survival at the end of 4–6 weeks. Whereas, regenerated plants from flower petal explants upon transfer to pots in glasshouse exhibited 75–82% survival at the end of 4–6 weeks.     

大白杜鹃组培与快繁研究——基本外植体和初代培养基筛选

以大白杜鹃茎尖、茎段、种子为试验材料,对大白杜鹃进行了初代培养研究。结果表明:茎段比茎尖更适合作为芽诱导培养材料;基本培养基以1/4 MS为宜,适合芽诱导培养基配方为1/4 MS+ZT 0.5 mg/L+NAA 0.01 mg/L,芽诱导率在92%以上。种子萌发培养基配方也为1/4 MS+ZT 0.5 mg/L+NAA 0.01 mg/L,萌发率达100%。     

Genotypic and exogenous factors affecting shoot regeneration from anther callus of linseed (Linum usitatissimum L.)

Summary The objective of this study was to investigate factors affecting the regeneration capacity of linseed anther culture. Four different environmental conditions in a phytotron were tested with regard to their effects on anther donor plants of cv. Hella. Anther response and shoot regeneration from anther callus was maximal when donor plants were grown in a 16 hrs-day at 14°C day/8°C night temperature. Anthers of four linseed genotypes were cultured on different media. Maximum shoot regeneration was achieved when the induced calli were transferred onto a modified N6 medium containing zeatin (1 mg l^-1). Most of the calli regenerated shoots in the second subculture on regeneration media. Shoots were rooted on modified B5 or MS media containing NAA (0.1 mg l^-1). Cytological examinations of incubated anthers and root tips of regenerated plants indicated that the anther calli were derived from microspores.Abbreviations B5 Gamborg's (1975) medium - BAP 6-benzylaminopurine - 2,4D dichlorophenoxyacetic acid - N6 Chu's (1978) medium - NAA -naphthaleneacetic acid - MS Murashige & Skoog's (1962) medium - ZEA zeatin     

Efficient In Vitro Shoot-regeneration Systems in Cassava (Manihot esculenta Crantz)

Two different protocols for in vitro regeneration of cassava using zygotic embryos and nodal axillary meristems have been developed. In both cases, buds were regenerated directly from excised explants without an intervening callus phase after a two-step culture procedure. In cotyledonary explants derived from zygotic embryos, prolific shoot formation occurred within 2—3 weeks on MS medium supplemented with 0.5—5 mg/1 BAP alone or in combination with 0.1 mg/1 NAA. Nodal explants with axillary meristems derived from aseptically grown seedlings or stem cuttings were used to initiate a round compact bulb-like structure on MS medium containing 10 mg/1 BAP. These latter structures, when cultured on MS medium supplemented with 0.1 mg/1 NAA, 1 mg/1 BAP and 0.1 mg/1 GA₃, produced multiple shoots. Somatic embryos isolated at the globular/torpedo stage from zygotic embryo explants were also capable of multiple shoot production on medium with 1 mg/1 BAP. Rooting of regenerated shoots exceeded 95 % in phytohormone-free MS medium. No change in their ploidy levels was observed. Therefore, the protocols developed should be of use in the particle gun and Agrobacterium-mediated genetic transformation of cassava.     

In vitro plant regeneration of non-toxic Jatropha curcas L.: Direct shoot organogenesis from cotyledonary petiole explants

Jatropha curcas, the energy plant has attained great attention in recent years because of its biodiesel production potential; however, oil and deoiled cakes are toxic. A non-toxic variety of J. curcas is reported from Mexico. A simple and efficient protocol has been developed for plant regeneration using cotyledonary petiole explants of non-toxic variety of J. curcas. The percentage of induction of shoot buds (59.11%), and the number of shoot buds (5.01) per explant was achieved on Murashige and Skoog’s (MS) medium supplemented with 2.27 μM thidiazuron (TDZ). These induced shoot buds multiplied when subcultured on MS medium supplemented with 10 μM kinetin (Kn), 4.5 μM 6-benzyl aminopurine (BAP), and 5.5 μM α-naphthaleneacetic acid (NAA) for 4 weeks and subsequent elongation achieved on MS medium supplemented with 2.25 μM BAP and 8.5 μM indole-3-acetic acid (IAA). Shoots more than 2 cm long were harvested and cultured on MS medium containing different concentrations and combinations of IBA, IAA, NAA, and 0.25 mg L^?1 activated charcoal, and 19.91% rooting was achieved in 15 μM IBA, 5.7 μM IAA, and 16.5 μM NAA after 4 weeks with more than 90% survival rate.