Explants For Callus Induction Research Articles

Callogenesis of Moringa oleifera seed cotyledon

Moringa oleifera has gained much importance in the past two decades due to its multiple uses and benefits to agriculture and industries. All the parts of the moringa plant are used for medicinal and other purposes. The roots, flowers, bark, stem, leaves and seeds of moringa possess antimicrobial properties, and hence it’s being regarded as a miracle plant. Different combinations of growth hormones have been used for plant tissue culture studies in M. oleifera but the difficulty in predicting a suitable medium for callus induction using different growth regulators in different localities is a major challenge. Studying the effect of different concentrations of growth hormones on callus induction of M. oleifera seed cotyledon is necessary to develop a reliable protocol for callus induction which is a prerequisite for the source of new metabolites which are not present in the wild. The seed cotyledon of indigenous M. oleifera seeds was used as an explant for callus induction. Seeds were surface sterilized with 90% ethanol for 1 min, washed 3 times with sterilized distilled water, surface sterilized using 3.5% aqueous solution of sodium hypochlorite containing few drops of Tween-20 for 10 min, followed by rinsing three times with sterile distilled water. The cotyledon explant was cultured on MS medium supplemented with different concentrations of 6- Benzyl amino purine (BAP), 2, 4-dichlorophenoxyacetic acid (2, 4-D) and α-naphthaleneacetic acid (NAA). Callus formation was monitored for a period of 5 weeks. The highest callus formation (90%) occurred on medium containing 1.0 mg/L BAP + 2.0 mg/L 2, 4-D + 0.5 mg/L NAA while the lowest callus formation (66%) was on medium containing 1.0 mg/L BAP + 2.0 mg/L 2, 4-D + 1.0 mg/L NAA. There was no callus formation on the medium lacking plant growth hormones. The T2 and T4 hormone combination would provide the basis for callus culture for the production of bioactive compounds and further in vitro genetic transformation in M. oleifera.

Response of Different Explants for Callus Induction in Cucumber

In vitro regeneration of cucumber is relatively difficult for genetic improvement. In this regard, different concentrations of growth regulators and three types of explants (cotyledon, hypocotyl and leaf disc) were investigated for their efficiency on callus induction potential. Among different explants explored for callus induction with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D), leaf disc responded earlier (4.67 days) and showed higher percentage of callus induction (91.50%) with 2 mg/l 2,4-D supplemented Murashige and Skoog (MS) media. The same concentration of 2,4-D resulted in the maximum callus fresh (0.56 g) and dry weight (0.39 g) from leaf disc explant. Then the callus was transferred to untreated, 2.0 mg/l BAP + 0.2 mg/l NAA + 1.0 mg/l Kn, 2.0 mg/l BAP + 1.0 mg/l NAA + 1.0 mg/l Kn and 2.0 mg/l BAP + 1.5 mg/l NAA + 1.0 mg/l Kn fortified MS medium. After transferring the callus of different explants to shoot regeneration media containing different concentrations of 6-benzylaminopurine (BAP), 1-naphthaleneacetic acid (NAA) and Kinetin (Kn), only cotyledon callus started to regenerate shoot. The combination of BAP (2 mg/l) + NAA (0.2 mg/l) + Kn (1 mg/l) showed highest shoot regeneration percentage (67.77%) and the maximum number of shoots (5.12) per explant were recorded in the treatment combination of 2 mg/l BAP + 0.2 mg/l NAA + 1 mg/l Kn. These results provided a basis for the optimization of the callus induction protocol of cucumber for genetic transformation.

Explant, Medium, and Plant Growth Regulator (PGR) Affect Induction and Proliferation of Callus in Abies koreana

Korean fir (Abies koreana E.H. Wilson) is a unique Pinaceae tree species endemic in Korea. In recent years, it is believed that climate change has caused many of them to die. Therefore, it has become extremely important to protect and preserve this tree species. In this study, the possibility of callus induction using different explants, media, and plant growth regulators (PGRs) was studied. After the dormancy period in May 2020, needles and stem segments that grew from the leaf buds as the explants were collected from one-year-old shoots. The explants were disinfected and subsequently transferred to culture media supplemented with different combinations of auxins and cytokinins. These explants were cultured in the dark in a culture room with a 16 h photoperiod, day/night temperature of 24/18 °C, and 80% relative humidity. After 8 weeks, significant differences were observed in the callus induction and proliferation, as affected by the explant type, basic medium, and PGR. The stem segments were more suitable as the explants for callus induction than needles were. Furthermore, fluffy calli suitable for differentiating the regeneration buds were observed on the calli induced from stem segments. The Murashige and Skoog (MS) medium was the most effective of the three media used in this study, namely MS, Douglas fir cotyledon revised (DCR), and Quoirin and Lepoivre (LP) media, with the highest callus induction ratio of stem segments being 100.0%. The highest fresh callus weight was also observed on the MS medium (819.3 mg). Moreover, the PGR combinations of α-naphthaleneacetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), and 6-benzylaminopurine (6-BA) consistently exerted a positive influence on callus induction throughout this study. In addition, the advantages of these two kinds of PGR were reflected in callus proliferation. The callus proliferation ratio reached 1147.6% as compared to the initial fresh weight, with a high concentration of 2,4-D (3.0 mg·L−1). In conclusion, the MS medium was optimal for callus induction on the stem segment explants, and 2,4-D promoted callus induction as well as an increased proliferation ratio of callus in A. koreana.

Statistical optimization of in vitro callus induction of wild and cultivated varieties of Mucuna pruriens L. (DC.) using response surface methodology and assessment of L-Dopa biosynthesis

Mucuna pruriens L. (DC.), is a valuable, economically significant medicinal crop, known worldwide for producing the anti-Parkinson's drug Levodopa (L-Dopa). Itching property of the plant poses certain constrains in its conventional breeding, but, in vitro cell culture systems offer advantage in which controlled conditions can be used for the production of valuable compounds. In the current investigation, a simple and efficient method for callus induction from the wild (var. pruriens) and cultivated (var. utilis) varieties of M. pruriens is described. Juvenile leaves and roots obtained from 30 day old aseptically grown seedlings were used as explants for callus induction. The leaves were found to be the best explants for obtaining maximum callus within a short period of time in 2.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) supplemented Murashige and Skoog (MS) medium. White compact root callus was produced from var. utilis in 2,4-D (2.0 mg/L) and indole 3-acetic acid (0.2 mg/L) + benzyl amino purine (2.0 mg/L) containing media. Whereas, callus formation was not observed from root explants of var. pruriens. Central composite design–response surface methodology (CCD-RSM) experiment was designed to analyze the linear-model and quadratic model (including pair-wise and interactive effects) of each variable to study the maximum biomass production from leaf and root explants. In this study, 1.5 mg/L concentrations of BAP as well as 2,4- D in plant tissue culture medium resulted in maximum callus biomass (2.378) and L-Dopa % yield (0.635 %). L-Dopa content in these varieties was investigated by high performance-thin layer chromatography (HP-TLC) using the methanolic extract prepared from callus cultures of both the varieties and compared with natural plant parts. L-Dopa content was found to be higher in seeds obtained from the naturally grown plants of var. pruriens followed by var. utilis (> 0.55 % and 0.494 % respectively). From the result obtained it can also be ascertained that root callus can serve as a source of L-Dopa extraction commercially.

Effects of Plant Growth Regulators and Sugars on Ehretia asperula Zoll. et Mor. Cell Cultures

Background: Belonging to the Boraginacae family, Ehretia asperula Zoll. et Mor., called “Xa den”, is a precious medicinal plant also known as the “cancer tree” by the Muong ethnic group in Hoa Binh Province, Vietnam. Xa den has been demonstrated to inhibit the development of malignant tumors, reduce oxidation and enhance the human immune system. This research focused on examining friable callus induction from young stems of Ehretia asperula Zoll. et Mor. Methods: Samples of Xa den were less than two years old. Young stems with 2 to 6 leaves served as explants for callus induction. Explants placed on autoclaved B5 nutrients incubated at 25oC, in the dark. The testing factors were concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) and Benzyl adenine (BA), types and concentrations of sugars.Result: Friable callus was induced on B5 medium with 0.4 mg/L of 2,4-D, 0.1 mg/L of BA and 30 g/L of glucose at the highest rate (100%). Additionally, callus grew best after 5 weeks of culture weighing 0.194 g. Friable callus was used as material for cell suspension cultures. After two weeks, the Xa den cell suspension cultures contained single cells and small cell clumps. The liquid medium had changed from dark yellow to light brown.

An efficient protocol for mass multiplication of Centella asiatica (L.) Urban and determination of its phenolic content

The present study was focused on standardizing a protocol for callus induction as well as regeneration in Centella asiatica from leaf and stem as explants. Stem and leaf explants have been inoculated in B5 media supplemented with BAP (0.1-2.5 mg/l), kn (01-04 mg/l) and NAA (0.1-0.5 mg/l), 2, 4-D (0.2mg/l) for callus induction. The combination of BAP and NAA leads to the formation of green, brown, compact and friable calli while Kn and 2, 4-D induced brown calli. Highest shooting was obtained from BAP (1.5 mg/l) and NAA(0.5 mg/l).When the shoots were inoculated in half strength of B5 media fortified with 0.1 mg/l BAP and 0.5 mg/l NAA showed cent percent rooting with the highest number of roots per shoot (11.05 cm) and maximum root length (1.86 cm). Stem showed the best explants for callus induction as compared to leaf explants. A low concentration of plant growth regulators was unable to induced callus response in leaf and stem explants. Phenolic content analysis showed that calluses contain more amounts of phenol (0.81 mg/gmdw) as compared to both leaf (0.63 mg/gmdw) and stem (0.59 mg/gmdw) explants.

Construction of Plant Regeneration System of <i>Glycyrrhiza mongolicum</i> and <i>Glycyrrhiza</i> Xinjiang

In order to establish the plant regeneration system of  Glycyrrhiza mongolicum  and  Glycyrrhiza  Xinjiang, this study used hypocotyls, leaves, cotyledons and stems to inducing callus and regenerated plant, and it screen out the most suitable explants and the best medium for plant regeneration. The experimental results showed that MS+2.0 mg/L NAA+2.0 mg/L 6-BA was the best medium for callus induction and plant regeneration. Among these, hypocotyls and cotyledons are the best explants for callus induction. The tissue induction rate is higher than 90%. The rapid propagation system established in this study can provide the theoretical reference and practical guidance for the breeding and production of fine  Glycyrrhiza uralensis  Fisch. varieties.

Induction, Multiplication, and Evaluation of Antioxidant Activity of Polyalthia bullata Callus, a Woody Medicinal Plant.

Polyalthia bullata is an endangered medicinal plant species. Hence, establishment of P. bullata callus culture is hoped to assist in mass production of secondary metabolites. Leaf and midrib were explants for callus induction. Both of them were cultured on Murashige and Skoog (MS) and Woody Plant Medium (WPM) containing different types and concentrations of auxins (2,4-dichlorophenoxyacetic acid (2,4-D), α-naphthaleneacetic acid (NAA), picloram, and dicamba). The callus produced was further multiplied on MS and WPM supplemented with different concentrations of 2,4-D, NAA, picloram, dicamba, indole-3-acetic acid (IAA), and indole-3-butyric acid (IBA) media. The quantification of total phenolic content (TPC), total flavonoid content (TFC) and antioxidant capacity was further carried out on P. bullata callus, and the results were subjected to correlation analysis. Among the media, the WPM + 16.56 µM picloram (53.33 ± 22.06%) was the best for callus induction while MS + 30 µM dicamba was the best for callus multiplication. The TPC, TFC, and EC50 of DPPH scavenging activity were determined at 0.657 ± 0.07 mg GAE/g FW, 0.491 ± 0.03 mg QE/g, and 85.59 ± 6.09 µg/mL in P. bullata callus, respectively. The positive correlation between DPPH scavenging activity with TPC was determined at r = 0.869, and that of TFC was at r = 0.904. Hence, the P. bullata callus has an ability to accumulate antioxidants. It therefore can be a medium for secondary metabolites production.

Callus induction and adventitious bud differentiation of Cyclocodon lancifolius (Roxb.) Kurz

Background: Cyclocodon lancifolius (Roxb.) Kurz is a perennial medicinal and edible plant with a huge potential economic value. The wild resources of this plant are gradually scarce by the serious destruction of the habitat and the limitations of sexual reproduction. This is the first attempt to establish an in vitro reproductive system for the species.
 Hypothesis: The suitable plant regulator types and its mass concentration range, combined with the explants, can induce the development of plants at various stages. We expected to establish an in vitro regeneration system of C. lancifolius based on these factors.
 Species studied: Cyclocodon lancifolius 
 Study site and years of study: Yunnan Breeding and Cultivation Research and Development Center of Endangered and Daodi Chinese Medicinal Materials, Yunnan University of Chinese Medicine, from 2017 to 2019.
 Methods: The plant regeneration of C. lancifolius was established by single factor, L9 (34) orthogonal and complete combination experiments.
 Results: Stem segments were the best explants for callus induction on MS medium containing 0.05 mg·L-1 KT, 0.5 mg·L-1 6-BA and 0.5 mg·L-1 NAA. MS medium with 0.2 mg·L-1 TDZ and MS medium were used alternately as the culture method to conduct differentiation and proliferation of adventitious shoot. The optimal protocol for the rooting was MS medium combined with 0.1 mg·L-1 6-BA and 1.0 mg·L-1 NAA.
 Conclusions: A rapid propagation system of C. lancifolius was established which provided a possible solution for the protection of wild resources and artificial cultivation.

Protocol optimization for rapid and efficient callus induction and in-vitro regeneration in rice (Oryza sativa L.) cv. CO 51

CO 51 is a recently developed semi dwarf, short duration variety of rice popularly grown in Tamil Nadu. Optimization of tissue culture protocol for the variety was one of the most important steps required; in order to make the variety suitable for genetic transformation and gene editing techniques. Immature embryos of CO 51 have been used as explant for callus induction. The immature embryos were cultured on callus induction media (NB media) containing Naphthalene Acetic Acid (NAA) 1 mg l-1, 6-Benzylaminopurine (6-BA) 1 mg l-1 and various concentrations of 2,4 Dichlorophenoxy acetic acid (2,4-D). NB media supplemented with 2.5 mg l-1of 2,4-D have been found to show the highest callus induction frequency that is 94.4%. The calli showing desired features were transferred from NB media to pre-regeneration media (NB-PR) having 2,4-D (2 mg l-1), 6-BA (1 mg l-1 ), NAA (1 mg l-1) where the calli tuned goldenyellow. These calli were then transferred to regeneration media (RNM media) supplemented with 6-BA (3 mg l-1) along with various concentrations of NAA. RNM media with1 mg l-1 NAA showed the highest frequency of shoot induction that is 72.2% with an average of 12 shoots per callus.

Effect of Different Strenght of Medium on Germination and Seedling Growth of Tomato and Sucrose Effect on Biomass of Tomato Callus

Bioactive compounds of plant cell culture extracts are currently being looked at for its potential for the development of nutraceutical products. Tomato callus is known to have cytoprotective activity. The availability for explants and its callus production are two important things. This paper reports the effect of different strengths of medium on seed germination and seedling growth of tomato cv. Permata and sucrose effects on their biomass callus. Seeds were grown on 4 kind of germination media. Hypocotyl were taken as explants for callus induction in MS medium supplemented by 2.0 mg/l BA and 0.2 mg/l NAA, 3% sucrose, and subcultured after 20 days on medium with 6 variations of sucrose. The highest values ​​for tomato hypocotyl’s height were obtained from the ½ and ¼ MS, while the highest fresh weight was obtained from the MS 0. Both the fresh weight and dry weight of the callus increased along with increasing sucrose concentration. The explant age and biomass need to be a concern regarding what kind of callus that will be produced. Application of 5% sucrose concentration is recommended for callus production in this study.

Induction and Growth Kinetics Callus of Tomato (Solanum lycopersicum)

Plant callus extracts are potential to be developed as ingredient in skincare products. Tomato callus is supposed to contain protein-derivatives and or other components such as secondary metabolites that play a role in skin regeneration. Therefore the production of calli is important to be studied for callus sustainable supply. This research aims to obtain optimum medium for callus induction and to analyze tomato callus development anatomically. In vitro culture response was assessed in tomato plant (Solanum lycopersicum L. ‘Permata’) for optimum callus induction. Seeds were grown on ¼ MS medium for 10-15 days. Hypocotyl was excised and cultured on MS medium + 2 mg/l 2,4-D for 15 days as the explants for callus induction. Callus was transferred to MS medium with 8 variations of PGRs including the combination of BAP + NAA, and 2,4-D. Both fresh and dry weight was measured every 5 days over 60 days to establish the growth kinetics and growth efficiency of callus. Anatomic characters of calli were examined through paraffin-embedded method. The result showed of MS medium supplemented with 2.0 mg/l NAA and 0.2 mg/l BAP is optimum for tomato callus induction, based on highest number of the absolute growth rate on fresh weight (73.77% per day), dry weight (3.84% per day), and callus initiation time (5.56 days) achieved by the medium. Cells in the ground tissue of tomato hypocotyl are competent to be dedifferentiated into a callus. This research results were expected to find out suitable methods for tomato callus production in preparation for skincare uses.

Reliable and Efficient Agrobacterium tumefaciens-Mediated Genetic Transformation of Dianthus spiculifolius

Dianthus spiculifolius is a perennial herbaceous flower with strong environmental adaptability and is an important ornamental ground cover plant. In this study, seeds of D. spiculifolius were used as explants for callus induction, adventitious bud differentiation, and rooting by adding different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D), 6-benzyl aminopurine (6-BA), and naphthaleneacetic acid (NAA) to Murashige and Skoog medium. The calli generated were co-cultured with Agrobacterium tumefaciens EHA105 containing pBI121-GUS or pBI121-GFP plasmids for 30 min, and transgenic regenerated plants were obtained by kanamycin (30 mg · L−1) screening. RT-PCR confirmed the stable expression of the exogenous GUS and GFP genes in the D. spiculifolius. The β-glucuronidase (GUS) histochemical staining confirmed GUS gene expression in transgenic calli, adventitious buds, and regenerated plants of D. spiculifolius. The green fluorescent protein (GFP) visual analysis showed GFP gene expression in transgenic calli. Furthermore, subcellular localization analysis showed that the three organelle marker proteins were not only successfully expressed but also accurately localized to their corresponding organelles in D. spiculifolius callus cells. These results indicated a successful establishment of a reliable and efficient A. tumefaciens-mediated genetic transformation system, which will contribute to functional gene research and genetic improvement of D. spiculifolius.

Analysis of capsaicinoid biosynthesis pathway genes expression in callus cultures of Capsicum chinense Jacq. cv. ‘Umorok’

The placental tissue of the highly pungent chilli cultivar, Capsicum chinense Jacq. cv. ‘Umorok’, is used as explants for callus induction. Callus cultures were subcultured after every 32 days and growth curves for a period of six consecutive growth cycles were studied till a stable capsaicinoids producing callus cultures were obtained. The capsaicinoids content in placental tissue explants decreased gradually during the first 2 months of culture as the explants dedifferentiated to form friable callus while the biomass and capsaicinoid content did not show much change in the subsequent growth cycles. The maximum callus biomass of 7.8 g freshweight (FW) or 0.56 g dry weight (DW) per culture were obtained on the 24th day of every growth cycle and the maximum average capsaicinoids content (1.6 mg g−1 FW capsaicin and 0.78 mg g−1 FW dihydrocapsaicin) were obtained on the 20th day of every growth cycle. To investigate the underlying dynamics for capsaicinoid biosynthesis during callus formation, comparative gene expression analysis of the genes involved in capsaicinoid biosynthesis pathway were also studied by qRT-PCR analysis. When compared with placental tissue, all the studied genes showed reduced expression during callus formation, especially putative aminotransferase (pAMT) and pungent gene 1 (Pun1), which were extensively down regulated from the 3rd month onwards in the callus cultures. Therefore, the present study revealed that the down-regulated expression of mainly two putative genes in capsaicinoid biosynthetic pathway (pAMT and Pun1) resulted in lower accumulation of capsaicinoids in callus cultures compared to placental tissues of fruits. The present study reports the gene expression analysis of the genes involved in capsaicinoid biosynthesis pathway during callus formation from placental tissue explants of Capsicum chinense Jacq.

Effect of growth regulators on micropropagation, callus induction and callus flavonoid content of Rumex pictus Forssk

THE CURRENT study investigates the effect of growth regulators on micropropagation, callus induction and callus flavonoid content of Rumex pictus Forssk; an endangered medicinal plant. Various combinations of kintin (KIN), 6-benzylaminopurine (BAP), Thidiazuron (TDZ) and indole-3-butyric acid (IBA) were used for micropropagation from shoot tip explants. Murashige and Skoog (MS) medium containing 2mg L-1 BAP was the best for micropropagation where shoot formation frequency was 70% with 12.6 shoots/explant. The highest root formation frequency resulted on half-strength MS medium fortified with 2mg L-1 naphthalene acetic acid (NAA) or 1mg L-1 IBA. One mg L-1 2,4-dichlorophenoxyacetic acid (2,4-D) combined with 0.4mg L-1 BAP induced the highest callus mass production from the investigated explants, particularly 1st foliage leaf that was the best explant for callus induction and proliferation. The accumulation of flavonoids in callus was diminished by BAP but enhanced by increasing 2,4-D concentration in culture medium. To our knowledge, this is the first report of micropropagation and callus induction of this endangered medicinal plant which will help in its rapid mass production, conservation and in vitro production of secondary metabolites.

In vitro callogenesis induction of Guarianthe skinneri (Bateman) Dressler & W.E. Higgins (Orchidaceae)

Guarianthe skinneri (Bateman) Dressler & W.E. Higgins., is a native orchid from Mexico, considered as threatened species by NOM-ECOL-059-SEMARNAT-2010, mainly due to the disappearance of its natural habitat and the illegal collection during its flowering season. The aim of this research was to induce in vitro callogenesis from different type of explants, using phytoregulators, in order to look for a massive production technique to contribute to its conservation. We evaluated the leaf and pseudobulb marrow explants growing in semi-solid medium MS adding BAP, 2, 4-D, Kin, the interaction of BAP/2, 4-D/Kin/Sad and a control without any type of plant growth regulators. Statistical analysis showed the pseudobulb marrow explants are more suitable for in vitro introduction in comparison to leaf explants, since they perform a lower percentage of contamination (18.8% in marrow and 73.2% in leaves). Likewise, the pseudobulb marrow explants increased callus formation (10.8%) in comparison to leaf explants (7.6%). Regarding the phytoregulators employed, BAP have allowed to increased callus formation (17%) compared to other phytoregulators (7-10%). This is the first report, which proposes the use of pseudobulb marrow as explant for callus induction in G. skinneri.

Effects of explant type, growth regulators and light intensity on callus induction and plant regeneration in four ecotypes of Persian shallot (Allium hirtifolium)

To establish an efficient protocol for shoot regeneration from callus, the effects of explant type, growth regulators and ecotypes on callus induction of Persian shallot (Allium hirtifolium) were evaluated. The results showed that basal plate was the best explant for callus induction when cultured on medium supplemented with 1.5mgl−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5mgl−1 6-benzylaminopurine (BAP). The highest callus growth index (69.04%) was achieved on medium with 1.5mgl−1 2,4-D in Zanjan ecotype. In second experiment the effects of different cytokinines, light intensity and ecotypes on shoot regeneration of A. hirtifolium callus were investigated. The proliferated calli were transferred to MS medium supplemented with different cytokinins (6-benzylaminopurine, kinetin and thidiazuron) in combination with 1-naphthaleneacetic acid (NAA) to investigate their potential for shoot induction. Shoots regenerated at the highest frequency when calli were cultured on medium with 1mgl−1 TDZ and 0.5mgl−1 NAA in almost all ecotypes. Shoot regeneration significantly influenced by light intensity and the greatest of shoot induction (77.58%) and number of shoots per callus (16.94) were achieved under a light intensity of 60μmolm−2s−1. This optimized protocol will be useful for any future breeding improvement programs of Persian shallot using biotechnological means.

Response of five triticale genotypes to salt stress in in vitro culture

Salinity is one of the important abiotic stresses that restrict plant development. Triticale is a highly adaptable crop, known for its high-quality grain, yield potential, and resistance to disease. Responses of five cultivated genotypes (Ümran Hanım, Mikham 2002, Melez 2001, Tatlıcak, and Alper Bey) of triticale to salt stress were tested in callus and embryogenic callus formation in this study. Cotyledon explants were selected as explants for callus induction and embryogenic callus formation. The five tested triticale genotypes varied in their callus growth and embryogenic callus formation. Ümran Hanım, Tatlıcak, and Alper Bey were observed for better callus induction; similarly, the same genotypes responded with better embryogenic callus formation in the salt in vitro media. A significant decrease in embryogenic callus growth was observed under salt stress. Based on the responses to NaCl in terms of embryogenic callus, the five triticale genotypes were ranked in the order of Tatlıcak > Ümran Hanım > Alper Bey > Mikham 2002 > Melez 2001. More proline and sugar were accumulated in these five triticale genotypes than in control plants when all were subjected to salt stress. Proline level peaked at 200 mM while the lowest and highest content was obtained at 0-200 mM salt concentrations. The accumulation of soluble sugars was strongly linked to 0-200 mM salt concentrations. Antioxidant enzyme activities exhibited an increasing trend in response to the increasing concentration of NaCl.

Effect of explant type and surface sterilants on asepsis and survival culture for callus induction in peach

For the optimization of surface sterilization of explants and their in vitro establishment for callus, aseptic culture and survival of explants were measured. The present study was carried out to investigate the influence of explant type, various surface sterilants and their exposure time on the establishment of explants for callus induction in peach (Prunus persica L. Batsch). The leaf disc and intermodal segment explants taken from newly growing twigs of peach cultured on MS medium supplemented with BAP (0.5 mg/L) + 2, 4-D (2 mg/L) for callus induction after surface sterilization with various surface sterilents. The overall results suggested that the best sterilization treatment for culture establishment in peach explants was sequential exposure of explants to ethanol (70%) 30 second + HgCl2 (0.1%) 3 minute + NaOCl (1.0%) 3 minute resulting 63.34 per cent aseptic culture with 80.00 per cent survival of explants in both leaf disc and internodal segment comparatively suitable among all the five treatments. Further increase in exposure time to various sterilants resulted in significant reduction in survival of explants. Hence, ethanol (70%) 30 second + HgCl2 (0.1%) 3 minute + NaOCl (1.0%) 3 minute was used for surface sterilization of explants in peach for establishment of explants for callus induction.

An Efficient Callus Induction and Regeneration Protocol for a Drought Tolerant Rice Indica Genotype AC39020

Most of the cultivated indica rice genotypes are less amenable to genetic modifications due to their poor callus induction and regeneration potential. The prerequisite for genetic enhancement of indica rice genotypes by biotechnological approach is to develop an efficient protocol for callus induction and plant regeneration. In the present study, we established an optimized regeneration protocol for rice genotype AC39020, which is moderately drought tolerant with high root growth and biomass. To use this genotype in the crop improvement program the prerequisite is callus induction and regeneration protocol in this indica rice genotype. The mature seeds of AC39020 used as explants for callus induction on LS, MS and N6 media with different hormones and amino acid concentrations. LS basal media with 2.5 mgL-1, 2, 4-D and 500 mgL-1 glutamine showed 91.3% callus induction frequency. Subsequently the embryogenic callus was cultured on MS media supplemented with BAP, Kinetin, NAA, and TDZ. The MS medium supplementedwith 4mg L-1 BAP and 0.5 mgL-1 NAA showed 75% regeneration efficiency. Since regeneration in indica rice varieties is tedious, far-reaching, highly genotype-specific, we exposed the embryogenic calli for mild desiccation stress for 24 h and 48 h. The desiccation treatment for 48h increased shoot regeneration frequency from 16.7 % to 40.2 % compared to non-desiccated calli. The protocol developed was highly reproducible and this protocol can also be used for further improvement of this rice genotype through genetic modification.