Concentrations Of Plant Growth Regulators Research Articles

Regeneration Technique of Bamboo Species through Nodal Segments: A Review

Micropropagation is an alternative technique to propagate at large scale plants to meet global plant demand. Various researchers have worked on the micropropagation technique to regenerate bamboo species by using nodal segments from years. Contamination, browning, necrosis, and acclimatization with physiological stress are the extreme problems of the micropropagation technique. But, many numbers of papers have been published on micropropagation of the bamboo species through nodal segments as explants. The proliferation of the bamboo shoots is dependent on the season of collection, size of explants, the position of explants, diversity of plants, concentration and combination of plant growth regulators, most adequate culture medium, environmental condition of the equipment, handling, and individual species. Bamboo is a monocarpic fast-growing, tall perennial grass and having the high potential to generate economic and social benefits. It helps to maintain land patterns and control soil erosion. The long life cycle of the bamboo produces a huge amount of seeds but unfortunately, mostly, they are non-viable. So, bamboos are propagated from vegetative by cutting and air layering. However, these methods are only for a small scale and they also tend to destroy large mother plant stocks and difficult to be transported. So, the in vitro propagation technique is useful to obtain large progenies from desired genotypes. Mostly, BAP and TDZ growth hormones are widely used for shoot multiplication and IBA, NAA and IAA are used for root initiation as per developed protocols in tissue culture for large scale production. This review intends to explore an overview of the recent literature reports to summarize the importance of micropropagation by using nodal segments of bamboo species and factors influencing it.

THE EFFECT OF ULTRAVIOLET (UV), BA, AND NAA RADIATION ON BRANCH EXTREMES TANACETUM PARTHENUIM L. PLANT GROWN OUTSIDE VIVO

The research was carried out in the plant tissue culture laboratory of the College of Agricultural Engineering Sciences for the period from February 2015 to August 2016, with the aim of studying the effect of UV treatment and some growth and interference organizations between them on the characteristics of vegetative growth. The experiment was carried out according to the complete random design (CRD) presented Seed to ultraviolet (UV.B) and for different periods of time 5,10,15,20 minutes, UV treatment for 15 minutes was the best and was adopted in conducting the experiment after which the plants were transplanted to MS medium equipped with different concentrations of Benzyl Adenine BA) ((0.0, 1.0, 2.0, 3.0 mg. L-1 ) interfered with Naphthalene Acetic Acid (NAA) (0.0, 0.1, 0.3, 0.5 mg. L 1- ) with 10 replicates per concentration. The dietary medium equipped with 1 mg. L - 1. of BA and 0.5 mg. L-1 . of NAA was better in increasing the number of vegetative branches and the soft and dry weight of exposed plants. UV (it recorded 7.300 branches. Plant 1., 1.996 g, 0.097 g respectively) compared to the measurement treatment for non-irradiated plants that were the lowest in achieving the increase, as it recorded 2.400 branches. Plant 1., 0.014 g and 0.010 g in succession . We conclude from the above that the treatment with ultraviolet radiation (UV) for a period of 15 minutes, treatment with different concentrations of plant growth regulators and their interaction had a significant effect on the growth characteristics of Tanacetum parthenuim L. planted tissue culture

Evaluation of sodium nitroprusside and putrescine on polyethylene glycol induced drought stress in Stevia rebaudiana Bertoni under in vitro condition

The present work aimed to regenerate Stevia rebaudiana Bertoni under in vitro drought condition induced by different concentrations (0%, 5%, 10 % and 15 %) of polyethylene glycol (PEG) 6000, and to investigate the mitigating effect of sodium nitroprusside (SNP; nitric oxide donor) and putrescine in relation to efficient multiplication. Varying concentrations of SNP (50, 100, 250 and 500 μM) and putrescine (0.05, 0.1, 0.3 and 0.5 mM), used singly or in combination in the MS medium, along with best selected concentration of plant growth regulator (kinetin 0.2 mg l−1) under in vitro drought imposed by 10 % PEG were taken for studies at 20, 40 and 60 days after inoculation (DAI). The best response with maximum values on the basis of morphological parameters was recorded; number of shoot and number of leaves were observed in half strength MS media supplemented with combination of both SNP and putrescine treatment i.e. SNP 100 μM + putrescine 0.05 mM followed by other treatments as compared to remaining treatments as well as control (10 % PEG only). On the basis of present investigation, it is concluded that in vitro drought stress significantly reduced the number of shoot, length of shoot (cm), number of leaves, number of roots, length of root (cm) and survival percentage. However, treatment with SNP and putrescine, alone or in combination, alleviated the negative impacts of drought stress up to a great extent. The production of more number of stevia leaves even under drought condition as a result of ameliorative treatment with SNP and putrescine has implication in R&D industries to target for production of maximum content of stevioside and rebaudioside, key principles in treating diabetes, if there is an increase in their content.

Influence of plant growth regulators and potassium nitrate on the qualitative parameters of acid lime (Citrus aurantifolia Swingle) during hasta Bahar in Northern dry zone of Karnataka

Qualitative parameters of acid lime (Citrus aurantifolia Swingle) were found to be influenced with the different concentrations of plant growth regulators and chemical during hasta bahar. GA3 @ 50 ppm in June - Cycocel @ 1000 ppm in September - KNO3 @ 2% in October resulted in maximum titrable acidity (7.19), total soluble solids (7.25), total sugar (1.81), reducing sugars (0.87), non-reducing sugars (0.94) and minimum number of seeds (8.06). However, the maximum juice percent (49.31) and least rind thickness were found in GA3 @ 50 ppm in June - Cycocel @ 2000 ppm in September - KNO3 @ 2% in October. Similarly, the maximum ascorbic acid (30.46) and least weight of seeds per fruit (0.62) were found in GA3 @ 50 ppm in June - Cycocel @ 1500 ppm in September - KNO3 @ 2% in October and GA3 @ 50 ppm in June respectively.

In vitro micro-propagation of Typhonium flagelliforme (Lodd.) Blume and its genetic fidelity using ISSR and RAPD markers

An araceous plant, Typhonium flagelliforme is in its extinct stage and require several ways to conserve its family. In the present study, an efficient In vitro protocol is established using apical meristem as an explant on basal Murashige and Skoog media supplemented with different concentrations of plant growth regulators. As an outcome, maximum number of multiple shoots (10.7±0.67) were generated on the media supplemented with 2.0 mg/L 6 - benzylaminopurine (BAP) and 0.5 mg/L α-napthalene acetic acid (NAA). The regenerated shoots were further sub-cultured on the fresh media containing 0.5mg/L BAP for elongation and proliferation. Media supplemented with 1.0 mg/L Indole-3-butyric acid (IBA) and 2% sucrose enhanced rooting in the proliferated shoots. In the process, an average of 90% plantlets survived, hardened and transferred to the field conditions. Further, genetic fidelity was exhibited among the tissue culture raised plants with the markers ISSR and RAPD. Thus, the modified tissue culture protocol and its standardization would be used for large-scale propagation and conservation of this medicinal plant.

CHIA SEED AS A SOURCE OF IN VITRO ESTABLISHMENT OF Salvia hispanica L. PLANTS

Technique of tissue culture for Chia (Salvia hispanica) micropropagation was achieved, this study investigated the impact of various concentrations of plant growth regulators on shoot multiplication and root induction with the Chia’s mature seed as a source explant. The highest percentage of shoot formation (80%), shoots number per explant(3.20) and shoot length(3.26 cm), were recorded on MS medium enriched with BAP(1.0 mgl-1) after eight weeks of seed culture. The optimal medium for the rhizogenesis was achieved on half strength MS medium fortified with 1.0 mgl-1 IBA after four weeks of culture, which had the highest rooting percentage (100%) with highest mean of roots number (5.6 roots per shoot) with (3.40 cm root length). The rooted plants were successfully adapted ex vitro with a survival rate of 85%.

An efficient protocol for regenerating shoots from paper mulberry (Broussonetia papyrifera) leaf explants.

Paper mulberry (Broussonetia papyrifera) is a tree species that has many economic, ecological, and social uses. This study developed an efficient protocol for regenerating shoots from leaf explants using Murashige and Skoog (MS) medium supplemented with different concentrations of plant growth regulators (PGRs), which play vital roles in shoot regeneration. The best result, 86.67% induction frequency and 4.35 shoots per explant, was obtained in the MS medium containing 2.0 mg/L N6-benzyladenine (BA) and 0.05 mg/L indole-3-butyric acid. The effects of explant age, orientation, and genotype were also investigated. Explants from young leaves had a greater regeneration frequency than those from old leaves, and the results were better when the distal end of the leaf explant contacted the medium versus the proximal end. Approximately 70.96% of the shoots rooted well in the MS medium containing 0.4 mg/L α-naphthalene acetic acid (NAA). Although some genotypes achieved poorer results, the regeneration protocol is still applicable for mass multiplication and genetic transformation.

Regulation of induction of phenylalanine ammonia lyase and its role in production of phenolic compounds in plants

Phenylalanine ammonia lyase or PAL is known to be the first committed enzyme of phenylpropanoid pathway which produces trans-cinnamic acid, the precursor of polyphenol biosynthesis. Some facts related to the physiology, enzymology and biochemistry of Phenylalanine ammonia lyase (PAL) from different organisms has been reviewed. Emphasis is given on the biological aspects of regulation of the induction of PAL by various stimuli and its role in producing polyphenolic compounds in plants. Levels of the enzyme are mainly affected by light, wounding, infection, ethylene level, concentration of plant growth regulators and metals. The possibility that PAL is involved in the control of polyphenol production has also been examined.

Genotype-specific requirements for in vitro culture initiation and multiplication of Magnolia taxa

Abstract The influence of basal media composition, concentration of plant growth regulators (PGRs), and the developmental stage of primary explants (dormancy, stage of bud opening and fruit ripening) on the initiation phase of nine Magnolia genotypes, including M. stellata /Sieb. & Zucc./Maxim., M. × soulangeana ‘Rustica Rubra’, M. denudata Desr., M. × soulangeana ‘Alexandrina’, M. liliiflora Desr., M. officinalis var. biloba Rehd. & Wils., M. salicifolia Maxim., M. × soulangeana ‘Lennei’, and M. kobus DC, was evaluated. The highest efficiency of primary culture initiation of seven Magnolia genotypes (except for M. liliiflora and M. salicifolia) was achieved from primary explants collected in the bud opening stage. A high positive correlation was found between total tannins and efficiency of the primary culture initiation at the fruit ripening stage (r = 0.833). Standardi and Catalano medium (S2) with 0.5 mg l−1 of 6-benzylaminopurine (BAP) was the most appropriate for multiplication of M. × soulangeana ‘Alexandrina’, whereas tissue cultures of M. × soulangeana ‘Lennei’ proliferated and grew better on S2 medium with 1.0 mg l−1 of BAP and 1.0 g l−1 of polyvinylpyrrolidone. The requirements for the composition of basal media and concentration of PGRs in the initiation and multiplication stages of micropropagation of various Magnolia species and cultivars are genotype-specific.

Production of high-Quality Ornithogalum thyrsoides cut flowers in one year from in vitro propagated plantlets influenced by plant growth regulators

The objective of this study was to investigate the optimum concentration of plant growth regulators for explants cultured in vitro to produce inflorescences of Ornithogalum thyrsoides ‘Chesapeake Starlight’ forcing directly from in vitro propagules in one year. Two sizes of explants (2 × 2 and 2 × 4 mm) were cultured on a Murashige and Skoog (MS) medium supplemented with 0, 1.35, 2.7, or 5.4 μM 2-(1-Naphthyl)acetic acid (NAA) and with 0, 3.3, 6.6, or 13.2 μM N-(phenylmethyl)-7H-purin-6-amine (BA); and with 0, 0.675, 1.35, or 2.7 μM NAA and with 0, 2.2, 4.4, or 8.8 μM BA at 21 °C. Explants propagated in a Petri dish were directly transplanted to 6.3 cm pots as a clump without separating plantlets from the explant (propagule), then transplanted to a tray, and forced at 16.5/16 °C (day/night). The number of days to flowering from the first and second scape (FS and SS, respectively) from the first, second, or third plantlets (FP, SP, and TP, respectively) formed from the clump of one explant was counted from the date of transplanting to pots, and scape length and diameter were recorded. Criteria for high-quality cut flowers were (1) flowering around 200–215 days in FS/FP and 230–245 days in SS/FP with a flowering rate of 90–100% in FS/FP and 70–80% in SS/FP, (2) a scape length greater than 50 cm in FS/FP and greater than 55 cm in SS/FP, and (3) a scape diameter above 8 mm. Based on these criteria, the optimum concentrations of NAA and BA were determined. High quality O. thyrsoides cut flowers flowering after 195–201 days, a flowering rate of 78–100% in FS/FP, and three or four scapes of SS/FP and FS/SP can be successfully produced from 2 × 2 mm or 2 × 4 mm explants cultured in MS medium supplemented with 1.35–2.7 μM NAA and 4.4–6.6 μM BA. This demonstrates that quality cut flowers can be produced in less than one year without separating plantlets grown in vitro as one clump which saves labor. Developing two scapes from each of two first plantlets may suggest competition for reserves of metabolites/endogenous plant hormones.

In vitro regeneration using twin scales for restoration of critically endangered aquatic plant Crinum malabaricum Lekhak & Yadav: a promising source of galanthamine

This study intended to develop a significant in vitro regeneration protocol for sustainable propagation, conservation and re-establishment of critically endangered aquatic plant species Crinum malabaricum Lekhak & Yadav (Malabar river lily). This plant is the natural source of galanthamine, the drug to treat Alzheimer’s disease. We present a scientific understanding, emphasizing the use of twin scales (separated from the large parent bulb) in direct regeneration of new shoots and proliferation of bulblets assisted by nutrients supply. The meristematic region of the bulb plate, present between the scales was activated using cytokinins to produce shoots (maximum 12 shoots per twin scale) on full strength Murashige and Skoog’s (MS) medium augmented singularly with 2.0 mg L−1 6-benzylaminopurine (BAP). Upon subculturing of shoots on diverse concentrations of plant growth regulators (BAP and IAA/NAA), BAP alone at 2.0 mg L−1 was served optimum for the better proliferation of shoots (53 shoots). The regenerated shoots were rooted in vitro on half strength MS medium fortified with various types of auxins. Highest number of roots (11.6 within 4 weeks) and bulblets (after 3 months) resulted with 1.0 mg L−1 Indole-3-butyric acid (IBA) under in vitro conditions. The rooted plants were hardened in the greenhouse and finally transferred to the natural stream with 83% survival rate. The SCoT (start codon targeted) and ISSR (inter simple sequence repeats) marker analysis of in vitro raised and mother plants confirmed the genetic stability of tissue cultured plants and the reliability of present protocol for C. malabaricum. It is the foremost report on in vitro regeneration and genetic fidelity analysis for restoration of this critically endangered aquatic plant using twin scale technique. The study could help in ex situ conservation, reintroduction and restoration of C. malabaricum population in its natural habitat. Crinum malabaricum is a critically endangered aquatic plant species and natural source of galanthamine. It is endemic to India and about 1000 plants only available in a private estate in the Western Ghats of India. In vitro regeneration protocol has been developed utilizing twin scales for conservation of this plant. It is the first report on effective in vitro propagation and bulblets formation in C. malabaricum.

Secondary metabolites in elaeocarpus grandiflorus cell culture in WPM medium with various concentrations of PGR

This study aims to analyze the influence of plant growth regulator (PGR) for secondary metabolites production in Elaeocarpus grandiflorus cell culture. Picloram (3.5, 5 and 7.5 ppm) and 2,4-D (1.5, 2.5 and 3.5 ppm) were used as PGR of cell suspension culture. Cell cultures were obtained from callus grown in liquid WPM medium with various concentrations of PGR. Culture is maintained in shakers at a speed of 120 rpm in dark conditions. Harvesting is done after the age of culture reaches 30 days. Extraction was done by the maceration method with methanol as a solvent. A qualitative test using a thin layer chromatography test (TLC) was conducted to analyze the presence of various secondary metabolites. Phenolic quantitative tests were performed using a spectrophotometer using gallic acid standard compounds. The results showed that the cell culture contained alkaloids, phenolics, terpenoids, flavonoids. All treatments showed the presence of phenolic with varying total phenolic concentrations. PGR affects the type and concentration of secondary metabolites produced by E. grandiflorus cell suspension culture.

Embryogenic callus induction of coffee [Coffea arabica L.] on several plant growth regulator concentration and incubation temperature

Clonal propagation using in vitro techniques to provide good quality seedling of coffee requires technological establishment, especially about the determinant factor for regeneration success. Therefore the study of regeneration methods in vitro in coffee plants needs to be done either through somatic embryogenesis or organogenesis. The purpose of this research was to obtain the optimal concentration of plant growth regulators and incubation temperatures to induce the embryogenic callus of coffee. The basic medium was used MS [Murasige and Skoog] with the addition of 1 g/L of active charcoal and 7 g/L of bactoagar. The experiment used a factorial completely randomized design. The first factor is the concentration of plant growth regulators consisting of 6 levels : 0.5 mg 2.4D L−1 + 1 mg TDZ L−1; 0.5 mg 2.4D L−1 + 2 mg TDZ L−1; 1 mg 2.4D L−1 + 1 mg TDZ L−1; 1 mg 2.4D L−1 + 2 mg TDZ L−1; 2 mg 2.4D L−1 + 1 mg TDZ L−1; 2 mg 2.4D L−1 + 2 mg TDZ L−1. The second factor is the incubation of temperature is consisting of 2 levels: 18°C and 26°C. Variables observed included: time of callus induction, percentage of callus induction, callus texture and callus color. The results showed that all medium tested only media with a concentration of 2 mg 2.4D L−1 + 2 mg TDZ L−1 which gave an optimal response to the percentage of callus induction which reached 100% with friable texture and yellowish-white. Based on observations it is also known that the incubation temperature of 26°C can induce callus faster than the incubation temperature of 18°C.

A Comparison of Chemical Profiles of Callus, Plant and Agarwood Extracts of Gyrinops walla using Thin Layer Chromatography

Agarwood produced by Gyrinops walla Gaertner, an endemic plant species of Sri Lanka, arguably the costliest wood, is used as a major constituent in cosmetic industries. Application of plant cell culture technique serves as the best alternative for the production of fragrance compounds of G. walla while ensuring the sustainability of the species. Using the advantages of plant cell culture and Thin Layer Chromatography (TLC), a preliminary study was carried out to compare the phytochemical constituents of callus and plant extracts (i.e stem, leaves, bark and agarwood) of G. walla. Different callus lines were developed on MS and modified MS media with reduced level of NH4NO3, supplemented with different combinations and concentrations of plant growth regulators and multiplied. Freeze dried samples were extracted with hexane, ethyl acetate and methanol and run on a TLC plate under different eluting solvent systems. A higher number of TLC spots were observed in the ethyl acetate extracts of all samples, under 15 percent methanol: chloroform solvent system. Based on TLC chemical profiles of all callus lines, MS media added with 1.0 mg/L BAP, 0.5 mg/L kinetin and 0.1 mg/L 2,4-D and ½ MS contained 1.0 mg/L BAP and 0.1 mg/L 2,4-D were selected as best lines. The extracts of the selected two callus lines matched with the fingerprint profiles of best plant samples i.e stem, bark and agarwood. Compounds present in the extracts of callus samples, plant samples and agarwood, appearing at Rf=0.56, 0.74 and 0.78, could be used as possible markers for G. walla. The chromatography profiling by TLC has proven the presence of similar phytochemical constituents in callus, plant samples and agarwood. Therefore, it can be concluded that plant cell culture technique guarantees the possibility to produce same compounds that are present in plant and agarwood of G. walla.

Effect of time of application and concentrations of plant growth regulators on growth and yield of sweet corn (Zea mays L.)

Plant growth regulator is one of the major factors affecting sweet corn growth and yield. Although many worldwide studies were done to evaluate the effect of this factor on sweet corn, it is still necessary to do more study to add knowledge in this area because environmental factors will have significant effect on growth and yield of sweet corn. Experiments were performed on August to December 2018 using split plot design with four replications. Analysis of variance (ANOVA) with probability value @ 0.05 using LSD was used to analyse the obtained data. Objective of the experiment was to increase quality component of high plant density using application of plant growth regulators. The experiment was carried out at Institute of Bioscience, UPM, Serdang with application of different type of plant growth regulators (IBA and GA3), different concentrations (0, 50 and 100 mg/l) and time of applications (vegetative and reproductive growth stages). A significant variation in growth rate when GA3 produced the tallest in plant height (4427.068 cm/week), while IBA produced optimum in stem diameter (16.420 cm/week) both at 100 mg/l at vegetative stage. Application of PGR during vegetative stage was the highly significant in cob weight (456.76 g) followed by reproductive stage (444.76 g). Indole-butyric acid produced the optimum significant results on cob length at 18.80 cm compared to gibberellic acid at 18.53 cm. Concentrations stated significant results with the highest was 100 mg/l on cob diameter at 5.66 cm followed by 50 mg/l at 5.46 cm and the lowest was 0 mg/l at 5.26 cm. For quantity components, application IBA at 100 mg/l during vegetative stage produced the highest yield per hectare at 51, 840 kg/ha. This experiment indicated that interaction of plant growth regulators and concentrations in two times of applications would optimize plant growth and afterwards increase yield components.

To study the effect of different concentrations of plant growth regulators on rooting of litchi (Litchi chinensis Sonn.) air layers

The present experiment entitled “To study the effect of different concentrations of plant growth regulators on rooting of litchi (Litchi chinensis Sonn.)) Air layers” was conducted at Punjab Agricultural University, Regional Research Station, and Gurdaspur during the year 2015-16 and 2016-17. The experiment was laid out in Randomized Block Design with thirteen treatments of different concentrations of plant growth regulators each of IBA and NAA i.e.1000ppm, 2000 ppm, 3000 ppm, 4000ppm, 5000ppm and 6000 ppm and replicated thrice with a unit of one plant in each replication of a treatment. The result showed that among different application of IBA (Indole-3-butyric acid), the 5000 ppm IBA treated layers took lesser days to root initiation (16days) and also gave better results with respect to all the parameters studied including per cent rooting (90.45%), number of roots (35.52), root length (12.5cm), percent survival (95.25), days to come leaf after detachment (12days), root thickness (1.62mm), fresh weight of root (3.35gm), dry weight of root(2.15gm),fresh weight of shoot (52.25gm), dry weight of shoot (32.25gm) and root: shoot ratio on dry weight basis (0.067) as compared to other treatments along with control. Similarly, among different treatments of NAA(1-Naphthaleneacetic acid), the 5000ppm NAA treated layers took lesser days to root initiation (20 days) and also gave better results with respect to all the parameters studied including per cent rooting (80.5), number of roots (30.25), root length (10cm), percent survival (84.2), days to come leaf after detachment (14), root thickness (1.42mm), fresh weight of root (2.75gm), dry weight of root (1.50gm), fresh weight of shoot (47.65gm), dry weight of shoot (27.42gm) and root: shoot ratio on dry weight basis (0.04) as compared to other treatments along with control.

Micropropagation of Lacy Tree Philodendron (Philodendron bipinnatifidum Schott ex Endl.)

The present study aimed to optimize the micropropagation of lacy tree philodendron using shoot tip explants. Axillary shoot regeneration was investigated in Murashige and Skoog (MS) medium with different types and concentrations of plant growth regulators, varied levels of MS medium salt strength, sucrose concentration, and light intensity and culture type. Adding 6-benzylaminopurine (BAP; 1 mg·L−1) significantly increased shoot multiplication compared with other cytokinins, and the combination of cytokinins and auxins [indole-3-butyric acid (IBA) and naphthalene acetic acid (NAA)], yielded more shoots than cytokinins alone, with the greatest number of axillary shoots (11.4 per explant) obtained using both BAP (1 mg·L−1) and IBA (0.5 mg·L−1). In addition, the use of half-strength salt concentrations significantly reduced shoot multiplication, and high sucrose concentrations (>30 g·L−1) reduced explant growth. High light intensity also reduced shoot multiplication and growth, owing to photoinhibition, and shoot multiplication was more efficient in gelled culture, whereas shoot growth was greater in liquid/bioreactor culture. The best rooting success (100%) and greatest root number and fresh weight were obtained using MS medium supplemented with NAA (1–2 mg·L−1). The resulting plantlets were successfully acclimatized, with a survival rate of 100%, and were morphologically similar to the mother plant.

TISSUE CULTURE OF Ficus carica VARIETY BTM-6

Ficus carica or commonly known as fig plant is a deciduous plant originated from southwest Asia and eastern Mediterranean. It has many benefits in medical field especially to treat diseases such as rheumatism and haemorrhoids due to its high laxative activity effect. The main objective of this study is to develop in vitro clonal propagation method for rapid production of Ficus carica variety BTM-6 plantlet using different plant growth regulators (PGRs) through shoot induction and multiplication, rootings and subsequent establishment in soil following acclimatization. Surface sterilisation of the explant was done using sodium hypochlorite as the disinfectant. Pre-treatment of the explants with carbendazim successfully reduced the occurrence of fungal contamination. To investigate the effect of plant growth regulators on shoot induction, explants were cultured in different concentrations of PGRs either singly or in combination. No shoot and root inductions were observed but calli were successfully induced on MS medium containing 2 mg/l BA only, 2 mg/l BA in combination with 0.5 mg/l NAA and MS media supplemented with 0.5 mg/l BA in combination with 0.5 mg/l NAA. A further in-depth study using other different types of plant growth regulators at various concentrations is required in order to establish a complete tissue culture protocol of this particular plant species.

Response of some soybean (Glycine max L. Merrill) varieties on flooded conditon with application of Benzyl Amino Purine (BAP) and Salicylic Acid (SA) in the R3 phase

Soybean production (Glycine max (L.) Merril) in Indonesia has fluctuation every year. The area of wetlands in Indonesia is about 24.5 million ha, but only about 8.5 million ha of wetlands are used as rice fields, the remaining 16 million ha have not been utilized. The study aims to determine the response of some soybean varieties on the application of benzyl amino purine (BAP) and salicylic acid (SA) in flooded conditions. The research initiated in research land of the Faculty of Agriculture Universitas Sumatera Utara, using the Randomized Block Design (RBD) with 3 treatment factors namely varieties consisting of 3 varieties (Demas 1, Dering 1 and Burangrang), the concentration of plant growth regulator consisting of 3 levels (control, 50 ppm BAP + 100 ppm of SA and 100 ppm of BAP + 200 ppm of SA) and the treatment of flooding stress consisting of 2 treatments (control and flooded). The results showed that the varieties had critical effect on the parameters of number of pods per plant and the weight 100 seeds. Synthetic plant growth regulator concentration had no effect on all the observation parameters, but flooding stress had significant induce on the parameter of number of pods per plant.

PRIMARY AND SECONDARY SOMATIC EMBRYOGENESIS OF CACAO: THE EFFECT OF EXPLANT TYPES AND PLANT GROWTH REGULATORS

<p class="abstrakinggris">The success of cacao somatic embryogenesis is affected by many factors, including the basal salt medium, the genotype, the explant type, and the concentration and composition of plant growth regulators (PGRs). The study aimed to evaluate the effects of PGRs composition on the primary somatic embryo (PSE) response and the effect of explant type and PGRs composition used in inducing PSE on the secondary somatic embryogenesis (SSE) response. PSEs were induced from basal petal and staminoid explants of MCC 01 and MCC 02 clones on DKW medium containing 2,4-D 2 mg l<sup>-1 </sup>+ kinetin 0.5 mg l<sup>-1</sup> or 2,4-D 2 mg l<sup>-1</sup> + kinetin 0.125 – 0.250 mg l<sup>-1</sup> + thidiazuron (TDZ) 2.5 – 5 µg l<sup>-1</sup> or 2,4-D 2 mg l<sup>-1</sup> + TDZ 10 µg l<sup>-1</sup>. Genotype, explant type, and PGR composition dependently affected PSE response. The best PSE response was obtained from staminoid explant of MCC 02 clone on medium containing 2,4-D 2 mg l<sup>-1</sup> + kinetin 0.5 mg l<sup>-1</sup> (20%, 9 embryos). The explant type and PGR composition used in inducing PSEs affect the SSE response. The highest SSE response of MCC 01 clone was obtained from petal explant with medium containing 2,4-D 2 mg l<sup>-1</sup> + kinetin 0.5 mg l<sup>-1</sup>. The formation of SSEs could increase the multiplication rate of MCC 01 clone by 7 times.</p>