Combinations Of Auxins Research Articles

Plant biotechnology for the conservation of Argania spinosa (Skeels L): optimising propagation and sustainable valorisation

ABSTRACT Argania spinosa, an endangered species from southwestern Morocco, is studied for preservation through plant biotechnology. The research aims to optimise argan tree propagation to boost production, preserve heritage, and use residual species. In vitro seedlings are transferred to a modified Murashige and Skoog medium with various phytohormones. Six combinations of auxins and cytokinins are tested for germination. Results show that a liquid medium with activated charcoal from argan shells promotes stem elongation. Meta-topoline at 0.5 mg L−1, combined with naphthalene acetic acid (NAA) at 0.2 mg L−1, enhances shoot growth, leaf formation, and callogenesis. Adding benzylaminopurine (BAP) at 0.1 mg L−1 and indole-3-butyric acid (IBA) at 0.02 mg L−1 to the medium elongates stems by 4.3 cm after 21 days. A 2000 ppm IBA concentration is key for a 90% rooting rate. These findings underscore plant biotechnology’s role in preserving and propagating argan trees, improving resource management, and supporting sustainability.

Effect of abiotic and biotic elicitors on vincristine accumulation in endosperm derived in vitro cultures in Catharanthus roseous (L.) G. Don

Catharanthus roseus (L.) G. Don (Apocynaceae) is a well-studied herb renowned for its in vitro culture as a source of the anti-cancer alkaloid, vincristine. However, despite the recognized advantages of triploid cells over diploid cells in terms of productivity, the triploid endosperm tissue of this important medicinal plant has not been utilized for in vitro culture initiation. In this investigation, zygotic embryos and endosperm tissues were cultured on Murashige and Skoog (MS) medium supplemented with various combinations of auxins and cytokinins. The medium containing 2.50 µM 6-Benzyladenine (BA) and 1.25 µM 2,4-Dichlorophenoxyacetic acid (2,4-D) proved to be the most effective for callus and cell culture formation. Ploidy analysis using ploidy analyzer confirmed that the endosperm-derived callus exhibited mixoploid, while the embryo-derived callus remained diploid. Liquid Chromatography Mass Spectrometry (LC–MS) analysis of callus and cell cultures grown on MS media with different combinations of auxins, cytokinins, elicitors, and precursors (both biotic and abiotic) revealed the accumulation of vincristine. Notably, treatment with a biotic elicitor derived from Aspergillus niger (300 mg/l) demonstrated superior efficacy in promoting the maximum accumulation of vincristine in endosperm-derived callus and cell biomass. These findings hold promise for the sustainable production of the anti-cancer alkaloid vincristine from endosperm-derived callus and cell cultures of Catharanthus roseus.

Effect of Plant Growth Regulators on Mass Propagation of Strawberry (Fragaria sp.)

Efficient in vitro regeneration protocols for strawberries are crucial for accelerating the propagation of superior cultivars and improving overall productivity through controlled manipulation of plant growth regulators. This study investigated the influence of different concentrations and combinations of plant growth regulators on in vitro regeneration process of strawberries. BARI Strawberry-1 runner tips were sterilized and placed on Murashige and Skoog medium (MS) supplemented with various combinations of cytokinins, including 6-benzylaminopurine (BAP) and kinetin (KIN), to initiate shoot growth. Notably, the combination of 1.5 mg/L BAP + 1.0 mg/L KIN led to the shortest duration for shoot initiation (9 days), resulting in the highest number of shoots per explants (6.33), longest shoot length (2.87 cm), and maximum number of leaves per shoot (4.00). Additionally, this combination also exhibited the highest rate of shoot regeneration (70.33%). Subsequently, the proliferated shoots were transferred to MS medium supplemented with various concentrations and combinations of auxins, specifically 3-indolebutyric acid (IBA) and 1-naphthaleneacetic acid (NAA), for root induction. The in vitro regenerated shoots cultured in MS medium supplemented with 1.5 mg/L IBA + 1.0 mg/L NAA showed the shortest duration for root formation (8 days), the highest number of roots per explants (4.00), and the longest root length (2.77 cm). Furthermore, this combination also resulted in the highest rate of root regeneration (40%). These findings contribute valuable insights for the mass production of healthy strawberry plantlets using in vitro culture techniques. J Bangladesh Agril Univ 22(2):178-184, 2024

Establishment of Efficient Protocols for In Vitro Regeneration of Hyptis Suaveolens (L.) Poit. Using Apical Shoots and Nodal Segments

The present work was undertaken with a view to standardize an efficient protocol for in vitro rapid propagation of Hyptis suaveolens. Shoot apices and nodal segments of H. suaveolens produced multiple shoot buds when cultured on MS medium supplemented with 1.5-3.0 mg/l BAP or Kn in the combinations with 0.5-1.0 mg/l IAA or NAA. Nodal explants exhibited highest proliferation (90%) and gave maximum number of shoots per culture (8.40 ± 0.18) on MS medium fortified with 1.5 mg/I BAP and 1.0 mg/l IAA. The shoot buds were elongated on MS medium fortified with different concentrations and combinations of auxins and cytokinins. Elongated shoot buds were further cultured in rooting media for root induction. One fourth MS medium -without PGR was - proved ·the most effective for - induction and proliferation of roots. The--rooted plantlets ·were 'established in the field through successive phases of acclimation and the survival rate was 70%. The Chittagong Univ. J B. Sci. 8(1&2): 99-105, 2013

Yield and Fruit Characteristics of Tomato Crops Grown with Mineral Macronutrients: Impact of Organo-Mineral Fertilizers through Foliar or Soil Applications.

The utilization of plant biostimulants has gained importance as a strategy by which to improve plant productivity and soil health. Two independent trials were conducted across two seasons (2021 and 2023) to evaluate the effects of foliar or soil applications of various commercial organo-mineral fertilizers (Futuroot®, Radicon® Amifort®) with biostimulant action that is exerted on yield and fruit characteristics of processing tomato crops (cv Taylor F1) that have been exposed to mineral macronutrients. These treatments were administered three times during the season: at the transplanting, pre-flowering and berry development stages. In the first trial, conducted in two fields characterized respectively by low and high fertility, foliar applications of Radicon®, which is based on humic acid and amino acids, increased the leaf greenness index SPAD compared with the control. Furthermore, the leaf green colour intensity (SPAD index), measured during the reproductive phases of the tomato exhibited a positive correlation (R2 = 0.726) with the marketable yield obtained. This increase in marketable yield was significant in the biostimulant treatment compared with the control in both soils, especially in the soil characterized by lower fertility (16.1%), when compared with the more fertile soil (6.8%). In the second trial, conducted in the low-fertility field mentioned above, soil applications of all biostimulants (Futuroot®, Radicon® and the combinations [Radicon® + Amifort-Plus®]) significantly increased the marketable yield by 27.8%, 13.5% and 27.7%, respectively, compared with the control. The most significant beneficial effects of both Futuroot® and [Radicon® + Amifort®] could be attributed to the combination of humic acids and auxins, cytokinins or microelements (Zn, Mn, MgO) present in the formulation of these products. Furthermore, the increase in marketable yield obtained when Radicon® was applied to leaves was higher (16.1%) than that observed with soil application (13.5%). In both trials, no relevant effects of biostimulant products were observed on most of the physicochemical characteristics of tomato fruits. In conclusion, the biostimulants based on humic acid and amino acids combined with chemical fertilizers tested in the present study and applied by fertigation were more effective in improving tomato yield, and therefore they can be recommended for efficient agricultural production.

Optimizing The Effects of Auxin and Cytokinin Combinations on Shoot and Root Induction of Dendrobium mussauense

Dendrobium mussaense, an orchid species of high ornamental value, was subjected to experimental treatments involving the addition of combinations of auxin and cytokinin, namely 2,4-D (2,4-dichlorophenoxyacetic acid) with BAP (6-benzylaminopurine) and 2,4-D with TDZ (thidiazuron). The research aim was to evaluate their effects on the emergence time of shoots and roots. The method used an experiment design with seven treatments. Among the treatments, the most effective was 2,4-D at a concentration of 1 mg/L combined with 0.75 mg/L of BAP. This treatment resulted in the shortest time for both shoot and root emergence. These findings underscore the importance of optimizing hormone combinations for efficient shoot and root induction in D. mussaense, providing valuable insights for orchid propagation and cultivation practices.

Effect of Different Plant Growth Regulators on In-vitro Micropropagation of Banana Cultivar Grand Naine (Musa spp.)

Banana (Musa sapientum) is one of the most important fruit crop cultivated in India. It is widely grown in more than 150 countries, producing on an average of 105 million tons of fruit per annum. Grand naine Banana variety is the most commonly cultivated banana with high yielding plantain. This variety mainly grown in the region of Uttar Pradesh state. Present study mainly focuses on the in-vitro micropropagation method which is described for banana cv. Grand naine. For this study, healthy sword suckers of three months old banana plantlets was used as explants. The explants was sterilized thoroughly and cultured on MS (Murashige and Skoog) media supplemented with the different concentration and combination of auxin and cytokinin like BAP, IAA and NAA which were used for the optimization of best plant growth regulator combination for multiple shoot generation and shoot growth. Among all the tested cytokinin 5 mg/l BAP along with 1mg/l IAA in medium concentration performed well and produced healthy shoots further at higher concentration of all tested cytokinin showed declining effect within the growth parameters. For the rooting purpose, MS media was supplemented with different levels of IBA, IAA and NAA. Results indicated that rooting was highly promoted in the medium supplemented with 0.5 mg/L IAA + 1.5 mg/L IBA.

Auxin and carbohydrate control flower bud development in Anthurium andraeanum during early stage of sexual reproduction

BackgroundFlower buds of Anthurium andraeanum frequently cease to grow and abort during the early flowering stage, resulting in prolonged planting times and increased commercialization costs. Nevertheless, limited knowledge exists of the mechanism of flower development after initiation in A. andraeanum.ResultsIn this study, the measurement of carbohydrate flow and intensity between leaves and flowers during different growth stages showed that tender leaves are strong sinks and their concomitant flowers are weak ones. This suggested that the tender leaves compete with their concomitant flower buds for carbohydrates during the early growth stages, potentially causing the abortion of the flower buds. The analysis of transcriptomic differentially expressed genes suggested that genes related to sucrose metabolism and auxin response play an important role during flower bud development. Particularly, co-expression network analysis found that AaSPL12 is a hub gene engaged in flower development by collaborating carbohydrate and auxin signals. Yeast Two Hybrid assays revealed that AaSPL12 can interact with AaARP, a protein that serves as an indicator of dormancy. Additionally, the application of exogenous IAA and sucrose can suppress the expression of AaARP, augment the transcriptional abundance of AaSPL12, and consequently expedite flower development in Anthurium andraeanum.ConclusionsCollectively, our findings indicated that the combination of auxin and sugar signals could potentially suppress the repression of AaARP protein to AaSPL12, thus advancing the development of flower buds in Anthurium andraeanum.

Temporary Immersion System as an Innovative Approach for In Vitro Propagation of Sorbus domestica L.

The genus Sorbus has maintained an extremely relevant role over time from a landscape and environmental perspective in many countries in the Mediterranean and Central Europe. Based on the requirements coming from the environmental policies provided in the European strategy Next Generation EU, Sorbus has been considered a valuable species to be introduced in urban and peri-urban areas. The purpose of this study was to propagate four Sorbus accessions selected in the Sicilian territory, Southern Italy, using the liquid substrate in temporary immersion bioreactors Plantform™. The results obtained showed that the presence of 1 mg L−1 mT in the substrate in combination with IBA 0.05 mg L−1 produced a significant number of shoots (4.7) and a greater length (2.2 cm). Among the accessions, there were statistically significant differences; the accession SN2 and SN1 produced more shoots (respectively, 4.0 and 3.6), and a greater length of the shoots was observed in the selections SN4 and SN3 (respectively, 2.4 cm and 2.3 cm). The relative growth rate (RGR) was significantly influenced by the presence of the culture substrate of the combination of cytokines and auxin; SN4 selection showed the best RGR results of 8.3 mg−1 d−1. The use of the bioreactor Plantform™ in Sorbus domestica L. has favored a better development of plants obtained in vitro, demonstrating that this system is a valid alternative for the micropropagation of Sorbus.

Optimization of conditions to achieve a high content of alizarin and purpurin in the adventitious roots of Rubia cordifolia L.

Rubia cordifolia L. (Indian madder) is a valuable medicinal plant known for its natural dye content, notably alizarin and purpurin, with applications in textiles and cosmetics. This study aims to optimize the concentrations of auxin, salicylic acid, elicitors, and precursors to maximize the production of alizarin and purpurin in adventitious roots. Various concentrations and combinations of auxins were systematically tested to explore their effects on the yield of adventitious root formation and dye compounds. Nodal explants cultivated in MS media supplemented with IAA + IBA + NAA (1.5 + 0.5 + 0.75 mg/L) at a pH of 5.7 exhibited the highest adventitious root production. Post-establishment of root cultures, the impact of salicylic acid, L-phenylalanine, elicitors (yeast extract, pectin, and Xylan), and the precursor α-ketoglutaric acid on the production of anthraquinones (AQ) was evaluated. High-performance liquid Chromatography (HPLC) analysis revealed enriched alizarin, purpurin, and total AQ content. The maximum amount of AQ (64.65 mg/g), alizarin (17.59 mg/g), and purpurin (19.61 mg/g) was observed when cultured on 30 mg/L of α-ketoglutaric acid, compared to other elicitors and precursors. This optimized condition provides valuable insights for the sustainable cultivation and utilization of R. cordifolia as a prominent source of natural dyes. It offers practical implications for the dye industry and its production.

An efficient approach of in vitro plant regeneration and propagation of Mungbean [Vigna radiata (L.) Wilczek

Mungbean [Vigna radiata L. (Wilczek)] is a valuable legume crop in Bangladesh. However, it faces severe difficulties forming viable roots during the growth stage. The successful root production of mungbean through an efficient tissue culture system has not been well established. Therefore, this study aims to investigate the problem of unsuccessful root formation in mungbean plants and to develop a very efficient method of in vitro regeneration using micropropagation. The BARI Mung-3 mungbean variety was used as an explant. Several shoots were produced from cotyledonary node (CN) explants obtained from 3-day-old seedlings that were germinated in vitro. The plant samples were cultivated on MSB5 medium enriched with 5.0 μM BAP. Shoot generation efficiency per plant was 5.36 ± 0.56 (80.08%). However, the viable root generation in a regulated setting was unsuccessful despite employing multiple combinations of rooting media, including full and half-strength MSB5 medium with different concentrations and combinations of auxins. To resolve this issue, a micrografting approach was applied with scion 3.0 cm in length and 14-day-old mungbean rootstocks. This system resulted in efficient shoots where the viable root generation efficiency rate was 55%. Interestingly, the micro-grafted plantlets successfully produced viable seeds. The successful micropropagation with viable root generation in mungbean plants successfully overcomes the difficulties in rooting and offers an efficient method for successful mungbean production. These new findings open new options for efficient plant generation with mass propagation for ready-smart mungbean production.

Direct Shoot Regeneration of Plumbago zeylanica Linn. through Tissue Culture Technology

ABSTRACT: Chitrak is scientifically known as Plumbago zeylanica Linn. belongs to Plumbaginaceae. Root shows medicinally valuable drug in pharmacological enterprise as the humanity is certainly prone to numerous contagious ailments due to ecological imbalance triggered by the current technology development. One of its remarkable phytoconstituents is plumbagin, a naphthoquinone molecule used to treat skin conditions, tumours, and tenacious chronic rheumatoid arthritis. The objective was to standardize the procedure of Plumbago zeylanica direct-organogenesis micropropagation. The solution contained various concentrations and combinations of auxin and cytokinins, and the nodal explant was used for quick micropropagation. The maximum multiple shoots (18.24 ± 0.51) per explant with shoot length 4. 2cm ± 0.20 cm was produced as the MS medium supplemented with B5 vitamins together with 2mg/l 6- Benzyleaminopurine (BAP) and 1mg/l Indole-3- acetic acid (IAA). The regenerated shoots were rooted in half strength MS medium with B5 vitamins that contained indole-3-butyric acid (IBA). The highest rooting frequency (100%) was seen in the 1.5 mg/l IBA-containing rooting media. The extreme roots were 9.2±0.14 per explant. The average root length was 4.2± 0.10 cm. The in vitro rooted Shoots were then transplanted in the field showing a 100 percentage survival rate.

Enhancing Gerbera Micropropagation Efficiency and Genetic Fidelity through Cytokinin and Auxin Combination Strategies

The present investigation was carried out to assess the impact of 6-benzyladenine (BA) in conjunction with Indole-3-butyric acid (IBA) on gerbera explant establishment under micropropagation. Additionally, the effects of BA, either individually or in combination with Kinetin (KIN), on shoot proliferation in two Gerbera cultivars, namely Kormoran and Dolores was experimented too. Throughout the experiment, various morphological changes were documented occurring during these micropropagation phases and also monitored potential genetic alterations using SSR markers. The studies revealed that the combination of BA and IBA yielded exceptional results, achieving a 100% success rate in explant regeneration within the shortest time frame. Notably, when BA and IBA were applied at lower concentrations, the number of shoots generated was reduced. However, the most substantial proliferation of shoots was observed when the growth medium contained 4 mg of BA and 0.5 mg of IBA per litre. Furthermore, our investigation into genetic fidelity using SSR analysis revealed no detectable polymorphism between the mother plant and the micropropagated plantlets in both the Gerbera cultivars, affirming the reliability of the micropropagation method in preserving genetic consistency.

Auxin and light-mediated regulation of growth, morphogenesis, and alkaloid biosynthesis in Crinum x powellii ‘Album’ callus

Crinum x powellii ‘Album’ belongs to the Amaryllidaceae medicinal plant family that produces a range of structurally diverse alkaloids with potential therapeutic properties. The optimal conditions for in vitro tissue growth, morphogenesis, and alkaloid biosynthesis remain unclear. Auxin and light play critical roles in regulating plant growth, development, and alkaloid biosynthesis in several Amaryllidaceae plants. Here, we have succeeded in showing, for the first time, that the combination of auxin and light significantly influence C. x powellii “Album” in vitro tissue growth, survival, and morphogenesis compared to individual treatments. Furthermore, this combination also upregulates the expression of alkaloid biosynthetic genes and led to an increase in the content of certain alkaloids, suggesting a positive impact on the defense and therapeutic potential of the calli. Our findings provide insights into the regulation of genes involved in alkaloid biosynthesis in C. x powellii “Album” callus and underline the potential of auxin and light as tools for enhancing their production in plants. This study provides a foundation for further exploration of C. x powellii “Album” calli as a sustainable source of bioactive alkaloids for pharmaceutical and agricultural applications. Furthermore, this study paves the way to the discovery of the biosynthetic pathway of specialized metabolites from C. x powellii “Album”, such as cherylline and lycorine.

Application of combination of auxins in callus induction and proliferation of shallot cv Trisula and Sumenep through in vitro technique

Shallot (Allium cepa L. var. aggregatum) is one of a strategic commodity in Indonesia. To increase of production of shallot seed, there needs a good tuber with high productivity tolerant to abiotic stress. One of the obstacles to increase of shallot production with tuber in good quality and tolerant to abiotic stress is not available. Tissue culture technique is one of the methods proved can propagate plant in large amounts and in a shorter time compared to the conventional method. The objectives of this research are to get the best media formulation for callus induction and proliferation. The explant used in this research are shoot tip of shallot from cultivar Trisula and Sumenep. The Media used were MS. The medium was enriched with (0,5 – 3 mg/l) 2,4-D + 2 mg/l picloram (0,5 – 3 mg/l) or NAA + with or without 3 gr/l Casein hydrolysate; and MS + 3 mg/l Picloram + 2 or 3 mg/l NAA + 3 g/l Casein Hydrolysate. The best media formulation for callus induction of Trisula variety was MS + 3 mg/l 2,4D + 2 mg/l picloram + 3 g/l Casein Hydrolysate, whereas the best media formulation for callus induction of Sumenep variety was MS + 0.5 mg/l 2,4-D + 2 mg/l picloram. The best media formulation for callusproliferation was MS + 0.5 mg/l 2,4-D + 2 mg/l picloram both Trisula and Sumenep varieties. These results could be used for plant propagation and breeding program of shallot in the future.

Growth of arabica coffee seeds (Coffea arabica L.) Sigarar Utang Variety as a response of treatment of various growth regulators and types of shade

Productivity of arabica coffee (Coffea arabica L.) Sigarar Utang Variety in Indonesia is still relatively low, especially in Simalungun Regency, Sumatera Utara. Some factors that need to be considered in nurseries are growth regulator and shade. This study aims to find out information on the type of growth regulators and the best shade density for the growth of arabica coffee seedlings. The experiment was carried out from March to June 2022 in Nagori Ujung Bawang, Simalungun Regency and Research Laboratory, Faculty of Agriculture, Universitas Sumatra Utara. The experiment used a Split Plot Design consisting of 2 factors and repeated 3 times. The first factor (main plot) consists of 4 levels, namely without shade, 50%, 70%, and 90% shade, while the second factor (sub-plot) consists of 3 levels are auxin growth regulator, cytokinin, and the combination of auxin with cytokinin. The results showed that the interaction of shade treatment and growth regulators had a significant effect on root canopy ratio. Root canopy ratio had a significant effect on the interaction of 90% shade treatment and a combination of auxin cytokinin of 5.27 g.

Shoot Culture of Ocimum sp. and Its Phytochemical Profile

The success of the in vitro culture technique is influenced by many factors, including the type of explants, culture medium and exogenous plant growth regulators (PGR). These factors greatly influence the speed and effectiveness of plant regeneration as well as the profile of the phytochemical compounds produced. Therefore, this study aims to determine the effect of the PGR combination on the growth response of in vitro node explants as well as the phytochemical profiles of Ocimum sp. Node explants obtained from 2 weeks old in vitro seedlings were cultured on MS medium with the addition of PGR, namely BAP and Kinetin (0.2 and 5 mg/l) combined with NAA (0.1 and 0.2 mg/l) and synthetic cytokinins alone namely Thidiazuron (TDZ) (1, 3, and 5 mg/l). The growth response of the explants and the potential for regeneration were observed for 8 weeks of culture. Effects of adding activated charcoal (AC) to root media were observed on growth of plantlets aged 2 weeks. Phytochemical profile of In vitro shoot was analyzed using GC-MS and LC-MS to be compared with its profile in in vitro callus tissue. The results showed that MS medium with the addition of a combination of cytokinin and auxin was able to induce shoot regeneration in node explants of Ocimum sp. in vitro. The Kinetin/NAA combination produced better shoot height growth, while the BAP/NAA combination produced a higher leaves number. Thidiazuron at all concentrations was able to induce shoots that were more likely to form rosettes. The addition of AC to the rooting medium did not have a positive effect on the response of shoot and plantlet growth. Chromatographic screening showed different profiles of secondary compounds in the callus and shoot tissues of Ocimum sp. in vitro. Callus composed of actively dividing cells do not produce some of the secondary compounds as produced by in vitro shoots. This shows the difference in the potential of cells or tissues in synthesizing secondary metabolites.

Conservation in Tissue Culture of Malacocarpus crithmifolius (Retz.) Fisch. C.A.Mey. - Relict Species from Mangyshlak

Malacocarpus crithmifolius is an endangered rare relict with small size populations grown in a limited area. The purpose of this study was to initiate in vitro and micro replication of Malacocarpus crithmifolius. The vegetative and reproductive explants and Murashige & Skoog medium (MS) supplemented with different concentrations and combinations of cytokinin and auxins were used. The response reaction of different explants and the plant growth regulators' effects on shooting frequency, the number of shoots, callusogenesis, and rooting percent were investigated. Culturing generative explants on the MS medium containing 6-Benzylaminopurine (BAP) combined with indole-3-acetic acid (IAA) or indole-butyric acid (IBA) led to direct shoot regeneration. The bud mass appeared in the leaf axil under inflorescences after one week of cultivation on the initiated medium. The replication was reached by micro-cutting of induced additional shoots and 3-fold passaging them on the fresh mediums. The average multiplication result at MS with BAP in combination with 1-Naphthaleneacetic acid (NAA) or IAA composed 5.85 after three months of cultivation. In conclusion, the applicable explant and phytohormonal composition of nutrient medium for initiation and micropropagation of M. crithmifolius were developed.

Response of various growth regulators and shade intensity to the growth of arabica coffee seedlings of Sigarar Utang variety

Abstract. Damanik RIM, Hanum C, Sembiring LJ. 2023. Response of various growth regulators and shade intensity to the growth of arabica coffee seedlings of Sigarar Utang variety. Nusantara Bioscience 15: 85-89. The productivity of Arabica coffee (Coffea arabica L.) of the Sigarar Utang variety in Indonesia is still relatively low, especially in Simalungun District, North Sumatra Province, Indonesia. Growth regulators and shade are some factors that must be considered in nurseries. This research aims to determine the best growth regulators type and shade intensity for Arabika coffee seedling growth. The experiment was conducted from March to June 2022 in Nagori Ujung Bawang, Simalungun District, and the Central Laboratory of Agriculture Faculty, Universitas Sumatera Utara, Medan, North Sumatra. The study used a Split Plot design of 2 factors and 3 replications. The first factor (main plot) consists of 4 levels, namely 0, 50, 70, and 90% shade intensity. The second factor (sub-plot) consists of the three growth regulator treatments, i.e., auxin, cytokinin, and the combination of auxin and cytokinin. The results showed that the interaction between shade intensity and growth regulators had a significantly different effect on increasing root length. The shade treatment significantly affected plant height, leaf area, and total chlorophyll content of leaves. However, it did not affect the stem diameter. A shade intensity of 90% significantly increased plant height, leaf area, and total chlorophyll content of leaves.

Plant Regeneration in Amorphophallus muelleri Blume. through Organogenic

Porang (Amorphophallus muelleri Blume.) usually used to functional food raw materials, caused its high glucomant content. Limitation of conventional propagation both vegetative and generative affected to decreasing of porang production to fulfil market demand. To solve the problem, plant tissue culture technique was chosen to rapid propagate bulbils of porang. So, the aim of this research to determine the combination and concentration of Plant growth Regulators (PGRs), such as 6-Benzylaminopurine (BAP), Naphthaleneacetic Acid (NAA), and Thidiazuron (TDZ) for quality of callus, also growth of callus and shoots for rapid propagation of porang, cause PGRs are one of factors that affect the success of in vitro propagation. Experimental design of this research was completely randomized designed with statistical analysis using analysis of variance (Anova) one way. Difference combination and concentration of cytokinin and auxin as manipulation variables, which several parameters growth of callus, shoots, and roots was observed to indicate the rapid organogenic of porang. The optimal shoot induction medium was Murashige and Skoog (MS) media with 5.0 mg.L-1 BAP and 0.2 mg.L-1 NAA on which number of shoots and shoot height reached 15±1.8 and (7.2±1.86) cm. After shoot formation stage, the proper media for rooting stage was determined, which was Murashige and Skoog (MS) media with 1.0 mg.L-1 NAA resulted the rooting rate reached 100% and roots appear earlier. Optimal combination and concentration of PGRs on micropropagation of Amorphophallus muelleri Blume. from bulbils explant should be known to increase the production of porang, which can fulfil the market demand.