Concentrations Of Plant Growth Regulators Research Articles

Successful shoot tip grafting of cacao (Theobroma cacao L.) due to the application of plant growth regulators on various concentrations

Cacao plays an important role in the Indonesia economy. Therefore, its production and area expansion have to increase to achieve maximum cacao productivity by the quality and superior cacao clones. Shoot tip grafting is one of the propagation methods to obtain superior cacao plants by applying Plant Growth Regulators (PGRs). Research on the effect of several PGRs with various concentrations on cacao (Theobroma cacao L.) shoot tip grafting was conducted at the Integrated Innovation Farmer Group, Belubus, Sungai Talang Village, Guguak District, Lima Puluh Kota Regency, West Sumatra from February until June 2022. This study aimed to determine the interaction between PGR type and concentration on the grafting success and growth of cacao shoot tip grafted seedling. The research was designed by a Factorial Completely Randomized Design with three replications. The first factor was the type of PGR, i.e., synthetic PGR (BAP), young corn seed extract, shallot extract, and young coconut water. The second factor was the concentration of PGR, i.e., 0%, 25%, 50%, 75% and 100%. The results showed an interaction between PGRs with some concentrations on the number of shoots, shoot length, and leaf length on the grafted cacao seedling. The natural PGR from young coconut water at a concentration of 75% gave the best effect on the number of shoots (3.33 shoots) and shoot length (24.50 cm) of cacao seedling.

Response of Dragon Fruit (Hylocereus sp.) Cuttings to Different Plant Growth Regulators.

Dragon fruit (Hylocereus sp.) is an exotic crop with a great potential for its cultivation in semi arid tracts throughout India. Its planting is mainly confined to harsh climates and degraded lands facing challenges in its establishment. Hence, availability of quality planting material is essential for attaining success. Due to long juvenile phase of the sexually propagated seedlings it can be propagated asexually by stem cuttings but proper rooting is not possible without exogenous auxin application. Hence, during 2022-2023 a research was carried out at the Horticultural Experimental area of Khalsa College, Amritsar to standardize the concentration of plant growth regulators viz. IBA, NAA and PHB for rooting and success rate in stem cuttings comprising of sixteen treatments with three replications arranged in randomized block design. The results revealed that the stem cuttings treated with IBA 4000 ppm proved to be superior for the sprouting and survival of the cuttings resulting in the improved vegetative growth with profuse, longer, thicker and the heaviest roots. Hence, the cutting treatment of IBA 4000 ppm can be proposed for dragon fruit plant propagation to meet the market demand in India.

Development of a Micropropagation Protocol for the Ex Situ Conservation of Nuttall's Scrub Oak (Quercus dumosa).

Worldwide, oak species are threatened with extinction due to habitat loss, pathogens, and changing fire regimes. Ex situ conservation through tissue culture may protect the remaining genetic diversity of Quercus dumosa, or the coastal sage scrub oak, from further loss. We designed three basal salt formulations based on the mineral composition of shoot tips and first leaves from mature Q. dumosa and explored carbohydrate source, stress-mitigating compounds, and plant growth regulator concentrations to develop a method of cultivating many Q. dumosa culture lines in vitro. All three novel basal salt formulations led to decreased necrosis compared with commercial basal salt formulas WPM, MS, and DKW. Substitution of 30 g L-1 sucrose with glucose and adding 250 mg L-1 ascorbic acid, 5.2 mg L-1 SNP sodium nitroprusside, and 103 mg L-1 y-aminobutyric acid improved culture health overall. In an experiment involving 115 culture lines, 0.66 mg L-1 6-benzylaminopurine produced the highest average shoots per explant, but 0.33 mg L-1 produced the greatest proportion of shoots 2 cm or greater. Incubation for 24 h in 20 mg L-1 indole-3-butyric acid led to the most rooting. These methods show promise for the ex situ conservation of many genotypes of endangered Q. dumosa.

PENGARUH PEMBERIAN ZAT PERANGSANG TUMBUH TERHADAP PERTUMBUHAN BIBIT TANAMAN GAHARU (Aquilaria malaccensis Lamk)  DI POLYBAG

This research was carried out in Penginjau Hamlet, Bathin II Pelayang District, Bungo Regency, at an altitude of ± 75 meters above sea level. The research was carried out from 05 January 2015 to 05 April 2015. This research aims to study to determine the effect of giving growth stimulants on the growth of gaharu plant seeds (Aquilaria malaccensis Lamk) in polybags. The aim of the research is to obtain a dose of growth stimulants that will give results to the growth of agarwood seedlings.The method used in this research was a completely randomized design (RAK), with 5 treatments and 4 replications. The concentration of Atonic growth stimulant used was as follows: A0: No treatment (as control), A1: 0.50 cc Atonic ZPT/liter of water , A2: 1.00 cc ZPT Atonik/ liter of water, A3: 1.50 cc ZPT Atonik/ liter of water and A4: 2.00 cc ZPT Atonik/ liter of water. The data obtained from the final observations were analyzed using variance, if they had a real effect then continued with the Duncan New's Multiple Range Test (DNMRT). The variables observed were plant height (cm), total leaf area (cm2), stem diameter (mm) and root volume (ml). From the experimental results, the administration of atonic plant growth regulator (ZPT) concentrations had no significant effect on plant height (cm), total leaf area (cm2), stem circumference (mm) and root volume (ml)

High frequency in vitro multiplication of polygonatum verticillatum (l.) All. From rhizome bud explants

This work aims to develop a rapid protocol for the in vitro establishment of Polygonatum verticillatum (L.) All., an astounding medicinal herb of Astavarga group of plants. Successful in vitro establishment was achieved utilizing rhizome bud segments of approx. 0.5 to 1.0 cm size as explants. Sterilized explants were cultured on MS medium containing graded concentration of different plant growth regulators used either singly or in various combinations. Maximum (85±10.0%) per cent shoot induction with maximum shoot length (6.50 ± 0.11cm) were recorded in TDZ (2.0 mg/l) + NAA(1.0 mg/l) + GA3 (2.0 mg/l) supplemented MS medium. NAA (1.0 mg/l) + Kn (0.5 mg/l) and IBA(1.0 mg/l) supplemented full strength MS medium with 3% sugar showed highest 70 ± 5.0% rooting response.½ MS+1.5 % sucrose medium augmented with IBA (1.0mg/l) showed the maximum average number of roots per explants (12.8 ± 1.07) with highest root length(6.12±0.27 cm). After hardening plantlets were transferred to pots in glasshouse produced healthy plants with 56% survival rate. Bangladesh J. Bot. 53(1): 203-208, 2024 (March)

Improvement of the potato seed production system on a virus-free basis in Almaty region

This article presents data on the induction of potato microtubers and the potency of different varieties to form microtubers in vitro. It has been established that the main factors influencing the process of tuberization in potato regenerated plants are: the concentration of carbohydrates and plant growth regulators in the nutrient medium and physiological state. Experiments were carried out to obtain microtubers from regenerated plants of 4 potato varieties of domestic selection (Alliance, Babaev, Miras and Pamyaty Konaeva) for the selection of virus-free primary material for seed production.As a result, a modified nutrient medium Murasige and Skoog (MS) containing 20 mg/L orotic acid was developed to accelerate the formation of microtuber formation of potato plants in vitro.

Induction, Proliferation and Differentiation of Callus in Paris polyphylla Sm. through Leaf Culture

Paris polyphylla Sm. is a vulnerable medicinal plant employed in the treatment of various ailments. This study seeks to establish a protocol for callus induction, proliferation, and differentiation of P. polyphylla. Immature leaf explants were cultured on MS medium with varying concentrations of plant growth regulators (PGRs), including 2,4-dichlorophenoxyacetic acid (2,4-D), kinetin (Kn), 6-benzylaminopurine (BAP), Thidiazuron (TDZ), α-Naphthalene acetic acid (NAA), and Gibberellic acid (GA3), along with 10% coconut water. After 12 weeks of primary culture, the optimal callus induction was observed in MS medium supplemented with 0.25 mg/l 2,4-D + 0.5 mg/l Kn. In the secondary culture at 8 weeks, the best callus proliferation, as determined by callus weight or growth index, occurred in MS medium supplemented with 2.0 mg/l BAP alone, 2.0 mg/l Kn alone, 1.0 mg/l TDZ alone, combinations of 2.0 mg/l Kn + 1.0 mg/l BAP + 2.0 mg/l GA3, and combinations of 0.5 mg/l NAA + 2.0 mg/l BAP + 2.0 mg/l GA3, as well as 10% coconut water. Furthermore, callus differentiation into mini rhizomes with root primordia was successfully achieved in MS media containing 2.5 mg/l Kn and 10% coconut water. This study reports, for the first time, the formation and differentiation of callus from leaf explants in P. polyphylla. Large-scale callus generation from leaf explants has the potential to enhance the production of bioactive secondary metabolites for therapeutic purposes and facilitate the development of plantlets through organogenesis.

In vitro propagation, cold preservation and cryopreservation of Taxus baccata L., an endangered medicinal and ornamental shrub

In vitro propagation, cold preservation, and cryopreservation are three essential approaches to preserve the genetic resources of red-listed plants, including English yew (Taxus baccata L.). Different concentrations of plant growth regulators (PGRs) and different pre-treatments of cold preservation and cryopreservation are the prerequisites of these three approaches. Apical bud as explant and Murashige and Skoog (MS) as the culture medium for all three sections of the research, kinetin (Kin) and indole-3-butyric acid (IBA) as PGRs for the micropropagation section, and encapsulation-dehydration as pre-treatment for the sections of cold preservation and cryopreservation were used. The results of the micropropagation section indicated that the highest number of shoots (5.40 per explant) and roots (5.98 per explant) were obtained from the culture of the explants on the media containing 1 mg L–1 IBA together with 1 and 2 mg L–1 Kin, respectively. The results of the cold preservation section revealed that the highest percentage of survival of germplasms (100%) after storage in the refrigerator was observed in the apical buds pre-treated by dehydration of encapsulated explants with 0.75 M sucrose for two hours, followed by dehydration under a laminar airflow cabinet for two hours. The results of the cryopreservation section demonstrated that the highest percentage of survival of germplasms (100%) after storage in liquid nitrogen was obtained in the apical buds pre-treated by encapsulation-dehydration under a laminar airflow cabinet for two hours. At the acclimatization stage, 100% of the plantlets acclimatized suitably with ex vitro conditions.

Effect of Plant Growth Regulators on Nutrient and Quality Changes in Zingiber officinale Rosc

Ginger is one of the oldest and renowned commercial spices well known for its medicinal and pharmaceutical value. Land degradation, availability of the quality rhizomes and diseases are some of the challenges faced in the ginger production. Since the productivity of a plant is influenced by a complex physiological process controlled by plant growth hormone balancing systems, the application of the growth regulators can have positive effect. Manipulating the PGR combinations and concentrations can lead to better quality and productivity in ginger. Hence, an experiment was conducted to study the effect of different plant growth regulators (PGRs) on nutrient and quality parameters in the ginger variety IISR Varada. Foliar spray of PGRs with 6-benzyl adenine purine (6-BAP), cycocel (Chlormequat chloride), gibberellic acid (GA) and paclobutrazol (PBZ) with five concentrations viz., 50ppm, 100ppm, 150ppm and 200ppm were applied 4th month after planting and water spray treated as control. Nutrients composition and biochemical components were observed on 5th month after planting and oleoresin was observed in the rhizomes after harvest. The results of pooled data over two years revealed that GA at 100 ppm recorded maximum nitrogen and chlorophyll content in leaves, potassium and protein in rhizomes. Regarding the oil content, maximum was noticed in treatment 100ppm Paclobutrazol followed by GA 100ppm.

Influence of different factors on in vitro multiplication and rooting of three local Juglans regia L. genotypes in Uzbekistan

The Persian walnut (Juglans regia L.) is one of the most lucrative and widely distributed nut crops. It is appreciated as a forestry and ornamental tree in addition to its benefits as a fruit crop. Although Central Asian countries, especially Uzbekistan, are among the origins of the Persian walnut; they are not considered as top industrial producers of walnuts. Uzbekistan possesses a wide range of walnut genetic resources and as a result of conducted research, several promising, fruitful, early-harvesting varieties and forms have been selected. The aim of this study is to optimize microclonal in vitro propagation of selected Uzbekistan local varieties and forms by evaluating concentrations of different plant growth regulators and genotype on multiplication and rooting stages. As mother plants, 2 forms and one variety were selected: the Ideal variety, 'Form PDM23' and 'Form 202YaKT'. ?n the proliferation stage, the growth rate of walnut microshoots on basal medium Driver and Kuniyuki Walnut Medium (DKW) with different concentrations of 6-benzylaminopurine (BAP) and Indole-3-butyric acid (IBA) (0.01 mg/L) was studied. The rooting stage was assessed in half strength macronutrient DKW medium containing different IBA concentrations (0.0, 2.0, 4.0 and 6.0 mg/L). The Ideal variety and 'Form PDM23' performed best in DKW medium supplied with 1.5 mg/L BAP and 0.01 mg/L IBA, whereas 'Form 202YaKT' performed best in DKW medium supplemented with 1.0 mg/L BAP and 0.01 mg/ L IBA for the proliferation stage. For all genotypes, 6.0 mg/L IBA provided the best rooting results.

Prohexadione-Calcium Mitigates the Overgrowth of Corn Seedlings

In the temperate climate of South Korea, specific corn varieties are cultivated using plug trays. The cultivation process is initiated from February to March within greenhouse facilities, maintaining a temperature below 10 degrees Celsius. Following this, in April, seedlings are transplanted to enable an exceptionally early harvest for increased profitability. However, the subsequent elevation in indoor temperatures leads to seedling overgrowth. This study explores the effectiveness of three plant growth regulators—paclobutrazol, prohexadione-calcium, and diniconazole–on super sweet corn seedlings. Significantly, the application of prohexadione-calcium at 2 ppm during the first leaf stage substantially reduces seedling height and impedes the growth of both the first and second internodes. This impact extends to leaf-related traits, manifesting reductions in the area, length, and width of the third leaf. Furthermore, prohexadione-calcium induces a significant decrease in both fresh and dried shoot weight, while simultaneously augmenting root weight. This alteration results in a noteworthy shift in the root–shoot ratio, particularly at 2 ppm. Subsequent experiments have identified the optimal concentration of prohexadione-calcium at 15 ppm, effectively mitigating overgrowth in both hybrid and inbred corn varieties. These findings provide essential insights for practitioners seeking to efficiently manage corn seedling overgrowth. The study contributes to understanding the retardant effect of prohexadione-calcium on various morphological traits, offering practical applications for optimizing plant growth regulator concentrations in corn cultivation strategies.

Development and Optimization of a Rapid In Vitro Micropropagation System for the Perennial Vegetable Night Lily, Hemerocallis citrina Baroni

The perennial herbaceous night lily, Hemerocallis citrina Baroni, is an important vegetable crop with an increasing production and consumption in China. The long lifecycle and slow growth of the night lily are becoming bottlenecks for the large-scale production of elite lines and various genetic and breeding studies. There is a lack of a protocol for rapid and efficient micropropagation for this crop. Here, we reported the systematic investigation and optimization of in vitro plant regeneration through tissue-culture-based organogenesis in the night lily variety ‘Datong Huanghua’. We evaluated various factors affecting the efficiency of callus induction and subculture, shoot regeneration, rooting and plantlet establishment, including explant type and age, inoculation methods, basal culture media and the type and concentration of plant growth regulator (phytohormones) in various growth media. We developed an optimized protocol, as follows. The highest efficiency of callus induction was observed on Murashige and Skoog (MS) medium supplied with 22.7 µM TDZ (thidiazuron) using the young scape (flower stem or stalk) as the explant, which was cut longitudinally in half to produce a segment approximately 0.5 cm in length. Callus subculture and proliferation were more efficient on MS medium containing 9.0 µM 2,4-D (2,4-dichlorophenoxyacetic acid) under light culture conditions. Shoot regeneration showed the highest efficiency on MS medium supplemented with 8.9 µM 6-BA (6-benzylaminopurine) + 5.4 µM NAA (α-naphthaleneacetic acid), while the best rooting medium was MS medium containing 2.7 µM NAA. After transplanting, the transplanted regenerated seedlings showed the highest survival rate (96%) on a substrate mixture with a 2:1:1 ratio of peat/perlite/vermiculite. A protocol and flowchart for the rapid in vitro micropropagation of night lily plants is proposed that will facilitate various genetic, genomic and breeding studies on this crop.

Machine learning-mediated Passiflora caerulea callogenesis optimization.

Callogenesis is one of the most powerful biotechnological approaches for in vitro secondary metabolite production and indirect organogenesis in Passiflora caerulea. Comprehensive knowledge of callogenesis and optimized protocol can be obtained by the application of a combination of machine learning (ML) and optimization algorithms. In the present investigation, the callogenesis responses (i.e., callogenesis rate and callus fresh weight) of P. caerulea were predicted based on different types and concentrations of plant growth regulators (PGRs) (i.e., 2,4-dichlorophenoxyacetic acid (2,4-D), 6-benzylaminopurine (BAP), 1-naphthaleneacetic acid (NAA), and indole-3-Butyric Acid (IBA)) as well as explant types (i.e., leaf, node, and internode) using multilayer perceptron (MLP). Moreover, the developed models were integrated into the genetic algorithm (GA) to optimize the concentration of PGRs and explant types for maximizing callogenesis responses. Furthermore, sensitivity analysis was conducted to assess the importance of each input variable on the callogenesis responses. The results showed that MLP had high predictive accuracy (R2 > 0.81) in both training and testing sets for modeling all studied parameters. Based on the results of the optimization process, the highest callogenesis rate (100%) would be obtained from the leaf explant cultured in the medium supplemented with 0.52 mg/L IBA plus 0.43 mg/L NAA plus 1.4 mg/L 2,4-D plus 0.2 mg/L BAP. The results of the sensitivity analysis showed the explant-dependent impact of the exogenous application of PGRs on callogenesis. Generally, the results showed that a combination of MLP and GA can display a forward-thinking aid to optimize and predict in vitro culture systems and consequentially cope with several challenges faced currently in Passiflora tissue culture.

Factors Affecting the Micropropagation of Sapindus trifoliatus from Nodal Explants of Mature Tree

Background:: Explant recalcitrance is one of the major challenges during the tissue culture of a tree species, especially when explants are derived from mature plants. It is mainly as-sociated with the genotypes/species, source and physiological status of explants, seasonal varia-tions, and competency/incompetency of explants towards PGRs for in vitro manipulations. There-fore, to optimize the appropriate conditions and minimize explant recalcitrance, it is necessary to elucidate the different factors influencing the tissue culture of a tree species. Objective:: Several factors influencing in vitro shoot induction from nodal explants derived from mature plants of Sapindus trifoliatus were investigated. Methods:: Nodal segment obtained from mature plants was used as an explant for shoot regenera-tion. The factors assessed in this study included the types and concentrations of plant growth reg-ulators, nutrient composition of MS (Murashige and Skoog) medium, sucrose concentrations, the position of nodes on their respective branches, seasonal variations, and successive transfers of mother explant. Results:: The performance of nodal explants was better on modified MS medium, i.e., M4 medi-um (half-strength of MS major salts and full-strengths of MS minor salts, Fe-EDTA and MS or-ganic nutrients each) than the full-strength MS medium. The addition of BAP in the medium re-sulted in a higher shoot induction rate than other cytokinins i.e., Kin, Zeatin, TDZ. M4 medium supplemented with 3.0 mg l-1 BAP and 2% sucrose was optimum for shoot proliferation. Howev-er, elongation of shoots was observed only when induced shoots, along with the mother explant, were subcultured on a medium containing 1.0 mg l-1 BAP. The shoot multiplication was positive-ly affected by the repeated transfer of the mother explant for different passages on the multiplica-tion medium. Mother explant transferred to multiplication medium (0.8% agar-solidified M4 me-dium + 2% sucrose + 1.0 mg l-1 BAP) proliferated maximum shoots after fourth passages. Regen-erated shoots were rooted in vitro and further successfully acclimatized in field conditions. Conclusion:: The in vitro regeneration system developed from an explant obtained from mature trees can be successfully exploited for mass multiplication of Sapindus trifoliatus, a medicinally and commercially important tree.

The appearance of amyloplasts as one of the features distinguishing the initial stages of the development of isolated endosperm in kiwiberry

The potency of plant cells’ reaction to dedifferentiation and then proliferation corresponds with cell reorganization. The details of cell modifications may rely on the fate of the cells. In this study, the characteristics of an endosperm and specific storage tissue under organogenic and non-organogenic development pathways were analyzed. The experimental system was based on isolated endosperm explants (with the seed coat and embryo removed) of kiwiberry cv. Bingo, placed on organogenic (OCIM) and non-organogenic (NOCIM) callus induction media that differed in the type and concentration of plant growth regulators. Histological and ultrastructural analyses of freshly isolated endosperm and explants afer selected periods of the culture were performed using stereoscopic, bright field, and transmission electron microscopy techniques. The dedifferentiation for both pathways– organogenic and non-organogenic – was similar at the morphological level for the first week of the culture. The histological and ultrastructural analyses revealed limited amyloplasts in the cells on OCIM. e organization of proliferated tissue differed significantly from two weeks of the culture: it was more compact for OCIM and looser for NOCIM. Additionally, at this period, there were more amyloplasts with starch granules in dedifferentiated cells on OCIM. The limited starch granules in proliferated cells on NOCIM were observed only afer four weeks of the culture. The presence of plastids with starch granules depends on the competence of endosperm-derived callus in kiwiberry to organogenic processes and can be an early marker of callus destination.

In Vitro Seed Germination and Seedling Development of Mimusops laurifolia (Forssk.) Friis.: An Endangered Plant Species

Mimusops laurifolia (Forssk.) Friis is an endangered medicinal plant and natural propagation of this plant through seeds is found to be very difficult due to its hard seed coat. To conquer this problem, an efficient in vitro seed germination as well as subsequent in vitro regeneration technique has been developed in conserving this endangered plant species. Seed germination was achieved on half strength of MS (HMS), full strength MS (FMS) and MS medium supplemented with different concentration and combination of Plant Growth Regulators (PGR) like BA, Kn and GA. The highest seed germination rate (18%) was obtained from water soaking de-coated seeds inoculated on full strength of MS (FMS), on the other hand, 12% germination of seeds was recorded on HMS medium, but both the conditions required more than 90 days to germinate. A similar rate of germination was also found on MS with PGRs, but it required 55-60 days. Best responses towards seed germination with elongated shoots (2.8 cm and 3.0 cm) were obtained when seeds were inoculated on MS with 3.0 mg/l BA, 0.5 mg/l Kn and 0.2 mg/l GA. After a long period of period of 8 months following germination, seedlings produced elongated tap roots only. Rooted seedlings were successfully transferred to soil for their further growth and development. Apart from this, for in vitro regeneration of shoots, explants of nodal segments and shoot tips from the natural plant were cultured on woody plant medium (WPM) supplemented with various combination and concentration of BAP, Kn and TDZ. In these cases, there was no positive response recorded towards the initiation of shoots from nodal segment and shoot tips. Plant Tissue Cult. & Biotech. 33(2): 143-153, 2023 (December)

Micropropagation from cotyledonary explants of grapefruit (<i>Citrus</i> <i>paradisi</i> Macf.) by indirect and direct organogenesis

Grapefruit (Citrus paradisi Macf.) is an economic fruit crop worldwide cultivated for its nutritional value, and aromatic flavours. However, the development of new varieties and high production of quality seedling constitutes a limit to improving grapefruit yields. An efficient regeneration protocol could be of great interest for grapefruit transformation, micropropagation, and germplasm conservation. In vitro plant regeneration systems of Citrus paradisi have been studied by using cotyledonary explants. Different concentrations of plant growth regulators were used to explore the organogenic potential of cotyledonary explants under laboratory conditions. For indirect organogenesis using cotyledon segment explants, a low concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) lead to the formation of white callus, while a high concentration of 2,4-D induced brown callus and adventitious root differentiation. The best response for callogenesis was obtained on Murashige and Skoog (MS) medium supplemented with 2 mg/L of 2,4-D. Only brown callus cultured on MS added with 2 mg/L 6-benzylaminopurine (BAP) has regenerated shoots, but the percentage of callus producing shoots was very low (6.66 ± 2.68%). Regarding direct organogenesis from the cotyledonary node explants, the best response for shoot proliferation was observed on MS supplemented with 4 mg/L BAP (86.66 ± 12.58% of explants regenerating shoots, and an average number of 5.45 ± 0.45 shoots per explant). Low percentages of In vitro rooting of regenerated shoots were observed with different concentrations of α-naphthalene acetic acid (NAA) or indole-3-butyric acid (IBA). Nevertheless, the highest rooting percentage (13.33 ± 2.88%) was obtained on MS containing 2 mg/L NAA. These results provide new information for mass regeneration and the production of healthy seedlings, and can be applied in grapefruit improvement programs.

The effect of exogenous plant growth regulators on elevated Cd phytoremediation by Solanum nigrum L. in contaminated soil.

Maximizing amendment potential is an emphasis in the HM-contaminated field of phytoremediation by hyperaccumulators due to the low bioavailability of HMs in soils and small biomass yields of plants. This study investigated the influence of different types and concentrations of plant growth regulators on Cd phytoremediation by Solanum nigrum in contaminated soil. Our conclusions showed that the shoot Cd extractions (μg plant-1) and the root and shoot biomasses at all the treatments remarkedly increased compared with that of the CK (p < 0.05), while the Cd concentrations at root and aboveground parts by S. nigrum, the extractable Cd concentrations, and pH value of soils did not change significantly compared with the CK (p < 0.05). Furthermore, correlation analysis showed that the shoot Cd phytoaccumulation and the root and aboveground biomasses of S. nigrum were particularly dependent upon the application of CTK and GA3 concentration gradient (p < 0.05). Moreover, some related physicochemical indexes were determined for supervising the growth conditions of plants, and these results pointed out that after exogenous PGRs treatments, the chlorophyll content and antioxidative enzymes POD and SOD activities in vivo of plants clearly advanced, while the H2O2 and MDA contents and CAT apparently declined. These consequence demonstrated that the exogenous PGR addition prominently reinforced the Cd phytoextraction capacity of S. nigrum in contaminated soil by stimulating plant growth and increasing shoot yields.

Growth and Yield of Tomato (Lycopersicum esculentum Mill.) Due to Application of Hormonic PGR and NPK Fertilizer

Tomatoes have high economic value with community demands increases every year. However, the productivity of tomatoes farmers in Indonesia can not meet the demands of Indonesian consumers. Efforts to solve low productivity in tomatoes cultivation can be made through certains cultivation techniques. The intention of this study is to acquire appropriate combination of “Hormonik” Plant Growth Regulator (PGR) concentrations and NPK fertilizer dosages for the optimum growth and yield of tomato plants. This study used a factorial experimental method with a completely randomized design (CRD). The first factor is Hormonik PGR concentrations (H) in 4 different treatment levels that consist of control variable (no PGR added) (H0), 6 ml/l (H1), 7 ml/l (H2), and 8 ml/l (H3). The second factor is NPK fertilizer dosages (N) in 4 different treatment levels that consist of 24 g/plant (N1), 32 g/plant (N2), 40 g/plant (N3), and 48 g/plant (N4). This study showed that combination of 6 ml/l Hormonik PGR and 40 g/plant of NPK fertilizer provide the highest number of fruits per plant by 49.0 and the weight of fruit per plant by 1,572.3 g. Keywords : Concentration of Hormonik PGR, Dose of NPK Fertilizer, Production, Tomato.

Regeneration of Cattleya Amazing Thailand in ½ MS Medium with The Addition of Several Concentration of PGR and Coconut Water

One of the Cattleya species with aesthetic and commercial value is Cattleya Amazing Thailand. An efficient protocol with a high rate of plantlet regeneration is through in vitro culture. Plantlet regeneration is affected by the addition of a Plant Growth Regulator (PGR). Auxin and cytokinin (2,4-D and BAP) combined with PGR from organic material such as coconut water can increase the growth of leave and roots in plantlet regeneration. The research aims to determine the best PGRs combination in regenerating the  Cattleya Amazing Thailand orchid in vitro. The research used the Completely Randomized Design (CRD) experimental method for five treatments. The parameter are survival rate, number of leave, and number of roots. Survival rate was analyzed descriptively and both of number of leave and roots were analyzed statistically. All treatments can form 100% plantlets on survival rate parameter. The treatment of 0.1 mg/L 2,4-D + 1 mg/L BAP gave significantly different results in the number of leaf (9.0) and was not significantly different in the number of root. 0.1 mg/L 2,4-D + 1 mg/L BAP is the best combination for in vitro regeneration of the Cattleya Amazing Thailand orchid.