Highest Number Of Roots Research Articles

Micropropagation of Camptotheca Acuminata Decne (Nyssaceae) - Endangered Ornamental and Medicinal Tree

Camptotheca acuminata Decne (Nyssaceae) (happy tree, tree of life, cancer tree) is a rapidly growing deciduous and endangered tree endemic to east Tibet and southern China (Liu et al., 2002). C. acuminata is an ornamental tree with monopodial growth, beautiful leaves and shade- and cold- tolerant in their natural environment. Recently, its demand has grown rapidly due to secondary metabolites production like Camptothecin and its derivatives with anti cancer and antivirus activity. The aim of the present study was to develop an efficient protocol for in vitro micropropagation of this valuable plant. Different cultural media based on both MS (Murashige and Skoog, 1962) or DKW (Driver and Kuniyuki, 1984) formulations with different cytokinins (6-benzylaminopurine, BAP or 2-isopentenyladenine, 2iP or meta-topolin, mT) have been involved. The aromatic cytokinin meta-topolin stimulated plant growth. The optimum multiplication rate of Camptotheca shoots occurred on the DKW basal medium, supplemented with 2.5 µM meta-topolin, grown under mixed LED light. The highest number of roots per plantlets was recorded on the rooting medium with 0.3 mgl-1 NAA.

Improving Net Photosynthetic Rate and Rooting Depth of Grapevines Through a Novel Irrigation Strategy in a Semi-Arid Climate.

Direct root-zone irrigation (DRZ) is a novel subsurface irrigation strategy initially tested in vineyards for economizing water and securing grape production in arid regions with unstable climatic patterns. However, studies are lacking on the responses of grapevine leaf carbon assimilation and deep rooting patterns to the novel irrigation strategy, which are essential for optimizing grapevine growth and alleviating extreme water stress during periods of heat and drought. Thus, a two-year field study was conducted in a commercial vineyard of Cabernet Sauvignon (Vitis vinifera L.) under a semi-arid climate in Washington, USA to compare the differences in leaf gas exchange and root distribution along the 0–160 cm soil profile, combined with measurements of specific leaf area and total carbon and nitrogen content in leaves and shoots to compare DRZ and traditional surface drip irrigation (SD) under three watering regimes. Compared to SD, significantly higher rates of net CO2 assimilation, stomatal conductance and transpiration in leaves, which positively correlated to midday stem water potential, were found in grapevines irrigated through DRZ in both years. Meanwhile, DRZ reduced total root number by 50–60% and root length density (RLD) by 30–40% in the upper 60 cm soil at high (0.75–0.80 crop evapotranspiration) and moderate (0.60–0.65 crop evapotranspiration) irrigation rates, but no significant differences were found at low (0.45–0.50 crop evapotranspiration) irrigation rate between DRZ and SD. Higher root number and RLD were detected under DRZ within 60–160 cm soil depths, accompanied by a decreased ratio of total carbon to nitrogen content in leaves with slightly increased specific leaf area. Decreased rainfall and increased temperature in 2018 possibly amplified the positive effects of DRZ. Our study indicates that grapevines under DRZ could develop deeper roots for water uptake, which helps ameliorate water stress and improve the photosynthetic rate as well as enhance grapevine adaptation to semi-arid climates.

Pioneer and fibrous root seasonal dynamics of Vitis vinifera L. are affected by biochar application to a low fertility soil: A rhizobox approach

The present work analyzes the impact of biochar-induced modification of soil physico-chemical properties on intra-annual growth dynamics of pioneer and fibrous grapevine roots. A scanner inserted into a buried rhizobox with a transparent side facing the plant root system was used to acquire images of pioneer and fibrous roots of control and biochar-treated plants throughout the vegetative season. Images were analyzed with ImageJ software to measure root traits. Biochar treatment increased soil pH, nutrient concentration, and water content during the driest and warmest period, while bulk density was reduced. Analysis of both pioneer and fibrous root traits highlighted a single peak of growth during the vegetative season. Pioneer roots were thicker and grew faster than fibrous roots, which were longer and more numerous. Amelioration of physico-chemical properties of biochar-amended soil stimulated an earlier root lengthening, and a higher root number at the onset of the season, which resulted in a greater canopy development compared to control plants. Later, in summer, as a consequence of the higher water content of biochar-treated soil, plants modified their root architecture, lowering the number of fibrous roots probably because of the reduced need to exploit soil for water and nutrient uptake.

PENGARUH WAKTU PERENDAMAN STEK BATANG VANILI DALAM ZAT PENGATUR TUMBUH ROTOONE – F TERHADAP PERTUMBUHAN VANILI (VANILLA PLANIFOLIA ANDREWS)

This study aims to determine the effect of immersion time with the vanilla stem cuttings of plan growth regulators Rotoone – F of credit for the growth of roots and shoots of vanilla cuttings. The treatment used in this study is A0 (without immersion), A1 (immersion time 5 min), A2 (soaking time 10 min), and A3 (soaking time 15 min) variable observation in this study is the number of shoots, root number, number of The firs day of growing shoots, shoots length, root length, root diameter, wet weight and dry weight of cuttings of vanilla. The result showed that root growth best to treatment with the immersion time of 15 min (A3) is indicated by the highest number of roots, root length and diameter to treatment with the highest root of soaking time 15 min (A3) in 14 to 28 HST HST. The result showed that the growth of shoots best to treatment with the immersion time of 15 min (A3) is indicated by a number of days the first shoots to grow the fastest, most number of shoots, shoot length, wet weight and dry weight of the highest in treatments with soaking time 15 (A3) in 14 HST to 28 HST.

Effects of vegetation indices, auxin, and biostimulator treatments on the rooting of Rhododendron pulchrum cuttings

The objective of our study was to develop a protocol enabling the use of vegetation indices to evaluate the rooting of Rhododendron pulchrum cuttings . Six root growth parameters were recorded after those cuttings were exposed to rooting media for 47 days. Among plants with different of soil-plant analysis development (SPAD) and normalized difference vegetation index (NDVI) values, those with higher values exhibited significantly higher values for the root number, root length, and root dry weight, suggesting that reflectance indices were useful in measuring the root growth parameters of R. pulchrum cuttings. Another aim of this work was to study the effects of a plant growth regulator (PGR) and biostimulant on rooting for cutting propagation. Treatments with indole-3-butyric acid (IBA) of 2000 mg×L -1 alone and combined with 1-naphthaleneacetic acid (NAA; 2000 mg×L -1 ), salicylic acid (SA; 10 -4 M), and thiamine (TA; 800 mg L - 1 ) were applied to cuttings of R. pulchrum . The same observations on six different rooting parameters were recorded and analyzed after cuttings were exposed to rooting media for 99 days for the auxin test, and 62 days for the SA and TA tests. Compared to NAA, IBA enhanced root growth and development as determined by increases in all parameters, and therefore it was used thereafter. Successful results for the root number and root dry weight were achieved using cuttings of R. pulchrum with a combination of IBA and SA. In addition, the mix of IBA and TA resulted in higher root numbers. These combined treatments are recommended for establishing stem cuttings for raising R. pulchrum plants in the nursery.

Genotypic Variation of Different Maturity Groups of Maize (Zea mays L.) for Seed Physiological Quality

Maize genotypes of different maturity groups with good seed quality had been developed, but there is little or no information on how the seed quality of the maize genotypes are affected by their maturity groups. Therefore, the objectives of this study were to evaluate maize varieties of different maturity groups for seed quality and determine genotypic variations that exist within the different maturity groups of maize for seed quality. Laboratory experiments were conducted in the Seed Science Laboratory of the Department of Crop Production and Protection, Obafemi Awolowo University, Ile-Ife, Nigeria. Seeds of sixteen maize genotypes of different maturity groups were subjected to imbibition, germination, accelerated ageing, conductivity and seedling vigor tests. The late maturity group (TZLCOMP.4DTF2,TZLCOMP. 1C6/DT.SYN-1-W, WHITEDTSTR/TZLCOMP.1-W, OBASUPER1) gave the best viability, speed of germination and days to complete germination while the extra early maturity group (2009TZEE-ORISTRQPM, 2000SYNEE-WSTR,2013TZEE-WDTSTR, TZEE-WPOPDTC2STRC5F2) had the least performance. The early (2014TZE –YDTSTR, 2013DTESTR–WSYN, EVDT-2000STRC0, 2009DTEWSTRSYN) and extra-early maturity groups had the longest root length and highest root number respectively. However, the different maturity groups of maize evaluated imbibed water at the same rate. TZEE-WPOP DT STR C5 F2, 2013 DTE STR – W SYN, AFLATOXIN R-SYN2, TZL COMP.1 C6/DT. SYN-1-W among extra early, early, intermediate and late maturity groups respectively performed best for viability and vigor tests.

Evaluation of explants for in vitro propagation of Citrus indica Tanaka - An Endangered Species

Of the five explants viz., shoot tip, nodal segment, leaf disc, cotyledon and root tip excised from exegenic seedlings of Citrus indica Tanaka shoot tip cultured in MS supplemented with 0.5 mg/l of BAP generated shoots within 4.74 days, exhibiting highest percentage of response (85.82%) with highest number of shoots (8.9) and shoot length (3.04 cm). On the other hand nodal segment cultured in MS supplemented with 1.0 mg/l BAP showed 80% response in 5.16 days with a shoot number of 5.41 and shoot length of 2.43 cm. Cotyledon explants inoculated on MS supplemented with1.0 mg/l of TDZ produced shoots in 20 days with the highest response of 69.88%, with 3.77 shoots per cotyledon and shoot length of 2.03cm. Viable callus was obtained from leaf disc cultured on half strength MS medium with less Ca++ with 2, 4-D 0.5 mg/l + Kn 0.25 mg/l. This callus when inoculated on half strength MS medium with Kn 1.5 mg/l showed highest shoot bud proliferation of 66.66% with 10.06 shoots per callus. Root tip explant failed to produce any shoots. In vitro raised shoots of Citrus indica when cultured on half strength MS medium supplemented with NAA (1.0 mg/l) showed 80 % rooting in 5.66 days, with highest number of roots (6.16 per shoot) and longest root (3.78cm). Ninety per cent of in vitro rooted plantlets of Citrus indica survived in open conditions.
 Plant Tissue Cult. & Biotech. 30(1): 87-96, 2020 (June)

Growth Response of Croton (Codiaeum variegatum pictum L.) to Aloe Vera Gel and Indol-Butyric Acid in Different Propagation Media

Croton is a species of plant in the genus, Codiaeum, which is a member of the family, Euphorbiaceae. They have a wide range of variations in leaf shape and coloration that have fascinated breeders, landscapers, horticulturists, and gardeners and a huge number of cultivars have been fixed for commercial production. Because of this crotons are in very regular demand and there is the need for fast propagation methods, with low cost and that assures the formation of vigorous, high-quality seedlings. The study, therefore, assessed the growth response of croton cuttings to different growth media and plant growth hormonesviz: Aloe vera gel and IBA. A 3x3 factorial Randomized Complete Block Design (RCBD) made up of three growth media (coco peat, sawdust, and topsoil) and two levels of growth-promoting hormones (Aloe vera gel and IBA) and a control was used. The study was carried out at the Multipurpose Crop Nursery at the College of Agriculture Education, Mampong Campus. Data was collected on sprouting response, the number of leaves, and the number of roots. The results indicated that the different growth media and hormones influenced sprouting response of croton at days to 50%, 70%, and 100% sprouting significantly (p > 0.05). Croton cuttings that were grown on topsoil and treated with Aloe vera gel recorded earlier days to sprout. The number of leaves and roots was higher among croton cuttings grown on topsoil and treated with Aloe vera gel. On the other hand, croton cuttings grown on sawdust recorded the least number of leaves at 28, 42, 56, and 70 DAP.). The results were similar for the number of roots. The study concluded that croton cuttings that were grown on a combination of topsoil and Aloe vera gel resulted in the earliest shoot response and a higher number of roots and leaves followed closely by those of IBA.

DEVELOPING AIR LAYERING PRACTICES FOR PROPAGATION OF DRACAENA MARGINATA LAM. UTILIZING PHLOROGLUCINOL AND SEAWEED EXTRACT AS IBA-SYNERGISTS OR ALTERNATIVES

In an experiment laid out in completely randomized block design, eight experimental treatments representing all-possible combinations between indole-3-butyric acid potassium salt at 300 ppm (IBA), phloroglucinol at 300 ppm (PG) and seaweed extract (SWE) at 2 ml/l were evaluated for their effects on rooting of Dracaena marginata Lam. air layers. The research was conducted under shade house conditions of the Nursery of Ornamental Plants, Faculty of Agriculture, Assiut University, Egypt during 2018 and 2019 successive growing seasons. All treated air layers with IBA, PG and SWE each alone or in combinations recorded significant increases in rooting percentage comparing to untreated control air layers. The highest rooting percentages were found in air layers received 10 ml/air layer from PG alone or the IBA + SWE or IBA + PG + SWE without significant differences between them. Air-layers exposed to IBA alone or in combination with PG and/or SWE attained the most favorable root traits in terms of high number of roots with appropriate length and a balanced mass and volume. High carbohydrate concentrations positively correlated with rooting percentage and roots weight and volume. Studying correlations between rooting characteristics and the internal contents of root zone tissues of total carbohydrates and total phenolics exhibited that rooting percentage correlated positively with total carbohydrates percentage and negatively with total phenolics in root zone tissues. While, the relationships between the other root traits of succeeded layers and total carbohydrates and total phenolics contents in rooting zones did not attain any significant relations.

Micropropagtion and DNA-barcoding of the endangered endemic Phlomis aurea plant of Saint Katherine

Saint Katherine is considered a “biodiversity hotspot” because of the high level of endemism of reported plant species. In this study, conservation of the endangered endemic plant; Phlomis aurea of Saint Katherine, Southern Sinai, Egypt, was carried out through micropropagation and DNA barcoding. The first efficient micropropagation protocol for Phlomis aurea was established as a mean of ex situ conservation of the plant. Shoot tips and nodal segments of in vitro germinated seedlings were established on Murashige and Skoog medium supplemented with 0.54 µM β-naphthalene acetic acid (NAA) and 2.46 µM N6-(2-isopentenyl) adenine (2iP) in combination with 6-benzylaminopurine (BA) or kinetin (Kin). The medium supplemented with 3.48 µM Kin considered optimum for both explants. For multiplication, BA was the most efficient cytokinin. The percentage of rooted explants reached 100% at the concentration of 14.7 µM indolebutyric acid (IBA), whereas the highest number of roots was recorded for 4.90 µM, which considered the optimum concentration with a percentage of 80% of rooting. Rooted plantlets were transplanted in the greenhouse with 75% survival rate. The present study also aimed to carry out DNA barcoding of Phlomis aurea for accurate identification to provide a database for establishing an efficient conservation program for the plant. Three chloroplast DNA markers were used [ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL), maturase K (matK) and RNA polymerase C1 (rpoC1)] and all were successful in amplifying target regions, however the performance of both rbcL and matK markers seemed to be species‐specific. The similarity percentage was maximum for rbcL (99.81%) and matK (100%) compared to the database of the same species.

ASYMBIOTIC SEED GERMINATION AND PLANTLET DEVELOPMENT OF Dendrobium spectabile (Blume) Miq.

Dendrobium spectabile (Blume) Miq. is one of Papuan orchids that is of economic value and threatened. At present, the optimal protocol for asymbiotic seed germination and planlet development of D. spectabile is not yet available. This research aimed to develop an optimal and comprehensive protocol for in vitro culture of D. spectabile to support the conservation and reintroduction of this species. The experiment was conducted using a completely random design, including seed sowing, protocorm subculture (subculture 1), plantlet subculture (subculture 2), and plantlet acclimatization. The highest germination rate at 3 MAS (months after sowing) was found in modified Knudson's C (92.59%). The first subculture at 4 MAP (months after planting) showed that the highest leaf and root growths were found in modified Vacin and Went (4.12 and 2.13, respectively). The second subculture at 6 MAP showed that the highest leaf growth was found in full strength of Murashige and Skoog supplemented with 100 g/l banana homogenate (5.49), while the highest number of roots and average root extension were found in half strength of Vacin and Went supplemented with 100 g/l banana homogenate (7.05 and 0.47 cm, respectively). The plantlets were best acclimatized in media consisting of tree fern fibre and sphagnum moss (2:1).

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.

Evaluation of vegetation indices and plant growth regulator use on the rooting of azalea cuttings

ABSTRACT The objective of our study was to develop a protocol enabling the use of vegetation indices to evaluate the rooting of Azalea (Rhododendron pulchrum cv. Sweet) cuttings. Six root growth parameters were recorded after exposing those cuttings to rooting media for 47 days. Among plants with different soil-plant analysis development (SPAD) and normalized difference vegetation index (NDVI) values, those with higher values exhibited significantly higher number of roots, root length, and root dry weight, suggesting that reflectance indices were useful in measuring the root growth parameters of the cuttings. Another aim of this work was to study the effects of plant growth regulators (PGRs) on rooting for cutting propagation. Azalea cuttings were soaked in the treatments with indole-3-butyric acid (IBA) at 2,000 mg L-1 or combined with 1-naphthaleneacetic acid (NAA; 2,000 mg L-1), salicylic acid (SA; 10-4 M), and thiamine (TA; 800 mg L-1). The same observations as SPAD and NDVI on six different rooting parameters were recorded and analyzed after cutting’s exposure to rooting media for 99 days for the auxin test, and 62 days for the SA and TA tests. Compared to NAA alone, IBA enhanced root growth and development as determined by increases in all parameters, and therefore it was used thereafter. Successful results for the number of roots and root dry weight were achieved using azalea cuttings with a combination of IBA and SA. In addition, the mix of IBA and TA resulted in higher number of roots and length of root. These combined treatments are recommended for establishing stem cuttings to produce nursery plants of azalea.

Emetine and cephaeline production and regulation by in vitro propagation of Psychotria ipecacuanha (Brot.) Stokes in semi-solid media and temporary immersion bioreactor

Psychotria ipecacuanha, is a plant species with known medicinal properties that is critically endangered due to overexploitation of natural populations. Although the difficulties in conventional propagation by seed and by vegetative propagation are generally understood, the present study enhances our knowledge by describing efficient plant regeneration and root induction protocols for P. ipecacuanha while comparing alkaloid content (emetine and cephaeline) in in vitro-derived tissues. Stem node explants were cultured on MS medium MS supplemented with indolbutiric acid (IBA) in semi-solid media and the RITA® temporary immersion bioreactor. The highest root formation (81%) was in MS + 1.5 mg L−1 IBA in the bioreactor. After 24 months of acclimatization, the plants cultivated in MS + 0.50 and 1.0 mg L-1 of IBA had the highest number of roots (3), with mean values of 10.47 and 9.40 cm, respectively. The cultures coming from 1.0 mg L−1 and 0.5 mg L−1 IBA in the bioreactor contained higher cephaeline content, with a relative area of 14.2 and 14.9%, respectively. For emetine, the 1.0 mg L−1 IBA cultures in the bioreactor, 0.5 mg L−1 IBA and MS0 cultures contained higher content than the other treatments, with a relative area of 10.2, 10.2 and 10.1%, respectively.

In Vitro Propagation of Pineapple (Ananas comosusL.) Shoots from Sipahutar North Sumatera Indonesia

Pineapple is a plant that needs to be developed on a plantation scale because the fruit is of economic value. The purpose of this study was to determine the best media combination on the growth of in vitro pineapple. This study used CRD with 12 treatments with 3 replications. Observation parameters consisted of the number of shoots, leaves and roots. Data analysis techniques used ANOVA followed by DMRT test. The results showed that administration of BA and vitamins could influence the propagation of in vitro pineapple shoots. The highest number of shoots was 8.00 shoots and 19.00 leaves produced MS + Vit 2 ppm + BA 2 ppm media. The highest number of roots 3.67 produced MS + Vit 0 ppm + BA 0 ppm media.

Microbial inoculants enhance the rooting and establishment of stem cuttings of cvs. Ruby and Mrudula of pomegranate (Punica granatum L.) for propagation

The influence of different microbial inoculants and their combination for inducing rooting in hardwood cuttings of pomegranate cv. Ruby and Mrudula in greenhouse and open condition was studied. Shoot and root parameter such as days taken for first sprouting, length of sprouts, plant height number and length of roots, dry weight of shoot and root, percentage of rooting were analysed. Among various microbial cultures used Trichoderma + Azotobacter each at 2.5 ml/kg of potting mixture resulted in maximum number of branches, diameter of shoot and plant height, followed by IBA 2000 ppm + Azotobacter at 5 ml / kg of potting mixture and IBA 2000 ppm + Trichodermaat 5 ml / kg of potting mixture. Maximum number of sprouts per cutting recorded at weekly interval and length of shoot recorded on 30th day after planting till 90th day after planting were observed in cv. Ruby, when treated with microbial inoculants vi iz., Azotobacter + Trichoderma each at 2.5 ml /kg of potting mixture. High number of adventitious roots, secondary roots, length of longest adventitious root, length of longest secondary root and establishment after transplanting were also in cv. Ruby compared to cv. Mrudula. Cuttings under high cost greenhouse performed better with respect to both vegetative parameters and root parameters than those kept in open condition. The interaction effect of varieties, microbial inoculants and growing condition also influence various shoot and root parameters of hardwood cuttings. The combination of IBA @ 2000 ppm +Azotobacterat 5 ml /kg of potting mixture performed better in greenhouse condition. Therefore, it is advisable to use microbial consortia in place of IBA, since it is cheaper and provides other benefits apart from producing quality, planting material which will be cost effective. Further, treating the cutting with IBA @ 2000 ppm + Trichoderma@ 5 ml/ kg of potting mixture (T6) under greenhouse gave better results while under open condition the treatment with Azotobacter + Trichoderma each @ 2.5 ml/kg of potting mixture (T4) was economically feasible for propagation of pomegranate.

EMBRYO CULTURE AND IN VITRO CLONAL PROPAGATION OF OAK (Quercus aegilops L.)

An attempt was done to develop a micropropagation protocol for oak using embryo culture. Oak is considered a hard-to-root woody plant by conventional propagation methods, that’s why using tissue culture techniques is a very suitable alternative method. For oak embryo culture, WPM was used and found to be better than MS medium for embryo germination which gave 66.13%. As well as adding of GA3 to the medium improved the germination rate of embryos (43.25% and 82.25 %). At initiation stage, WPM was used and found to be the best medium by giving the highest number of shoots/ explant which was 1.80, the highest number of leaves (15.17 leaves/ explant) and the longest shoots (1.42 cm) followed by MS medium then GD which gave the lowest parameters which gave 0.98 shoots/ explant, 7.20 leaves/ explant and 1.06 cm shoot length. At shoot multiplication stage, BA was better than Kinetin for multiplication of oak explants. The addition of BA at 3 mg.l-l gave the highest number of shoot and leaves which were 3.33 and 26.11 respectively. The longest shoots were achieved when 4.5 mg.l-l of BA was used. Furthermore, kinetin at 3 and 4.5 mg-l gave the lowest parameters which were 1 cm in length and 1.54 leaves/ explant. For rooting stage, NAA was better than IAA in giving better parameters and rooting percentage. The highest number of roots and rooting percentage were achieved when 1 mg.l-l was added by giving 6 roots/ explant and 100% rooting percentage. While the longest roots were achieved when 0.5 mg.l-l of NAA was used (3.67 cm) followed by 1.5 mg.l-l IAA which gave 3.55 roots/ explant with rooting percentage 90%. The produced plantlets were successfully acclimatized and transferred to the open-air conditions with a rate reached 85%.

Mikropropagasi Rubia akane Nakai dari Eksplan Tunas Pucuk dan Buku

Rubia akane Nakai is a medicinal plant which contains antraquinone and natural dyes producing plants because it contains alizarin and purpurin. Propagation of this plant is usualy done through seeds. One alternative to mass propagation which is not seasonal dependent is by tissue culture techniques. The purpose of this study was to conduct R. akane micropropagation on MS media containing cytokinin Kinetin or BAP respectively at 0 (control); 0,5; 1; and 2 ppm using shoot tips and nodes explants. The explants used were shoot containing 1 bud and shoot containing 2 buds, and single node. The results showed that 8 weeks after planting, the highest shoots were produced from MS media without cytokinins from shoot containing 1 bud explants that were 8,36 cm, the highest total number of leaves was produced on MS media with the addition of 0,5 ppm Kinetin at 45,86, the number the highest internodes was obtained from shoots containing 2 buds on MS media with the addition of 0,5 ppm BAP which is 4,72 segments, the highest number of lateral shoots was obtained from shoots containing buds planted on MS media which were 4,57 shoots, and the highest number of roots was obtained from shoot containing 1 shoot planted on MS media that was 9,14. The survival rate of planlet in the greenhouses from MS media containing BAP (83,33%)was higher compared to planlets derived fromMSmedia containing Kinetin (60,42%).

Nh hưởng của một số yếu tố nuôi cấy lan hoàng thảo kèn (Dendrobium lituiflorum Lindl.) trong điều kiện thoáng khí

Dendrobium lituiflorum Lindl. is endemic, rare and threatened Vietnam orchids. Therefore, in order to meet the demand for a large scale production, a good propagation technique of high quality D. lituiflorum transplants is essential. In this study, the effects of sucrose concentration (0, 5, 10, 15, 20 g/L), mineral medium strength (MS, ½MS, ¼MS) on the development of shoots, roots, ex vitro planlets in shoot ventilation culture of D. lituiflorum were evaluated. The highest number of roots and ex vitro plantlet survival was observed on ½MS and ¼MS medium. Increasing numbers of shoot and root were observed in high sucrose-containing medium. However the highest survival rate was observed in ½MS medium supplemented with 10g/L sucrose (70%). This study suggests that sucrose concentration, mineral medium strength is key factors to increase plantlet survival during acclimatization.

Comparative Effects of Organic Cocoa Shell-Based and Inorganic NPK Fertilization on the Growth and Yield of Four Cassava Varieties

Looking of finding an alternative to the use of chemical fertilizers to increase yields of cassava (Manihot esculenta), trials were carried out in the Lamto zone in central Cote d’Ivoire. Thus, the effects of compost and ash from cocoa shell and NPK were tested on the agronomic parameters of cassava. The trial was conducted for two years with four varieties of cassava: Yace, Alleda agba, Six mois and Bonoua, grown on elementary plots treated with one of these fertilizers. The experimental design was complete randomized blocks with three replicates. Analysis of the results showed that the Six mois variety gave the longest stems (131, 67 cm) with the cocoa shell compost. The Bonoua variety, on the other hand, gave the largest diameter of the stem base (21.56 mm), a higher number of leaves (77.30) and a large wingspan (136.89 cm) with cocoa shell compost. The leaves developed by the plants of this variety were wider (19.30 cm) and longer (17.96 cm) with cocoa shell compost. Also, this Bonoua variety treated with shell compost yielded a high number of tuberized roots (5.11), high average weight per plant (5.83 kg/plant) and higher yield (58.29 t/ha). This compost of cocoa shell has also allowed a better conservation of the cultivated soils quality.