Highest Mean Number Of Roots Research Articles

In Vitro Rooting of <em>Gyrinops walla</em> in Activated Charcoal-Containing Semi-Solid Culture and Filter Paper-Bridged Liquid Culture Systems

Plant tissue culture is the best option in producing planting material for cultivation programmes of Gyrinops walla. Perfection of in vitro rooting protocol for this species is the most decisive step in micropropagation. In the present study the effect of physical state of substrate, different concentrations of sucrose, IBA and NAA in media containing activated charcoal on in vitro rooting was investigated. In experiment-1, 0.2% (w/v) activated charcoal was added in to the ½ MS medium fortified with 30 or 40 g/L sucrose and varying concentrations of IBA or NAA (0, 0.1, 0.5, 1.0 and 2.0 mg/L). In experiment-2, filter paper-bridged liquid medium was used with 40 g/L sugar and varying concentrations of IBA or NAA (0, 0.1, 0.5, 1.0 and 2.0 mg/L). The treatments were arranged in completely randomized design with three replicates. Percentage of rooted microshoots and number of roots per shoot were recorded. The ½ MS semi-solid medium with 0.2% activated charcoal, 40 g/L sucrose and 0.1 mg/L NAA resulted in the significantly highest rooting percentage (50%)while the significantly highest number of roots (6.0) were noted in ½ MS charcoal added (0.2%) basal medium with 40 g/L sucrose and 0.5 mg/L NAA. Shoots supported with filter paper bridge on ½ MS liquid medium, supplemented with 0.5 mg/L IBA, had the highest rooting percentage (66.7%) and the highest mean number of roots per shoot (3.0) (P<0.05). Results confirmed that in vitro rooting of G. walla could be perfected by optimizing the culture medium and its constituents.

Development of a Suitable in vitro Regeneration Protocol for Rahangala Pear (Pyrus pyrifolia L.) in Sri Lanka

The limitation of planting material is the major drawback to expanding pear cultivation in Sri Lanka. Hence, an in vitro protocol was developed to produce planting material for the pear variety of Rahangala. Pear shoots were used as explants and surface sterilization of explants was done using 0.5% and 1% (w/v) AgNO3 for 15 min, 5% and 10% (v/v) NaOCl for 5, 10 and 15 min. In vitro shoot multiplication and root induction were found to be suitable in full and half strengths of MS medium respectively supplemented with various concentrations of BAP (1, 1.5, 2, 2.5, 3 mg/l), IBA (0, 0.5, 1, 2, 3, 4 mg/l) and NAA (0.1 mg/l). Acclimatization was conducted in pots containing different proportions of topsoil, compost, coir dust and sand. Completely Randomized Design (CRD) was used as an experimental design for this study. During sterilization of explants, the survival rate of 86.6% was recorded after 3 weeks where the treatment was done with 1% AgNO3, and 10% NaOCl for 10 min. BAP (3.0 mg/l) produced the best shoot multiplication (1.46 ± 0.2). Significantly (p<0.05), the highest mean number of roots (1.93 ± 0.98), average length (60.6 mm), and rooting percentage (68%) were observed in ½ MS medium with 4.0 mg/l IBA. After five weeks of transplantation in pots, 100% of plantlets survived in topsoil, compost, coir dust, and sand in a ratio of 1:1:1:1 Plant Tissue Cult. & Biotech. 34(1): 25-33, 2024 (June)

In vitro mass propagation of Dendrocalamus asper (Giant bamboo) through direct organogenesis

Dendrocalamus asper (giant bamboo) is a clumping type of bamboo belonging to the Poaceae family. Due to its economic and environmental value, demand for this species has increased tremendously. Conventional propagation methods have limitations due to low seed viability and the lack of healthy clumps. Therefore, an in vitro mass propagation protocol was developed to provide healthy plants for large-scale plantations. Seeds were used as the explant and they were surface sterilized and cultured on MS medium free of growth regulators. Nodal segments taken from in vitro germinated seedlings were used for shoot initiation. The best medium for shoot induction (MS medium supplemented with 0.0–2.5 mg/L BAP), best medium for multiple shoot induction (MS medium supplemented with 0.0–5.0 mg/L BAP), effect of shoot cluster size (shoot clusters containing 1–4 shoots) and effect of physical state of the medium (semisolid and liquid media) on multiple shoot induction were determined using shoots per node, mean shoot length and mean number of leaves per shoot after 6 weeks of incubation. Elongated shoots were transferred into a rooting medium and the best medium for root induction (MS medium supplemented with 0.0–5.0 mg/L IBA and IAA) and effect of cluster size (shoot clusters containing 1–4 shoots) on rooting were determined using the number of roots and root length after 6 weeks of incubation. All the cultures were maintained under a 16-hour photoperiod. Well-developed plantlets were transferred to coir pellets and after four weeks transferred into different potting mixtures containing different combinations of sand, compost and coir dust. Unless otherwise mentioned there were at least twenty replicates in all treatments. The highest mean number of shoots per node (16.87±0.52), mean shoot length (4.12±0.27 cm) and mean number of leaves per shoot (4.80±0.33) were observed in the MS medium supplemented with 1.0 mg/L BAP. The MS medium supplemented with 2.0 mg/L BAP was the best for multiple shoot induction, shoot cluster with 3 shoots was the best cluster size and the liquid medium had a better effect on shoot multiplication. The half-strength MS medium supplemented with 2.0 mg/L IBA was the best for in vitro root induction with the highest mean number of roots (7.15±0.77) and a mean root length of 10.79±1.11 cm. Shoot clusters with 3 shoots was the best cluster size for root induction. A sand: compost: coir dust (1:1:1) mixture was the best potting mixture giving 100% survival. These findings provide a reliable micropropagation protocol for D. asper, which holds great promise for meeting the growing demand for bamboo resources and promoting sustainable bamboo cultivation.

In vitro propagation of theDendrobium wardianum

In the present study, we investigatedthepropagation of Dendrobium wardianum by in vitro culture technique. The results showed that:the most suitable protocorm multiplication medium is MS mediumsupplemented with 2 mg/l BAP, 1 mg/l IBA, 40 g/l mashed banana after 8 weeks of culture, with a protocorm multiplier of 18.8;MS medium supplemented with 1.5 mg/l KIN, 30 g/l mashed carrot gave the best on in vitro shoot regeneration after 8 weeks of culture, with 32.58 shoots/explant, shoot height of 2.5 cm and 3.5 leaves/shoot. Shoots were rooted well on MS medium supplemented with 1 mg/l αNAA, 30 g/l mashed carrot with the highest mean number of roots (10.8 roots per shoot) and the longest mean root length (3.01 cm) after 6 weeks of culture.In the nursery, a mixture of forest moss, volcanic pumice, and coconut fibre (30:30:40) ratio was regarded as the best substrate due to the high survival rate of plantlets (96.6%) and healthy plantlets (9.10 cm in height with 8.7 leaves and 3.8 new roots/plantlet) at 6 weeks after planting.

AN ATTEMPT TO CONSERVE A VULNERABLE TREE SPECIES OF Santalum album L. THROUGH MICROPROPAGATION

A rare kind of tropical plant in the Santalaceae family is Santalum album. The active ingredient in S. album, santalol, is also referred to as sandalwood oil and is highly prized in the fragrance business for its fixative qualities and pleasant, enduring scent. Out of all the species in the genus Santalum, S. album has the greatest oil concentration (about 6%). The wild plants are overharvested for their wood, which is used to make santalol, as well as for other uses including woodcarving and traditional medicine. S. album is an easily hurt plant. Thus, the creation of an in vitro mass propagation protocol for this valuable species is necessary in order to generate homozygous clones with large yields for the establishment of sandalwood plantations. In this study, a full-strength MS medium supplemented with varying concentrations of BAP and Kn (0.5-2.5 mg/l) was used to cultivate the shoot tip and intermodal portions of S. album that were collected from the wild. The maximum shoot development (4.50±0.50) occurred at a BAP concentration of 1.5 mg/l. IBA and IAA were added to the rooting medium along with the developing shoots. IBA (2.0 mg/l) had the highest mean number of roots (4.90±0.25) and root length (5.75±0.47 cm). Shoots that had been successfully rooted were moved to the field to harden. According to the current study, MS medium with 1.5 mg/l of BAP and 2.0 mg/l of IBA is an appropriate technique for micropropagating and conserving S. album is fragile tree species.

In Vitro Clonal Propagation of Korarima (Aframomum Corrorima (Braun) P.C.M. Jansen) on Improved Varieties of Bonga and Benchmajji

Korarima (Aframomum corrorima (Braun) P.C.M. Jansen) is a diploid, 2n = 48, monocious, perennial and aromatic herb species under family Zingiberaceae. It is a native plant used as a spice in regular Ethiopian dishes and locally used in traditional medicine. However, commercial exploitation of this crop is hampered due to poor rate of seed germination and slow multiplication rate of the rhizomes along with other agronomic predicaments. Thus, the present study was aimed at in vitro micro propagations of two Aframomum corrorima cultivars of Bonga1 and Benchmajji1. Based on the results, better response was observed in rhizome bud explants with the highest mean number of shoots per explants, 4.33±0.33 and 4.67±0.33 for cv. Bonga1 and Benchmajji1 respectively, whereas 3.33±0.33 and 3.00±0.00 for cv. Bonga1 and Benchmajji1 respectively on the MS medium supplemented with BA 2.0mg/l and KN 0.5 mg/l. For multiplication, the highest mean number of shoots per explants (4.67±0.33) was obtained from the MS medium supplemented with combination of 3.0mg/l BA and 0.5 mg/l KN for cv. Bonga1, and the highest mean number of shoots per explants (4.00±0.00) was obtained from the MS medium supplemented with 2.0mg/l BA from shoot tip explants. For rooting induction, the highest mean number of roots per explants (15.00±1.15) was obtained in the MS supplemented with 1.0mg/l NAA for cv. Bonga1, and the highest mean number of roots per explants (17.33±0.88) was observed in the MS supplemented with 1.5mg/l IBA and 2.0mg/l for genotype cv. Benchmajji1, but the highest root length was obtained in ex vitro rooting with sand and vermi-compost at ratio of 2:1 with 1mg/l IBA three times per a week. Keywords: In vitro clonal propagation, Shoot multiplication, Rooting induction and Ex-vitro DOI: 10.7176/JBAH/12-17-04 Publication date: September 30 th 2022

Study on in vitro micropropagation of Rosa sp.

Tissue culture has long been recognized as an ideal experimental paradigm for studying the mechanisms governing plant cell growth, division, and physiological and biochemical processes. The present investigation was undertaken to establish a standard method for callus induction, shoot and root regeneration of rose at Genetic Engineering and Biotechnology Laboratory, University of Rajshahi, Bangladesh in 2010. Shoot tip and nodal segments were used as experimental materials excised from field grown plants for callus induction. The direct shoot was observed from both shoot tip and nodal segments for shoot regeneration. In vitro regenerated shoot cuttings were used for root regeneration. Proper manipulation of auxin (2, 4 -D and NAA) was used to induce callus from different explants. Different growth regulators (BAP, KIN and GA3) were casted-off in combination for shoot regeneration and proliferation. Again, different concentrations of auxins (IBA, NAA, and IAA) were applied for root initiation. Among the hormonal supplements used, 2, 4 -D was found best in all respect of callusing response for all types of explants. The highest percentage (90%) of callus induction was observed in media having MS (Murashige and Skoog) + 4.0 mg/L 2, 4 -D. In case of shoot regeneration, 100% of cultured explants regenerated shoot in media with MS + 2.0 mg/L BAP + 0.5 mg/L KIN. While, 2.0 mg/L BAP + 0.5 mg/L KIN + 0.1 mg/L GA3 induced 100% shoot proliferation. Moreover, for root induction, ½ MS + 1.0 mg/L IBA + 1.0 mg/L NAA proved to be the best (80%) from in vitro regenerated shoot cuttings, and the highest mean number of roots was 5.0. Rooted shoots were acclimatized and successfully established in a natural condition where 60% of the transplanted plants survived. Bangladesh J. Agri. 2022, 47(1): 66-74

Propagation of agroforestry tree species by airlayering: a case study of Canarium schweinfurthii Engl. in the Western Highlands of Cameroon

Objective: As a contribution to the domestication of Canarium schweinfurthii (Black olive tree), the present study examined its potential for clonal propagation by air-layering. Methodology and Results: Three substrates Topsoil, Sawdust and mixture of Sawdust and Topsoil in a 1:1 (v/v) ratio] and five concentrations (0, 1, 2.5, 5 and 10 g/l) of exogenously applied indole butyric acid (IBA) were tested for their effects on the rooting of air-layers. Results showed that the percentage of rooted layers and the mean number of roots per rooted layer were significantly (p ˂ 0.001) influenced by substrate and IBA concentration, whereas the layers’ mortality rate was influenced only by substrate (p ˂ 0.001). The highest percentage of rooted layers (78.57 ± 7.78%) was recorded with the combination of Sawdust substrate and 5 g/l IBA. The same treatment combination resulted in the highest mean number of roots per rooted layer (34.95 ± 0.76). The lowest mortality rate of layers (6 ± 1.94%) was recorded with Sawdust substrate. Conclusion and application of findings: C. schweinfurthii is amenable to vegetative propagation through air-layering technique. For prolific rooting of air-layers, Sawdust substrate and application of 5 g/l IBA are recommended. With the increasing demand for C. schweinfurthii fruits, these study findings would contribute to rapid and mass propagation of this multifunctional indigenous tree species which have suffered neglect in research. Selecting trees with desirable traits and propagating them asexually using simple and inexpensive method as described in this work would improve establishment of this plant whose fruits trade raises the living standard of many populations in Western and Central Africa. Keywords: Canarium schweinfurthii, Domestication, Non-timber forest products, Vegetative propagation, Western Highlands of Cameroon

Response of ‘Bignay’ [Antidesma bunius (Linn.) Spreng] to cutting origins, IBA and BioGroe treatments

The response of ‘Bignay’ [Antidesma bunius (Linn.) Spreng] to the cutting origins and different levels of plant bio-regulators consist of Indole-3-butyric Acid (IBA) and Biogroe treatments were investigated by means of 3 x 9 factorial experiment in Completely Randomized Design (CRD) using an automated mist propagator. Two hundred sixteen (216) healthy seedlings containing 9 nodes each were used in the study. Results revealed that cutting origins significantly increased shoot length but have no influence on the root number, percent rooting and percent survival. The cuttings originated from the bottom portion of the stem recorded the longest mean in terms of shoot length (12.48 mm) including the highest percent survival and percent rooting (82.41%). Highest mean number of roots were observed on the top cuttings (1.93). Indole-3-butyric Acid (IBA) and Biogroe treatments on cuttings have no effects on the different parameters evaluated. The interaction effect between cutting origins and IBA/Biogroe treatments significantly increased the percent rooting and percent survival except the shoot length and root number of Bignay cuttings. Overall, the findings inferred that A. bunius can be propagated by any cutting origin derived from the main stem of the donor plants tested. Cuttings can effectively be induced to produce roots and survive and can be economically mass propagated even without the application of different concentrations of IBA and BioGroe.

In vitro Propagation and Caulogenesis of Dracaena draco Plants

Dracaena draco is a monocot from family Asparagaceae. The dragon tree is a subtropical plant and features many botanic and Mediterranean gardens worldwide. D. draco has been categorized as vulnerable in Europe and endangered worldwide in the IUCN Red List of Threatened Species (IUCN, 1998). The aim of this study is to develop an efficient protocol for rapid in vitro propagation and caulogensis of D. draco Plants via enhanced axillary bud proliferation from single nodal explants cultured on full strength MS medium, 30g/l sucrose, 4g/l gelrite augmented with various concentrations of plant growth regulators as BA, NAA, IBA and their combinations. In general, the present study concluded that the best results for the initiation stage were recorded on MS medium fortified with NAA and BA at 2.00 and 1.00 mg/l, respectively. Meanwhile, supplemented medium with BA and NAA at 4.00 and 1.00 mg/l, respectively, gave rise to the best results for the multiplication stage. Regarding rhizogenesis stage, the best results were recorded when the neoformed shoots of the multiplication stage were divided singly and cultured on MS medium plus IBA and NAA at 1.00 and 0.50 mg/l, respectively which led to the highest mean number of roots formed per propagule. For callus induction, the internodal segments cultured into MS medium supplemented with BA and NAA at 0.50 and 2.00 mg/l, respectively, gave rise to the best results for the percentage of explants formed callus and callus size. Concerning the percentage of direct organogenesis and number of shoots formed per explants best results obtained from BA and NAA at 0.250 mg/l and 0.00 mg/l, respectively.Neoformed plantlets were acclimatized ex vitro and in vivo vigorously in a mixture of perlite and peat moss at (1:1) or (2: 2) or (2:3) and (3:3) consecutively, in addition to fixed volume (1 portion) of sterile sand; which resulted in the highest mean value of survival percentage/plant (100%) and showed true-to-type plants ex vitro.

In vitro and ex vivo vegetative propagation and cytokinin profiles of Sceletium tortuosum (L.) N. E. Br.: a South African medicinal plant

Sceletium tortuosum is a South African protected species with tremendous value in traditional and modern medicine. The plants’ mesembrine-type alkaloids are potential therapeutics for a plethora of psychological, neurological and inflammatory disorders. In our in vitro and ex vivo studies, vegetative propagation and growth of this species were investigated. Cytokinin (CK) profiles were also explored. Shoot multiplication was induced on Murashige and Skoog (MS) medium supplemented with 2.5 µM indole-3-butyric acid (IBA). In vitro-generated shoots were inoculated on MS medium supplemented with 0, 2.5, 5.0 and 10.0 µM IBA or indole-3-acetic acid (IAA). Optimal rooting (55%), mean number of roots (3.80 ± 0.83) and new leaf pairs (4.65 ± 0.67) were achieved by 10.0 µM IBA. After greenhouse acclimatization, 45–90% of plantlets survived. All ex vivo shoot cuttings rooted well (90–100%). The highest mean number of roots (11.20 ± 1.37) and root length (57.18 ± 3.85 mm) were obtained by 5.0 µM IBA. Although spontaneous rooting was observed in both experiments, auxins enhanced multiple growth parameters. Cytokinin analyses of tissue-cultured (auxin-treated) and greenhouse (untreated) plants revealed higher cytokinin levels in vitro. These investigations provide rapid and efficient propagation techniques for Sceletium tortuosum which will be valuable to conservationists and pharmaceutical companies. Plant tissue culture and cuttings enabled rapid propagation of Sceletium tortuosum. Exogenous plant growth regulators were not essential for shoot multiplication, flowering and rooting. Auxins effectively improved growth parameters.

Optimization of growth regulators on in vitro propagation of Moringa stenopetala from shoot explants

BackgroundMoringa stenopetala belongs to the flowering family Moringaceae and genus Moringa. It is often referred to as the East African Moringa tree because it is native only to southern Ethiopia and northern Kenya. The expansion of its cultivation and utilization throughout the world especially in Africa is becoming important. For such expansion, the existing propagation method is limiting, so it needs a good propagation system to supply enough planting material with a uniform genotype. Therefore, the main objective of this study was to optimize an in vitro shoot multiplication protocol for M. stenopetala by using shoot tip as explants.ResultsShoots were sterilized and cultured on Muraghige and Skoog (MS) medium for in vitro shoot initiation. For multiple shoot induction, the explants were cultured on MS medium supplemented with different concentrations of kinetin (0.5, 1.0, 1.5, 2.0, 2.5 mg/L) with Indole-3- butyric acid (IBA) or α -naphthalene acetic acid (NAA) (0.01, 0.1, 0.5 mg/L) and maintained at 25 ± 2 °C for four weeks. Rooting was achieved by culturing well developed shoots in half-strength MS medium containing IBA (0.1, 0.5, 1.0, 1.5, 2.0 mg/L), NAA (0.1, 0.5, 1.0, 1.5, 2.0 mg/L), and 0.5 mg/L IBA with NAA (0.1, 0.5, 1.0, 1.5, 2.0 mg/L). Statistical analysis revealed that there was a significant difference among all treatments applied in both shoot multiplication and rooting experiments. The maximum number of shoots per explant (3.43 ± 1.41) and 7.97 ± 4.18 leaves per explant were obtained on MS medium containing 0.5 mg/L kinetin with 0.01 mg/LNAA. The highest mean number of roots per shoot (1.63 ± 1.03) and mean root length (0.87 ± 1.22 cm) were obtained on MS medium containing 1.0 mg/LNAA and 0.1 mg/LIBA alone respectively. After acclimatization, 76% of plants were survived in the greenhouse.ConclusionIn general, using NAA with kinetin for shoot multiplication was effective than kinetin with IBA. On the other hand, the application of 1.0 mg/L NAA alone and 1.0 mg/L NAA with 0.5 mg/L IBA were more effective for root induction.

In vitro propagation of Securidaca longipedunculata (Fresen) from shoot tip: an endangered medicinal plant

BackgroundSecuridaca longipedunculata Fresen is an indigenous medicinal plant in Africa that has an important place in both traditional and modern medicine. This plant is endangered because of high seed dormancy, low germination rate, and over exploitation. Therefore, micropropagation method is important to address these problems. The objective of this study is to develop a micropropagation protocol for S. longipedunculata from shoot tip explants. ResultsAmong different Clorox concentrations, seeds sterilized with 10% Clorox for 10 min resulted in 85% decontamination and 80% germination. Among different media used to evaluate the rate of seed germination, seeds that were de-coated and transversally cut at the tip and cultured on basal MS medium resulted in 100% germination. The highest percentage of shoot initiation (87%) was obtained on MS medium containing 1.0 mg/l 6-Benzylaminopurine (BAP). The highest mean shoot number per explant (8.5 ± 0.69) was achieved on MS multiplication medium containing 1.5 mg/l BAP in combination with 0.1 mg/l Indole-3-butyric acid (IBA). The highest mean number of roots per explant (3.73 ± 0.69) was obtained on MS medium containing 2.0 mg/l Indole-3-acetic-acid (IAA). Among plantlets transferred to greenhouse, 60% survived after acclimatization. ConclusionsThis micropropagation protocol can be used for mass propagation of S. longipedunculata that contributes to its conservation and genetic improvement.

Exogenous auxins and leaf area affect the rooting of Xylopia aethiopica (Dunal A. Rich.) stem cuttings

ABSTRACTThe amenability of Xylopia aethiopica to vegetative propagation was assessed. Twelve auxin treatments and three ranges of leaf area were investigated for their effects on the propagation of stem cuttings in non-mist propagator. Results showed that the highest mortality rate (58.3%) was recorded with leafless cuttings while the lowest (5%) was recorded with 25–35 cm2 leaf area cuttings. There was no linearity in the relationship between auxin concentration and the mortality rate. Cuttings with 10–15 cm2 and those with 25–35 cm2 leaf areas rooted at higher percentages (74.5% and 73.6%, respectively) than leafless cuttings which rooted at 32%. Considering all leaf areas together the highest rooting percentage (90%) was recorded with 1% IBA powder while the lowest (22.2%) was recorded with the control. Whilst leaf area did not affect roots count, the highest mean number of roots per cutting (7.6) was recorded with 1% IBA powder. IBA powder treatment at 1% and 25–35 cm2 leaf area resulted in the highest mean root biomass (520.6 and 480.5 mg/cutting, respectively). The use of cuttings with 25–35 cm2 leaf area and treatment with 1% (w/w) IBA powder is thus recommended for vegetative propagation of X. aethiopica through stem cutting.

Rooting of <i>Vaccinium corymbosum</i> L. microshoots cv. «Blue-Berry» in culture <i>in vitro</i> and <i>ex vitro</i>

This paper discusses a method of micropropagation of Vaccinium corymbosum L. cv. Blue-Berry. The results showed that WPM supplemented with 1,0 mg/l of zeatin in combination with 0,1 mg/l of indolyl-3-butyric acid was more effective for the multiplication of blueberry axillary shoots. The maximum increase in the number of healthy axillary shoots was observed in the fourth subculture, whereas the phenomenon of hyperhydration (vitrification) began to appear in the fifth subculture. In addition, it was established that the presence of indolyl-3-butyric acid and 1,0 g/l of activated charcoal in the nutrient medium lead to the development of good root system of the Vaccinium corymbosum cv. Blue-Berry. The highest mean number of roots formed per explant was obtained on WPM medium, supplemented with 0,5 mg/l indolyl-3-butyric acid after 10 weeks. Acclimatization of in vitro regenerated plantlets of Vaccinium corymbosum with a developed root system in ex-vitro conditions (pH 3,54) showed a 100% survival rate.

Hormones Affected Cutting Propagation of Cupressus sempervirens 'Stricta'

Cupressus semperviens ‘Stricta’ is a member of Cupress family, also called Italian cypress or Mediterranean cypress, native to the eastern Mediterranean region. It has been widely cultivated as an ornamental tree all over the world because of its evergreen, drought resistant, heat tolerant, pH adaptable, salt tolerant and narrow-straight-tall habit. To meet the increasing market demands, we carried out the stem cutting propagation in January and treated with different types and various concentration hormones: liquid KIBA 1000, 3000, 8000 mg/L and powder Hormodin #1, #2, #3. Hormone has a significant effect on rooting percentage. The highest rooting percentage, 56.25%, was obtained under the treatment of KIBA 3000 mg/L, 28.13% and 30.25% for KIBA 1000 mg/L and 8000 mg/L, respectively. Cuttings treated with Hormodin had rooting percentage from 25%, 37.5%, 53.125% under Hormodin #1, #2, #3 respectively. Hormodin #3 yielded 23.75, which was the highest mean number of roots in all treatments. The total length of roots under treatment KIBA 3000 mg/L, Hormodin #2 and Hormodin #3 was 101.20, 103.46 and 109.29 cm respectively, which had significant different to other treatments. Both KIBA and Hormodin could increase the rooting percentage and the recommended should be KIBA 3000 mg/L and Hormodin #3.

Vegetative propagation of Rambutan (Nepheliumlappaceum) by marcotting: effect of indole-3-butyric acid concentration

Rambutan tree (Nepheliumlappaceum L.) is an important but a lesser known fruit tree in Ghana and has several nutritional and medicinal uses. Efforts to establish plantation of Rambutan in Ghana to ensure its sustainable use is challenged with unavailable planting materials because the seeds are recalcitrant in nature, loses viability easily when exposed to dryness. Seeds are therefore sown directly after extraction from fruit, even with this, most of the seeds do not germinate. A vegetative propagation technique by marcotting was devised to produce planting materials within 3 months. Four plant species of the same physiological age and spaced 4m apart were tested in complete random design fashion. Marcots were treated with four Indole-3-Butyric Acid (IBA) concentrations (0 Mg/L, 2000 Mg/L, 4000 Mg/L and 6000 Mg/L). Data collected were analysed on number of calluses formed in marcots, survival, shoot and root formation and root length. Comparable but highest survival of marcots was recorded in the 2000 Mg/L of IBA (14.67 +0.33) representing 97.78%. Marcots with 2000 Mg/L IBA concentration recorded highest mean number of roots (8.67 +0.33) formed. Root length ranged from 33.60 +0.52 in the 6000 Mg/L to 19.77 +1.26 in the control (0 Mg/L). Marcots with no IBA recorded 9.00 +0.58 as mean number of callused marcots. It is concluded that vegetative propagation technique by marcotting can be a suitable technique for Rambutan planting materials.

In Vitro micropropagation of Acacia auriculiformis from selected juvenile sources

The effects of 6- Benzylaminopurine (BA), different basal medium, sucrose concentration and gelling agent were investigated for shoot induction and multiplication of Acacia auriculiformis. Nodal ex¬plants derived from 5-month-old seedlings yielded the highest shoot multiplication rate in Murashige and Skoog medium (MS) with 0.44 μM BA, 30 g/L sucrose and 2 g/L Gelrite. The highest mean number of shoots (10) and mean length of shoots (5.07mm) were also obtained in this medium. Qualitative obser¬vation of the shoots cultured in 0.44 μM BA were greener and vigorous in growth as compared to shoots cultured on higher concentrations of BA (22.2 μM). MS medium produced a significantly higher number of shoots (18) compared to Woody Plant Medium (WPM) (11) and B5 medium (10). Media solidified with different gelling agents also produced a significantly different number of shoots with 2 g/L Gelrite produced the highest number of shoots (23). The highest percentage of shoots rooted was found in the MS medium without any growth regulators (40.0%) followed by medium supplemented with Indole-3-bu¬tyric acid (IBA) at 9.84 μM and the combination of 9.84 μM IBA with 5.37 μM α-naphthalene acetic acid (NAA) (33.3%). MS medium without any plant growth regulators produced the highest mean root length (84.33mm), whereas medium supplemented with 9.84 μM IBA produced the highest mean number of roots per shoot (4.33). Out planting of in vitro rooted shoots in shredded coconut husk as the substrate gave the highest percentage of survival (90%) during acclimatization in the greenhouse.

English

Brassica carinata (A. Braun) is an amphi-diploid species that originated from interspecific hybridization between Brassica nigra and Brassica oleracea in the highlands of Ethiopia. The crop has many desirable agronomic traits but with oil quality constraints like high erucic acid and glucosinolate contents. In this study, two genotypes and two types of explants were tested for callus induction, shoot and root regeneration in Murashige and Skoog (MS) medium under different concentrations of naphthalene acetic acid (NAA), 2,4-dichlorophenoxy acetic acid (2,4-D), and 6-benzyl amino purine (BAP). Cotyledon proved to be most responsive for callus induction at a higher rate in a short period of time. Growth regulator type and concentration had a significant effect on the callus induction and physical appearance. The highest frequencies of callus growth (80.7 and 95%) were observed on hypocotyl and cotyledon explants, respectively, cultured on MS basal medium supplemented with 0.5 mg/L 2,4-D in Yellow Dodola. Two types of calli were obtained: white and friable callus with large cells; green and compact callus with smaller cells. For shoot induction, successful shoot regeneration from white/friable callus was achieved when MS medium was supplemented with 6-benzyl amino purine (2 mg/L). Significant genotypic difference was observed between the genotypes, Yellow Dodola giving the highest response. Maximum shoot induction was recorded in the hypocotyls of Yellow Dodola (90%) when MS medium with 2 mg/L BAP was used. Highest percentage of shoots with roots (98.7%) and highest mean number of roots per shoot (9) occurred on medium with 0.3 mg IBA, while the maximum root length (4.7 cm) was attained on MS medium without plant growth regulator (MSO) in Yellow Dodola. Plantlets were successfully acclimatized in potting medium containing a mixture of 25% sand, 50% red soil and 25% compost on acclimatization pots (1:2:1). The in vitro regeneration protocol developed can be used for further undertaking of other tissue culture and genetic engineering work on B. carinata. Key words: Auxin, callus, cotyledon, cultivars, cytokinin, in vitro regeneration, hypocotyls.

High–frequency in vitro plantlet regeneration from apical bud as a novel explant of Carum copticum L.

To develop an in vitro regeneration system to increase the recovery of Carum copticum L. plantlets as a part of developing a metabolic engineering program. The efficacy of different concentrations and combinations of 6-benzyladenine, indole-3-acetic acid and indole butyric acid on direct shoot regeneration and rooting of ajowan from apical bud explants were assessed. All explants were cultured on Murashige and Skoog (MS) medium supplemented with different combinations of 6-benzyl amino purine (BAP) (0, 2.2, 4.4, 8.8 µmol/L) and indole-3-acetic acid (IAA) (0, 0.5, 1.1, 2.2 µmol/L). The maximum shoot regeneration frequency (97.5%) and the highest number of shoots produced from apical buds (34 shoots per explant) were obtained on MS medium fortified with BAP (4.4 µmol/L) and IAA (0.5 µmol/L). Low shoot regeneration frequency was observed in BAP free treatments. The effects of different strengths of MS medium and various concentrations of IAA and indole-3- butyric acid on rooting rate, length and average number of roots were also investigated. Application of indole-3- butyric acid (6 µmol/L) in full-strength MS medium, was more effective than IAA and resulted in highest shoot regeneration frequency with the rooting rate of 100% and highest mean number of roots per shoot (41.8). The rooted plantlets were acclimatized successfully in greenhouse conditions with a survival rate of 90%. In this study, a simple and reliable regeneration and acclimatization protocol for Carum copticum has been presented. This protocol can be found very advantageous for a variety of purposes, including mass multiplication of Carum species, medicinal plant breeding studies and transgenic plant production.