Indole-3-butyric Acid Levels Research Articles

Foliar application of Boron, Calcium, and Indole-3-butyric acid on onion plants to improve seed production

Onion is the third most important cultivated vegetable crop around the world. Two types of varieties are cultivated: Open pollinated cultivars (OP) and first generation hybrids (F1). Little is known about the effects of foliar applications on onion seed production. This study was conducted to evaluate the enhancement of onion seed yield and seed quality through foliar applications of Boron (B), Calcium (Ca), and an auxin, indole-3-butyric acid (IBA). Male-sterile lines (MSL), and OP planted in pots and open field conditions were used over four seasons. The experiments were carried out with different levels of nutrients and IBA applied to the plants. Our results showed that foliar applications of nutrients and plant growth regulators were effective methods to improve onion seed yield and the number of seed per fruit, while seed quality parameters remained stable. The seed yield was enhanced by B by up to 83 %, but with an increasingly wide variability in comparison to the control. Indole-3-butyric acid improved yields when it was applied alone and mixed with B and Ca (40–45 % for OP and MSL, respectively) compared to the control. Therefore, foliar application of IBA, B and Ca could be effective in improving onion seed yields.

The impact of auxin on the vegetative and reproductive growth of carrot (Dacus carota L.)

Seed is a basic component of every crop species and quality seed is essential for farmers to achieve greater crop production and higher yields. Seed yield can be improved by using the growth hormones. Indole-3-butyric acid (IBA) IBAplays a vital role in reproductive and seed development of crop plant. An investigation is being conducted to determine effect of rooting hormone IBA on reproductive growth that leads to seed developement. Roots treated with three levels of IBA (500 ppm, 1000 ppm and 1500ppm) along with control in a 3 replication. Results showed that roots treated with IBA @ 1500 ppm had taken least number (28.4) of days to flowering with maximum plant height (34.3cm), number of leaves (15.3), leaves length (19.6 cm), number of secondary (10) and tertiary umbels (13.7), diameter of secondary (12.7 cm) and tertiary umbel (4.4), weight of secondary (5.1 g) and tertiary umbel (3.5), seed weight of secondary (4.4 g) and tertiary umbels (1.5 g) and biological weight of the plants (81.0 g) respectively. However, the diameter, weight and seed weight of primary umbel was good in IBA @ 1000 ppm. Thus it is recommended that IBA application at concentration of 1500 ppm can significantly improve growth of carrot seed plants, hence increasing production and seed quality

English

Taro (Colocasia esculenta L. Schott) is an important crop for food and nutrition security, incomes, and livelihood of people in developing countries. Its cultivation and productivity have been limited mainly due to a lack of quality planting materials. Therefore, this study developed an effective micropropagation method for two common taro varieties in Kenya (Purple Wild and Dasheen) using apical meristem derived from portions of the corm and base of leaf petioles. This study optimized the 6-benzylaminopurine (BAP) and indole-3-butyric acid (IBA) levels for a better shoot and root development. The highest shoot induction was observed in both varieties when Murashige & Skoog (MS) media was supplemented with 2 mg/L of BAP. Similarly, the maximum rooting response was achieved in both varieties on half-strength MS media supplemented with 0.5 mg/L of IBA. The study also revealed significant interactions between variety × BAP levels and variety × IBA levels (P<0.0001) for shoot and root development, respectively. This apical meristem-based micropropagation method developed in this study can be used for rapid multiplication of genetically clean planting materials for commercial uses and to establish taro transformation protocols.   Key words: Taro, 6-benzylaminopurine (BAP), indole-3-butyric acid (IBA), shoot induction, root induction, regeneration.

The Effect of Different Levels of Indole-3-butyric Acid (IBA) and Naphthaleneacetic acid (NAA) on the Rooting of The Effect of Different Levels of Indole-3-butyric Acid (IBA) and Naphthaleneacetic acid (NAA) on the Rooting of Pear Stem CuPear Stem Cutting

The Effect of Different Levels of Indole-3-butyric Acid (IBA) and Naphthaleneacetic acid (NAA) on the Rooting of The Effect of Different Levels of Indole-3-butyric Acid (IBA) and Naphthaleneacetic acid (NAA) on the Rooting of Pear Stem CuPear Stem Cutting

The Arabidopsis NRT1/PTR FAMILY protein NPF7.3/NRT1.5 is an indole-3-butyric acid transporter involved in root gravitropism

Active membrane transport of plant hormones and their related compounds is an essential process that determines the distribution of the compounds within plant tissues and, hence, regulates various physiological events. Here, we report that the Arabidopsis NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER FAMILY 7.3 (NPF7.3) protein functions as a transporter of indole-3-butyric acid (IBA), a precursor of the major endogenous auxin indole-3-acetic acid (IAA). When expressed in yeast, NPF7.3 mediated cellular IBA uptake. Loss-of-function npf7.3 mutants showed defective root gravitropism with reduced IBA levels and auxin responses. Nevertheless, the phenotype was restored by exogenous application of IAA but not by IBA treatment. NPF7.3 was expressed in pericycle cells and the root tip region including root cap cells of primary roots where the IBA-to-IAA conversion occurs. Our findings indicate that NPF7.3-mediated IBA uptake into specific cells is required for the generation of appropriate auxin gradients within root tissues.

EFFECT OF DIFFERENT LEVELS OF I.B.A CONCENTRATION ON CLONAL PROPAGATION OF EUCALYPTUS SPECIES IN GHANA WEST AFRICA

Effective rooting and survival of cuttings has become more important owing to increased global wood demands and climate change. This study assesses the survival of ten (10) clones each of Eucalyptus grandis x Eucalyptus urophylla (E. grandis x E. urophylla) and Eucalyptus pellita (E. pellita) clonal cuttings when treated with different Indole-3-butyric acid (IBA) auxin concentrations of 0 ppm (control), 2000 ppm, 3000 ppm and 4000 ppm respectively. Overall, the mean survival of cuttings with respect to both species (10 clones each) was low (i.e < 50%) for all concentrations of IBA used. E. grandis x E. urophylla cuttings had the highest mean survival (43.39%) when treated with 2000 ppm of IBA and lowest mean survival (37.86%) when treated with 0 ppm. E. pellita (P) cuttings had the highest mean survival (27.14%) when treated with 2000 ppm of IBA. Individual clones however showed higher survival with respect to IBA treatments. Eucalyptus grandis x Eucalyptus urophylla clone (GH11) achieved a mean survival rate of 75% with 2000ppm of IBA. E. pellita clone P2 achieved its highest survival (52.68%) in the control experiment (0 ppm). Although IBA application had significant effect on cutting survival, parent material (individual clones) also plays a vital role in cutting survival as some clones such P51 and P82 achieved survivals of less than 10% given all four levels of IBA used. Individual clones also respond to IBA concentration differently. GH3 and GH10 had their highest survivals (i.e 66.07% and 61.61% respectively) in the control (0ppm of IBA). Results from this study can be used in plus tree clonal selection regimes to identify the best economically rewarding clones in terms of cutting survival to be used in forest plantation establishments.

Overexpression of UGT74E2, an Arabidopsis IBA Glycosyltransferase, Enhances Seed Germination and Modulates Stress Tolerance via ABA Signaling in Rice.

UDP-glycosyltransferases (UGTs) play key roles in modulating plant development and responses to environmental challenges. Previous research reported that the Arabidopsis UDP-glucosyltransferase 74E2 (AtUGT74E2), which transfers glucose to indole-3-butyric acid (IBA), is involved in regulating plant architecture and stress responses. Here, we show novel and distinct roles of UGT74E2 in rice. We found that overexpression of AtUGT74E2 in rice could enhance seed germination. This effect was also observed in the presence of IBA and abscisic acid (ABA), as well as salt and drought stresses. Further investigation indicated that the overexpression lines had lower levels of free IBA and ABA compared to wild-type plants. Auxin signaling pathway gene expression such as for OsARF and OsGH3 genes, as well as ABA signaling pathway genes OsABI3 and OsABI5, was substantially downregulated in germinating seeds of UGT74E2 overexpression lines. Consistently, due to reduced IBA and ABA levels, the established seedlings were less tolerant to drought and salt stresses. The regulation of rice seed germination and stress tolerance could be attributed to IBA and ABA level alterations, as well as modulation of the auxin/ABA signaling pathways by UGT74E2. The distinct roles of UGT74E2 in rice implied that complex and different molecular regulation networks exist between Arabidopsis and rice.

Optimization of in vitro rooting protocol for tomato (Lycopersicon esculentum mill.) varieties

In vitro rooting of micropropagated shoots were carried out with the aim of evaluating the root induction responses of two tomatoes (Lycopersicon esculentum MILL) varieties (Gelilema and Chali) using Indole -3- butyric acid (IBA). Seven levels of IBA (0.0, 0.25, 0.5, 0.75, 1.0, 1.25 and 1.5 mg L-1) were used in a completely randomized design (CRD) in factorial combinations (seven level of IBA*two varieties) with three replications. After the plantlets were kept in the rooting media for three weeks, data on rooting percentage, number of roots/shoots and root length in cm were collected. The analysis of variance showed that the interaction of IBA*Var was highly significantly different for rooting percentage, a number of roots/shoot and root length at p<0.01. The highest rooting percentage (100.00±0.00), number of roots/shoot (14.20±0.35) and root length (10.7±0.29) were received from Chali on free Murashige and Skoog medium (MS). At the same time, the lowest percentage of rooting (11.11±0.00), number of roots/shoot (0.887±0.19) and root length (1.00±0.00 cm) were obtained from Gelilema on MS+1.5mg/l IBA. For acclimatization, the in vitro rooted shoots were transplanted into plastic pots containing a mixture of oven sterilized soil and sand at a ratio of 2:1. After three weeks, a survival rate of 67.7% for Chali and 58.1% for Gelilema was obtained. From the above result, it can be concluded that free MS medium was the best for in vitro rooting of the two tomato varieties. The optimized protocol will be useful for rapid in vitro multiplication of the two tomato varieties.

Arabidopsis thaliana GH3.15 acyl acid amido synthetase has a highly specific substrate preference for the auxin precursor indole-3-butyric acid

Various phytohormones control plant growth and development and mediate biotic and abiotic stress responses. Gretchen Hagen 3 (GH3) acyl acid amido synthetases are plant enzymes that typically conjugate amino acids to indole-3-acetic acid (IAA) or jasmonic acid (JA) to inactivate or activate these phytohormones, respectively; however, the physiological and biological roles of many of these enzymes remain unclear. Using a biochemical approach, we found that the Arabidopsis thaliana GH3.15 (AtGH3.15) preferentially uses indole-3-butyric acid (IBA) and glutamine as substrates. The X-ray crystal structure of the AtGH3.15·AMP complex, modeling of IBA in the active site, and biochemical analysis of site-directed mutants provide insight on active site features that lead to AtGH3.15's preference for IBA. Assay-based in planta analysis of AtGH3.15-overexpressing lines indicated that their root elongation and lateral root density were resistant to IBA treatment but not to treatment with either IAA or JA. These findings suggest that AtGH3.15 may play a role in auxin homeostasis by modulating the levels of IBA for peroxisomal conversion to IAA. Analysis of AtGH3.15 promoter-driven yellow fluorescent protein reporter lines revealed that AtGH3.15 is expressed at significant levels in seedlings, roots, and parts of the siliques. We conclude that AtGH3.15 is unique in the GH3 protein family for its role in modifying IBA in auxin homeostasis and that it is the first GH3 protein shown to primarily modify a plant growth regulator other than IAA and JA.

Interaction Effects of 6-Benzylaminopurine (BAP) and Indole-3-Butyric Acid (IBA) on Ex Vitro Propagation of Sugarcane

Ex vitro propagation of micropropagated sugarcane plantlets of three selected sugarcane genotypes was carried out with the objective of evaluating their propagation responses to the interaction effects of BAP and IBA. Accordingly, six levels of IBA (0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 mg L-1) and eight levels of BAP (0.0, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0 and 2.25 mg L-1) with three sugarcane genotypes, each replicated three times were tested. The treatments were arranged in a factorial completely randomized design. Data on the number of tillers per shoot, average shoot length (cm) and number of active leaves per shoot were collected twice every 30th day after 30 days of treatment application. Analysis of variance revealed that the interaction effects of BAP, IBA and the sugarcane genotypes was very highly significant (P<0.0001) on the number of tillers per shoot, average shoot length and number of active leaves per shoot. The optimum number of tillers per shoot (5.67), average shoot length (40.77 cm) and number of active leaves per shoot (6.97) were obtained at 0.1 mg/l IBA+0.75 mg/l BAP in C132-81. In C86-56, the optimum number of tillers per shoot (4.50) was obtained at 0.1 mg/l IBA+1.5 mg/l BAP while the maximum average shoot length (48.33 cm) and maximum number of active leaves per shoot (7.67) were obtained at 0.2 mg/l IBA+0.75 mg/l BAP. In SP70-1284, the optimum number of tillers per shoot (6.43) was obtained at 0.3 mg/l+1 mg/l BAP with 16.05 cm average shoot length and 4.87 active leaves per shoot. Thus, it can be deduced that production of an average of 5.5 plantlets per shoot within a month can be possible.

Growth and development of moringa (Moringa oleifera L.) stem cuttings as affected by diameter magnitude, growth media, and indole-3-butyric acid

The acknowledged status of Moringa oleifera L. in sub-Saharan Africa, especially western Africa, has of recent accorded it the significance of being a good source of income to a large segment of many of its populace. Intensification of research into the realization of its full economic potential will be of utmost value to impoverished societies globally. One way to achieve this is the full exploration of all possible means that will facilitate its successful growth, propagation, and domestication. Even though it can be successfully raised through seeds, the high level outcrossing (64.3%) observed is a hindrance to realization of true to type trees. Vegetative propagation can be employed as an option to tackle the noted limitation, ease the cultivation process, and achieve the required realization of its economic potential. Our trial was carried out to study the influence of two growth media and three levels of indole 3-butyric acid (IBA) on root and shoot development in cuttings taken from a coppiced moringa tree existent in Universiti Putra Malaysia. Semi-hardwood cuttings of moringa, of between 20 and 30 mm diameter, cut into 25 cm length, were obtained, rinsed with a fungicide, then dipped, through their basal portion, inside varying levels (0, 1000, 2000, and 3000 ppm) of indole-3-butyric acid (IBA) for between 7 and 10 seconds. The treated cuttings were then transplanted into a polyethylene bags (23 cm × 36 cm), containing two growth media - a munchong series soil (M) and a combination of a munchong series soil thoroughly mixed with biochar (MB) in a 3:1 ratio sequence. The trial was conducted inside a shade house where the humidity of the experimental area was manipulated through a regular daily manual hand sprinkling. Plant height, percentage of primary branch produced, leaf area, and dry matter (DM) were found to be significantly (P 0.05) influenced. The MB growth media was observed to significantly affect the plant height, percentage root number, and root length as compared to the M growth media. For a successful vegetative propagation and subsequent domestication, the MB growth media coupled with a higher stem diameter size are recommended.

Tracking biochemical changes during adventitious root formation in olive (Olea europaea L.)

The activity of oxidative enzymes and the levels of free auxins were determined during adventitious root formation in olive explants. Rooting trials were performed both with in vitro-cultured microshoots of the cultivar ‘Galega Vulgar’, treated with indole-3-butyric acid (IBA) and with salicylhydroxamic acid (SHAM)+IBA, as well as with semi-hardwood cuttings of the cultivars ‘Galega Vulgar’ (difficult-to-root) and ‘Cobrançosa’ (easy-to-root), treated with IBA. The auxin (IBA) was used in all experiments as a rooting promoter, while SHAM was used in micropropagation trials as rooting inhibitor, providing a negative control. Free indole-3-acetic acid (IAA) and IBA concentrations were determined in microshoots, as well as in semi-hardwood cuttings, throughout the rooting period at pre-established time-points. At the same time-points, the enzymatic activity of polyphenol oxidases (PPO), peroxidases (POX), and IAA oxidase (IAAox) was evaluated in the microshoots. Microshoots treated with SHAM+IBA revealed higher POX and IAAox activity, as well as lower PPO activity, than those treated only with IBA. IAA levels were higher in IBA-treated microshoots during induction phase, but lower during early initiation phase. In contrast, free IBA levels were higher in microshoots treated with SHAM+IBA during induction, but lower during initiation. A similar pattern of free auxin levels was observed in semi-hardwood cuttings of the two contrasting cultivars under evaluation. The similarities found on the auxin patterns of microshoots treated with SHAM and those of semi-hardwood cuttings of the difficult-to-root olive cultivar allow considering SHAM a reliable control for when simulation of a difficult-to-root behavior is necessary. The inhibitory effect of SHAM in root formation could be related with 1) the inhibition of alternative oxidase (AOX), leading to a downregulation of phenylpropanoid biosynthetic pathways, which would decrease the concentration of phenolic substrates for PPO; 2) an increase in IAAox activity resulting in lower free IAA levels or; 3) a defective conversion of IBA into IAA.

In vitro Meristem Culture for Rapid Regeneration of Papaya Plantlets in Liquid Media

Papaya (Carica papaya L.) is an important crop in Kenya, produced both for local consumption and export. Papaya propagation via seeds makes it difficult in differentiating gender at seedlings phase. However, in vitro system could offer a solution to this problem. This study was an attempt to determine rapid in vitro methods for regeneration of papaya plantlets using liquid and semi solid/liquid double layer media and different concentration of growth regulators. Shoot meristems were harvested from hermaphrodite 30 cm tall papaya seedlings raised in greenhouse and cultured in Murashige and Skoog basal media supplemented with 30 g sucrose, and different concentrations of hormones which were treatments in liquid medium. The treatments comprised five levels (0, 0.05, 0.1, 0.15, and 0.2) of mg.L 2 Chloro 4 Pyridy – N Phenyl-urea (CPPU) in liquid and semi-solid/liquid double layer combination for shoot induction. For root initiation, four levels of Indole-3butyric acid (IBA) (0, 2.0, 2.5 and 3.0 mg.L) were used. The experiments were laid out in Original Research Article Gatambia et al.; ARRB, 9(1): 1-7, 2016; Article no.ARRB.22056 2 a completely randomized design with 3 replicates. Number of shoots, shoot length and leaf number were recorded every 2 weeks for 8 weeks. The percentage number of shoots that produced roots was also recorded. There was significant differences between the liquid and semi-solid /liquid media and the level of hormones used on shoot induction. The highest number of shoots (10), shoot length and number of leaves was recorded in the semisolid/ liquid double layer combination with CPPU at 0.15 mg.L. The highest root initiation (73.33%) was at 3.0 mg.L of IBA. Results indicated that semi-solid/liquid double layer combination could be used for rapid regeneration of papaya plantlets of known gender.

Effects of Naphthalene Acetic Acid (NAA) and Indole -3- Butyric Acid (IBA) on In Vitro Rooting of Sugarcane (Saccharum officinarum L.) Micro- Shoots

In Vitro rooting of micropropagated micro-shoots of two commercial sugarcane varieties was carried out with the aim of evaluating the root induction responses of the sugarcane varieties (B41-227 and N14) to alpha naphthalene acetic acid (NAA) and Indole -3- butyric acid (IBA). Accordingly, four levels of NAA (0, 1, 2, and 3 mg L-1) and IBA (0, 1, 2 and 3 mg L-1) in a completely randomized design with 4 × 4 × 2 factorial treatment combination arrangements were tested. Data on the number of roots per shoot and average root length (cm) were collected after 30 days of culture on ½ MS root induction medium. Analysis of variance revealed that the interaction effects of NAA, IBA and the sugarcane genotypes on number of roots per shoot and average root length of both sugarcane varieties was very highly significant (P<0.0001). Culture medium containing 2 mg L-1 NAA and 1 mg L-1 IBA for B41-227 and 1 mg L-1 NAA alone for N14 was found to be optimum. On these medium, B41-227 gave 33 ± 0.15 roots per shoot with 2.92 ± 0.18 cm root length and N14 produced 35± 0.20 roots per shoot with 3.2 ± 0.25 cm root length. The rooted plantlets were survived 100% after four weeks of acclimatization in greenhouse on Farmyard manure and soil at 2:8 ratios. The optimized protocol can be used to develop healthy and profuse root system in the sugarcane micro-shoots, an essential stage in sugarcane micropropagation.

Effects of indol butyric acid concentration on propagation from cuttings of papaya cultivars ‘Golden’ and ‘Uenf/Caliman 01’

Introduction. Papaya is one of the very few fruit crops multiplied by seed. Unfortunately, the use of seedlings hampers the preservation of favorable plant characteristics and delays the appearance of the first flowers. In addition, the polygamous nature of papaya imposes planting 3-4 seedlings per hole in order to be certain of obtaining the right sex type. These shortcomings can be circumvented by clonal multiplication. This work aimed to multiply selected papaya cultivars from cuttings using the rooting promoting auxin indole-3-butyric acid (IBA). Materials and methods. Two experiments were conducted; the first one followed a completely randomized factorial design, with cultivars ’Golden’ and ‘Uenf/Caliman 01’ as levels of the first factor, and 0, 500, 1,000, 1,500, and 2,000 ppm IBA as levels of the second factor. In this first trial, rooted cuttings of ‘Uenf/Caliman 01’ were taken to the field and compared to seedlings soon after planting and 4.5 months later. In the second experiment, IBA levels were increased aiming to enhance rooting percentage. Physiological assessments of rooted cuttings were also performed in this second experiment. Results and discussion. A concentration of 3,000 ppm IBA gave the best results for ‘Golden’, while lower concentration (1,500 ppm) seemed indicated for ‘Uenf/Caliman 01’. Rooting success in ‘Uenf/Caliman 01’ was improved by using cuttings obtained from beheaded mother plants. The analyses showed that a few roots were sufficient to maintain good water status and photosynthetic rate in new plantlets. Conclusion. Plants propagated from cuttings had early flowering and produced first fruits at a lower height than seedlings in the field.

The Development and Application of ELISA for 3-Indole-Butyric Acid

Indole-3-butyric acid (IBA) is a plant growth hormone used to improve the formation of roots during the culture of cuttings in the greenhouse. According to new EC regulations, IBA levels should approach zero at the time the plantlets are entering the market (30 days). In order to be able to measure IBA in soil samples, polyclonal antibodies and corresponding ELISA was developed. Both chicken (IgY) and rabbit (IgG) were raised and used to evaluate direct and indirect ELISAs. It appeared that rabbit antibody in the indirect ELISA showed the best performance. Due to matrix effects, the standard curve was made in blank soil extract in a range of 0-500 μg/mL. The detection limit at 3SD from zero standard varied from 0.35-3.1 μg/mL. The antibody was highly specific for IBA and showed a mean recovery of 74.5% after two consecutive extraction steps of spiked blank samples. This ELISA was used to monitor IBA in cutting soils extracts from 0-30 days after application (Day 0-1-3-8-30). It appeared that at day 8 IBA was already undetectable. The results were confirmed with HPLC. It may be concluded that the ELISA for IBA developed was suitable to analyze IBA in soil samples and that plantlets in cutting soil treated with IBA are allowed to market according to EC regulations.

Effect of Indole 3-Butyric Acid and Media Type on Adventitious Root Formation in Sheanut Tree (&amp;lt;i&amp;gt;Vitellaria paradoxa&amp;lt;/i&amp;gt; C. F. Gaertn.) Stem Cuttings

Shea nuts play an important role in food security for rural folks within sub-Sahara Africa, serving as the main source of income for many people living in Northern Ghana. Unfortunately, the full economic potential of the Sheanut tree has not been fully realized due to the difficulty involved in its domestication. This difficulty in vegetatively propagating sheanut trees has greatly hindered its cultivation and the realization of its true economic potential. Two experiments were conducted to investigate the effects of rooting media and varying indole 3-butyric acid (IBA) concentrations on adventitious root formation in cuttings taken from coppiced sheanut trees. Results indicated that 3000 ppm produced significantly (p 0.05) better rooting (57.5%) than 5000 ppm (30%), 7000 ppm (45.0%) and the control (7.5%). Although the levels of soluble sugars (SS) and total free phenols (TFP) in the cutting were significantly (p 0.05) higher at the end of the experiment (after IBA treatment) compared to the start (prior to IBA treatment), the SS and TFP trends observed did not clearly explain the rooting differences found between the IBA levels investigated. Callus formation was significantly (p 0.05) higher (35.0%) in the control (no IBA). Generally, callus formation decreased with increasing IBA concentration. In the rooting media experiment, rooting was significantly (p 0.05) higher in the rice husk medium (35.0%) compared to that in the palm fiber (18.3%), saw dust (14.1%) and top soil (16.7%) media.

Effects of Indole-3-butyric Acid on the Rooting Ability of Semi-hardwood Bougainvillea sp. Cuttings

The experiment was carried out to investigate the effect of different concentration of Indole-3-butyric acid (IBA) on the rooting ability of semi-hardwood Bougainvillea flower. The treatments were control (without IBA), 2000, 3000 and 4000 ppm IBA. The cuttings were treated with IBA solution for 7 seconds and immediately transferred to the rooting medium. Perlite was used as a rooting substrate. Treatment was evaluated in a completely randomized design (CRD) with 3 replications. According to the obtained results, there was no significant difference between IBA treatment and control on rooting percentage. The best effect of different levels of IBA on the number of root (8.67 roots per plant) was obtained at 2000 ppm IBA. The highest root length (151.42 mm) was observed at control and there was no significant difference between control and 2000, 4000 ppm IBA. It can be concluded that using perlite as a rooting substrate without using IBA (control) affected rooting ability in bougainvillea flower.

Establishment of an efficient callus induction and plant regeneration system in some wheat (Triticum aestivum L.) cultivars grown in Sudan

A procedure for callus induction and plant regeneration was developed for wheat ( Triticum aestivum ) cultivars grown in Sudan. Mature embryos of cultivar Khaleefa removed from surface sterilized seeds were used as explants. For callus induction, explants were cultured on Murashige and Skoog medium (MS) supplemented with different levels (1.5 to 4.0 mg/l) of 2,4-dichlorophenoxy acetic acid (2,4-D), indole-3- butyric acid (IBA) and indole-3- acetic acid (IAA). After 4 weeks of culture, the highest callus fresh weight (0.05 ± 0.01 g) was obtained on MS medium supplemented with 2.0 mg/L of 2,4-D. For shoot regeneration, the developed calli were transferred to MS medium without growth regulators or with different levels (0.1 to 3.0 mg/l) of 5-phenylcarbamoylamino-1,2,3-thiadiazole (thidiazuron) (TDZ), benzyladenine (BA) and kinetin (KN) alone or in combination with 2.0 mg/L of 2,4-D. After 6 weeks of culture, the best result for regeneration percentage (40%) was obtained on MS medium without growth regulators. Callus derived shoots were rooted most effectively in half-strength MS medium without or with different levels of IBA. To determine the genotypic effect, the developed procedure was used to evaluate the regeneration ability of other 5 Sudanese wheat cultivars. Significant differences were observed between genotypes for plant regeneration ability, indicating that these criteria are genotype dependent. The acclimatized regenerated plants were morphologically uniform with normal leaf shape and growth pattern under greenhouse conditions. Key words : Triticum aestivum , callus induction, regeneration, 2,4-dichlorophenoxyacetic acid (2,4-D), genotypes.

Effect of phase of medium, growth regulators and nutrient supplementations on in vitro shoot-tip necrosis in pear

The incidence of shoot-tip necrosis (STN) was observed during the in vitro shoot multiplication and rooting stages of five Pyrus genotypes. During shoot multiplication, there was no incidence of STN in any of the five pear genotypes after 2 weeks of culture. However, after 6 weeks of culturing, necrotic apices were observed in all the pear genotypes, except wild pear. After 8 weeks of culture, 79.31% STN was observed in Punjab Beauty, followed by Patharnakh (49.60%), kainth (24.65%), shiara (17.68%) and wild pear (7.32%). Irrespective of the genotype, STN increased with an increase in BA concentration only in 8-week-old cultures. During in vitro rooting, the incidence of STN also varied with the genotype. In all five pear genotypes, the use of liquid media for in vitro rhizogenesis was useful in reducing the incidence of necrotic apices. The auxin type and level also influenced the occurrence of STN significantly. In wild pear, the incidence of necrotic apices increased with an increase in the concentration of auxins. A combination of Naphthalene acetic acid (NAA)+Indole-3-butyric acid (IBA) resulted in a higher incidence of STN than IBA or NAA alone at higher concentrations. Lower concentrations of IBA (0.62 to 2.46 µM L−1) resulted in a higher incidence of STN compared with the lower levels of NAA (0.67 and 1.34 µM L−1). In kainth, there was no significant difference in the incidence of STN at higher concentrations of IBA (5.37 and 10.74 µM L−1) and NAA (4.92 and 9.84 µM L−1). 2, 4-D resulted in a higher incidence of STN in comparison with IBA, NAA or NAA+IBA in the rooting medium. In Punjab Beauty, the percentage of necrotic apices at 0.67 and 1.34 µM L−1 NAA (40.46% and 40.04%, respectively) was on a par with the control (37.92%), but it was significantly less than the STN observed at 0.62 and 1.23 µM L−1 of IBA. In Patharnakh, IBA resulted in a significantly higher incidence of STN than NAA at all tested concentrations. In shiara, all the auxin treatments significantly increased STN. At lower levels (0.62 and 1.23 µM L−1), IBA resulted in a higher incidence of STN than the lower concentration of NAA (0.67 and 1.34 µM L−1), whereas at higher levels (2.46 to 9.84 µM L−1) IBA was on a par with NAA (2.69 to 10.74 µM L−1). Supplementation with calcium and boron significantly affected the percentage of necrotic apices in wild pear, Punjab Beauty and Patharnakh. In wild pear, raising the calcium level to 3 mM reduced the STN to 2.60%. In Punjab Beauty and Patharnakh, STN increased with an increase in calcium levels. Boron supplementations eliminated the incidence of STN in wild pear. Similarly, in Patharnakh, boron (500 µM and 1000 µM) significantly reduced the STN. Callus development was also observed at the base of pear shoots showing STN symptoms during rooting phase, but it did not show any significant trend. Higher levels of IBA, NAA+IBA and 2, 4-D resulted in the formation of large-sized calluses and STN in wild pear shoots on solid medium. There was a high incidence of STN in Punjab Beauty, Patharnakh and shiara but, the basal callus development in these genotypes was much less.