Indole-3-butyric Acid Research Articles

Plant Growth Regulators and Rooting Media: A Viable Approach for Growth and Performance of Citrus

Plant growth regulators accompanied with appropriate growth medium can boost up the growth and performance of plants to a greater extent. PGRs such as auxin, gibberellin and cytokine play an exaggerative role in growth and development of the citrus. Moreover, the study reflects a clear overview of the impact of PGRs and different growth media to encourage rooting percentage, number of leaves, survival percentage, sprouting time, and root length of citrus cuttings. Citrus is a versatile fruit crop having a huge number of varieties, cultivars, and species; comes in different colours and flavours. Although, there are different methods used in the multiplication of citrus plant which includes budding, grafting, cutting, air layering, etc. However, propagation by cutting technique is the most commercial and farmer’s friendly approach. Different elements such as concentration of PGRs, age of plants and environmental factors are responsible for the successful growth of the citrus cuttings. Naphthalene acetic acid (NAA) and indole-3-butyric acid (IBA) are the two types of auxin, which are most commonly utilized in citrus propagation. Rooting medium plays a crucial role in the supply the minerals and availability of water in citrus. An absolute rooting medium must have more enough nutrients and water holding capacity with better drainage as well as sufficient air spores for excellent gaseous exchange that fruitfully influence the rooting ability and also have a profound effect on growth and development in citrus cutting. The best time for cutting of citrus stems is in between the July and August.

Effect of two different base cuts and indole-3-butyric acid (IBA) doses on rooting of stem cuttings of wild Silene compacta Fischer

Silene compacta Fisch. ex Hornem., which grows naturally, is a plant species with high ornamental plant potential in the Silene L. genus of the Caryophyllaceae family. Vegetative propagation is one of the important ways to preserve naturally growing and cultivated plant species. In this study, the effect of two different cutting areas of the cutting base (above the node-below the node) and five different indole-3-butyric acid (IBA) doses (control, 500, 1000, 2000 and 4000 ppm) on the rooting of stem cuttings taken from individuals of the natural S. compacta species were investigated. IBA was applied to the cuttings’ bases in a commercial rooting powder. Perlite+peat mixture at a ratio of 1:1 (v/v) was used in the rooting medium. Survival rate, rooting percentage, blooming rate, root number, root length, seedling height, seedling stem diameter, side shoot number, shoot length and shoot stem diameter were evaluated. The evaluation was made one month after the start of the experiment. As a result, the highest survival rate in cuttings was obtained from above-node control group (100%) and under-node 2000 ppm IBA (95%) application, and the highest rooting percentage was obtained from under-node 2000 ppm IBA (68%) and above-node control group (65%), respectively. Based on the results, it can be concluded that different cuttings of the cutting base and IBA concentrations have different effects on the rooting success of the S. compacta species with stem cuttings.

Long-term organogenic callus cultivation of Ranunculus illyricus L.: a blueprint for sustainable ex situ conservation of the species in urban greenery

The growing trend of introducing wild plant species into urban environments necessitates the identification of novel species adapted to prevailing conditions. A promising reservoir of such species may be xerothermic communities where Ranunculus illyricus occurs. This study aimed to establish a micropropagation protocol for R. illyricus using indirect organogenesis. The protocol includes initiation of culture from various explants, callus proliferation, shoot regeneration, multiplication, and concurrent rooting. Callus appeared on most types of vegetative explants tested, but stolons were considered the best due to their good availability, high disinfection (85%), and robust callus production (maximum increase − 363.1%). The growth rate of the callus fresh matter (CFM) obtained from stolons was calculated. Greater CFM was obtained on the medium with the supplemented picloram 8.0 mg L− 1 with kinetin 5.0 mg L− 1 and in second part of experiment on medium with the addition of 2,4-D (2,4-dichlorophenoxyacetic acid) 2.0 mg L− 1 alone or picloram 6.0 mg L− 1 with kinetin 8.0 mg L− 1. Shoot organogenesis was observed on macronutrients B5 (Gamborg medium), micronutrients MS (Murashige and Skoog) medium with the addition of 2.0 mg L− 1 IBA (indole-3-butyric acid) and 4.0 mg L− 1 BAP (6-benzylaminopurine). To document the process of callus differentiation, microscopic preparations were prepared. Subsequently, the regenerated plants underwent acclimatisation and their growth in an ex situ collection was monitored over three growing seasons. In particular, in vitro-origin plants exhibited developmental patterns similar to those of their seed-origin counterparts. The incorporation of R. illyricus into urban landscapes not only increases aesthetic appeal, but also ensures the preservation of valuable genetic resources for this rare species, potentially contributing to effective ex situ conservation in the future. This marks the first scientific report on in vitro cultures of R. illyricus.

In vitro multiplication and phytochemical evaluation of Apios americana Medik for enhanced production of the staple food and tissues with versatile bioactivities

Apios americana Medik tissues, including tubers, flowers, leaves, and vines have both nutritional and therapeutic benefits. These tissues are extensively used in products like beverages and food supplements, driving an exponential increase in worldwide demand for the plant. However, conventional propagation of A. americana through seeds and tubers faces several challenges, including limited seed sets under manual pollination, resulting in reduced production. To overcome these challenges, micropropagation emerges as a promising solution. The current research study has developed an effective in vitro propagation strategy for A. americana using direct regeneration from apical segment explants. Full-strength Quoirin and Lepoivre (QL) medium, supplemented with vitamins and 2.0 mg/L benzylaminopurine (BAP), yielded the highest number of shoots (7.50 ± 0.06) per apical segment explant. QL medium fortified with 1.0 mg/L indole-3-butyric acid (IBA) demonstrated the highest root number (2.80 ± 0.30), length (85.80 ± 7.49 mm), and surface area (10.40 ± 0.82 cm2) in regenerated A. americana shoots. The survival rate of the regenerants in the ex vitro environment was 92.7% after acclimatization. In vitro-regenerated A. americana plants and mother plants exhibited similar ploidy level, chlorophyll content, photosynthetic rate, phytochemical composition, and antioxidant capacity, indicating similarity in their physiological and biochemical properties. This protocol offers a rapid and scalable method for generating high-quality, A. americana plant stocks with stable genome size/ploidy level, meeting the exponentially growing demand for plant tissues. Additionally, it holds potential applications in A. americana breeding and germplasm preservation.

EFFICIENT CLONAL PROPAGATION OF GUAVA CULTIVARS BY MINI SOFTWOOD CUTTINGS

Guava (Psidium guajava L.) is commercially propagated by seeds in Punjab and vegetative propagation systems are lacking. Propagation by stem cuttings is handicapped by the non-availability of plant material in bulk for cuttings and season dependency. Hence, juvenile mini softwood (MSW) shoot cuttings (3"-4") of Gola (Round) cultivar having two to three nodes were treated with plant growth regulators (PGRs) including indole butyric acid ‘IBA’ or naphthalene acetic acid ‘NAA’ in combinations with benzyl aminopurine ‘BAP’ and planted in sand, silt and coco peat (40:40:20 v/v) under CRD layout for PGR optimization. Cuttings treated with BAP and IBA (2 mgL-1 + 3 mgL-1) started early sprouting in 8 days and induced a greater number of branches (5-6), number of leaves (11), number of roots (6-7) and long roots (14 cm). Whereas, sprout length was higher up to 14 cm in cuttings treated with BAP and IBA (3 mgL-1 + 1 mgL-1). In the second part of the study, application of the optimized PGR treatment of BAP and IBA (2 mgL-1 + 3 mgL-1) to MSW cuttings of different commercial strains of cultivars Gola (Round) and Surahi (Pyriform) showed a better number of roots (5, 4), root length (13 cm, 11 cm), bud sprouting (100% and 80%) and number of nodes (5 each) in Gola (Sadabahar ‘G1’) and Surahi (Sindhi Bao ‘S2’), respectively. The rooted cuttings were maintained under standard growth room conditions and higher humidity till proper plant growth and the established plantlets were transferred to green house. This study established an efficient clonal propagation system using MSW cuttings thus reducing the plant material and PGRs required for mass multiplication of elite guava cultivars. Keywords: Auxin, cytokinin, softwood cuttings, shoot, rooting.

Does the Physiological Age of Stock Plant Material Affect the Uptake of Indole-3-Butyric Acid (IBA) in Leafy Cuttings of Prunus subhirtella ‘Autumnalis’?

The aim of this study was to investigate the uptake of exogenously added indole-3-butyric acid (IBA) as an adventitious root (AR) inducer. The concentration of indole-3-butyric acid (IBA) in leafy cuttings of Prunus subhirtella ‘Autumnalis’ from stock material of different physiological ages was analyzed at three evaluation time points (1, 4, 24 h). We examined three stock plants: a physiologically mature stock plant (approximately 60 years old); physiologically rejuvenated plants (16 years old) that were previously propagated by cuttings from semi-mature stock material; and in vitro juvenile stock material. For IBA to effectively induce AR formation, it must first be converted into the active hormone indole-3-acetic acid (IAA). The total concentration of IAA in the first 24 h after cutting was evaluated according to the physiological age of the stock material and the IAA concentration in the cuttings according to the evaluation time points was assessed. We also examined rooting success and the quality of the adventitious root system depending on the physiological age of the stock material. High performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS) was used to identify and quantify the phytohormones. The difference in rooting and quality of the developed AR was observed between semi-mature stock and mature stock material. Cuttings from semi-mature plants rooted in 95.00 ± 5.00% of cases, while cuttings from mature stock plants only rooted in 68.33 ± 4.09%. Successfully rooted cuttings from mature stock material were accompanied by callus formation, which was significantly lower in cuttings from semi-mature stock material. Our results show that the interaction between physiological age and time after severance had no effect on IBA concentration in the cuttings (p = 0.907). Duration of time elapsed since severing (evaluation time points) had a significant effect on the uptake of IBA (p = 0.002 **) and IAA (p = 0.0009 ***) in the cuttings. Physiological age had a significant effect on IAA concentration in the early stages of AR formation in the cuttings (p = 0.038 *). Our results suggest that the dynamics of other endogenous phytohormones and the physiological state of the stock plant are also important for AR formation, as the proportion of successfully rooted cuttings from semi-mature stock material was significantly higher than the proportion of successfully rooted cuttings from mature stock material, irrespective of IBA uptake in stock material of different ages.

Effects of natural and chemical rooting stimulants on some root traits of two varieties of pomegranate (Punica granatum L.) cuttings

The experiment ran from the middle of February until the start of November 2023 under the plant canopy of the Department of Horticulture and Landscape, College of Agriculture, University of Kerbala. The study employed a Randomized Complete Block Design (R.C.B.D.) as a factorial experiment, with two pomegranate varieties (Yamani and Bashkan) as the first factor and various combinations of natural and chemical rootings as the second factor. These included extracts of moringa leaves (M0, M1) and licorice roots (L0, L1) at concentrations of 0 and 15 g L-1 each, as well as indole butyric acid at a concentration of 0 and 10 mg L-1 (B0, B1). The majority of the root features of the resultant seedlings demonstrated that, overall, the Bashkan variety outperformed the Yamani variety; however, this superiority varied when combined with other rooting combinations. Between the rooting stimulant combinations utilized in the study, the cuttings' dipping results differed. When it came to the quantity, size, and fresh and dry weight of the root system, indole butyric acid in combination with B1M0L0 performed better. It resulted in 250.000 root seedlings-1, 2.270 cm3, 20,680 g, and 6,650 g, respectively. In contrast, the B0M0L1 licorice root treatment demonstrated superior root length, reaching 38,100 cm. Both the percentage of rooting and the average root diameter were the largest in the combination including both extracts, B0M1L1, reaching 5.170% and 1.603 mm, respectively. Given that natural extracts have outperformed chemical radicals in the majority of the rooting qualities under study—such as licorice root extract and moringa leaf extract—it is possible to conclude from the aforementioned results on their suitability for usage as an alternative.

Growth, vegetative rescue and vegetative propagation in Eucalyptus species and hybrids

The objective of the study was the evaluation of survival and productivity indicators in different species/hybrids of Eucalyptus in the adult stage, as well as the vegetative rescue of adult trees and cuttings, testing for species/hybrids, concentration of growth regulator and substrates in rooting. In the evaluation of species/hybrids, height (m), diameter at breast height (DBH, cm) and individual volume (m3 per individual) were measured, and survival was evaluated. In the vegetative rescue treatment, the number of shoots produced at 90, 120 and 210 days was evaluated. In the cutting experiments, the species that produced rescue shoots were tested, in addition to indole-3-butyric acid (IBA) doses (0, 1 500, 3 000 and 4 500 mg L−1) and four substrates for rooting cuttings. The experiments of IBA doses and substrates were carried out using Eucalyptus saligna plants. In the cutting experiments, after 120 days of cultivation, the following variables were evaluated: callus formation (%), survival (%), rooting (%), number and length of roots. The best results regarding survival and quantitative variables of the species/hybrids were obtained for E. dunnii, E. dunnii × E. grandis and E. pellita. In the vegetative rescue, E. dunnii × E. grandis and E. pellita had the highest formation of shoots and the girdling vegetative rescue method had the best results in terms of generated shoots. E. saligna had better results regarding the variables related to the rooting of cuttings. The substrate S3 and the use of 1 500 mg L−1 of IBA provided the highest survival rate and better variables related to the rooting of the cuttings.

Treatments of Coleus forskholii that increase rooting to get larger crude forskolin extract

The aim is study of effect of some phytohormones and microelements in a tissue culture system to extract forskolin by different solvents from hairy roots in Plectranthus barbatus Andr. (Syn.Coleus forskohlii Briq.). Our results indicated that, the best parameters for increasing the number and length of roots were by indole butyric acid. Low concentrations of boron and silicon also promote rooting of Coleus cuttings. Methanol is a more efficient solvent than ethanol and ethyl acetate in forskolin extraction. Root hairs of the terminal cuttings of Coleus forskohlii appear after treatment with bacterial inoculum Agrobacterium rhizogenes. Forskolin levels increased to 13 and 5.3 mg/L in hair roots after 4 weeks of incubation. Forskolin extraction from tissue culture media is more efficient (40 mg/L per g wet weight) compared to extraction from root cuttings (13 mg/10 g wet weight).

Incision in the base and indolebutyric acid to promote the rooting of 'Bengal' litchi cuttings

A alternative to producing litchi (Litchi sinensis Sonn.) seedlings is by cuttings. However, the main drawback of using this method is related to the difficulty of rooting presented by this species. Thus, the objective of this study was to evaluate the rooting of semihardwood cuttings of litchi ‘Bengal’ at different concentrations of indolebutyric acid, with or without incision in the base. The experimental design was completely randomized with five replicates of 10 cuttings in a factorial 3X2 (three IBA concentrations: 0, 1.000 and 2.000 mg L-1; with or without incision in the base). After 126 days, the variables evaluated were: cutting survival, leaf retention, cutting with callus not rooted, rooted cutting, number of roots per cutting, length of major roots per cutting and dry weight of roots per cutting. For rooting, the IBA application was efficient only when the cuttings were not injured. In addition, there was no influence of the types of cuttings in the IBA concentrations. However, in those with incision at the base, the means were higher without the application of the plant growth regulator. Thus, the 'Bengal' litchi can be multiplied by semihardwood cuttings with incision at the base of the cuttings, without the use of IBA.

An Efficient Method for the Propagation of Bougainvillea glabra ‘New River’ (Nyctaginaceae) from In Vitro Stem Segments

Bougainvillea, an evergreen climbing shrub of the Nyctaginaceae family, holds significant ornamental, economic, and medicinal value. Bougainvillea glabra ‘New River’ is widely used in landscapes due to its strong adaptability to the environment, abundance of flowers, and frequent flowering. Traditionally, Bougainvillea glabra ‘New River’ cultivation has relied on methods such as cuttings or grafting, with limited research on in vitro tissue culture propagation. This study aimed to optimize the tissue culture system, exploring a combination of plant growth regulators (PGRs) for Bougainvillea regeneration from in vitro stem segments. The Murashige and Skoog (MS) medium supplemented with indole-3-butyric acid (IBA), 6-benzylaminopurine (6-BA), and 1-naphthlcetic acid (NAA) was employed. The optimal sterilization of Bougainvillea stem segments involved a 30 s treatment with 75% alcohol and 10 min with 1% NaClO. The synergistic effect of 0.1 mg·L−1 of NAA and 2.5 mg·L−1 of 6-BA maximized the shoot sprouting frequency, while 2.5 mg·L−1 of 6-BA and 0.1 mg·L−1 of NAA produced the maximum shoots. Furthermore, 1.5 mg·L−1 of IBA and 0.1 mg·L−1 of NAA induced the highest rooting levels. This work demonstrates the successful adaptation of a greenhouse environment to efficiently regenerate plants in vitro from stem segments. This approach allows for the mass production of Bougainvillea glabra ‘New River’.

Comprehensive study on in vitro propagation of some imported peach rootstocks: in vitro explant surface sterilization and bud proliferation

The present study was conducted in the Laboratory of Tissue Culture, Horticulture Department, Faculty of Agriculture, Damietta University, Egypt. The objective of this study was to establish a micropropagation protocol suitable for three imported peach rootstocks: Okinawa (P. persica), Nemared (P. persica × P. davidiana) × P. persica), and Garnem (P. dulcis × P. persica) in vitro. The results showed that soaking the explants in sodium hypochlorite (NaOCl) at 20% for 15 min produced the highest responsiveness (82.81%), survival (96.61%), with the lowest mortality (3.14%) and contamination (0.24%). Explants of the Garnem genotype had the best response (89.12%), survival (90.62%), lowest mortality (0.00%), and highest contamination (9.37%) when compared to the other genotypes. In comparison with axillary buds, the shoot tip displayed the highest responsiveness, survival, and death (100, 87.40, and 12.59%, respectively), as well as the least significant contamination (0.00%). Additionally, the percentages of responsive, survived, dead, and contaminated explants at the various collection dates varied significantly. The 6-benzylaminopurine (BAP) concentrations used (3 to 5.0 mg/L) demonstrated similar behavior in terms of in vitro proliferation, with rates of 3.77 to 6.11, 4.33 to 8.88, and 3.33 to 7.44 shoot numbers per explant for the Okinawa, Nemared, and Garnem peach rootstocks, respectively, indicating that the number of shoot proliferations is genotype-dependent. Additionally, using 5.0 mg/L BAP in combination with 0.2 mg/L IBA significantly increased average shoot proliferation (96.29%), number of shoots per explant (7.48), and average leaf number/explant (16.33) compared to the other treatments. Based on these results, adventitious bud development was enhanced during in vitro multiplication of the Okinawa, Nemared, and Garnem peach rootstocks by the synergistic interaction of indole-butyric acid (IBA) and 6-benzylaminopurine (BAP).

Transcriptome profiling of indole-3-butyric acid–induced adventitious root formation in softwood cuttings of walnut

Inducing adventitious root (AR) formation in mature walnut species (Juglans L.) is challenging. However, the AR formation of mature trees can be improved by rejuvenation. In rejuvenated cuttings, exogenous indole-3-butyric acid (IBA) is essential for AR formation, and the underlying mechanism is still not well understood. Therefore, we utilized transcriptome sequencing to investigate the mechanism of IBA-induced AR formation. Our results revealed that, in comparison to the control group, IBA treatment (9 mmol · L-1) significantly increased the endogenous indole-3-acetic acid (IAA) content, leading to an enhanced rooting rate. We performed RNA sequencing to identify differentially expressed genes (DEGs) between the IBA-treated and control (CK) groups at 1, 2, 3, and 5 days after cutting (DAC). The results showed that, compared to the control cuttings, there were 1 539, 889, 785, and 984 up-regulated genes and 2 791, 2 936, 3 017, and 1 752 down-regulated genes, at 1, 2, 3, and 5 DAC, respectively. Analysis of RNA-seq data revealed that G-type ATP-binding cassette 36/37 (ABCG36/37) and ATP-binding cassette subfamily D 1 (ABCD1), associated with IBA transport, were down-regulated in the rejuvenation cuttings. In contrast, PIN-FORMED (PIN) and PINOID (PID), associated with auxin efflux, were up-regulated. We identified 49 auxin/indole-3-acetic acid (AUX/IAA)-encoding genes, including IAA1, IAA3, IAA5, IAA6, IAA8, IAA11, IAA12, IAA19, and IAA20, which were up-regulated at 1–5 DAC in the rejuvenated cuttings. This study highlights that the overexpression of JrWOX5/11 in poplar significantly enhance AR growth, as evidenced by increased root length, surface area, volume, and quantity. Moreover, the co-expression network analysis involving JrWOX11 and JrWOX5 in walnut cuttings elucidates complex genetic interactions, underscoring their pivotal role in the formation of AR. Our data supported the following molecular mechanism of IBA-induced adventitious root formation. Firstly, IBA is converted to free IAA in peroxisomes. Then, the highly concentrated IAA in the procambium and parenchyma cells induces WUSCHEL-related homeobox 11 (WOX11) expression at two days. Finally, WOX11 acts redundantly to up-regulate WOX5, initiating the development of root primordia cells.

Preserving the Heritage "Kapok Tree" [Ceiba pentandra (L.) Gaertn.] of the University of the Philippines through Vegetative Propagation

A Ceiba pentandra at the University of the Philippines Los Baños was a centennial tree that was felled as it posed a threat to the community. To preserve its historical value and sustain its lineage, a low-cost technique of vegetative propagation was undertaken by determining the effect of varying leaf numbers (one, two, and three leaves) and indole-3-butyric acid (IBA) doses (0, 100, and 500 ppm). Results of the analysis of variance revealed significant (P = 0.012) to highly significant (P < 0.001) variations in all rooting parameters after 2 wk, whereas significant (P = 0.037) only in terms of shoot length after 3 and 4 wk. Meanwhile, significant (P = 0.002) variations due to IBA were observed only on shoot length after 2 wk but not after 3 and 4 wk. A comparison of the means revealed the superiority of cuttings with the greatest number (3) of leaves. Furthermore, root traits and cutting sizes associations obtained positive and significant (r2 = 0.17–0.98, P < 0.0001). Both the weakest and strongest associations were detected in cuttings after 2 wk, whereas increasing percentages of the highest, positive, and significant correlations (r2 = 0.80–0.98, P < 0.0001) were observed from Weeks 2–4, suggesting that the effect of varying carbohydrate may be detected after 2 wk and tend to be more pronounced the longer they stayed in the improvised rooting chamber.

Effect of brassinosteroids on rooting of the ornamental deciduous shrubs

Brassinosteroids are a developing group of growth regulators. They are a group of steroid hormones involved in plants’ physiological and developmental processes. Among other things, they are responsible for cell wall regeneration or cell elongation. This experiment aimed to examine the effect of rooting stimulants on rhizogenesis in cuttings of two deciduous shrub species: Philadelphus ’Virginal’ and Hydrangea paniculata ’Limelight’. Aqueous solutions of indole-3-butyric acid (IBA) at 200 mg·L–1, Brassinolide (BL) at 0.05% and 24-epibrassinolide (24epiBL) (0.05%) were used in this study. The results obtained showed that both auxin and both of the brassinosteroids used increased the percentage of rooted cuttings almost twice, the degree of rooted cuttings and root length – for BL + IBA – longer roots than the control by 41% in jasmine and by 59% in hydrangea. The growth regulators applied during the rooting of cuttings also caused changes in the organic compound content of plant tissues and the activity of oxidative stress enzymes. The studies and results suggest that brassinosteroids may soon replace the popular rooting stimulants.

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

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

The frequency and phenological stage of foliar application of nutrients and biostimulant can increase sugarcane yield and biomass and bioenergy productions

AbstractThe impacts of sugarcane (Saccharum spp.) production include an extensive area of cultivation, high use of technology, and the generation of by‐products that must be utilized. Achieving higher productivity while reducing the expansion of cultivation is challenging. A potential strategy for increasing sugarcane yields and productivity is the foliar application of nutrients and biostimulants at different stages of sugarcane growth. The present study assessed the impact of the foliar application of nutrients (N, B, Cu, and Zn) and a growth regulator as biostimulant (indole butyric acid, gibberellic acid, and kinetin) on sugarcane metabolism, stalk and sugar production, and quality. Field experiments were performed at 17 sites during four growing seasons (2017–2018, 2018–2019, 2019–2020, and 2020–2021) using sugarcane with three harvest times (early, mid‐late, and late harvests). The treatments were as follows: (i) no foliar application of the biostimulant and nutrients (control), (ii) foliar application of the biostimulant and nutrients at the vegetative stage (VS) of sugarcane, (iii) foliar application of the biostimulant and nutrients at the maturation stage (MS) of sugarcane, and (iv) foliar application of the biostimulant and nutrients at both the vegetative and maturation stages (VMS). Foliar application did not increase ribulose 1,5‐bisphosphate carboxylase activity but increased phosphoenolpyruvate carboxylase activity and the activities of the antioxidant enzymes. Peroxidase and catalase activities were higher, >100% and 45%, respectively, in VMS, whereas superoxide dismutase activity increased by 54% in MS compared with control. Consistent with these results, sugarcane had low hydrogen peroxide and malondialdehyde contents in VMS. In addition, the plant biometric parameters were highest in VMS, which sugarcane produced 105, 92, and 86 Mg stalk h−1 in early, mid‐late, and late harvest seasons, respectively. In summary, the foliar application of the biostimulant and nutrients efficiently promoted the growth, productivity, and quality of early, mid‐late, and late harvest seasons. The positive effects of foliar application on the enzymatic and physiological responses of sugarcane can be achieved when applications are performed in both the VMS in all harvest seasons.

Sesame (Sesamum indicum L.) Response to Soil Additives Applied in-Furrow at Planting

Aims: Studies were conducted to study the response of sesame to soil additives applied in-furrow. 
 Study Design: Randomized complete block with 4 replications.
 Place and Duration of Study: Field experiments were carried out during the 2016 through 2018 growing seasons in south-central Texas near Yoakum (29.27704o N, -97.12453o W).
 Methodology: Sesame seed was planted < 2.54 cm deep. Treatments were applied using a CO2-pressurized sprayer in 46.8 L ha-1 of water with one Teejet® orifice disc #45 nozzle per row immediately after seed drop but prior to furrow closure. Each plot consisted of two rows spaced 97 cm apart and 7.6 m long. Sprinkler irrigation was applied on a 2- to 3-wk schedule throughout the growing season as needed. S-metolachlor at 1.4 kg ha-1 was applied preemergence while clethodim at 0.11 kg ha-1 and diuron at 1.12 kg ha-1 were applied postemergence to control annual grasses and broadleaf weeds that were present. 
 Results: In 2016, treatments containing 7% N + 10% chelated Fe, gibberellic acid + 3-indolebutyric acid (0.045%) + cytokinin as Kinetin (0.09%), and pop-up fertilizer (9-30-0 + Zn) resulted in the greatest sesame emergence. In 2017, 2% N, bifenthrin + Bacillus amyloliquefaciens strain D747, and humic acids + Bacillus spp. resulted in greater emergence (90-97%) while in 2018, Azospirillum brasilense and 2% N resulted in the greater emergence (90-91%). In 2016, 2% N produced the greatest yield while in 2018 2% N and the 3-way combination of cytokinin as kinetin (0.090%) + gibberellic acid + indole-3-butyric acid (0.045%) resulted in up to a 117% increase in yield over the untreated. 
 Conclusion: The 3-way combination of gibberellic acid + 3-indolebutyric acid (0.045%) + cytokinin as kinetin (0.090%) and 2 % N proved to be the most consistent soil additives and resulted in a yield increases in the two years that the studies were harvested.

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

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

Efficient regeneration of in vitro derived plants and genetic fidelity assessment of Phalaenopsis orchid

This study uses inflorescence stalk node as explants to establish an efficient and quick Phalaenopsis orchids cloning procedure for the most significant monopodial orchid in floriculture, without callus formation. The current study aimed to develop a rapid and easy regeneration process utilizing flower stalk nodes as explants, while also evaluating the clonal fidelity of the in vitro micropropagated plants through the analysis of RAPD markers. The tissue-cultured plantlets were grown on a solidified half-strength Murashig and Skoog (MS) base medium enriched with 15% coconut water (CW), 150 mg L−1 activated charcoal, and a mixture of 6-benzylaminopurine, BAP (cytokinins) and α-napthalene acetic acid, NAA and indole 3-butyric acid, IBA (auxins). After 14 weeks of growth, the early production of shoot bud was reported in ½ MS medium enriched with 2.5 mg L−1 BAP alone. Maximum shoot bud multiplication was observed in ½ MS fortified with BAP (2.5 mg L−1) + NAA (1.0 mg L−1), while the lowest was observed in 1.5 mg L−1 BAP + 0.5 mg L−1 IBA after 4 months of culturing. In this investigation, roots emerged simultaneously with shoot elongation from the axil, indicating the absence of a distinct rooting stage. The largest number of roots (3.25) was produced by BAP (2.5 mg L−1) + IBA (1.0 mg L−1) compared to NAA. Control, on the other hand, displayed no signs of root growth. Tissue cultured plantlets with well developed root systems while planted in a potting mixture of brick and charcoal (1: 1) resulted in a 70% survival rate during hardening. The clonal faithfulness of in vitro regenerated crop plantlets to the mother plant was demonstrated by the DNA extraction method with ten micropropagated plants’ young leaves as well as the mother plant using random amplification of a polymorphic DNA marker.