Plant Growth Regulator Treatments Research Articles

Adventitious Rooting of Lavandula x intermedia Cuttings

Abstract Due to challenges associated with lavender propagation, Texas hybrid lavender (lavandin) growers require revised propagation information. Therefore, experiments investigated effects of media and plant growth regulators (PGR) on rooting of three different lavandin (Lavandula x intermedia) cultivars. PGRs applied to cuttings were naphthaleneacetic acid (NAA), or indole-3-butyric acid (IBA) at three concentrations. In addition, four rooting media were examined. Cuttings exposed to a peat moss/sand medium had the greatest mean overall rooting percentage, number of roots, and regardless of cultivar, cuttings exposed to the peat moss/sand medium had the longest roots. In general, mean rooting data were also greatest for cuttings dipped in NAA at 0.5 and 1.0 g·L−1 (500 and 1000 ppm, respectively). Overall, across all media and PGR treatments ‘Grosso' cuttings tended to have the greatest rooting percentage and longest roots. In addition, compared to the no PGR treatment, ‘Provence' and ‘Hidcote Giant' cuttings exposed to the peat moss/sand medium and greater PGR concentrations produced cuttings with an increased mean rooting percentage and longer roots. When rooting lavandin cultivars, results indicate correct media selection, PGR formulation, and PGR concentration determine propagation success. Index words: lavandin, Lavandula x intermedia Emeric ex Loisel, peat moss, perlite, rooting percentage, root quality, sand. Chemicals used in this study: indole-3-butyric acid (IBA; 0.5, 1.0, and 1.5 g.L−1); naphthaleneacetic acid (NAA; 0.5, 1.0, and 1.5 g.L−1). Species used in this study: ‘Grosso', ‘Provence', and ‘Hidcote Giant' lavandin (Lavandula x intermedia Emeric ex Loisel.).

Assessing fine fescue mixtures and plant growth regulator applications to determine their effect on traffic tolerance and divot recovery

AbstractThere has been some transition to using low‐input fine fescues on golf courses, but these species have poor traffic tolerance and divot recovery, making them impractical for playable areas on golf courses. The objectives of this study were to determine the effect of the plant growth regulator (PGR) trinexapac‐ethyl on the performance of fine fescue mixtures when managed as a golf course fairway and to identify fine fescue mixtures that perform well under traffic stress. Twenty‐five mixtures were tested that combined ‘Treazure II’ chewings fescue (Festuca rubra L. ssp. commutata Gaudin), ‘Beacon’ hard fescue (Festuca brevipila Tracey), ‘Navigator II’ strong creeping red fescue (Festuca rubra L. ssp. rubra Gaudin), ‘Shoreline’ slender creeping red fescue [Festuca rubra L. ssp. littoralis (G. Mey.) Auquier], and ‘Quatro’ sheep fescue (Festuca ovina L.). Field experiments were conducted in St. Paul, MN, with PGR, mixture, and traffic treatments. The benefits of the PGR trinexapac‐ethyl on fine fescue fairway quality was relatively small compared with the benefits of traffic management and mixture selection. Hard fescue, slender creeping red fescue, strong creeping red fescue, and sheep fescue had the greatest impact on increasing visual turfgrass quality after traffic treatments. There was no significant difference in divot recovery with any mixtures, and no divots had recovered after 12 mo.

Plant growth regulators and rooting substrates affect growth and development of Salix koriyanagi cuttings

Salix koriyanagi is an endemic species with high conservation priority in Korea because of its isolated distribution. We evaluated the effects of plant growth regulators (PGRs), including 500 mg L-1 or 1000 mg L-1 IBA, 1000 mg L-1 or 2000 mg L-1 NAA and rootone, and rooting substrates such as phenolic foam, bonded medium, and perlite on the growth and development of S. koriyanagi cuttings. The highest percent rooting was observed in the cuttings treated with 500 mg L-1 IBA in phenolic foam. PGR treatment increased the number of roots on the cuttings, and the highest root fresh and dry weights were observed in the cuttings treated with 500 mg L-1 IBA in phenolic foam. These results suggest that treatment with 500 mg L-1 IBA in phenolic foam was the most effective for root initiation in this species and can be used for the mass production of Korean endemic S. koriyanagi through cuttings.

Volatile profiles of three Mentha species and the effect of plant growth regulators (PGRs) on the volatile organic compounds (VOCs) in Mentha spicata

ABSTRACT The study profiled the volatiles in Mentha longifolia, M. piperita and M. spicata and examined the effect of plant growth regulators (PGRs) - IAA, NaDK and SA on the modulations of volatile organic compounds (VOCs) in M. spicata. GC-MS was used to analyze and identify the compounds in hexane extractions from the selected Mentha sp. Sixteen metabolites belonging to monoterpenes, sesquiterpenes, esters, ethers, ketones, phenols and carbobicyclic compounds were detected. Some important metabolites viz., β-pinene, 1,8-cineol, 1,4-benzenediol, 2,5-dimethyl-, (Z)-β–caryophyllene, cis-β-farnesene, cis-muurola-4 (14),5-diene, germacrene D were found which increased in their relative concentrations compared to control after PGRs treatment.

Effect of different treatments and light quality on Ulmus pumila L. germination and seedling growth

Ulmus pumila L. has potential benefits for erosion control, landscape ornamentals, and the bark contains substances that may have therapeutic value. To determine optimal growth conditions, we investigated the effect of water, sucrose, and exogenous plant growth regulator (6 benzylaminopurine: BA, indolebutyric acid: IBA and gibberellic acid: GA3) treatments as well as light quality (dark, fluorescence, and 2:1 or 4:1 Red:Blue (R:B) LED) on U. pumila seed germination and seedling growth. Seeds soaked in a 3% sucrose solution had the highest germination rate and germination energy in addition to the shortest germination time compared to seeds treated with water or PGRs, except the control. Light quality only affected germination energy, with seeds exposed to 2:1 R:B LED light having the highest germination energy and those exposed to fluorescent light having the lowest. Following transfer to a greenhouse with exposure to natural sunlight, the performance of seedlings varied depending on the light conditions under which they were germinated. In contrast, treatments during the germination stage such as incubation with PGRs had no effect on seedling growth in the greenhouse. Seedlings that germinated under 2:1 or 4:1 R:B LED lights grew taller and had thicker root collars compared to those grown in the dark or under fluorescent lights. The influence of light conditions persisted for at least seven months after the germination, even though the chlorophyll content was similar among seedlings exposed to different growth conditions. Taken together, these results show that light quality in particular during the germination stage can positively affect the growth of the U. pumila seedlings.

Plant Growth Regulator Impacts on Vegetative Cutting Production of Moroccan Pincushion (Pterocephalus depressus) Plants

Abstract Moroccan pincushion (Pterocephalus depressus) is a drought-tolerant perennial that is being used in landscapes throughout arid areas of the western United States. This paper describes two experiments researching vegetative cutting production from stock plants. Moroccan pincushion stock plants received foliar applications of gibberellic acid (GA3), benzyladenine, ethephon, or auxin [indole-3-butyric acid (IBA)] plant growth regulators (PGR). Plant growth regulators were applied singularly and in combination with GA3 to determine efficacy on stock plant growth. A propagation study was conducted simultaneously to determine effects of these different PGR treatments applied to stock plants on the rooting of moroccan pincushion cuttings. The stock plant study showed GA3 + benzyladenine application increased cutting production over other PGR treatments. Fresh weight of moroccan pincushion cuttings did not differ among treatments. While cuttings did not differ in dry weight in experiment 1, statistical differences were observed in experiment 2. However, these differences in dry weight did not affect the quality of the cuttings. Cuttings from stock plants treated with GA3 + IBA treatment had the highest numerical growth index [(height + width + width)/3]. Cuttings from stock plants treated with GA3 alone or in combination with another PGR were all greater in average growth index and statistically differed from those without GA3 being applied. PGR treatments did not affect rooting percentages of the cuttings with nontreated stock plant cuttings successfully rooting at an average rate of 95%. However, GA3 + IBA was the only treatment where cuttings had 100% rooting for both experiments, indicating potential rooting benefits. Index words: Plant growth regulator, propagation, Pterocephalus depressus, vegetative cuttings. Species used in this study: Moroccan pincushion [Pterocephalus depressus Archibald]. Chemicals used in this study: gibberellic acid (GA3), benzyladenine, ethephon, indole-3-butyric acid (IBA).

Shoot Multiplication and Callus Induction of Labisia pumila var. alata as Influenced by Different Plant Growth Regulators Treatments and Its Polyphenolic Activities Compared with the Wild Plant.

This study aims to investigate whether the in vitro-cultured L. pumila var. alata has higher antioxidant activity than its wild plant. An 8-week-old L. pumila var. alata nodal segment and leaf explants were cultured onto Murashige and Skoog (MS) medium supplemented with various cytokinins (zeatin, kinetin, and 6-benzylaminopurine (BAP)) for shoot multiplication and auxins (2,4-dichlorophenoxyacetic acid (2,4-D) and picloram) for callus induction, respectively. The results showed that 2 mg/L zeatin produced the optimal results for shoot and leaf development, and 0.5 mg/L 2,4-D produced the highest callus induction results (60%). After this, 0.5 mg/L 2,4-D was combined with 0.25 mg/L cytokinins and supplemented to the MS medium. The optimal results for callus induction (100%) with yellowish to greenish and compact texture were obtained using 0.5 mg/L 2,4-D combined with 0.25 mg/L zeatin. Leaves obtained from in vitro plantlets and wild plants as well as callus were extracted and analyzed for their antioxidant activities (DPPH and FRAP methods) and polyphenolic properties (total flavonoid and total phenolic content). When compared with leaf extracts of in vitro plantlets and wild plants of L. pumila var. alata, the callus extract displayed significantly higher antioxidant activities and total phenolic and flavonoid content. Hence, callus culture potentially can be adapted for antioxidant and polyphenolic production to satisfy pharmaceutical and nutraceutical needs while conserving wild L. pumila var. alata.

Differential Expression of Key Floral Initiation Genes in Response to Plant Growth Regulator Application and Alternate Bearing in Pecan

Regarding pecan (Carya illinoinensis), alternate bearing, which is a biennial fluctuation of crop yield, is a major hindrance for the pecan industry. Little is known about the internal cues that trigger pecan shoots to become reproductive. This 2-year study approached the mysteries of alternate bearing of pecan by determining whether pecan homologs of three genes known to control floral initiation in other species are expressed differently at various times of the growing season or in distinct plant tissues, and whether expression of these genes can be manipulated by plant growth regulator (PGR) application when compared with an untreated control group. The flowering genes of interest were pecan homologs of leafy (CpLFY), apetala1 (CpAP1), and flowering locus t (CpFT). During year 1 (2014), PGRs ethephon and gibberellin GA3 were applied at the shoot level 1 week before each of three tissue sampling dates (13 June, 3 July, 29 July). During the following year (2015), two more PGRs were added to the study [a second double rate (2X) of gibberellin GA3 and ethylene inhibitor aminoethoxyvinylglycine (AVG)] for a total of four PGRs (applied on 10 June, 1 July, and 23 July) plus the untreated control. Experimental leaf and bud tissues were sampled from fruiting and nonfruiting shoots on mature ‘Western’ pecan trees and analyzed separately. Normalized expression levels of CpLFY and CpAP1 were significantly higher in buds than in leaves. Normalized expression of CpLFY in bud tissues differed statistically based on the sampling date in 2014, with the earliest date (13 June) having higher expression than the two later dates that year. In 2015, a treatment × date interaction revealed that, compared with the untreated control, CpLFY expression was significantly lower in shoots treated with both gibberellin GA3 dosages on 1 July. A few weeks later (23 July), CpLFY expression was lower in the 2X GA3 treatment group and higher in samples treated with AVG. In 2014, CpAP1 expression in buds was significant, with a treatment × date interaction in which ethephon increased CpAP1 expression, but only on one date (29 July). In 2015, bud CpAP1 expression was significantly higher in fruiting than in nonfruiting shoots; however, again, only on one date. The results reveal differential expression of these key flowering genes based on tissue type, sampling date, and fruiting status of the shoot and PGR treatment. Results suggest that more research of the effects of PGRs is necessary for understanding the flowering behavior of pecan and mitigating the intensity of alternate bearing.

Development of cracks in early-harvested persimmon cultivar and their reduction by preharvest treatments

ABSTRACT Diospyros Kaki Cv (Qiyuezao) 117 is an early ripening persimmon cultivar, ready to be harvested in August. One of the pitfalls of this cultivar is the development of cracks on its surface. These cracks turn brown after astringency removal, preventing the commercialisation of this cultivar. Pre-harvest treatment with Superlon™ (containing benzyl adenine (BA) + gibberellic acid (GA4+7) at 40 mg/L of each) or Turbo™ (containing Thidiazuron (TDZ) at 5 mg/L) reduced cracks of different maturity fruit (green, green orange, and orange fruit) at harvest and following 5 days of astringency removal. Cracks remained low in the Plant growth regulators (PGRs)-treated fruit also following three months of storage. The PGRs treatments also reduced damage and Alternaria infection, developed during storage. Although fruit lost their firmness during storage, the PGRs-treated fruit remained firmer. Both PGRs treatments increased the number of cells in the peel. Thidiazuron was as effective as BA+GA4+7 treatment at eight times lower concentration of each of the compounds. Hence, in-orchard TDZ treatment can be used to reduce persimmon cracks.

Pertumbuhan dan Perkembangan Protocorn Like Bodies (PLB) Anggrek Papua Dendrobium discolor dengan Perlakuan Auksin dan Sitokinin

Dendrobium could meet the demands of domestic and foreign consumers from time to time because of their very charming flower blossoms. Orchid flowers are attractive because of the variety their color, size, shape, composition, number of buds the blossom of flowers, especially for the color it is vary greatly. One of the potential Dendrobium Papua orchids is Dendrobium discolor. To fulfill the needs of Dendrobium orchids in pots or in peaces it is depend on the success of Protocorn Like Bodies (PLB) cultivation. The purpose of this study was to determine the growth and development of PLB cultivated in vitro on Vacint & Went (V&W) base media with a combination of different plant growth regulators. The method used wasPLB cultivation with tissue culture techniques in vitro on V&W media with a factorial completely randomized design (CRD). The first factor was auxin treatment (2,4D) with 5 concentrations 1, 2, 3, and 4 ppm plus control (without plant growth regulator treatment), while the second factor was cytokinin treatment with 5 concentrations 1, 2, 3, and 4 ppm plus 1 control (without plant growth regulator treatment). Each treatment repeated 5 times, threfore, there are 125 treatment units in total 125 treatment units. The media used were Vacin and Went (VW). The variables measured were leaf length and the number of leaves per plantlet in each combination treatment of plant growth regulator (PGR) after one month of cultivation. Data were analyzed by using variance (ANOVA) to determine the significance. The results of this study indicated that the combination treatment of auxin and cytokinin PGR in V&W media had a significant effect on the length and number of plantlets leaves and the most significant treatment was the combination of PGR auxin: cytokinin = 0:3 ppm. So it can be concluded that the best medium for PLB culture is a combination of PGR auxin: cytokinin = 0:3 ppm. with an average value of 3.5 cm plantlet leaf length and number of 6 leaves per plantlet. Key words: Protocorn Like Bodies; tissue culture; V&W medium; auxins; cytokinins.

Suppression of Annual Bluegrass in Creeping Bentgrass Putting Greens Using Plant Growth Regulators

Decreased stand uniformity together with reduced aesthetics and playability caused by annual bluegrass (Poa annua) intrusion in creeping bentgrass (Agrostis stolonifera) putting greens is one of the major problems that golf course superintendents face with managing newer playing surfaces. Few herbicides are registered for selective control of annual bluegrass in creeping bentgrass greens, and the risk of herbicide resistance remains an issue, thus use of plant growth regulators (PGRs) is still the primary method of annual bluegrass suppression. This study was conducted to evaluate eight PGR treatments, employed as a series of 15 consecutive, biweekly applications to suppress annual bluegrass encroachment in ‘Pure Distinction’ creeping bentgrass maintained as a golf course putting green in Los Angeles, CA. Best annual bluegrass suppression was observed with products containing flurprimidol (FP) at 0.256 lb/acre, paclobutrazol (PB) at 0.119 lb/acre, or three-way mixture of FP, trinexapac-ethyl (TE), and PB (FP+PB+TE) at 0.055, 0.014, and 0.055 lb/acre, respectively. Although all treatments caused some significant creeping bentgrass injury, which increased over time, PB at 0.119 lb/acre and FP+PB+TE at 0.055, 0.014, and 0.055 lb/acre, respectively, appeared to be safest among effective treatments. Additionally, those treatments caused significantly darker green turf, which may be desirable on putting greens. This research confirms the potential of PGR use to limit annual bluegrass infestation on creeping bentgrass greens in a Mediterranean climate and reveals the most effective treatments that could be used in a putting green maintenance program.

Influencing Stock Production of Mojave Sage and Cape Daisy with the Application of Plant Growth Regulators

This study aimed to assess the effects of plant growth regulators (PGRs) on stock plant production of mojave sage (Salvia pachyphylla) and ‘Avalanche’ cape daisy (Osteospermum hybrid) that received foliar sprays of the following three PGRs: 200 and 400 ppm ethephon; 250 and 500 ppm benzyladenine; and 50 and 100 ppm gibberellic acid 4 and 7 (GA4+7) plus benzyladenine. Vegetative growth [height and width growth index (GI)], the number of vegetative cuttings, and fresh weight (FW) and dry weight (DW) of the harvested vegetative cuttings data were collected. A propagation study was conducted concurrently to determine the effects of the PGR treatments on rooting vegetative cuttings. GA4+7 plus benzyladenine (50 and 100 ppm) increased the production of both mojave sage and ‘Avalanche’ cape daisy cuttings by ≥18% more than the other treatments. The GI, FW, and DW results showed similar trends across experiments 1 and 2 for each perennial. In the propagation study, the rooting percentage did not differ after 4 weeks, indicating that the use of GA4+7 plus benzyladenine in production protocols could benefit producers of both perennials.

Ex vitro vegetative propagation technique for sustainable utilization of Hypoxis hemerocallidea corms

Hypoxis hemerocallidea is a highly utilized medicinal plant, with the potential to treat testicular tumors, prostate hypertrophy and urinary infections. Although currently classified as of least concern in its conservation status, its ongoing, unsustainable harvesting and habitat loss remain threats to its natural populations. The potential of using one-half of H. hemerocallidea corms for propagation and the other half for medicinal purposes was investigated in an effort to develop sustainable utilization strategies for this plant. The corms were cut transversely into upper and lower halves, following which the upper halves were either cut into four or eight equal segments, or used without any further cutting. The segments were soaked for 30 min in 6-benzyladenine (BA) or gibberellic acid (GA3) at concentrations of 50 or 100 mg/L, while soaking in distilled water served as the control. Upper parts of the corm cut into four segments, and soaked in 50 mg/L BA resulted in a high number of cormlets. The propagation coefficient of the upper corm parts cut into four segments and soaked in 50 mg/L BA was 140%. The cutting method alone or combined with plant growth regulator treatments significantly affected the number of cormlets produced. Cutting the upper corm parts into four segments and soaking in distilled water resulted in a propagation coefficient of 90%. Cutting the upper corm parts into four segments is advantageous as the segments are not too small to compromise food reserves, while soaking allows for the leaching out of possible growth retardants. The study successfully developed a method, which can be recommended for sustainable harvesting and propagation of H. hemerocallidea.

Corn (Zea mays L.) Physiology and Yield Affected by Plant Growth Regulators Under Drought Stress

It is important to find methods, which may improve corn physiology, including nitrogen (N) metabolism, and yield production under drought stress. The use of plant growth regulators (PGR) is among the methods, which has been found effective on the alleviation of drought stress on corn physiology and yield. However, in this research, some new PGR, which has been rarely investigated and may improve plant nitrogen (N) under drought stress including (A) control, (B) 6-benzyl adenine (10,000 mg/L), (C) proline (2.5 ml/L), (D) glutamine (1 ml/L), (E) B + C, (F) B + D, (G) B + C + D, and (H) superoxide dismutase (2.5 ml/L) were proposed and examined on corn (genotype Single Cross 640) physiology and yield components under field conditions. The experiment was a split plot on the basis of a completely randomized block design with three replicates, and in addition to PGR (subplots) the main plots (drought stress) based on 70 (D1), 90 (D2) and 110 mm (D3) of evaporation from an evaporating pan were examined. Different corn physiology- and yield-related components including relative water (RW) and proline contents (Pro), weight of 100 grains (100GW), number of grains per corn (NGC), biological yield (BY), corn fresh yield (CFY), and grain yield (GY) were determined. According to the results, corn physiology and yield components were significantly affected by drought stress as Pro increased and RW and yield-related components decreased. However, interestingly the use of PGR (treatment G) significantly improved corn physiology and yield components by increasing RW (to a maximum of 63.81%), CFY (from a minimum of 80,542 kg/ha at control to a maximum of 100,263 kg/ha), and BY (from a minimum of 49,842 kg/ha at control to a maximum of 62,277 kg/ha). Although the effect of PGR was not statistically significant on GY, treatment G resulted in a 2500-kg increase compared with control. The interaction of drought stress and PGR significantly affected different corn physiology- and yield-related components except NGC and BY. The most effective PGR treatment on the alleviation of drought stress on corn physiology and yield production was treatment G containing 6-benzyl adenine, proline, and glutamine. It is possible to improve corn physiology and yield production under drought stress using the PGR tested in this research.

Features of leaf mesostructure organization under plant growth regulators treatment on broad bean plants

It was studied the mesostructure organization of leaf apparatus and pigment content of leaves under application of growth regulators with a different mechanism of action-chlormequat chloride (1%) (retardant of quaternary ammonium compounds group) and Emistim C (0,1 ml/l) (growth stimulator) on broad bean plants. The plant growth regulators treatment on broad beans led to the thickening of leaves due to an increase in the growth of columnar and spongy leaf parenchyma. Growth regulators influenced the formation of the stomatal apparatus of broad beans leaves in different ways. The inhibitory compound chlormequat chloride caused a decrease in the number of lower epidermal cells and stomata with a simultaneous increase in the area of the stomatal cell. The application of stimulator compound Emistim C led to an increase in epidermal cells, without differences in the number of stomata but the area of stomatal cells increased significantly. It has been established the enhancement of photosynthetic processes due to an increase in the chlorophyll content in assimilative cells of leaves under chlormequat chloride on broad beans.

Effect of different growth regulators on in vitro regeneration of cotyledon explants of rough lemon (Citrus jambhiri Lush.) via callus induction

In order to establish in vitro protocols for raising aseptic cultures of cotyledon segments excised from five-week-old in vitro raised seedlings were used as explant material. Among surface sterilants, mercuric chloride 0.1% for three minutes provided least rate of contamination (24%) and the maximum explant survival (76%). The highest per cent culture establishment of 97.79% was obtained in cotyledon explants on Murashige and Skoog (MS) containing 2,4-D (3.0 mg/l) and maximum callus induction (95.41%) was observed on MS medium supplemented with 2,4-D (2.0 mg/l). Among different plant growth regulator treatments, maximum callus regeneration of 82.19% was observed on MS medium supplemented with BAP (3.0 mg/l) whereas, minimum callus regeneration (4.33%) was found in MS medium supplemented with BAP (3.0 mg/l) in combination with IAA (0.75 mg/l) and malt extract (500 mg/l). Maximum rooting response (96.00%) was recorded on MS (half strength) medium with NAA (2.0 mg/l) and was at par with rooting percentage of 92.00% on MS (half strength) medium supplemented with NAA (1.5 mg/l). The plantlets were successfully acclimatized in different potting mixtures and highest survival rate (91.35%) was achieved in potting mixture containing garden soil with sand and farmyard manure (1:1:1).

In vitro GYNOGENESIS OF Jatropha curcas L. var ALJC01

<pre><strong><span lang="EN-US">Background. </span></strong><em><span lang="EN-US">Jatropha curcas</span></em><span lang="EN-US"> L. is a crop whose oil can be converted to biodiesel. However, there is lack of varieties with high yields that limiting commercial production of the crop. An alternative is to obtain <em>in vitro </em>plants from unpollinated female gametophytes is known as gynogenesis which can provide an alternative to </span><span lang="EN-US">produce </span><span lang="EN-US">varieties with increased seed production.<strong> Objective</strong>. The objective was to establish a protocol for obtaining <em>in vitro</em> plants from unfertilized ovules of <em>Jatropha curcas</em> L. ovules. <strong>Methodology</strong>. The ovules were extracted from unfertilized inflorescences pretreated for 0, 1, 3 and 7 days at 2 to 5 ° C. Three combinations of plant growth regulator treatments were applied to culture media for induction of gynogenic calli. Gynogenic calli were cultured on MS basal medium with BAP and IBA for development of green, friable. The </span><span lang="EN-US">gynogenic </span><span lang="EN-US">calli from the development treatment </span><span lang="EN-US">were transferred to experiments to determine a regeneration treatment. </span><span lang="EN-US">The gynogenic plantlets were transferred to different treatments for root development. <strong>Results</strong>. The results show that pretreatment of inflorescences at 2 to 5°C had no significant effect on the number of ovules that formed friable white calli. Induction of gynogenic friable white calli occurred in the dark conditions, on half-strength </span><span lang="EN-US">Murashige and Skoog basal medium (</span><span lang="EN-US">½</span><span lang="EN-US"> MS) </span><span lang="EN-US">supplemented with two combinations of growth regulators: (i) 5.37 µM naphthalene acetic acid (NAA) combined with 6.65 µM 6-benzylaminopurine (BAP) and, (ii)</span><span lang="EN-US">8.05 µM NAA with 22.09 µM BAP. Development of green, friable, gynogenic calli under light–dark conditions was possible under treatment with complete Murashige and Skoog (1962) (MS) basal medium with 6.66 µM BAP and 4.9 µM indole-butyric acid (IBA).</span><span lang="EN-US">Friable green callus formed gynogenic embryos on MS basal medium supplemented with </span><span lang="EN-US">22.09 </span><span lang="EN-US">µM</span><span lang="EN-US">BAP and </span><span lang="EN-US">3.40 </span><span lang="EN-US">µM</span><span lang="EN-US"> paclobutrazol (PBZ), embryos regeneration occurred in photoperiod conditions</span><span lang="EN-US">. </span><span lang="EN-US">Embryos were able to develop and convert to plantlets in the treatment on MS basal medium containing 2.22 µM BAP and 0.28 µM of indole-3-acetic acid (IAA).</span><span lang="EN-US"> Root development of </span><span lang="EN-US">plantlets</span><span lang="EN-US"> occurred in </span><span lang="EN-US">½</span><span lang="EN-US"> MS basal medium with 18.65 µM IBA. <strong>Implications</strong>. A protocol of <em>in vitro</em> gynogenesis in <em>Jatropha curcas</em> would contribute to the improvement of its cultivation, reducing the time required for the generation of pure lines that would allow us to obtain varieties with increased seed production. <strong>Conclusions. </strong>The<strong> </strong></span><span lang="EN-US">work presented here describes a reproducible protocol to produce plants <em>in vitro</em> from unfertilized ovules of <em>Jatropha curcas</em> L. T</span><span lang="EN-US">his methodology will facilitate to obtain homozygotic lines with significant reduction in the time required by conventional methods. </span><strong></strong></pre>

Effects of Plant Growth Regulators and N Rate on the Morphological Traits of Generative Tillers and Seed Yields of Chewings and Strong Creeping Red Fescue

Plant growth regulators (PGRs) are used as a management tool to minimize plant height and subsequent stem lodging in grass seed crops. Their efficacy is influenced not only by the method of application, but also by the management and genetic variations within and between species. This aim of the study was to evaluate the effect of PGRs on morphological traits of generative tillers and seed yield of Festuca rubra L ssp. rubra (strong creeping red fescue) and F. r. L ssp. commutata (Chewings red fescue) under low and medium doses of spring nitrogen fertilization (40 and 70 kg N ha−1). PGRs were applied as: chlormequat chloride (CCC) at BBCH 30–31; CCC at BBCH 30–31 + ethephon (ET) at BBCH 37–39; CCC at BBCH 30–31 + trinexapac-ethyl (TE) at BBCH 37–39. All the application methods of PGRs resulted in the shortening of the second internode, and the sequential application of CCC with ET or TE also resulted in the shortening of the third internode. In each PGR treatment, the lodging index in the plant (canopy height to tiller length ratio) was higher than that of the control. PGRs had a beneficial effect on the seed yield. The greatest increase in the seed yield was recorded after the application of CCC+TE. No interaction between PGRs and spring N fertilization rates on the seed yield of red fescue. The increase in the dose of spring nitrogen fertilizer from 40 to 70 kg N ha−1 resulted in a significant increase in yield. Seed yield of chewing red fescue cv. Dorosa was 29% higher than strong creeping red fescue cv. Nista, mainly due to an increase in the number of generative tillers.

Effect of Plant Growth Regulators on Growth, Yield and Quality of Strawberry (Fragaria × ananassa Duch.) Cv. Winter Dawn under Open Field Conditions of South Gujarat

Background: The South Gujarat hilly part is considered to be a non-traditional area of strawberry cultivation in India. The poor farmers of this region are cultivating strawberries under open field condition. Both, the yield and quality of strawberry fruits of this region are not up-to-the-mark as there in other parts of the country. Hence, a low-cost improved production technology is required to maximize yield as well as improve the quality of strawberry fruits. Method: Uniform runners of strawberry cv. Winter Dawn were grown in open field under paddy straw as bedding material. Foliar spraying of plant growth regulators viz. NAA (50, 75, 100 and 125 mg l-1) and GA3 (50, 75, 100 and 125 mg l-1) were done at 30 and 60 days after planting. The experiment was laid out in randomized block design with control plants receiving no spray treatments and replicated thrice. Result: The plant growth parameters like plant spread, number of leaves, number of crowns, leaf area, length of petiole, number of runners were recorded maximum with the application of 100 mg l-1 GA3. This treatment was also found to be the best in respect of number of flowers, number of fruits, fruit weight, marketable and total fruit yield of strawberry. Strawberry fruits with the highest total soluble solid, ascorbic acid, reducing sugar, non-reducing sugar and total sugar content were recorded in the plants which received 125 mg l-1 NAA. However, the plant growth regulator treatments failed to influence any significant effect on days taken to 50.0% flowering, fruit firmness and acidity content of strawberry fruits.

Tissue Culture, In Vitro Organogenesis and Regeneration of Plantago lanceolata

Introduction: Plantago lanceolata is one the most important species of the Plantago genus and has valuable medicinal secondary metabolites. Materials and Methods: The effect of different factors on germination of P. lanceolata seeds was studied and leaf and root explants of in vitro growth seedling were cultured on Murashige and Skoog (MS) medium supplemented with combination of 6-benzylaminopurine (BAP) or thidiazuron (TDZ) (0, 0.5, 1, 1.5, 2 and 3 mg/L) and auxins: α-naphthaleneacetic acid (NAA) (0, 0.2, 0.5, 1 mg/L), Indole-3-acetic acid (IAA) (0.1, 0.5, 1, 1.5 mg/L) or Indole-3-butyric acid (0.5, 1, 1.5, 2 mg/L) (IBA) at different concentrations. Results: The results showed that cold pre-treatment, daylight and 1/8 MS salt concentration are more suitable for high germination. The best shoot organogenesis rate (95%) in leaf explants was observed in 1:1 mg/L, and 1.5:1 mg/L TDZ: IBA. The highest percentage of shoot organogenesis (100%) was observed in most of the plant growth regulator (PGR) treatments in root explants. About 58.67 and 60 shoot numbers obtained with 2 mg/L TDZ in leaf and 1:1.5 mg/L BAP: IBA in root explants, respectively. Conclusions: It can be suggested that the best shoot organogenesis and proliferation medium is MS basal medium containing cytokinin TDZ and auxin IBA in comparison with other hormone compounds on leaf and root explants. The result behind this fact is high callus induction and regeneration potential of explants in all concentrations.