scholarly journals SEQUENCING OF FORCING SOLUTION PLANT GROWTH REGULATORS ENHANCES MACROPROPAGATION OF LIGUSTRUM VULGARE L. BY SOFTWOOD CUTTINGS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 608a-608
Author(s):  
Guochen Yang ◽  
Paul E. Read
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Woody Plants ◽  
Woody Plant ◽  
Shoot Elongation ◽  
Root Number ◽  
Negative Effects ◽  
Rooting Of Cuttings ◽  
Forcing Solution

A forcing solution containing 200 mg 8-hydroxyquinoline citrate per liter and 2% sucrose has been demonstrated to extend the season for obtaining softwood growth suitable for use as explants in micropropagation (Yang & Read 1989). Forcing dormant woody stems in the off-season in this fashion also enhances the macropropagation of woody plant species by providing softwood outgrowth that can be rooted as softwood cuttings. GA3, IBA, IAA and NAA were incorporated into softwood growth which was later used as cuttings for rooting by adding plant growth regulators at various concentrations to the forcing solution. GA3 incorporated into the forcing solution hastened bud break, increased shoot elongation, but inhibited rooting of softwood cuttings taken from stems forced in this manner. IBA, IAA and NAA in the forcing solution exhibited typical auxin effects on rooting of cuttings by increasing root number per cutting and root elongation. In order to expedite macropropagation of woody plants, GA3 and IBA were added SEQUENTIALLY to the forcing solution. Addition of IBA to fresh forcing solution following initial use of GA3 in the forcing solution counteracted the negative effects of GA3 and stimulated rooting. This protocol is proposed as a method to assist propagation in rooting difficult species by softwood cuttings in the off-season.

scholarly journals PRE-FORCING TREATMENTS AND PLANT GROWTH REGULATORS IN THE FORCING SOLUTION PROMOTE MACRO- AND MICRO-PROPAGATION OF WOODY PLANT SPECIES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1124d-1124
Author(s):  
Gouchen Yang ◽  
Paul E. Read
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Plant Species ◽  
Growth Regulators ◽  
Woody Plant ◽  
Shoot Proliferation ◽  
Bud Break ◽  
Woody Plant Species ◽  
Forcing Solution

BA, IBA and GA3 were incorporated into softwood tissues to be cultured in vitro or rooted as cuttings by adding the plant growth regulators (PGR) at various concentrations to a forcing solution containing 200 mg/l 8-hydroxyquinoline citrate and 2% sucrose. BA and GA3 helped break bud dormancy in autumn-collected stems and increased percent bud-break. IBA inhibited bud break and shoot elongation. Rooting of forced softwood cuttings was enhanced by IBA in the forcing solution, while GA3 inhibited the rooting of plant species tested. When dormant stems were forced with periodic additions of BA (10 mg/l) in the forcing solution, in vitro shoot proliferation was enhanced. However, inclusion of GA3 in the forcing solution reduced shoot proliferation. A pre-forcing NaOCl soak and a pre-forcing treatment with wetting agents accelerated bud break, size and number of shoots available for both micro- and macro-propagation of the woody plant species tested. The forcing solution protocol described is an effective PGR delivery system and it can be used by the propagator to extend the season for obtaining softwood growth suitable for use as in vitro explants or softwood cuttings.

scholarly journals USE OF FORCING SOLUTIONS TO STUDY PLANT GROWTH REGULATOR EFFECTS ON VANHOUTTE'S SPIRAEA CULTURED IN VITRO

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1124e-1124
Author(s):  
Guochen Yang ◽  
P. E. Read
Keyword(s):  
Plant Physiology ◽  
Plant Growth ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Woody Plant ◽  
Shoot Proliferation ◽  
Plant Tissues ◽  
Forcing Solution

Vanhoutte's spiraea has been propagated in vitro using explants from softwood growth of dormant stems forced in a solution containing 200 mg/l 8-hydroxyquinoline citrate (8-HQC) and 2% sucrose (Yang and Read, 1989). Objectives to further utilize this system were to determine the feasibility of applying plant growth regulators (PGR) via the forcing solution to softwood growth from forced dormant stems and to study the resulting influence on in vitro culture. BA and GA3 were placed in the forcing solution at various concentrations, including a zero PGR control. Explants were cultured on Linsmaier and Skoog (LS) medium containing zero PGR or different amounts of BA or thidiazuron (TDZ) or combinations of BA and IAA. Control explants placed on LS medium supplemented with 5uM BA with or without 1 or 5uM IAA, or with 0.5 or 0.75 uM TDZ alone produced the best shoot proliferation. BA in the forcing solution stimulated micropropagation, while GA3 caused less proliferation than explants from control solutions. Forcing solutions containing PGR are useful for manipulating responses of plant tissues cultured in vitro and for studying PGR influence on woody plant physiology.

scholarly journals Plant Growth Regulators Modify Fruit Set, Fruit Quality, and Return Bloom in Sweet Cherry

HortScience ◽  
2021 ◽  
pp. 1-10
Author(s):  
Irfan Ali Sabir ◽  
Xunju Liu ◽  
Songtao Jiu ◽  
Matthew Whiting ◽  
Caixi Zhang
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Fruit Quality ◽  
Sweet Cherry ◽  
Prunus Avium ◽  
Fruit Set ◽  
Foliar Application ◽  
Negative Effects ◽  
Return Bloom

Sweet cherry (Prunus avium L.) is a valuable fruit crop worldwide. Farmers’ incomes are closely related to fruit quantity and quality, yet these can be highly variable across years. As part of a broader project for optimizing fruit set and fruit quality in sweet cherries, this study was conducted to evaluate the potential of various plant growth regulators (PGRs) for improving fruit set and fruit quality. Cytokinins, gibberellins, auxin, and polyamines were used as treatments. Treatments were applied as foliar sprays at full bloom to ‘Bing’ and three low-productivity genotypes, ‘Regina’, ‘Tieton’, and ‘PC8011-3’. We assessed the fruit set, fruit quality, and return bloom from each treatment. 4-chlorophenoxyacetic acid (4-CPA) increased fruit set by 53% and 36% in ‘Bing’ and ‘Tieton’, respectively. The combination of gibberellin (GA)3 + GA4/7 was more effective for improving fruit set than other isomers of gibberellin alone. Cytokinin treatments had slight adverse effects or no effect on fruit set except for CPPU. In ‘PC8011-3’, both N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU) and 4-CPA enhanced fruit set by ≈81% and 100% compared with untreated control. The response of cherry trees to polyamine sprays depended on the properties of the cultivars and the treatment concentration. Foliar application of GA3, GA4/7, or N-phenyl-N'-(1, 2, 3-thiadiazol-5-yl) urea (TDZ) in ‘Bing’ trees has negative effects on return bloom, whereas GA1 can increase the yield and flower buds. These results suggest that PGRs may have varied effects on sweet cherry fruit set and that more work is needed to develop practical programs for improving yield security.

scholarly journals Development of New Plant Growth Regulators from a University Perspective

2002 ◽  
Vol 12 (1) ◽  
pp. 71-74 ◽  
Author(s):  
Duane W. Greene
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Evaluation Process ◽  
Major Change ◽  
Negative Effects ◽  
Quality Product ◽  
Critical Components ◽  
High Quality Product ◽  
Profit Potential

Plant growth regulators (PGRs) play an important commercial role in horticulture. Although often expensive, they are generally used on high value crops where the costs can be retrieved through the increased value their usage creates in a given crop. The impetus for development of new PGRs is generally initiated by the agrochemical industry where they perceive a need that has a profit potential, whereas the motivation for the development of a PGR by researchers is largely to aid the industry they serve. University and government researchers initially follow a prescribed protocol early in the development process, but once they have gained personal experience with a PGR, further research is often guided by personal observations and keen technical insight. During the development and evaluation process, university and government researchers are optimistic, and negative effects are generally viewed as challenges, that can and will be overcome. Discussion and effective communication are critical components in the overall development of a new PGR. Researchers generally exchange information very freely, unless restricted from doing so by a nondisclosure or other contract agreement. The underlying goal for university and government researchers is to get approval of a new PGR product and/or use that will allow growers to produce a high quality product for consumers with an improved profit margin for growers. Development of new PGRs is undergoing major change that unfortunately will lead to the development and registration of fewer compounds. There are not as many agrochemical companies, there are a decreasing number of university and government researchers, and diminishing funds available to support the development of new PGRs.

scholarly journals 107 Silver Thiosulfate (STS) Alone and in Combination with Gibberellic Acid (GA3) in the Forcing Solution Influences Budbreak and Shoot Elongation of Dormant Woody Plant Species

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 460A-460
Author(s):  
Bahget T. Hamooh ◽  
Paul E. Read
Keyword(s):  
Gibberellic Acid ◽  
Effective Treatment ◽  
Woody Plants ◽  
Woody Plant ◽  
Shoot Elongation ◽  
Shoot Length ◽  
Solution System ◽  
Silver Thiosulfate ◽  
Cornus Alba ◽  
Forcing Solution

Research was conducted to further modify the forcing solution system in order to expedite the propagation of woody plants, such as Spiraea canescens, Lonicera maakii, and Cornus alba. Time of immersion in solutions containing 5 mM silver thiosulfate (STS) was compared with the basic forcing solution reported by Yang and Read (1989), a solution containing 200 mg 8-hydroxyquinoline citrate per liter and 2% sucrose. Other treatments employed were gibberellic acid (GA3) 50 mg per liter for 24 h and a combination of STS and GA3 for the same amount of time. Increasing the time in STS solution up to 24 h led to higher percent budbreak and shorter time to budbreak for all the three species examined. The combination of STS and GA3 was the most effective treatment overall in reducing time of budbreak and increasing percent of budbreak. All STS treatments studied showed similar responses in shoot elongation. However, treatments with GA3 alone, and in combination with STS showed more than a doubling in shoot length compared to all STS treatments studied and the control. Implications based on SEM observations will be presented.

scholarly journals 569 PB 012 A MODIFIED FORCING SOLUTION SYSTEM PROMOTES PROPAGATION OF WOODY SPECIES

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 513c-513
Author(s):  
Guochen Yang ◽  
Paul E. Read
Keyword(s):  
Root Length ◽  
Woody Species ◽  
Shoot Elongation ◽  
Bud Break ◽  
Root Number ◽  
Negative Effects ◽  
Solution System ◽  
Forcing Solution

A forcing solution containing 200 mg 8-hydroxyquinoline citrate per liter and 2% sucrose has enhanced availability of cutting materials by forcing dormant woody stems in the off-season. Anxins, such as IBA, included in the forcing solution promoted subsequent rooting by increasing root number per cutting and root length for privet. Inclusion of IBA in the forcing solution following the initial use of GA3 in the forcing solution counteracted the undesirable effects of GA3 on rooting and stimulated rooting after taking advantage of the favorable effects of GA3 on bud break and shoot elongation. However, the ability of IBA to counteract the negative effects of GA3 on rooting was dependent on the length of GA3 treatment. The modification of forcing solution system by sequentially including GA3 and then replacing GA3 with IBA expedited propagation of privet. Production of candidate cuttings or explants was stimulated by including GA3 in the forcing solution, and rooting of the cuttings was promoted by subsequent auxin or cytokinin inclusions in the forcing solution to replace GA3 This modified forcing solution system also proved to be a successful and efficient model for propagation of other difficult to propagate woody species.

An Entomogenous Nematode Steinernema carpocapsae is Compatible with Potting Media Environments Created by Horticultural Practices

1991 ◽  
Vol 26 (4) ◽  
pp. 390-394 ◽  
Author(s):  
Ronald D. Oetting ◽  
Joyce G. Latimer
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Galleria Mellonella ◽  
Steinernema Carpocapsae ◽  
Pine Bark ◽  
Peat Moss ◽  
Negative Effects ◽  
Significant Difference ◽  
Potting Media

Three experiments were conducted to evaluate the effect of different potting media and horticultural practices on the infectivity of Steinernema carpocapsae (Weiser). Bioassays were conducted with S. carpocapsae added to potting media containing Galleria mellonella (L.) larvae. Potting media tested were aged pine bark, new pine bark, peat moss, aged cow manure, and a peat/vermiculite soilless medium (Pro-Gro 200). The horticultural practices tested were potting media pH level, fertilization, salt level, and application of plant growth regulators. The plant growth regulators ancymidol, paclobutrazol, chlormequat, and daminozide were each applied as a medium drench. The LC50s of the nematodes against G. mellonella, in potting media with different horticultural practices, were all between 0.50 and 2.06 with no significant difference in infectivity. Nematodes could be used for insect control with no negative effects under these growing conditions.

scholarly journals Evaluation of In Vitro Shoot Elongation and Rooting of Date Palm, and Determination of Physiological Characteristics of Regenerated Plantlets

2019 ◽  
Vol 11 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Reda MEZIANI ◽  
Mouaad Amine MAZRI ◽  
Mahassine ARHAZZAL ◽  
Ilham BELKOURA ◽  
Chakib ALEM ◽  
...  
Keyword(s):  
Survival Rate ◽  
Stomatal Conductance ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Culture Medium ◽  
Date Palm ◽  
Shoot Elongation ◽  
Physiological Characteristics

The effects of various culture conditions on shoot elongation, rooting and plantlet acclimatization were tested. Adventitious shoots obtained through direct organogenesis of date palm (Phoenix dactylifera L.) cv. ‘Mejhoul’ were used as explants. The effects of culture medium texture, plant growth regulators, polyvinylpyrrolidone, adenine, myo-inositol, L-glutamine, and carbon source on in vitro plantlet quality and subsequent acclimatization were evaluated. The most effective culture medium was the semi-solid and half-strength Murashige and Skoog medium without plant growth regulators, supplemented with 30 g L-1 sucrose. After 3 months of culture on this medium, the average shoot length was 13.6 cm, the average number of adventitious roots per shoot was 3.6, and the average root length was 3.85 cm. The survival rate of these plantlets in acclimatization was 90%. On the other hand, liquid medium, plant growth regulators, polyvinylpyrrolidone, adenine, myo-inositol and L-glutamine did not increase the survival rate during acclimatization. Along with these experiments, some physiological characteristics of the plantlets obtained in vitro were also determined. Chlorophyll content and fluorescence, foliar surface and stomatal conductance were measured after 3 months of culture in each medium. The ranges were as follows: Chlorophyll content, 11.7-31.8 CCI; chlorophyll fluorescence, 0.633-0.795; foliar surface, 7.35-13.29 cm2; and stomatal conductance, 10.3-36.0 mmol m-2 s-1. Interestingly, positive correlations between the physiological characteristics of the plantlets and their survival percentage in the glasshouse were revealed. The findings of this investigation will be valuable for large-scale and cost-saving production of date palm cv. ‘Mejhoul’ plants.

scholarly journals Increasing In Vitro Shoot Elongation and Proliferation of ‘G.30’ and ‘G.41’ Apple by Chilling Explants and Plant Growth Regulators

HortScience ◽  
2016 ◽  
Vol 51 (7) ◽  
pp. 899-904 ◽  
Author(s):  
Fang Geng ◽  
Renae Moran ◽  
Michael Day ◽  
William Halteman ◽  
Donglin Zhang
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Shoot Growth ◽  
Shoot Elongation ◽  
Shoot Length ◽  
Optimum Concentration ◽  
Shoot Number ◽  
Collection Date

These studies were conducted to determine the most effective methods for increasing shoot elongation during the initial proliferation stage of micropropagation in two dwarfing apple, Malus ×domestica (Borkh.), rootstock cultivars. Several experiments were conducted to compare explant collection date, exposure to chilling (5 ± 1 °C) temperatures, and varying concentrations of plant growth regulators in Murashige and Skoog (MS) media. Microshoot growth of ‘Geneva 41’ (‘G.41’) was very low and unaffected by chilling duration from 0 to 8 weeks or by gibberellic acid (GA3) concentration from 0 to 1.0 mg·L−1, but was improved by an additional subculture which increased shoot length from 1 to 15 mm. In ‘Geneva 30’ (‘G.30’), shoot elongation was most affected by date, chilling explants, and by optimizing cytokinin concentration and type. Explant collection date in April increased shoot growth compared with August or November. Microshoot growth of ‘G.30’ was increased by chilling nodal explants for 4 and 6 weeks when explants were collected in August and November, but not in April. Eight weeks chilling was detrimental for explants collected in April, and generally had little or no effect with August and November. The cytokinin 6-benzylaminopurine (BA) increased shoot number to a greater extent than thidiazuron (TDZ) or zeatin (ZT), and was also more effective for increasing shoot elongation with concentrations of 0 to 2.0 mg·L−1. In ‘G.30’, GA3 increased shoot growth at the optimum concentration of BA, but not with lower concentrations. ‘G.30’ microshoots were fewer and shorter with 24-epi-brassinolide (EBR) at concentrations of 0.1 and 1.0 mg·L−1. Chemical names: N-phenyl-N’-(1,2,3-thiadiazol-5-yl)urea (TDZ), 6-(4-hydroxy-3-methylbut-2-enylamino)purine (ZT).

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