scholarly journals Long-term Effect of Winter Gibberellic Acid Sprays and Auxin Applications on Crop Value of `Clausellina' Satsuma

2006 ◽  
Vol 131 (5) ◽  
pp. 586-592 ◽  
Author(s):  
Amílcar M.M. Duarte ◽  
Amparo García-Luis ◽  
Rosa Victoria Molina ◽  
Consuelo Monerri ◽  
Vicente Navarro ◽  
...  

A winter gibberellic acid (GA3) spray consistently reduced flower formation, but had a variable effect on the amount of first-grade fruit in the early harvest of `Clausellina' satsuma (Citrus unshiu Marc.), and in the long term these applications had no significant effect on the value of the crop. Auxin applications increased the amount of first grade-early harvested fruit, and increased crop value as compared to hand-thinned trees. No significant differences in yield or fruit grade could be found among the different auxin applications tried, namely an application of 20 mg·L-1 2,4-dichlorophenoxyacetic acid (2,4-D) at flowering, or applications of 25 mg·L-1 naphthaleneacetic acid (NAA), or 50 mg·L-1 2,4-dicholorophenoxypropionic acid (2,4-DP) at the end of fruitlet abscission. Apart from their effect on size, the auxin applications had only a marginal effect on fruit quality.

1984 ◽  
Vol 62 (6) ◽  
pp. 1245-1249 ◽  
Author(s):  
L. S. Kott ◽  
K. J. Kasha

Somatic embryogenesis was induced in callus previously initiated from immature embryos of barley. These cultures ranged in age from 6 weeks to 30 months. Embryoids were readily initiated from homogenized suspension-grown aggregates when plated on modified B5 media with 2,4-dichlorophenoxyacetic acid. Low concentrations (0.1 and 0.05 mg∙L−1) of abscisic acid promoted further maturation of embryoids, while gibberellic acid (1 mg∙L−1) and kinetin (0.1 mg∙L−1) were used in the media to encourage embryoid germination. The development of somatic embryoids from initiation through maturation and germination is described.


1984 ◽  
Vol 62 (7) ◽  
pp. 1393-1397 ◽  
Author(s):  
M. D. Zhou ◽  
T. T. Lee

The callus-promoting activity of most commonly known as well as some rarely tested auxins was compared with that of 2,4-dichlorophenoxyacetic acid (2,4-D) for in vitro culture of the excised embryo of spring and winter wheat (Triticum aestivum L.), cv. Chinese Spring and cv. Fredrick. Different auxins in a concentration range from 1 to 50 μM showed widely different activities. Also the two wheat cultivars responded differently to the auxins. When rapid callus formation with limited root growth was used as the basis for comparison, 2-(2-methyl-4-chlorophenoxy)propionic acid (2-MCPP), α-naphthaleneacetic acid, 3,6-dichloro-2-methoxybenzoic acid (dicamba), 4-amino-3,5,6,trichloropicolinic acid (picloram), γ-(2,4-dichlorophenoxy)butyric acid, 2,4,5-trichlorophenoxyacetic acid, and 2,4,5-trichlorophenoxypropionic acid, in the order of effectiveness, were superior to 2,4,-D for callus induction from the embryo of 'Chinese Spring,' although the concentration required was higher than that of 2,4-D. For the winter wheat 'Fredrick,' however, only picloram, dicamba, and 2-MCPP performed as well as 2,4-D. All auxins tested promoted shoot growth; 2-methyl-4-chlorophenoxypropionic acid was most effective for 'Chinese Spring,' whereas picloram was most effective for 'Fredrick.'


2017 ◽  
Vol 9 (2) ◽  
pp. 27
Author(s):  
Wang Yue ◽  
Sun Fulai ◽  
Gao Qingrong ◽  
Zhang Yanxia ◽  
Wang Nan ◽  
...  

Branched spike wheat is a hexaploid germplasm with branched rachis on its main rachises, and the crucial period for branched rachises occurrence and development is just after the two ridges stage of shoot apex. Natural [indole-3-acetic acid (IAA), indole-3butyric acid (IBA)] and synthetic [(1-naphthaleneacetic acid (NAA), 2,4-Dichlorophenoxyacetic acid (2,4-D)] auxins were applied at this period to investigate the spike traits, seedling growth and photosynthesis related characters and expression of a putative homologue of the LEAFY in branched spike wheat. The four types of experienced auxins induced similar effects on these foresaid characters, although the impact extents were different among the auxins treatments. More branched rachis, spikelets, fertile florets and longer branched rachis were obtained in plants with IAA and IBA at 0.1 mM or NAA and 2,4-D at 1.0mM than those plants with no auxin treated. Auxin treatments also increased fresh and dry mass, photosynthetic pigment and parameters. TFL, a LEAFY-like gene was cloned in branched spike wheat and TFL mRNA expression was quantified using real-time reverse transcriptase-PCR. Application of the auxins accelerated the rise in TFL expression during the periods of branched rachises occurrence and extension. The data supports the hypothesis that auxins play a central role in the regulation branched spike development and TFL might correlate with the development of branched rachises in branched spike wheat.


1982 ◽  
Vol 60 (12) ◽  
pp. 2547-2555 ◽  
Author(s):  
Gaëtan Harvais

A new medium for growing Cypripedium reginae Walt. axenically from seed was designed. Liquid culture proved unsuitable, hence a 1% agar medium supplemented with 5% potato extract was used to investigate optimal mineral element, vitamin, amino acid, sugar, and growth regulator supplements for germination, and subsequent growth. A modified Pfeffer solution with 1400 mg/L NH4NO3 + 19 mg/L ammonium citrate + 2% dextrose + 10 mg/L niacin + 5 mg/L calcium pantothenate + 5 mg/L thiamine HCl + 1 mg/L kinetin + 0.1 mg/L α-naphthaleneacetic acid gave best germination and growth to 2 years with little or no phenolic production. Gamborg's B5 medium and Murashige–Skoog (MS) medium were less than optimal when tested against the above medium. Growth regulators were more active when sterilized by membrane filtration instead of autoclaving. Of the three aminopurines tested, kinetin, benzylaminopurine (BAP), and 6(γ,γ-dimethylallylamino) purine (γγ), the order of activity was initially γγ → BAP → kinetin, but kinetin produced better greening of protocorms and plantlets, and eventually greater survival. Hence, it was chosen for further study. The auxins indole-3-acetic acid (IAA), naphthalene acetic acid (NAA), indole-3-butyric acid (IBA), and 2,4-dichlorophenoxyacetic acid (2,4-D) were also tested alone and in combination with the aminopurines. They did not stimulate germination, but improved growth and survival when combined with aminopurines. The most active of the auxins were NAA → IAA → IBA → 2,4-D. A kinetin:NAA ratio of 10:1 was very satisfactory.


1972 ◽  
Vol 50 (4) ◽  
pp. 723-726 ◽  
Author(s):  
T. T. Lee ◽  
A. N. Starratt

The root tissues of Euphorbia esula and E. cyparissias form callus on chemically defined medium. Both species require an exogenous supply of auxin for growth, but the appearance and color of the tissue and their responses to kinetin, 2,4-dichlorophenoxyacetic acid (2,4-D) and indoleacetic acid (IAA) are different. The tissue growth is more satisfactory with α-naphthaleneacetic acid (NAA) than with 2,4-D, IAA, or 4-amino-3,5,6-trichloropicolinic acid (picloram). Gibberellic acid has no effect. The callus tissues of E. esula become intensely green under light but are not autotrophic.Triglycerides, palmitic acid, and β-sitosterol are the major lipid constituents of the callus tissue of E. esula. Chromatographic analysis reveals no significant differences in the composition of extracts from the non-green and green tissues. Long-chain aldehydes, alcohols, and triterpenes found in the plant are not detected in the cultures.


HortScience ◽  
2019 ◽  
Vol 54 (5) ◽  
pp. 920-925
Author(s):  
Nguyen Phuc Huy ◽  
Vu Quoc Luan ◽  
Le Kim Cuong ◽  
Nguyen Ba Nam ◽  
Hoang Thanh Tung ◽  
...  

Paphiopedilum spp. is one of the most commercially popular orchids because of its variety of shapes, sizes, and colors. However, it is at risk for extinction because of its exploitation. Regeneration of orchid plants using internode segments is extremely difficult. In this study, young P. callosum plants (1.5 cm) were exposed to eight dark–light cycles (14 days of dark and 1 day of light) for stem elongation to increase the number of nodes to obtain internode tissues. After 75 days of culture, the highest callogenesis (31.25%) was achieved when internode tissue was cultured on liquid Schenk and Hildebrandt (SH) medium containing 30 g·L−1 sucrose, 1.0 mg·L−1 Thidiazuron (TDZ), 1.0 mg·L−1 2,4-Dichlorophenoxyacetic acid (2,4-D), and cotton wool as the support matrix. The optimal media for induction of protocorm-like bodies (PLBs) were the same compositions as previously mentioned and were supplemented with 9 g·L−1 Bacto agar as the gelling agent. PLB clumps (5–6 PLBs/clump) produced the best shoots on medium containing 0.5 mg·L−1 α-Naphthaleneacetic acid (NAA) and 0.3 mg·L−1 TDZ. Among the organic substances tested, 200 g·L−1 potato homogenate (PH) added to Hyponex N016 medium supplemented with 1.0 mg·L−1 NAA, 30 g·L−1 sucrose, 170 mg·L−1 NaH2PO4, 1.0 g·L−1 peptone, and 9 g·L−1 Bacto agar resulted in the best rooting. The rooted plantlets with four to five leaves were acclimatized and had a 100% survival rate. The method presented in this research provides a strategy for the development of highly effective propagation of Paphiopedilum species using ex vitro explants for both conservation and horticultural purposes.


2020 ◽  
Vol 11 (2) ◽  
pp. 30-38
Author(s):  
Nor Hasima Mahmod ◽  
Zakiah Mustapha ◽  
Ahmad Hilman Ariffin Husni ◽  
Nurul Anisah Ishak ◽  
Hafsah Jaafar

Dioscorea hispida Dennst produces tuber which possess valuable medicinal properties but unsustainable harvesting has led to its reduction. The plant propagates slowly because of its low tuber sprouting rate. In average, Dioscorea hispida Dennst tubers took approximately 60 d to break dormancy and sprout. Hence, callus culture is proposed as a possible efficient type of culture for manipulation of this species.  In the present study, calli were induced from stem segments to evaluate callus culture potential of Dioscorea hispida Dennst. Results indicate that the combination of 1 mgL-1 naphthaleneacetic acid (NAA), 1 mgL-1 6- benzylaminopurine (BAP) and 0.5 mgL-1 2,4-dichlorophenoxyacetic acid (2, 4-D) in Gamborg (B5) medium improved callus multiplication and differentiation in the stem culture as opposed to those in Murashige and Skoog (MS) medium. The findings from the present study provide the basis of callus culture protocol for stem explant of Dioscorea hispida Dennst with B5 being the more effective basal medium.


Sign in / Sign up

Export Citation Format

Share Document