Germination of Lomandra sonderi (Dasypogonaceae) Promoted by Pericarp Removal and Chemical-Stimulation of the Embryo

1995 ◽  
Vol 43 (2) ◽  
pp. 223 ◽  
Author(s):  
JA Plummer ◽  
AD Crawford ◽  
SK Taylor

Lomandra Labill. is a common genus in the understorey of the jarrah (Eucalyptus marginata Sm.) forest of Western Australia. Species in this genus are difficult to propagate by seed and do not readily re establish following mining. Limiting factors for germination success were explored and identified. Lomandra sonderii (F.Muell.) Ewart set very few seed (seeds per flower = 0.122). Tetrazolium tests indicated that seed viability was relatively high (50%). Germination was inhibited (0%) by the inner pericarp tissues which surround the seed and are part of the diaspore. Manual removal of the inner pericarp or leaching overcame this inhibition with a fifth of seeds subsequently germinating. Similar treatments improved germination of L. drummondii (F. Muell. ex Benth.) Ewart from 40% to 80%. Soaking L. sonderi seeds in gibberellic acid (GA3, 50 mg L-1) further improved germination (28%). Ants (Camponotus sp. and Iridomyrmex sp.) collected and dispersed L. sonderi seed and are likely to improve germination in the forest by removing and consuming the inner pericarp. Only half of the Viable excised embryos of L. sonderi grew in vitro, indicating the presence of embryo dormancy. Embryo dormancy was overcome by GA3 (0.5 mM) and zeatin (0.5 mM) in the liquid culture medium. In vitro culture may be a practical means of propagating Lomandra if seed is scarce.

Weed Science ◽  
1990 ◽  
Vol 38 (3) ◽  
pp. 201-205 ◽  
Author(s):  
James L. Hilton ◽  
Parthasarathy Pillai ◽  
Helen A. Norman

The herbicide safener OTC (L-2-oxothiazolidine-4-carboxylic acid) increased the amount of reduced thiol compounds in sorghum [Sorghum bicolor(L.) Moench. ‘DK 427′] seedlings. When seedlings were grown in liquid culture medium containing35S-OTC, the compound was metabolized to radiolabeled cysteine and glutathione. The addition of tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2-trichloroethyl)oxirane] increased conversion of35S-OTC to cysteine and resulted in the formation of one additional35S-labeled compound. When35S-glutathione was injected into germinating seeds it was converted to35S-cysteine and both thiols were subsequently found in roots and shoots. Seeds injected with35S-OTC both translocated the compound to developing roots and shoots and metabolized35S-OTC to cysteine and glutathione. Excised roots and shoots also metabolized35S-OTC to the thiols. In an in vitro assay the enzyme 5-oxoprolinase converted OTC to cysteine.


2019 ◽  
Vol 49 ◽  
Author(s):  
Ana Paula de Azevedo Pasqualini ◽  
Gabriela Xavier Schneider ◽  
Hugo Pacheco de Freitas Fraga ◽  
Luiz Antonio Biasi ◽  
Marguerite Quoirin

ABSTRACT In plant micropropagation, the establishment stage is difficult, due to the presence of microorganisms in tissues from field-grown matrices, especially for bamboo. This study aimed to establish an efficient asepsis protocol for Bambusa oldhamii explants from field plants, as well as to carry out the molecular identification of a possible endophytic bacterial isolate. The explants were exposed to 70 % alcohol, 1 % sodium hypochlorite (NaOCl), 0.1 % mercuric chloride (HgCl2), thiophanate-methyl (Cercobin®) and chlorhexidine digluconate (2 % Riohex®) in different combinations, and introduced into Murashige and Skoog culture medium (solid or liquid), supplemented or not with 4 mL L-1 of Plant Preservative Mixture (PPMTM), totaling seven treatments. The asepsis and immersion of the explants in the liquid culture medium containing 4 mL L-1 of PPMTM visually inhibited the bacterial and fungal growth, allowed the development of shoots with a mean length of 2.2 cm and posterior subcultures, being the best treatment used for the in vitro establishment of B. oldhamii. The molecular identification of an endophytic bacterium performed by 16S rDNA sequencing allowed to identify the bacterial isolate as Ralstonia sp., with 100 % of similarity, and the phylogenetic analysis grouped it with Ralstonia pickettii. In addition, the bacterial isolate showed to be sensitive to 4 mL L-1 of PPMTM by the minimum inhibitory concentration test.


2019 ◽  
Vol 49 ◽  
Author(s):  
Daniela Werner Ribeiro dos Santos ◽  
Théo Piucco Rocker ◽  
Thiago Sanches Ornellas ◽  
Miguel Pedro Guerra

ABSTRACT The contamination by microorganisms and oxidation of explants in the in vitro establishment of bamboo are recurrent problems for its micropropagation. In the present study, effects of the biocide Plant Preservative Mixture (PPM™), the antibiotic kasugamycin and the consistency of the culture medium were evaluated in the in vitro establishment of Bambusa vulgaris,Phyllostachys bambusoides and Dendrocalamus asper. The presence of PPM™ in the culture medium had a significant effect using 2 mL L-1 or 4 mL L-1 concentrations, as well as in the liquid culture medium, increasing the plants established in the autumn. Kasugamycin promoted variable responses for all the three species, depending on the season. There was interaction among the factors, demonstrating that higher rates of viable plants can be obtained by combining different strategies to reduce the oxidation and contamination. For the in vitro establishment of B. vulgaris,P. bambusoides and D. asper, it is recommended to add 2 mL L-1 or 4 mL L-1 of PPM™ to the liquid culture medium.


2010 ◽  
Vol 53 (4) ◽  
pp. 793-799 ◽  
Author(s):  
Esmael Lopes dos Santos ◽  
Antonio Eduardo Pípolo ◽  
Ricardo Tadeu de Faria ◽  
Cássio Egidio Cavenaghi Prete

Aiming at evaluating genotype influence on the concentration of protein and oil, immature seeds of cultivars CD 202 and CD 206 were removed from the mother-plant, in the stage R5, and were grown in vitro, in a liquid culture medium which contained 20, 40 and 60 mM of glutamine, during eight days. Afterwards, the concentrations of oil and protein were compared to the contents of the seeds cultivated in vivo. With a higher availability of glutamine for the seed, there was an increase of protein content. The genotypes were statistically different as far as the protein concentration was concerned,which confirmed that the genotype had influence on the concentration of protein in the seed. Oil and protein concentrations were inversely related when a variation of glutamine concentration occurred.


2017 ◽  
Vol 86 (3) ◽  
Author(s):  
Agnieszka Kiełkowska ◽  
Adela Adamus

<span>Phytosulfokines (PSK) are peptidyl growth factors with the potential of inducing cell proliferation. We examined the effect of supplementation of liquid culture medium with 0.1 µM phytosulfokine-α (PSK-α) on protoplast viability and division frequencies in seven accessions of <em>Brassica oleracea</em> var. <em>capitata</em> L., including cultivars and breeding lines. Protoplasts were isolated from leaves and hypocotyls of in vitro grown plants and immobilized in calcium-alginate layers. Cabbage protoplast-derived cells cultured in medium supplemented with 0.1 µM of PSK-α had higher viability and division frequencies compared to cells cultured in PSK-α-free control medium. The effect of PSK-α was more pronounced in low-responding accessions (‘Sława z Gołębiewa’, ‘Ramkila F1’, LM, and LM98); however, in two cultivars with very low response (‘Badger Shipper’ and ‘Oregon 123’), although the division frequencies in the media supplemented with PSK-α were increased over the control, the differences were not significant. Obtained callus colonies were subjected to regeneration. PSK-α supplemented into the liquid culture medium had an indirect effect on shoot regeneration by inducing sustained cell divisions leading to an increase in shoot regeneration in Sława z Gołębiewa and both breeding lines.</span>


1995 ◽  
Vol 4 (5-6) ◽  
pp. 513-518
Author(s):  
Yang-Dong Guo ◽  
Seppo Pulli

Brassica campestris (Brassica rapa L. ssp. oleifera) is an important oilseed crop, particularly in Finland. Pollen culture techniques for haploid production have been developed, but B. campestris is relatively recalcitrant in pollen culture. Twenty eight genotypes of B. campestris were included in this study. The donor plants were grown in the greenhouse and transferred to the growth cabinet before bolting. Buds (2-4 mm long) were selected, macerated in B 5 medium, then NLN liquid culture medium was added. The microspores were incubated in the dark at 32°C for 72 h, then at 25°C for a further three weeks. Nineteen genotypes produced microspore-derived embryos. The highest yield was more than 300 embryos per 100 buds. Activated charcoal (150 mg/L) promoted embryogenesis, pollen development was faster and the embryo yield was higher. Plants were regenerated after transferring embryos to a solid B 5 medium. Colchicine solution was used to double the chromosome complements. About 100 regenerate plants have been obtained in our laboratory, and these haploids will be useful for the oilcrop breeding.


2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Amanda Pereira Honório ◽  
Roseli Dos Reis Goulart ◽  
Eunice Maria Baquião

One of the limiting factors in coffee production is the aureolated spot caused by the bacterium Pseudomonas syringae pv. garcae.  This work aimed to evaluate different Bayfolan® copper concentrations in the growth of two isolates of P. syringae pv. garcae in vitro.  P. syringae pv. garcae 157 and 59 isolates were used. Two experiments were carried out in a completely randomized design (CRD) with 7 treatments and 5 replications, in a total of 35 experimental units. Each experimental unit consisted of a Petri dish. For the installation of the experiment, Bayfolan® copper was added and homogenized into Kado 523 culture medium at concentrations of 0; 625; 1.250; 1.875; 2.500 and 3.000 ppm, and as positive control the product Kasumin® was used at 3.000 ppm concentration. Bayfolan® copper reduced the growth of the two isolates evaluated in vitro with increasing concentration. At concentrations of  2.500 and 3.000 ppm, Bayfolan® copper inhibited completely the growth of both isolates, similarly to the Kasumin® treatment. The research reveals that Bayfolan® copper is efficient to control P. syringae pv. garcae in vitro from concentrations of 2.500 ppm onwards.


Author(s):  
Carlos Alberto Peláez-Jaramillo ◽  
Maria Del Pilar Jiménez-Alzate ◽  
Pedronel Araque-Marin ◽  
Chiung-Yu Hung ◽  
Natalia Castro-Lopez ◽  
...  

Coccidioides is a soil-borne fungal pathogen and causative agent of a human respiratory disease (coccidioidomycosis) endemic to semi-desert regions of southwestern United States, Mexico, Central and South America. Aerosolized arthroconidia inhaled by the mammalian host first undergo conversion to large parasitic cells (spherules, 80–100 μm diameter) followed by endosporulation, a process by which the contents of spherules give rise to multiple endospores. The latter are released upon rupture of the maternal spherules and establish new foci of lung infection. A novel feature of spherule maturation prior to endosporulation is the secretion of a lipid-rich, membranous cell surface layer shed in vivo during growth of the parasitic cells and secretion into liquid culture medium during in vitro growth. Chemical analysis of the culture derived spherule outer wall (SOW) fraction showed that it is composed largely of phospholipids and is enriched with saturated fatty acids, including myristic, palmitic, elaidic, oleic, and stearic acid. NMR revealed the presence of monosaccharide- and disaccharide-linked acylglycerols and sphingolipids. The major sphingolipid components are sphingosine and ceramide. Primary neutrophils derived from healthy C57BL/6 and DBA/2 mice incubated with SOW lipids revealed a significant reduction in fungicidal activity against viable Coccidioides arthroconidia compared to incubation of neutrophils with arthroconidia alone. Host cell exposure to SOW lipids had no effect on neutrophil viability. Furthermore, C57BL/6 mice that were challenged subcutaneously with Coccidioides arthroconidia in the presence of the isolated SOW fraction developed disseminated disease, while control mice challenged with arthroconidia alone by the same route showed no dissemination of infection. We hypothesize that SOW lipids contribute to suppression of inflammatory response to Coccidioides infection. Studies are underway to characterize the immunosuppressive mechanism(s) of SOW lipids.


2016 ◽  
Vol 7 ◽  
Author(s):  
Gustavo Rubens Castro Torres ◽  
Laureen Michelle Houllou ◽  
Robson Antônio De Souza

The aim of this work was to test techniques to reduce microbial contamination in the phases of introduction and establishment of the <em>in vitro</em> cultivation of <em>Bambusa vulgaris</em> through two experiments. The first experiment was carried out in a completely randomized design using a factorial arrangement (pre-treatment of nodal segments using or not a solution of Derosal 500 SC<sup>®</sup> and Chloramphenicol × culture medium with half or full concentration of salts × culture medium with presence or absence of sucrose × culture medium with presence or absence of Plant Preservative Mixture<sup>TM</sup>). In a second experiment, carried out in a completely randomized design, the effect of different fungicides associated to Chloramphenicol in a liquid culture medium was tested. It was possible to verify that the isolated effects of the pre-treatment by immersion of the nodal segments in a solution of 4 mL L<sup>-1 </sup>of Derosal 500 SC<sup>® </sup>and 200 mg L<sup>-1 </sup>of Chloramphenicol for 30 minutes and explants placed in a sucrose-free medium reduced fungal contamination. In the second experiment, the treatment that reduced fungal contamination corresponded to explants placed for seven days in a liquid medium with half the concentration of salts, sucrose-free, with 2 mL L<sup>-1</sup> of Plant Preservative Mixture<sup>TM </sup>and with 4 mL L<sup>-1 </sup>of <sup> </sup>Derosal 500 SC<sup>®</sup> and 200 mg L<sup>-1 </sup>of Chloramphenicol.


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