https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1961.6.1.0099

Marine Algae of the Eastern Tropical and Subtropical Coasts of the Americas

The seed constitutes the main vector of plant propagation and it is a critical development stage with many specificities. Seed longevity is a major challenge for the conservation of plant biodiversity and for crop success. Seeds possess a wide range of systems (protection, detoxification, repair) allowing them to survive in the dry state and to preserve a high germination ability. Therefore, the seed system provides an appropriate model to study longevity and aging.

Iconography : Seed longevity: Survival and maintenance of high germination ability of dry seeds

Evaluation of proline functions in saline conditions.

Effects, tolerance mechanisms and management of salt stress in grain legumes.

Seed priming is a presowing technique in which seeds are moderately hydrated to the point where pregermination metabolic processes begin without actual germination. Seeds are then redried to near their actual weight for normal handling. Seeds can be soaked in tap water (hydropriming), aerated low-water potential solutions of polyethylene glycol or salt solutions (KNO3, KH2PO4, KCl, NaCl, CaCl2 or MgSO4; osmopriming), plant growth regulators, polyamines (hormonal priming), plant growth-promoting bacteria (biopriming), macro or micronutrients (nutripriming) or some plant-based natural extracts. Here, we review: (1) seed priming as a simple and effective approach for improving stand establishment, economic yields and tolerance to biotic and abiotic stresses in various crops by inducing a series of biochemical, physiological, molecular and subcellular changes in plants; (2) the tendency for seed priming to reduce the longevity of high-vigour seeds and improve the longevity of low-vigour seeds; (3) the advantages of physical methods of seed priming to enhance plant production over conventional methods based on the application of different chemical substances; (4) the various physical methods (e.g. magneto-priming and ionising radiation, including gamma rays, ultraviolet (UV) rays (UVA, UVC) and X-rays) available that are the most promising presowing seed treatments to improve crop productivity under stressful conditions; and (5) effective seed priming techniques for micronutrient delivery at planting in field crops. Seed priming as a cost-effective approach is being used for different crops and in different countries to improve yield, as a complementary strategy to grain biofortification and in genetically improved crop varieties to enhance their performance under stress conditions, including submergence and low phosphorus. Some of the challenges to the broad commercial adaption of seed priming include longevity of seeds after conventional types of priming under ambient storage conditions and a lack of studies on hermetic packaging materials for extended storage.

Seed priming in field crops: potential benefits, adoption and challenges

Improvement of Pisum sativum salt stress tolerance by bio-priming their seeds using Typha angustifolia leaves aqueous extract

The present study was undertaken to assess the in vitro antifungal activity of petroleum ether, chlo-roform, methanol and aqueous extracts of Datura metel L. leaves and flowers, against two Trichoderma species (Trichoderma harzianum and Trichoderma viride) and three formae speciales of Fusarium oxysporum, that is, Fusarium oxysporum f. sp. melonis, Fusarium oxysporum f. sp. lycopersici and Fusarium oxysporum f. sp. tuberosi. Radial growth of the pathogen on PDA plates was recorded after 3 to 7 days of incubation at 25°C. Results revealed an important antifungal activity of D. metel leaf and flower aqueous extracts at all concentrations tested (1, 2, 3 and 4%) against pathogenic fungus.How-ever, the extent of response to extracts was species specific. In fact, the highest inhibition (69%) of T. viride mycelial growth was observed with flower aqueous extracts. Indeed, F. oxysporum f. sp. melonis was found to be more susceptible than the other fungal species to organic extract; radial growth inhibition varied from 24 to 76% and from 31 to 76% in the presence of leaf and flower organic extracts, respectively. In addition, the radial growth of F. oxysporum f. sp. Lycopersici was reduced by all organic extracts. The fungicidal activity of leaf extracts was more effective against F. oxysporum f. sp. tuberosias compared to flower extracts. Both Trichoderma species were less sensitive to D. metel organic extracts than Fusarium species. Our findings showed that D. metel extracts can be used as potential source of fungicides to control the phytopathogenic fungi tested.

	 

	Key words: Antifungal activity, aqueous and organic extracts, Datura metel, Fusarium, Trichoderma, radial growth.

Antifungal activity of Datura metel L. organic and aqueous extracts on some pathogenic and antagonistic fungi

In the present research work, Nicotiana glauca Graham was used as a potential source of biologically active compounds. The antifungal activity of leaf and flower aqueous and organic extracts (petroleum ether, chloroforme and methanol) was assessed in vitro against three phytopathogenic fungi and two antagonistic agents. These target fungi were subjected to the different types of extracts already incorporated into the Potato Dextrose Agar (PDA) medium at various concentrations. Results revealed an important antifungal activity of N. glauca leaf and flower aqueous extracts at all concentrations tested (1, 2, 3 and 4%). However, a relative difference in the extent of the response of the same fungal agent to the extracts tested was observed. In fact, Trichoderma viride was found to be more sensitive than the other target species, where the radial growth inhibition noted varied from 37.4 to 63.14% depending on aqueous extracts concentrations and the maximum inhibition was obtained with leaf aqueous extracts applied at 1 and 2% concentrations. Moreover, T. viride and Fusarium oxysporum f. sp. melonis were found to be the most sensitive to leaf and flower organic extracts as compared to the other agents. Growth of T. viride was inhibited by 33.7% in the presence of chloroform leaf extract and petroleum ether flower extracts tested at 3000 and 9000 ppm, respectively. Furthermore, the radial growth of F. oxysporum f. sp. melonis was reduced by more than 31 and 20% with leaf petroleum ether and flower chloroform extracts, respectively, applied at 9000 ppm. T. harzianum, F. oxysporum f. sp. tuberosi and F. oxysporum f. sp. lycopersici were found to be less sensitive to N. glauca organic extracts as compared to aqueous extracts.

	 

	Key words: Antifungal activity, aqueous extracts, allelopathy, Nicotiana glauca Graham,Fusarium, Trichoderma and radial growth.

https://www.academicjournals.org/article/article1380723413_Rinez et al.pdf

Assessment of the antifungal activity of Nicotiana glauca Graham aqueous and organic extracts against some pathogenic and antagonistic fungi.

/pdf/improving-salt-tolerance-in-pepper-by-bio-priming-with-3owxchy9dj.pdf

Improving salt tolerance in pepper by bio-priming with Padina pavonica and Jania rubens aqueous extracts

Abstract This study aims to evaluate the effect of seed priming for two pepper varieties by extracts of two algae thalli on the performance of growth at vegetative stage. The seeds were soaked in thalli aqueous extracts (at 20, 40, 60, 80 and 100 g/L), for 24 h at 28±2°C, rinsed thoroughly with distilled water and then dried to their initial weight as a first batch (SD), a second batch of seeds was considered, corresponding to seeds placed in Petri dishes to germinate directly after washing (SND). Untreated seeds were the control. The results showed than the priming has improved seedlings growth for both varieties. Seed priming with algae aqueous extracts has improved roots and shoots length. The best stimulations were 220% and 70%, respectively, recorded for seedlings of Baklouti and Chargui varieties, following the priming with the extract of Padina pavonica at 40 g/L concentration. These improvements appear to be related to a better photosynthetic intensity, an increase in the number of leaves and the water content, which were noted in plants from pretreated seeds. Finally, the results indicate that, generally, the plantlets from SND were more vigorous. The results of this work show that algae could be an inexhaustible resource of substances, that can be used as an alternative to chemicals used in the pretreatment of seeds, reducing the risk of pollution and preserving the biological material.

Imen Rinez

Papers

Improvement of Pisum sativum salt stress tolerance by bio-priming their seeds using Typha angustifolia leaves aqueous extract

Antifungal activity of Datura metel L. organic and aqueous extracts on some pathogenic and antagonistic fungi

Assessment of the antifungal activity of Nicotiana glauca Graham aqueous and organic extracts against some pathogenic and antagonistic fungi.

Improving salt tolerance in pepper by bio-priming with Padina pavonica and Jania rubens aqueous extracts

Performance of Pepper Seedlings Developed from Seeds Pretreated with Algal Aqueous Extracts