scholarly journals Seed germination of Leersia perrieri (Poaceae), a rare crop wild relative from Madagascar

2021 ◽  
Vol 49 (2) ◽  
pp. 135-140
Author(s):  
Botovao Auguste Ramiandrisoa ◽  
Cyrille Maharombaka ◽  
Maria S. Vorontsova ◽  
Hery Lisy Tiana Ranarijaona

Madagascar is home to a diversity of aquatic grasses. One of these is a rare rice relative, Leersia perrieri (known as Ahitsiriry or Tsingirifiry in the Malagasy language), which is found in a restricted area around the Mahajanga wetlands. A germination test was carried out on two types of local substrate and a control with randomised selected seeds. Seed germination on the control and clay substrates reached 50% while on the organic substrate germination failed to reach 40% during 22 days of observation. The GLM analysis of the final germination showed significant differences between the three treatments. The germination percentage (GP%) was higher in the control and significantly decreased on the clay and organic substrates. Our results help explains our field observations where L. perrieri tends to form monodominant stands on clay substrate, and dispersed multispecies assemblages with fewer individuals on organic soils. This work will be of direct benefit to our panned conservation activities and eventually germplasm availability for crop improvement research.

2020 ◽  
Vol 50 (5) ◽  
Author(s):  
Gabriel Streck Bortolin ◽  
Alfredo José Salinas-Arcienega ◽  
Yutcelia Carolina Galviz-Fajardo ◽  
Luciano do Amarante ◽  
Carlos Eduardo da Silva Pedroso ◽  
...  

ABSTRACT: The objective of the following research was to investigate the physiological responses of two bahiagrass genotypes (Paspalum notatum Flügge) submitted to water restriction, induced by polyethylene glycol (PEG6000), during seed germination. Seeds of cv. Pensacola (diploid) and Bagual ecotype (tetraploid) were placed on paper moistened with osmotic solutions at potentials of 0.0; -0.1; -0.2 and -0.3 MPa. Composed of two subsamples of 100 seeds and four experimental units per treatment, the germination test was conducted in a germination chamber under alternating temperatures of 30 °C (8 hours) and 20 °C (16 hours), with presence of light during the higher temperature. Final germination percentage and germination speed index of the seeds, as well as early growth, activity and expression of antioxidant enzymes of seedlings were evaluated. The water restriction induced by PEG6000 reduced the percentage of germination in Pensacola (from 74% to 59%) and Bagual (34% to 10%). For the latter, the evaluation of seedlings showed higher dry mass in relation to cv. Pensacola (1.7 times higher in root and 1.6 times in shoot). In response to moderate water restriction, the genotypes showed increases in root growth (1.7 times higher in -0.1 compared to 0.0 MPa), both in expression and enzymatic activity (superoxide dismutase and catalase).


Pastura ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 94
Author(s):  
Ubaidillah ◽  
A. V. Zulaiha ◽  
R. Dianita

This experiment was aimed to reveal the effect of seed physical scarification and various growing mediaon vigor of Moringa oleifera. This study was conducted in greenhouse and consisted of two phases ofexperiment; first was studied the effect of physical scarification on seed germination of M. oleifera and thesecond was studied the effect of seed physical scarification and various sub optimum growing media onvigor of M. oleifera. The germination test was arranged in randomized completely design with 4 treatmentsthat were P0 = non scarification, P1 = one side scarification, P2 = two sides scarification, and P3 = full sidescarification. The variables measured were germination percentage (%) and seedling dry weight (g/plant).The second study was arranged in a factorial randomized completely design with the four treatments ofscarification (P0, P1, P2 and P3) over six growing media (sands, bricks, bricks and sands mixture, bricksand soils mixture, soils and sands mixture, and soils). The variables observed were petioles number, plantheight (cm/plant), and plant dry weight (g/plant). The scarification was significantly affect (P<0.05) thegermination percentage and seedling dry weight. Scarification and growing media also affected the vigorof M. oleifera significantly (P<0.05). Two side seed scarification improve the germination and seedling dryweight instead of control. Combination of scarification in two sides and growing media of soils and sandsmixture given the highest vigor of M. oleifera reflected on petioles number, plant height, and plant dry weight. Keywords: germination, M. oleifera, scarification, sub optimum media, vigor


HortScience ◽  
2017 ◽  
Vol 52 (8) ◽  
pp. 1117-1121
Author(s):  
Alexandre Bosco de Oliveira ◽  
Wagner A. Vendrame ◽  
Luciana Cardoso Nogueira Londe

To investigate the effects of different cryoprotectants on germination and seedling development of jatropha (Jatropha curcas L.) seeds after cryopreservation, two experiments were performed under in vitro and ex vitro conditions. Nine treatments were used for both experiments, as follows: T1—No cryoprotectants (control); T2—glycerol 2 m (20 minutes); T3—sucrose 0.4 m (20 minutes); T4—glycerol 2 m (20 minutes) + PVS2 (10 minutes); T5—glycerol 2 m (20 minutes) + PVS2 + phloroglucinol 1% (10 minutes); T6—sucrose 0.4 m (20 minutes) + PVS2 (10 minutes); T7—sucrose 0.4 m (20 minutes) + PVS2 + phloroglucinol 1% (10 minutes); T8—glycerol 2 m (20 minutes) + sucrose 0.4 m (20 minutes) + PVS2 (10 minutes); and T9—glycerol 2 m (20 minutes) + sucrose 0.4 m (20 minutes) + PVS2 (10 minutes) + phloroglucinol 1% (10 minutes). After cryopreservation, seeds without cryoprotectants (T1) or with sucrose 0.4 m + PVS2 (T6) returned the best germination percentages after seven days of in vitro culture, 29.5% and 25%, respectively. However, they were not significantly different. For the ex vitro experiment, seed germination percentage was higher in organic substrate. These results indicate that cryopreservation of jatropha seeds can be accomplished without cryoprotectants, and faster germination is obtained in organic substrate.


2018 ◽  
Vol 2 (1) ◽  
pp. 11-15
Author(s):  
Mohammed Dadach ◽  
Zoheir Mehdadi ◽  
Abd Latif Adjouj

Abstract Global warming and soil salinity are major constraints threat speared of Mediterranean endogenous flora, however little is known about the effect of these phenomena on seed germination patterns, particularly in Algeria. Germination test under laboratory controlled conditions had been carried out using seeds of Marrubium vulgare, Sideritis incana and Stachys ocymastrum. Seeds were submitted at temperatures of 5, 10, 15, 20, 25, 30 and 35 °C, after that and within optimum temperatures, various sodium chloride (NaCl) concentrations of 0, 34, 68, 102 and 136 mM were set to evaluated salinity effect. Germination was more satisfactory on temperatures ranged between 15 and 25 °C. Whereas, increased or decreased temperatures from the optimum bring to germination fall. High seed germination capacity had been showed on non-saline solution. While, germination had depressed by enhanced NaCl solution up to 136 Mm in which Final Germination Percentage are either significantly decreased (for S. ocymastrum seeds 18% germination) or absolutely inhibited (for M. vulgare and S. incana seeds), as well Initial Germination Day are delayed. Overall, data showed that germination patterns response varies among species, given that seed germination is remarkably limited by extremes temperatures and salinity.


2014 ◽  
Vol 36 (spe1) ◽  
pp. 281-287 ◽  
Author(s):  
Juliana Iassia Gimenez ◽  
Gisela Ferreira ◽  
Jaqueline Malagutti Corsato

The objective of this study was to evaluate the effect of different water contents achieved by Annona emarginata (Schltdl.) H. Rainer seeds during immersion in GA3 solutions, in variation of soluble sugars levels and germination. Seeds with 10% of initial water content were submitted to imbibition in GA3 solutions with concentrations of 0; 250; 500; 750 and 1000 mg L-1 and when they reached the water content of 15%, 20%, 25%, 30% and 35%, the quantification of soluble sugars levels and germination test were performed. Seeds immersed up to they reach 15% of water with GA3 and immersed up to the water acquisition of 20% without GA3, presented higher soluble sugars levels and germination percentage, which were decreased when the seeds reached 30% and 35% of water, independently of the presence of the plant growth regulator. It was conclude that different water contents reached by the seeds in immersion treatments with GA3 affect the soluble sugars levels and germination percentage of Annona emarginata seeds. Thus, in treatments with Annona emarginata, the seeds must remain immersed in water without GA3 up to they reach 20% of water, as higher water contents (35%) reduce the soluble sugars levels and the seed germination percentage.


1994 ◽  
Vol 30 (6) ◽  
pp. 237-246 ◽  
Author(s):  
A. Carucci ◽  
M. Majone ◽  
R. Ramadori ◽  
S. Rossetti

This paper describes a lab-scale experimentation carried out to study enhanced biological phosphate removal (EBPR) in a sequencing batch reactor (SBR). The synthetic feed used was based on peptone and glucose as organic substrate to simulate the readily biodegradable fraction of a municipal wastewater (Wentzel et al., 1991). The experimental work was divided into two runs, each characterized by different operating conditions. The phosphorus removal efficiency was considerably higher in the absence of competition for organic substrate between P-accumulating and denitrifying bacteria. The activated sludge consisted mainly of peculiar microorganisms recently described by Cech and Hartman (1990) and called “G bacteria”. The results obtained seem to be inconsistent with the general assumption that the G bacteria are characterized by anaerobic substrate uptake not connected with any polyphosphate metabolism. Supplementary anaerobic batch tests utilizing glucose, peptone and acetate as organic substrates show that the role of acetate in the biochemical mechanisms promoting EBPR may not be so essential as it has been assumed till now.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 338
Author(s):  
Naeem Ahmed ◽  
Asad Masood ◽  
Kim S. Siow ◽  
M. F. Mohd Razip Wee ◽  
Rahmat Zaki Auliya ◽  
...  

In general, seed germination is improved by low-pressure plasma (LPP) treatment using precursors such as air, nitrogen, argon, or water (H2O). Here, H2O-based LPP treatment using the optimized parameters of 10 W and 10 s improves the germination of Bambara groundnut seeds by 22%. LPP increases the wettability and roughness of the seed hilum while oxidizing the surface with carboxyl and amine groups. In this H2O-based treatment of Bambara groundnut seeds, combinatory etching and chemical modification facilitated the imbibition process and increased the germination percentage. The success of this method has the potential to be scaled up to solve food security with seeds otherwise facing germination-related issues.


2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Chih-Hsin Yeh ◽  
Kai-Yi Chen ◽  
Yung-I. Lee

Abstract Background Vanilla planifolia is an important tropical orchid for production of natural vanilla flavor. Traditionally, V. planifolia is propagated by stem cuttings, which produces identical genotype that are sensitive to virulent pathogens. However, propagation with seed germination of V. planifolia is intricate and unstable because the seed coat is extremely hard with strong hydrophobic nature. A better understanding of seed development, especially the formation of impermeable seed coat would provide insights into seed propagation and conservation of genetic resources of Vanilla. Results We found that soaking mature seeds in 4% sodium hypochlorite solution from 75 to 90 min significantly increased germination. For the culture of immature seeds, the seed collection at 45 days after pollination (DAP) had the highest germination percentage. We then investigated the anatomical features during seed development that associated with the effect of seed pretreatment on raising seed germination percentage. The 45-DAP immature seeds have developed globular embryos and the thickened non-lignified cell wall at the outermost layer of the outer seed coat. Seeds at 60 DAP and subsequent stages germinated poorly. As the seed approached maturity, the cell wall of the outermost layer of the outer seed coat became lignified and finally compressed into a thick envelope at maturity. On toluidine blue O staining, the wall of outer seed coat stained greenish blue, indicating the presence of phenolic compounds. As well, on Nile red staining, a cuticular substance was detected in the surface wall of the embryo proper and the innermost wall of the inner seed coat. Conclusion We report a reliable protocol for seed pretreatment of mature seeds and for immature seeds culture based on a defined time schedule of V. plantifolia seed development. The window for successful germination of culturing immature seed was short. The quick accumulation of lignin, phenolics and/or phytomelanins in the seed coat may seriously inhibit seed germination after 45 DAP. As seeds matured, the thickened and lignified seed coat formed an impermeable envelope surrounding the embryo, which may play an important role in inducing dormancy. Further studies covering different maturity of green capsules are required to understand the optimal seed maturity and germination of seeds.


Weed Science ◽  
2020 ◽  
pp. 1-29
Author(s):  
Yonghuan Yue ◽  
Guili Jin ◽  
Weihua Lu ◽  
Ke Gong ◽  
Wanqiang Han ◽  
...  

Abstract Drunken horse grass [Achnatherum inebrians (Hance) Keng] is a perennial poisonous weed in western China. A comprehensive understanding of the ecological response of A. inebrians germination to environmental factors would facilitate the formulation of better management strategies for this weed. Experiments were conducted under laboratory conditions to assess the effects of various abiotic factors, including temperature, light, water, pH and burial depth, on the seed germination and seedling emergence of A. inebrians. The seeds germinated at constant temperatures of 15, 20, 25, 30, 35°C and in alternating-temperature regimes of 15/5, 20/10, 25/15, 30/20, 35/25, 40/30°C, and the seed germination percentages under constant and alternating temperatures ranged from 51% to 94% and 15% to 93%, respectively. Maximum germination occurred at a constant temperature of 25°C, and germination was prevented at 45/35°C. Light did not appear to affect seed germination. The germination percentage of seeds was more than 75% in the pH range of 5 to 10, with the highest germination percentage at pH 6. The seeds germinated at osmotic potentials of 0 MPa to -1.0 MPa, but decreasing osmotic potential inhibited germination, with no germination at -1.2MPa. After 21 d of low osmotic stress, the seeds that did not germinate after rehydration had not lost their vitality. The seedling emergence percentage was highest (90%) when seeds were buried at 1 cm but declined with increasing burial depth and no emergence at 9 cm. Deep tillage may be effective in limiting the seed germination and emergence of this species. The results of this study provide useful information on the conditions necessary for A. inebrians germination and provide a theoretical basis for science-based prediction, prevention and control of this species.


1975 ◽  
Vol 5 (3) ◽  
pp. 419-423 ◽  
Author(s):  
Carey Borno ◽  
Iain E. P. Taylor

Stratified, imbibed Douglas fir (Pseudotsugamenziesii (Mirb.) Franco) seeds were exposed to 100% ethylene for times between 0 and 366 h. Germination rate and germination percentage were increased by treatments up to 48 h. The 12-h treatment gave largest stimulation; 30% enhancement of final germination percentage over control. Treatment for 96 h caused increased germination rate for the first 5 days but reduced the germination percentage. Germinants were subject to continuous exposure to atmospheres containing 0.1 – 200 000 ppm ethylene in air, but it did not stimulate growth, and the gas was inhibitory above 100 ppm. Although some effects of high concentrations of ethylene may have been due to the lowering of oxygen supplies, this alone was insufficient to account for the full inhibitory effect. The mechanism of stimulation by short-term exposure to ethylene is discussed.


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