scholarly journals Seed germination and removal of Michelia champaca L. (Magnoliaceae) in eucalypt stands: the influence of the aril

2004 ◽  
Vol 28 (3) ◽  
pp. 327-332 ◽  
Author(s):  
Giovano Candiani ◽  
Mauro Galetti ◽  
Victor Jose Mendes Cardoso

We tested the influence of the aril on seed germination in controlled conditions and on the removal of M. champaca seeds in natural environment. Germination assays were kept at 25 ± 2 °C under continuous white light. Removal experiments were carried out in three "old" (39 to 62-years old) and three "new" (15-years old) eucalypt stands in Horto Florestal Navarro de Andrade, Rio Claro, SP. The results show that the aril inhibits the germination and the seeds exhibit a positively photoblastic reaction. We found higher seed removal in old eucalypt stands than the new ones, probably due to the higher density of rodents in the old stands. In the new stands, we found higher seed removal of arillated seeds by ants. Ants are important to remove the aril of seeds dropped by birds, not only enhancing seed germination but also preventing seed predation by rodents.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paula M. A. Fiedler ◽  
Alice De Lapparent ◽  
Jeremie Razafitsalama ◽  
Justin Sanamo ◽  
Kim J. E. Steffens ◽  
...  

AbstractForest restoration is a prime goal within the 2021–2030 UN “Decade of Ecosystem Resoration”. As part of these activities, natural regeneration has to be promoted for biological as well as for economic reasons. For this, the processes of seed dispersal, seed predation and germination have to be understood in the original as well as in degraded vegetation formations. We used seed removal experiments to assess post-dispersal processes that influence recruitment along a gradient of forest degradation in Madagascar analyzing seeds of three animal dispersed tree species. The percentage of seeds consumed or dispersed, declined from forest (28.6%) to degraded forest (17.2%) to savanna (10.8%). Only three out of 1080 seeds were cached and remained intact during the 14-day experiment. All three seeds were cached in the forest habitat and none in the degraded forest and savanna. The low percentage of seeds removed may be due to the lack of endemic rodents caching seeds, as only introduced rats were recorded in the area. The species-poor fauna of potential secondary seed dispersers of the region and especially in the degraded areas might represent an obstacle for diverse regeneration in degraded regions of Madagascar.


2004 ◽  
Vol 47 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Simone Godoi ◽  
Massanori Takaki

Seeds of Cecropia hololeuca were submitted to regimes of constant and alternating temperatures, associated with photoperiods of white light, "shade light" and continuous darkness under controlled conditions in laboratory. Seeds did not germinate at constant temperatures of 10°C to 20°C and above 35°C. Seeds only germinated in the darkness when the temperature was alternated. "Shade light" inhibited germination. We concluded that the regime of alternating temperatures suppressed the light effects on seed germination of this species.


2021 ◽  
Vol 23 ◽  
pp. 684-693
Author(s):  
Anna Piotrowska

Deterioration of the natural environment as a result of violation of its natural structures and self-regulatory mechanisms causes an urgent need to replace chemicals with effective and multidirectional biopreparations. Reduction of the amount of chemicals used in agriculture becomes possible through the use of Effective Microorganisms. This will reduce the burden on the environment. Agriculture that uses EM technology can count on help with germination rates; emergence uniformity; and crop yields, for example. EM formulations contain a mixture of different coexisting microorganisms. The following paper presents the results of own research on the use of Effective Microorganisms in seed dressing of spring wheat. It was shown that the microbial preparation EM Naturally Active affects the increase of wheat seed germination dynamics.


2008 ◽  
Vol 8 (2) ◽  
pp. 63-68 ◽  
Author(s):  
Edson Simão ◽  
Massanori Takaki

The effect of light and temperature on Tibouchina mutabilis seed germination was analyzed by isothermic incubations in the range of 10 to 40 °C, with 5 °C intervals under both continuous white light (32.85 µmolm-2s-1) and darkness and alternating temperatures (15-20; 15-25; 15-30; 15-35; 20-25; 20-30; 20-35; 25-30; 25-35 and 30-35 °C) under both photoperiod of 12 hours and continuous darkness. The seeds of T. mutabilis need light to trigger the germination and no germination was observed in darkness. The range of optimum temperatures for germination was between 25 to 30 °C and the 20-25 °C alternating temperatures. These results indicate that T. mutabilis behaves as a pioneer species and daily alternating temperatures did not change the light sensitivity of seeds.


2021 ◽  
Vol 12 (2) ◽  
pp. 51-66
Author(s):  
Luciana Pinto Paim ◽  
Eduarda Demari Avrella ◽  
Juliana Carolina Alves Horlle ◽  
Claudimar Sidnei Fior ◽  
Marília Lazarotto ◽  
...  

Contextualization: Lupinus bracteolaris is a heliophite species that vegetates low lands, open slopes and sandstone hills. Knowledge gap: Despite the high rusticity and potential for covering poor soils, there is still no information to assist in the analysis of its seeds. Purpose: To determine pre-germinative treatments, substrate, temperature, luminosity and water intake in the vigor of Lupinus bracteolaris seeds. Methodology: Fruits were collected from 20 matrix plants, then the seeds were processed and submitted to the following tests: pre-germinative methods (six treatments at 25°C); substrates and temperatures (sand and paper at 20, 25 and 30°C); photoblast test (white light, diffuse-green light and continuous dark under 20°C) and the imbibition curve (control and scarification between sandpaper under 20°C). Evaluations: percentage of germination and formed seedlings, germination speed index, average germination time and seedling formation, using a completely randomized design. Results and conclusions: According to the analyzed variables, the results showed superiority for the pre-germinative treatment between sandpapers for 20 seconds. In addition, the substrate paper germibox and the temperature of 20°C were the most suitable during seed germination. The seeds of Lupinus bracteolaris were classified as neutral-photoblastic and without dormancy.


2007 ◽  
Vol 59 (3) ◽  
pp. 227-231 ◽  
Author(s):  
S. Zivkovic ◽  
M. Devic ◽  
B. Filipovic ◽  
Z. Giba ◽  
D. Grubisic

The influence of high NaCl concentrations on seed germination in both light and darkness was examined in the species Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum, and C. tenuiflorum. Salt tolerance was found to depend on the life history of the seeds. To be specific, seeds of all five species failed to complete germination when exposed to continuous white light if kept all the time in the presence of 100-200 mM and greater NaCl concentrations. However, when after two weeks NaCl was rinsed from the seeds and the seeds were left in distilled water under white light for an additional two weeks, all species completed germination to a certain extent. The percent of germination not only depended on NaCl concentration in the prior medium, but was also species specific. Thus, seeds of C. pulchellum, C. erythraea, and C. littorale completed germination well almost irrespective of the salt concentration previously experienced. On the other hand, seeds of C. tenuiflorum completed germination poorly if NaCl concentrations in the prior media were greater than 200 mM. When seeds after washing were transferred to darkness for an additional 14 days, they failed to complete germination if previously imbibed on media containing NaCl concentrations greater than 400 mM. However, the seeds of all species, even if previously imbibed at 800 mM NaCl, could be induced to complete germination in darkness by 1 mM gibberellic acid. .


Author(s):  
Wazir Ahmed ◽  
Sumreen Siddiq ◽  
Muhammad Yaseen ◽  
Qurban Ali ◽  
Muhammad Arshad

1965 ◽  
Vol 18 (3) ◽  
pp. 798-804 ◽  
Author(s):  
S. P. Mittal ◽  
S. N. Mathur

Revista CERES ◽  
2010 ◽  
Vol 57 (5) ◽  
pp. 576-580 ◽  
Author(s):  
Cristiane Pimentel Victório ◽  
Nina Cláudia Barbosa da Silva ◽  
Maria Apparecida Esquibel ◽  
Alice Sato

This study was carried out to investigate the effects of light spectra, additional UV-A, and different growth regulators on the in vitro germination of Senecio cineraria DC. Seeds were surface-sterilized and inoculated in MS medium to evaluate the following light spectra: white, white plus UV-A, blue, green, red or darkness. The maximum germinability was obtained using MS0 medium under white light (30%) and MS + 0.3 mg L-1 GA3 in the absence of light (30.5%). S. cineraria seeds were indifferent to light. Blue and green lights inhibited germination. Different concentrations of gibberellic acid (GA3) (0.1; 0.4; 0.6; 0.8; 1.0 and 2.0 mg L-1) and indole-3-acetic acid IAA (0.1; 0.3 and 1.0 mg L-1) were evaluated under white light and darkness. No concentration of GA3 enhanced seed germination percentage under white light. However, when the seeds were maintained in darkness, GA3 improved germination responses in all tested concentrations, except at 1.0 mg L-1. Under white light, these concentrations also increased the germination time and reduced germination rate. Germination rate, under light or darkness, was lower using IAA compared with GA3.


Sign in / Sign up

Export Citation Format

Share Document