Dispersal and germination syndromes of tree seeds in a monsoonal forest in northern India

2005 ◽  
Vol 15 (1) ◽  
pp. 29-42 ◽  
Author(s):  
R.C. Thapliyal ◽  
S.S. Phartyal

This paper describes the dispersal–germination characteristics of seeds of 77 native tree species in a seasonal monsoon forest in Uttaranchal state, northern India. Results indicate that 50% of the species dispersed in the hot, dry summer months, 18% during the rainy season, 23% during the cold season and the remainder in late spring. Germination tests on fresh and laboratory-stored seeds revealed a relationship between morphological features of the fruit and both germination percentage and mean germination time (MGT). Highest mean germination (50%) was for dry-dehiscent fruits with winged wind-dispersed seeds, followed by dry-dehiscent fruits with non-winged seeds (38%) and seeds of dry-indehiscent fruits (37%). Lowest germination (29%) was for seeds from fleshy or pulpy fruits. MGT followed the reverse course. Germination data for seeds stored dry in the laboratory during one seeding cycle indicated six patterns of seed germination: (1) average germination percentage of fresh seeds lower than that of stored seeds, indicating an after-ripening requirement; (2) initial high germination percentage followed by low values, indicating a steep to moderate decline in viability following harvest; (3) no germination after 1 or 2 months of seed storage, due to complete loss of viability, indicating short seed longevity; (4) fresh seed germination in some species equalled the average germination value of stored seeds, indicating constant germination for one whole seeding cycle; (5) germination of both fresh and stored seeds remained consistently low throughout the season, indicating a requirement for some kind of pre-treatment or having poor quality of seeds; (6) initial high germination followed by decline and again increase, showing a seasonal rhythm of germination.

2019 ◽  
Vol 42 ◽  
pp. e42825 ◽  
Author(s):  
María Manuela Urtasun ◽  
Eugenia Mabel Giamminola ◽  
Marta Leonor de Viana

In this work, we report the effects of the harvesting time, the stages in fruit ripening and the influence of potassium nitrate in V. quercifolia seed germination. In addition, information about the storage period and light requirements is provided. Fruits were harvested at the beginning and at the end of the fruiting season, and they were classified into five ripening categories. Seed germination was evaluated with two factorial experiments: 1) harvesting time, fruit ripening, and pre-germination treatment; 2) storage and light requirements. The response variables were germination percentage, mean germination time, and seedling vigor. Seeds harvested at the beginning of the season appeared to be less dormant and they were not influenced by fruit ripening or pre-germination treatments. By contrast, seeds harvested at the end of the season were influenced by fruit ripening and pre-germination treatments. Light and seed storage had a positive effect on germination. Mean germination time varied from 12 to 40 days, and vigor index was positively influenced by potassium nitrate. V.quercifolia seeds are photoblastic positive at constant temperatures and their dormancy can be influenced by harvest time, fruit ripening and a storage period.


2013 ◽  
Vol 5 (3) ◽  
pp. 325-331 ◽  
Author(s):  
Reyhaneh AZIMI ◽  
Hassan FEIZI ◽  
Mohammad KHAJEH HOSSEINI

The goal of this study was to evaluate concentrations of nanosized TiO2 at 0, 5, 20, 40, 60 and 80 mg L-1 with bulk TiO2 for possible stimulatory effects on wheatgrass seed germination and early growth stage. After 14 days of seed incubation, germination percentage improved by 9% following exposure to 5 ppm nanosized TiO2 treatment comparing to control. Similar positive effects occurred in terms of germination value and mean daily germination. Application of bulk TiO2 particles in 80 ppm concentration greatly decreased the majority of studied traits. Therefore phytotoxicity effect observed on wheatgrass seedling by application of bulk TiO2 particles in 80 ppm concentration. Exposure of wheatgrass seeds to 5 ppm nanosized TiO2 and bulk and nanosized TiO2 at 60 ppm obtained the lowest mean germination time but higher concentrations did not improve mean germination time. In general, there was a positive response by wheatgrass seed to some concentrations of nanosized TiO2. Usage of nanoparicles in order to improve germination and establishment of range plant in adverse environments similar to rangeland could be possible.


Botany ◽  
2012 ◽  
Vol 90 (8) ◽  
pp. 731-742 ◽  
Author(s):  
Félix Pérez-García ◽  
Federico Varela ◽  
M. Elena González-Benito

Gentiana lutea L. (yellow gentian, Gentianaceae) is an important medicinal plant under protection as endangered species in most European countries. The aim of this work was to evaluate variation in seed mass, seed water content, and seed germination among 56 wild accessions of G. lutea. The effect of gibberellic acid (GA3), putrescine, moist chilling, and level of ripeness of seeds on subsequent germination was also investigated. Seeds of G. lutea showed physiological dormancy (final germination percentages ranged from 0% to 11%, depending on the accession) and GA3 enhanced seed germination drastically in all the accessions. The highest germination (99%) of GA3-treated seeds was reached at 15 °C. Final germination percentage and germination rate (as expressed by mean germination time), as well as seed mass and seed water content, varied significantly among accessions. In general, 1 year moist chilling did not significantly enhance G. lutea seed germination. For most accessions, no significant differences were found between fully ripe seeds and less ripe seeds for seed water content, seed mass, and seed germination. Applications of GA3 were always most effective than those of putrescine for increasing seed germination.


2018 ◽  
Vol 66 (2) ◽  
pp. 918
Author(s):  
Jhon Alexander Vargas-Figueroa ◽  
Alba Marina Torres-González

Seed germination and seed longevity under different environmental conditions are fundamental to understand the ecological dynamics of a species, since they are decisive for its success within the ecosystem. Taking this into account, seed germination and seed storage behavior of a pioneer species of tropical dry forest (Tecoma stans) were studied in the laboratory, to establish the effect of different environmental conditions on a local tree population. Two seed lots collected in July 2011, from Cali (Colombia), were evaluated under three alternating temperatures (20/30, 20/25, 25/30 ºC; 16/8 h) and four light qualities (12-hour white light photoperiod, darkness, and 15 minutes of red light -R and far red light -FR). Final germination was recorded for all treatments; for white light treatment the daily germination was recorded to calculate mean germination rate, mean germination time, and two synchronization indices. To assess the effect of light quality on physiological variables, a destructive germination test was carried out. For this test, another seed lot was evaluated under the same light conditions using an alternating temperature of 20/30 °C - 16/8 h, recording germination during six days for every treatment. In addition, seeds were stored at two different moisture contents (7.7, 4.1 %) and three storage temperatures (20, 5, -20 ºC), during two time periods (one and three months); a seed germination test was conducted for each treatment. Four replicates of 35 seeds per treatment were used for all experiments. Germination was high (GP > 90 %) with all alternating temperatures under white light, whereas under R, FR, and darkness germination was evenly successful at low temperatures, but at higher temperature, half of the seeds entered into secondary dormancy (GP= 45-65 %). However, mean germination rate and synchronization under R and FR decreased significantly in comparison to white light treatment and, consequently, mean germination time increased. Seed storage behavior of this species is orthodox due to the high germination (GP > 90 %) obtained under all treatments. In conclusion, T. stans seeds have a negative germination response at high incubation temperatures in the absence of white light, entering into a secondary dormancy. In contrast, an environment with a lower temperature and without white light delays the germination, but at the end seeds are able to reach the same germination values. This seed dependence on incident light in limiting conditions suggests a physiological mechanism on the seed tissues of this species, probably mediated by phytochromes. Finally, the orthodox seed storage behavior of T. stans is a reason to include this species in ex situ seed conservation programs for restoration and recovery of the tropical dry forest; however, long-term studies should be conducted in order to evaluate the maintenance of this characteristic throughout longer periods of time. Rev. Biol. Trop. 66(2): 918-936. Epub 2018 June 01. 


2020 ◽  
Vol 49 (3) ◽  
pp. 625-632
Author(s):  
Muhammad Akram ◽  
Mehwish Zahid ◽  
Abu Bakr Umer Farooq ◽  
Muhammad Nafees ◽  
Atta Rasool

Effects of four different levels of NaCl (05, 10, 15, 20 dS/m) on the seed germination of cluster bean (Cyamopsis tetragonoloba L.) cultivars were investigated. Only distilled water was used in the control. The experiment was conducted in the Petri dishes under laboratory condition and laid out in CRD comprising five replicates. The results indicated that the germination index (GI), seed vigor index (SVI), germination stress index and seedling length (radicle and plumule) decreased with increase of salinity levels and germination percentage (GP) was reduced significantly at the highest level of salinity (200 mM). However, mean germination time (MGT) and time taken for 50% germination (T50) increased by increasing salinity levels. Correlation coefficient between all possible combinations was estimated and the results indicated that GP, GI, MGT, T50, and SVI had significant positive or negative correlation with each other.


2021 ◽  
Vol 21 (No 1) ◽  
Author(s):  
Vian Dler Ali ◽  
Farhad Hassan Aziz

Gundelia tournefortii L. is adapted to mountains area climate, and the germination of this plant is not easily. This research conducted to study the effect of different seed treatments in various treatment durations in two experiments in petri dish in the laboratory and in seedling tray in the lath house to breaking seed dormancy and germination stimulus. Results indicated that there is significant enhancement of germination by all treatments and the maximum germination percentage was obtained by seed freezing 99.17% in the laboratory and 93.33% in the lath house for all treatment durations 12, 14, 48 and 72 hours. The other parameters of seed germination like germination speed, peak value, mean daily germination, mean germination time, germination value, radicle length, radicle elongation velocity, plumule length, plumule elongation velocity, seedling fresh and dry weight escalated by seed freezing and seed soaking in tap water at all soaking durations 12, 24, 48 and 72 hours. Gundelia tournefortii L. germinated seed was an anatomically examined by paraffin method and calculated diploid number of chromosomes 2n=2x=18 by aceto-carmine squash methods


2020 ◽  
Vol 16 (4) ◽  
pp. 102-109
Author(s):  
Haron Victor Ferreira Camargo ◽  
Letícia Siqueira Walter ◽  
Mônica Moreno Gabira ◽  
Dagma Kratz

This study aimed to evaluate the germination behavior of two morphotypes of P. cattleyanumsubmitted to storage and pre-germinative treatments. The experiment was designed in a factorial scheme 2 x 3 x 3 (morphotypes x storage periods x pre-germinative treatments) completely randomized, using for each treatment 5 replicates with 30 seeds. The seeds were stored in semipermeable packages in a cold chamber at 5 ± 2 °C, for 14, 45,and 90 days. After each storage period, the seeds were submitted to treatments to overcome dormancy: immersion in water at 80 °C,kept in imbibition for 24 and 48 hand control, without any treatment. The seeds were arranged under moistened substrate in transparent plastic boxes and allocated in a germination chamber at 25 °C and photoperiod of 8 h for evaluation of germination percentage (G), germination speed index (GSI)and mean germination time (MGT). The red morphotype seeds showed higher germination percentages than the yellow morphotype and did not have a reduction in these values after 90 days of storage. MGT for yellow morphotype was lower in all pre-germinativetreatments. The GSI had better results at 45 days in the control treatments and 24 h in immersion in water and 90 days for the three pre-germinative treatments. The red morphotype does not require pre-germinative treatments, while the yellow morphotype presents better germination when the seeds are stored for 45 days and immersed in water at 80 °C for 48 h.


HortScience ◽  
1994 ◽  
Vol 29 (12) ◽  
pp. 1445-1448 ◽  
Author(s):  
N. Wartidiningsih ◽  
R.L. Geneve ◽  
S.T. Kester

High germination seed lots of purple coneflower [Echinacea purpurea (L.) Moench] were evaluated for laboratory germination following osmotic priming or chilling stratification. Compared to nontreated seeds, osmotic priming at 25C in salts (KNO3 + K3PO4; 1:1, w/w) or polyethylene glycol 4000 (PEG) increased early (3-day) germination percentage at 27C of all seed lots, and improved total (10-day) germination percentage of low-germination seed lots. Total germination percentage was unaffected or increased by priming for 4 days compared to 8 days, and by priming at –1.0 MPa compared to –0.5 MPa (except for one low-germination seed lot). Chilling stratification in water at 5 or 10C increased early and total germination of all seed lots, except for that same lot, compared to nontreated seeds. Total germination percentage was unaffected or increased by stratification at 10C rather than at 5C. Neither extending stratification ≥20 days nor lowering osmotic potential with PEG during stratification improved total germination percentage.


Author(s):  
Sofia ARGYRIOU ◽  
Panayiota PAPASTYLIANOU ◽  
George STAVROPOULOS ◽  
Angeliki KOUSTA ◽  
Ioanna KAKABOUKI ◽  
...  

Helichrysum amorginum is a perennial shrub, endemic on the Greek island of Amorgos and used for medicinal, cosmetic and ornamental purposes. Information concerning germination behavior and seedling survival is considered essential for the establishment and cultivation of wild species. The objective of this study was to investigate the effect of temperature and light on germination of Helichrysum amorginum seeds. A set of experiments was conducted under completely randomized design with four replications of 200 seeds at three different suboptimal germination temperatures (15, 20 and 25°C) in light and dark conditions for 10 days. Seed material was collected from two different fields of the island (Aegiali and Katapola). The germination performance was evaluated by final germination percentage and mean germination time. The effect of temperature on seed germination percentage and mean germination time was significant in all cases. The presence of light enhanced germination, especially at the optimum temperature of 20°C. In most cases the mean germination time increased at the lower temperature of 15°C. Seeds from Aegiali exhibited higher germination ability than the seed lot from Katapola. Knowledge of seed germination behaviour is of major importance in order to establish effective protocols for seed propagation in Helichrysum amorginum.


2019 ◽  
Vol 97 (3) ◽  
pp. 413 ◽  
Author(s):  
Valeria Flores-Enríquez ◽  
Guillermo Castillo ◽  
Margarita Collazo-Ortega

<p><strong>Background</strong>: Podostemaceae are extremely susceptible to local extinction by habitat loss. Since ~70 % of the river systems in Mexico show some degree of water contamination, it is relevant to generate information about seed storage and germination behavior to design germplasm conservation strategies (<em>e.g</em>., <em>ex situ</em> seed banks) of Mexican podostemads.</p><p><strong>Hypotheses</strong>: Seed germination decreases as seed storage time increases. Further, light quality, temperature and collection site influence similarly the germination response of both species.</p><p><strong>Studied species</strong>: <em>Marathrum foeniculaceum</em> Humb. &amp; Bonpl., <em>Noveloa coulteriana</em> (Tul.)<em> </em>C. Philbrick</p><p><strong>Study site and years of study</strong>: 13 different seeds collections (1996-2013), at four locations in the rivers Horcones and Arroyo del Rincon Jalisco, México. </p><p><strong>Methods</strong>: A germination chamber experiment was performed to evaluate the effect of temperature, light quality and storage time on the germination of both species.</p><p><strong>Results</strong>: Seeds lose viability after nine years of storage. In both species, the time to reach the highest Accumulated Germination Percentage (AGP) was faster in seeds of one-two yr compared to seeds of six-seven yr. <em>N. coulteriana</em> have significant differences in Final Germination Percentage (FGP) between collection rivers. Storage time affects AGP of <em>N. </em>coulteriana more than in <em>M. foeniculaceum.</em></p><p><strong>Conclusions</strong>: Both species can form <em>ex situ</em> seed banks up to 8 yr age in paper bags storage. <em>N. coulteriana</em> is more susceptible to variation in storage conditions compared to <em>M. </em><em>foeniculaceum</em>. Collection site affect seed germination after storing.  Long-term conventional <em>ex situ</em> seed germination storage is not a viable strategy to conserve germplasm of Podostemaceae.</p>


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