Effects of partial drying on seed germination in the aquatic grasses Zizania palustris L. and Porteresia coarctata (Roxb.) Tateoka

1992 ◽  
Vol 2 (4) ◽  
pp. 199-205 ◽  
Author(s):  
C. D. Aldridge ◽  
R. J. Probert

AbstractPartial drying of non-dormant seeds had little effect on germination behaviour compared with undried controls. In contrast, partial drying resulted in a marked increase in the germination response of freshly harvested (dormant) seeds of Z. palustris. Partial drying also resulted in a 100-fold reduction in the concentration of gibberellins (GA4+7) required for maximum germination. Although the concentration range of applied abscisic acid (ABA) that permitted germination was unaltered, partial drying increased the final germination percentage at all concentrations tested. The concentration of ABA above which germination was reduced in freshly harvested (dormant) seeds of Z. palustris was 3.16 × 10−7m compared with 10−4m in fresh (non-dormant) seeds of P. coarctata. Changes in the germination response of Z. palustris seeds to applied growth regulators, following partial drying or cold stratification might be explained by similar changes in hormonal status.

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.


HortScience ◽  
1990 ◽  
Vol 25 (2) ◽  
pp. 191-193 ◽  
Author(s):  
Phil S. Allen ◽  
Susan E. Meyer

To determine optimum germination temperatures and effective dormancy-breaking procedures, field-grown (1983-85) seeds of `Bandera' Rocky Mountain penstemon (Penstemon strictus Benth), `Cedar' Palmer penstemon (Penstemon palmeri Gray), and firecracker penstemon (Penstemon eatonii Gray) were subjected to various cold stratification and incubation temperature treatments. Increased germination following an 8-week stratification occurred in seed lots containing dormant seeds, but a 2-week stratification generally failed to break dormancy. Older (1983) seeds of `Bandera' and `Cedar' penstemon germinated to full viability without stratification. All species showed a marked decrease in germination percentage above 20C; 15C consistently produced maximum germination after 4 weeks. At 15C, mean times to 90% of total germination were 11, 22, and 29 days for `Bandera', `Cedar', and firecracker penstemon, respectively. Transfer of seeds failing to germinate at warm temperatures (25 and 30C) to 15C and applying 720 μm gibberellic acid (GA3) solution was effective in breaking primary dormancy of firecracker penstemon and secondary dormancy of `Bandera' penstemon. Our findings suggest that incubation below 20C, combined with 8 weeks of stratification or the use of after-ripened seed, may improve seed propagation efforts for these species.


HortScience ◽  
2016 ◽  
Vol 51 (7) ◽  
pp. 887-891 ◽  
Author(s):  
Khalid M. Elhindi ◽  
Yaser Hassan Dewir ◽  
Abdul-Wasea Asrar ◽  
Eslam Abdel-Salam ◽  
Ahmed Sharaf El-Din ◽  
...  

Peppermint (Mentha piperita), sweet basil (Ocimum basilicum), and coriander (Coriandrum sativum) are important medicinal plants in the pharmacological industry. These plants are produced in commercial scale but their seeds exhibit low germination percentages under favorable germination conditions. Enhancing seed germination is thus crucial for improving the production of these plants. The influence of gibberellic acid (GA3), indole-3-acetic acid (IAA), indol-3-butyric acid (IBA), and naphthalene acetic acid (NAA) on seed germination of the three plants were investigated. The seeds were soaked in each plant growth regulator at 50, 100, and 150 mg·L−1 for 24 hours at 25 ± 2 °C. Seed germination was checked daily for 20 days and germination parameters including final germination percentage (FGP), corrected germination rate (CGRI), and number of days lapsed to reach 50% of FGP (GT50) were recorded. The phosphorus and protein contents were determined in germinated seedlings on day 21 of culture. All plant growth regulators enhanced seed germination as compared with control. However, GA3 improved seed germination more than IAA, IBA, and NAA. GA3 at 100 mg·L−1 significantly increased the FGP from 22.3% and 33.3% (control) to 74% and 65.6% for peppermint and sweet basil, respectively. Low concentration of GA3 at 50 mg·L−1 increased the FGP for coriander from 27% to 52.3%. GA3 also increased CGRI, GT50, phosphorus, and protein contents in germinated seedlings as compared with control. Seeds of peppermint, sweet basil, and coriander possess a physiological dormancy that could be elevated by GA3 presowing treatment. This study established a successful methodology for optimizing seed germination to satisfy the demand for the medicinal parts of these plants in the pharmacological industry.


2021 ◽  
Vol 13 (4) ◽  
pp. 11044
Author(s):  
Manisha THAPLIYAL ◽  
Namitha N. KALIYATHAN ◽  
Kanupriya RATHORE

Knowledge of seed germination behaviour of different seed sources of tree species is useful in selecting the most responsive and adaptive ones for propagation and germplasm conservation. The wild Himalayan pear (Pyrus pashia Buch-Ham ex D. Don) produces highly nutritious edible fruits that are consumed by local communities. The populations of the species are threatened due to exploitation and lack of adequate conservation programmes. The study was conducted to examine the germination response of P. pashia seeds from two sources (S1-Champawat and S2-Pithoragarh) in Uttarakhand state of India, to different GA3 treatment and also to assess the viability and longevity of the seeds in cold storage (5 °C) for three years. In both sources germination percent (GP) increased significantly under GA3 treatment and speed of germination was also enhanced (reduction in mean germination time). In Source, 1 GP increased under all GA3 application, highest being 94% under GA3 500 ppm treatment. In Source 2, GP of seeds doubled under 100 ppm GA3 treatment while its higher concentrations did not improve the germination. However, the differences observed in germination between the seed sources could be due to differences in the dormancy levels and/or sensitivity to dormancy breaking elements across their geographical range. Thus, exogenous application of GA3 is suggested for enhancing the germination in seeds of P. pashia. Seeds responded to cold storage by increased germination with duration, i.e. highest after three years in storage, indicating that the seeds got the required chilling treatment for overcoming dormancy.


Botany ◽  
2016 ◽  
Vol 94 (8) ◽  
pp. 653-659 ◽  
Author(s):  
Alba Cuena-Lombraña ◽  
Marco Porceddu ◽  
Caterina Angela Dettori ◽  
Gianluigi Bacchetta

Gentiana lutea L. subsp. lutea is a geophyte that occurs in the central-southern European mountains. We investigated its germination ecophysiology with the main aim of evaluating seed germination behaviour under controlled and natural conditions. Seeds from four natural sites were tested for germination requirements under a range of different temperatures, and by comparing the results with those obtained under both cold stratification at 5 °C and treatment with GA3. We simultaneously carried out germination tests at each collecting site, and soil temperatures were recorded. Our results indicate that germination under controlled conditions is limited by high temperatures (25 °C), below which GA3 has a remarkable effect on germination percentages. Cold stratification did not have an influence on the germination response, thus suggesting that a temperature of 5 °C is not sufficient to break seed dormancy; this result was supported by soil temperatures. Gentiana lutea created a short-term persistent seed bank, and seeds mainly germinated in their first year. The germination under controlled conditions was similar in all accessions, while different responses were found in the field, where a potential influence of the aspect was observed. These findings underscore the importance of understanding germination behaviour in the field to define the real thermal requirements of a taxon.


2017 ◽  
Vol 68 (2) ◽  
pp. 188 ◽  
Author(s):  
Jixiang Lin ◽  
Yujie Shi ◽  
Shuang Tao ◽  
Xingyang Yu ◽  
Dafu Yu ◽  
...  

Leymus chinensis has important forage value and is considered a useful grass species for grassland restoration in Northeast China. However, little information exists concerning the germination responses of this species to interactions of cold stratification, light, temperature and low water potential caused by salinity and drought. Experiments were conducted in growth chambers, and the results showed that in all conditions of light, temperature and water stresses, the germination percentages of cold-stratified seeds were higher than of non-stratified seeds. Light had an inhibitory effect on germination percentage under both non-saline and salt stress conditions; darkness is beneficial for germination of this species. In addition, seeds germinated much better under alternating temperature regimes than under constant temperatures. Both salt and drought stresses decreased the germination percentage of Leymus chinensis, but the reductions under drought stress were much greater. Moreover, after being transferred to distilled water, most non-germinated seeds under drought stress germinated well, and the total percentage reached that of the non-saline condition level. Therefore, cold stratification is an effective measure to increase seed germination and salt or drought tolerance, especially in darkness. We conclude that Leymus chinensis has definite salt and drought tolerance during the germination stage and it is a promising species for the restoration of deteriorated grassland in Northeast China.


Author(s):  
H.M. Botey ◽  
J.O. Ochuodho ◽  
L. Ngode ◽  
H. Dwamena ◽  
I. Osei-Tutu

Background: A preliminary study of the African eggplant seeds obtained from farmers sources recorded a wide variation in percentage germination under ambient conditions (25±2°C). The germination percentage ranged from 0% to 25%, while fresh seeds ranged between 53% and 87%. As temperature and light are important factors of seed germination, the current study investigated the effect of temperature on the germination pattern and the influence of light interaction with temperature on seed germination of African eggplant (Solanum aethiopicum L.) under controlled conditions. Methods: Seeds of two cultivars of African eggplant were subjected to constant and alternating temperatures and under three light exposure regimes. Seed quality was accessed by per cent germination, mean germination time, time to reach 50% germination, germination index and mean daily germination. Result: The highest percentage germination under constant temperatures was recorded at 25°C (76%) and 20°C (74%). The maximum temperature and light conditions required for maximum seed germination quality (76-95%) at the shortest time (4-5 days) was 30/20°C under alternating 8/16 hours light and dark.


2016 ◽  
Vol 1 (2) ◽  
pp. 36 ◽  
Author(s):  
J. Lalitha ◽  
Haseena Rafath ◽  
M. Subash

The experiment was undertaken with an objective to investigate the effect of various concentrations of plant growth regulators, i.e., Gibberellic acid (GA3) and Indole 3-acetic acid (IAA) on seed germination of Macrotyloma uniflorum. Seeds were soaked for 12 hours in different concentrations substances (1.0, 2.0, 3.0 and 4.0 mg/L) of IAA, GA3 and control set was soaked only in distilled water.  Three replicates of each treatment with fifty seeds per replicate were arranged for precise physiological analysis. Significant variation was found in all aspects after analysis of variance (ANOVA) of each mean value. After two weeks of seed soaking, it was noted that germination percentages were significantly accelerated by lower concentrations (1 and 2 mg) of used hormones. Amongst the two potential growth regulators, 2 mg/L was found most effective because it showed highest germination percentage for IAA (93%) and GA3 (88%). A great deal of information relating to seed germination practices shows that these plant growth regulators were efficient in overcoming dormancy leading to rapid seed germination. IAA was selected as best hormone in this study, which showed highest seed germination (93%). 


HortScience ◽  
2005 ◽  
Vol 40 (6) ◽  
pp. 1838-1842 ◽  
Author(s):  
James A. Schrader ◽  
William R. Graves

The genus Dirca L. (Thymelaeaceae) consists of three species of understory shrubs. Dirca palustris L. is sparsely distributed across eastern North America, D. occidentalis Gray is endemic near the San Francisco Bay, and D. mexicana Nesom & Mayfield is known only in one population in northeastern Mexico. Despite interest in the horticultural use of Dirca, plants seldom are marketed. Difficult propagation impedes production of Dirca. We sought to define protocols that promote uniform seed germination of all three Dirca spp. Endodormancy and paradormancy cause sporadic germination over several years under natural conditions, but endocarp removal, cold stratification, and treatment with GA3 increased germination percentage, speed, and uniformity. Dirca occidentalis was most responsive; up to 94% of seeds germinated after endocarp removal, 24 hours in GA3 at 50 mg·L–1, and stratification at 4 °C for 30 days. Treatments also were effective for D. palustris (up to 68% germination), but seeds of D. mexicana were unresponsive and germinated at 25% or less. Seed treatments should facilitate production of D. occidentalis and D. palustris, but further research is needed to define methods to propagate D. mexicana for horticultural use and for conserving this rare species in the wild.


Seeds ◽  
2022 ◽  
Vol 1 (1) ◽  
pp. 28-35
Author(s):  
Gregorio Barba-Espín ◽  
José A. Hernández ◽  
Cristina Martínez-Andújar ◽  
Pedro Díaz-Vivancos

(1) Background: Peach cv. GF305 is commonly used in breeding programs due to its susceptibility to numerous viruses. In this study, we aimed to achieve a methodology for rapid and uniform seed germination of peach cv. GF305 in order to obtain vigorous seedlings; (2) Methods: A combination of cold stratification and H2O2 imbibition was tested on peach seeds with or without endocarp. In addition, the levels of non-enzymatic antioxidants ascorbate and glutathione as well as the hormone profile in seedling roots and shoots were determined; (3) Results: We found that H2O2 imbibition of peach seeds without endocarp after 8 weeks of stratification increased germination rate and resulted in seedlings displaying good vegetative growth. The H2O2 imbibition also affected the levels of ascorbate, glutathione, and the phytohormones abscisic acid and jasmonic acid in peach seedlings; (4) Conclusions: Although stratification periods of 12 weeks have been previously established as being appropriate for this cultivar, we have been able to reduce this stratification time by up to 4 weeks, which may have practical implication in peach nurseries.


Sign in / Sign up

Export Citation Format

Share Document