scholarly journals Southern highland papaya (Vasconcellea quercifolia A. St.-Hil.): Do fruit ripening and harvesting time affect seed 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.

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.


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.


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.


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.


2016 ◽  
Vol 40 (4) ◽  
pp. 649-660 ◽  
Author(s):  
Márcia Adriana Carvalho dos Santos ◽  
Mailson Monteiro do Rego ◽  
Manoel Abilio de Queiroz ◽  
Bárbara França Dantas ◽  
Wagner Campos Otoni

ABSTRACT The Brazilian guava (Psidium guineense Swartz) is seed-propagated and, being native to the Caatinga biome, may frequently have uneven germination.Thus, we aimed to evaluate the synchronization of the in vitro seed germination of three accessions of the Brazilian guava, using water, polyethyleneglycol (PEG 6000), and potassium nitrate (KNO3) at different potentials and times of osmotic priming. Seeds from three accessions of the Brazilian guava (Y85, Y93,and Y97) from the UNEB/BA Germplasm Active Bank were subjected to the following pretreatments: -0.6, -1.0, -1.4, and -1,8 MPa PEG 6000; 10 and 20% KNO3 for 24h; 10 and 20% KNO3 for 48h; water for 24 and 48h; and non-primed seeds as the control. The experimental design was therefore a 10x3+1 factorial scheme. We assessed the germination percentage (G), mean germination time (MGT), germination speed (GS), and germination speed index (GSI). Data was subjected to analysis of variance followed by a means test (Duncan at 5% probability) and regression. There was interaction between the priming treatments and accessions for all evaluated features, except G. PEG 6000 decreased the MGT (from 6 to 8 days) and increased GS and GSI of seeds from all three accessions at potentials -1.0 to -1.5 MPa.Water-priming had a positive effect on MGT, GS, and GSI of accession Y85 seeds. KNO3 negatively affected germination of seeds from all three accessions. Thereby, we could synchronize seed germination of accessions Y85 and Y97 with PEG 6000.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Daryush Talei ◽  
Alireza Valdiani ◽  
Mahmood Maziah ◽  
Mohammad Mohsenkhah

Germination is a key process in plants' phenological cycles. Accelerating this process could lead to improvment of the seedling growth as well as the cultivation efficiency. To achieve this, the effect of microwave frequency on the germination of rice seeds was examined. The physiological feedbacks of the MR 219 rice variety in terms of seed germination rate (GR), germination percentage (GP), and mean germination time (MGT) were analyzed by exposing its seeds to 2450 MHz of microwave frequency for one, four, seven, and ten hours. It was revealed that exposing the seeds to the microwave frequency for 10 hours resulted in the highest GP. This treatment led to 100% of germination after three days with a mean germination time of 2.1 days. Although the other exposure times of microwave frequency caused the moderate effects on germination with aGPa3ranged from 93% to 98%, they failed to reduce theMGTa3. The results showed that ten-hour exposure times of microwave frequency for six days significantly facilitated and improved the germination indices (primary shoot and root length). Therefore, the technique is expected to benefit the improvement of rice seed germination considering its simplicity and efficacy in increasing the germination percentage and rate as well as the primary shoot and root length without causing any environmental toxicity.


2016 ◽  
Vol 34 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Fabio Ernesto Martínez M. ◽  
Diego Miranda L. ◽  
Stanislav Magnitskiy

This research sought to establish the response of the germination percentage (PG), synchrony index (E), mean germination time (MGT) and mean germination rate (MGR) of Annona squamosa L. seeds from Apulo (province of Cundinamarca) and Castilla (province of Tolima), Colombia, to treatments with 0, 50, 100, 200, 400, 600, or 800 mg L-1 of gibberellic acid (GA). All of the treatments with GA increased the PG at each point of time of seed incubation. The 600 mg L-1 GA treatment resulted in higher PGs (92.3% at 16 days for Apulo and 95% at 24 days for Castilla) and lower MGTs (8.75 and 5.38 days for Apulo and Castilla, respectively) than those found with the concentration of 0 mg L-1 GA (17.68 and 10.88 days for Apulo and Castilla, respectively). Also, treating the seeds with 600 mg L-1 GA generated higher MGRs (0.18 and 0.12 germinated seeds/day for Castilla and Apulo, respectively) than those obtained with 0 mg L-1 GA (Castilla = 0.09 and Apulo = 0.06 germinated seeds/ day). Likewise, the germination was synchronized with the application of any concentration of GA. The results evidenced a positive response to the GA application, which provided a tool for the characterization of the phenomenon of dormancy in the A. squamosa seeds.


2013 ◽  
Vol 31 (1) ◽  
pp. 39-51 ◽  
Author(s):  
A Tanveer ◽  
M Tasneem ◽  
A Khaliq ◽  
M.M Javaid ◽  
M.N Chaudhry

An understanding of seed germination ecology of weeds can assist in predicting their potential distribution and developing effective management strategies. Influence of environmental factors and seed size on germination and seedling emergence of Convolvulus arvensis (field bindweed) was studied in laboratory and greenhouse conditions. Germination occurred over a wide range of constant temperatures, between 15 and 40 ºC, with optimum germination between 20 and 25 ºC. Time to start germination, time to 50% germination and mean germination time increased while germination percentage and germination index decreased with an increase in temperature from 20 ºC, salinity and osmotic stress. However, germination was tolerant to low salt (25 mM) or osmotic stress (0.2 MPa), but as salinity and osmotic stress increased, germination percentage and germination index decreased. Seeds of C. arvensis placed at soil surface showed maximum emergence and decreased as seeding depth increased. Seeds of C. arvensis germinated over a wide range of pH (4 to 9) but optimum germination occurred at pH 6 to 8. Under highly alkaline and acidic pH, time to start germination, time to 50% germination and mean germination time increased while germination percentage and germination index decreased. Increase in field capacity caused decreased time to start germination, time to 50% germination and mean germination time but increased germination percentage and germination index. Bigger seeds had low time to start germination, time to 50% germination and mean germination time but high germination percentage and germination index. Smaller seeds were more sensitive to environmental factors as compared to larger or medium seeds. It can be concluded that except for pH, all environmental factors and seed sizes adversely affect C. arvensis as regards seed germination or emergence and germination or emergence traits, and larger seeds result in improved stand establishment and faster germination than small seeds, regardless of moisture stress or deeper seeding depth.


2019 ◽  
Vol 113 (2) ◽  
pp. 203 ◽  
Author(s):  
Bekim GASHI ◽  
Mirsade OSMANI ◽  
Sali ALIU

<p><em>Tulipa scardica</em> and <em>T. kosovarica</em> are rare, endemic and endangered plants in Kosovo. This research was carried out to study the dormancy breaking treatment in Tulipa scardica and T. kosovarica seeds by pre-chilling and various concentration of potassium nitrate (KNO3), gibberellic acid (GA3), kinetin, thiourea and sulfuric acid (H2SO4). The experiment was conducted with untreated seeds (without stratification) and with stratified seeds (8 weeks) and treated with different concentration of some chemicals and plant growth regulators. Results showed that the final germination percentage (FGP) of seeds without stratification at both Tulipa plant species was zero, while germination was enhanced by pre-chilling (stratification) especially after treatment of these seeds by above mentioned treatments. Both Tulipa species showed an increase in mean germination time (MGT), an indication of slower germination, as different chemicals or plant growth regulators increased. Depending on treatments, germination was ranging from 80 % to 90 %, the maximum germination was detected in seeds treated with KNO3, GA3, and their combination, while the minimum germination in seeds without treatments and treated with thiourea. The conservation of these plants in botanic gardens by cultivation or propagation for commercial use as ornamental plants could give an effective contribution to the conservation of these plants.<br />Abbreviations: KNO<sub>3 </sub><strong>– </strong>potassium  nitrate; GA<sub>3 </sub>- gibberellic acid; H<sub>2</sub>SO<sub>4</sub> – sulfuric acid; FGP – final germination percentage; MGT – mean germination time<br /><br /></p>


Author(s):  
Ari Wibowo ◽  
Dwi Nugroho ◽  
Ucu Sumirat

Coffee seeds are classified into intermediate seeds which require high moisture content during the storage and possess a short shelf life. Seed germination testing aims to determine the potential of a seed lot, evaluate seed quality during the storage and also to estimate the success of seedling in the nursery. This experiment aimed to determine the germination performance of several Arabica coffee varieties after being stored for six months at controlled temperature. Nine varieties of Arabica coffee, namely Abesinia-3, Andungsari-1, BLP, Gayo-2, Goiaba, Kartika-1, Kayumas, MP-3, and S-795 were used in this study. The seeds were harvested in the 2019 harvest season (September) and the germination was tested in April 2020. The germination test was carried out in laboratory by using petridish. The result showed that the tested Arabica coffee seeds still had a high germination percentage which was more than 85%. Only three varieties namely S-795, Abesinia-3, and Goiaba had low germination growth (<80%). Meanwhile, Kayumas, BLP, and Kartika-1 coffee varieties had the best germination growth with an average length of 34.19 mm; 39.79 mm and 39.41 mm, respectively. Kartika-1 variety needs 6–7 days to germinate; Kayumas, BLP, and Goiaba varieties took 7–8 days; S-795 and MP-3 took 10 days; as well as Andungsari-1, Abesinia-3, and Gayo-2 which took 10–12 days. Arabica coffee seeds that had a short germination time will had a high germination rate and otherwise. Each variety displayed a different germination performance. BLP, Kartika-1, Gayo-2 and MP-3 varieties had high potential germination, 86.67%; 89.17%; 86.67%, and 93.33%, respectively. Kayumas, BLP, and Kartika-1 varieties showed significantly longer germination, namely 34.19 mm; 39.79 mm and 39.41 mm, respectively. The fastest of average germination time was possessed by Kartika-1 variety (6.54 days) and the highest seed germination rate was also possessed by Kartika-1 variety (0.153 per day). 


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