scholarly journals Embryo Development, Seed Germination, and the Kind of Dormancy of Ginkgo biloba L.

Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 700 ◽  
Author(s):  
Jing Feng ◽  
Yongbao Shen ◽  
Fenghou Shi ◽  
Chengzhong Li
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Ginkgo Biloba ◽  
Germination Percentage ◽  
Transverse Diameter ◽  
Seed Collection ◽  
Significant Difference ◽  
Different Temperatures ◽  
Mean Germination Time ◽  
Morphological Dormancy

The embryos of Ginkgo biloba L. are generally reported to undergo after-ripening and be underdeveloped at the time of dispersal, which suggests that the seeds have morphological dormancy (MD) or morphological physiological dormancy (MPD). The aim of this work is to determine whether embryos of a G. biloba population are well-developed at the time of seed dispersal, and whether the seeds are dormant or not. From 8 September, which was the 140th day after flowering (140 DAF), seeds were collected separately from trees (T) and the ground (G) every 10 days until 7 December (230 DAF), resulting in a total of 10 samples. The changes in vertical diameter, transverse diameter, fresh weight, water content, and embryo length during seed development were measured. Simultaneously, the effects of different temperatures (15, 25, 30, and 35 °C) on seed germination, dormancy, and germination characteristics of G. biloba seeds were studied. Results showed that the embryos of G. biloba seeds were well developed and had no morphological dormancy. On 18 September (150 DAF), embryos were visible with a length of 2.5 mm. On 7 December (230 DAF), at the time of seed dispersal, their length was 17.1 mm. The germination percentage of the isolated embryos and seeds increased as the delay in seed collection increased, but there was no significant difference between T and G (p > 0.05). On 7 December (230 DAF), the germination of the isolated embryos reached 98%, indicating that the embryos were nondormant. Without pretreatment, seed germination was 82.57% within four weeks at 25 °C. Furthermore, the germination test at different temperatures showed the highest germination percentage at 30 °C (84.82%). Obviously, the G. biloba seeds were nondormant. The mean germination time (MGT) of the seeds at 30 and 35 °C was significantly lower than that of the seeds at 15 and 25 °C, and the speed of germination (SG) was significantly higher than that of the seeds at 15 and 25 °C. Although there was no significant difference in the seed-germination percentage between 30 and 35 °C, a portion of the seeds (9.5%) rotted at 35 °C. Therefore, 30 °C was the most favorable germination temperature for G. biloba seeds. This is the first study that reports G. biloba seeds with no dormancy.

scholarly journals Embryo Development of Cypripedium formosanum in Relation to Seed Germination In Vitro

2005 ◽  
Vol 130 (5) ◽  
pp. 747-753 ◽  
Author(s):  
Yung-I Lee ◽  
Nean Lee ◽  
Edward C. Yeung ◽  
Mei-Chu Chung
Keyword(s):  
Seed Germination ◽  
Embryo Development ◽  
Developmental Stages ◽  
Culture Media ◽  
Nile Red ◽  
Germination Percentage ◽  
Zygotic Embryogenesis ◽  
Seed Collection ◽  
Significant Difference

This investigation documents the key anatomical features in embryo development of Cypripedium formosanum Hayata, in association with the ability of embryos to germinate in vitro, and examines the effects of culture media and seed pretreatments on seed germination. A better understanding of zygotic embryogenesis for the Cypripedium L. species would provide insights into subsequent germination events and aid in the in vitro propagation of these endangered species. In seeds collected at 60 days after pollination (DAP), soon after fertilization, no germination was recorded. The best overall germination was found at 90 DAP (≈70%), at which time early globular to globular embryos with a single-celled suspensors can be observed. After 135 DAP, the seeds germinated poorly. At this time the inner integument shrinks and forms a tight layer, which encloses the embryo, the so-called “carapace.” Using Nile red stain, a cuticular substance was detected in the carapace, which may play a role in the impermeability of the mature seed and may help the seeds survive in the stringent environment. At maturity (after 210 DAP), the embryo proper has an average size of eight cells along its length and six cells across the width. Lipids and proteins are the main storage products within the embryo. To improve seed germination, experiments were conducted to test the suitability of various media and pretreatments of seeds. When different media were used, except for the Harvais medium at 120 DAP, there was no significant difference in seed germination at three different developmental stages tested. Soaking mature seeds in 1% NaOCl or treating them with ultrasound may slightly increase the germination percentage. For seed germination, our results indicate that the timing of seed collection outweighs the composition of medium and the seed pretreatments.

scholarly journals SEED GERMINATION AND SEEDLING ESTABLISHMENT OF CHERIMOYA (ANNONA CHERIMOLA MILL.) AT DIFFERENT TEMPERATURES

2020 ◽  
Vol 53 (2) ◽  
pp. 185-194
Author(s):  
A. KHELOUFI ◽  
L. M. MANSOURI ◽  
H. KHETTACHE
Keyword(s):  
Seed Germination ◽  
Room Temperature ◽  
Germination Percentage ◽  
Annona Cherimola ◽  
Seedling Length ◽  
Different Temperatures ◽  
External Conditions ◽  
Mean Germination Time ◽  
Coefficient Of Velocity ◽  
Kinetics Of

Cherimoya (Annona cherimola Mill.) has an exceptional flavor and aroma, which makes it a fruit with great potential. However, little is known about its propagation by seeds. According to the scientific literature, the germination of cherimoya seeds is affected much more by external conditions than by internal conditions. Germination of cherimoya variety ‘Concha Lisa’ were tested for germination at constant temperatures of 25, 30, 40°C, and at room temperature, varying from 20-25°C, coupled with total darkness. Seeds were sown in Petri dishes (0.8% agar water), for 25 days of incubation. The kinetics of germination was determined according to five closely related parameters, viz. final germination percentage (FGP), mean germination time (MGT), coefficient of velocity of germination (CVG), time to 50% germination (T50) and seedling length (SL). The temperature of 30°C was found optimally suitable with 70.8% FGP, 17.5 days MGT and 3.91 cm SL, while the room temperature of 20-25°C slightly improved germination with only 25% FGP. Furthermore, significant decrease in FGP and SL was observed at 25°C and 40°C of temperature in comparison to 30°C. The analysis also revealed that cherimoya seed germination, day 10-15 after seed sowing is suitable for final counts. An overview on the emergence of cherimoya seedlings, during a 12-week period in pots is presented.

scholarly journals Contribución de Pheidole fallax y Ectatomma ruidum (Hymenoptera: Formicidae) en la dispersión y germinación de semillas en áreas rehabilitadas de la mina de carbón del Cerrejón, Colombia

2017 ◽  
Vol 65 (2) ◽  
Author(s):  
Bleydis Paola Gutierrez Rapalino ◽  
Yamileth Del Carmen Domínguez Haydar
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Control Sample ◽  
Germination Percentage ◽  
Significant Difference ◽  
Ectatomma Ruidum ◽  
Seed Extraction ◽  
And Control ◽  
Number Of Seeds ◽  
Control Samples

Seed dispersal is a key process in the re-establishment of vegetation on reclaimed lands. The aim of this study was to determine the contributions of the ant species Ectatomma ruidum and Pheidole fallax to seed dispersal and germination on reclaimed lands in the Cerrejón coal mine, Colombia. Four 6 x 40 m plots were installed in each area, in which the number of nests by species was counted and distances between closest nests of each species were measured. Five of the nests counted were chosen for seed extraction, and a nearby control sample was taken from each nest. In total, 295 nests were counted: 59 nests during the dry season and 236 nests during the rainy season, of which 84 belonged to P. fallax and 211 belonged to E. ruidum. A total of 21 304 seeds were found in nests and control samples, of which 19 349 were obtained from P. fallax nest refuse, and 318 were obtained from E. ruidum nests; 597 seeds were found in control samples. The number of seeds extracted from nests was significantly higher than the number of seeds removed from control samples. There was a significant difference between the number of seeds removed by P. fallax and the number of seeds removed by E. ruidum. The seed germination percentage from nests was higher than the percentage from seeds in control samples. In the case of P. fallax, the germination percentage was lower in control samples and higher in nests and refuse. The results suggest that the ant species E. ruidum and P. fallax may contribute to seed dispersal and re-establishment of vegetation in areas where they were found. These ants may thus significantly contribute to restoration processes in areas degraded by mining.

scholarly journals Asymbiotic germination of Vanilla planifolia in relation to the timing of seed collection and seed pretreatments

2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Chih-Hsin Yeh ◽  
Kai-Yi Chen ◽  
Yung-I. Lee
Keyword(s):  
Seed Germination ◽  
Seed Development ◽  
Seed Coat ◽  
Germination Percentage ◽  
Vanilla Planifolia ◽  
Outermost Layer ◽  
Seed Collection ◽  
Seed Pretreatment ◽  
Immature Seeds ◽  
Mature Seeds

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.

scholarly journals Seed longevity of maize conserved under germplasm bank conditions for up to 60 years

2021 ◽  
Author(s):  
Filippo Guzzon ◽  
Maraeva Gianella ◽  
Jose Alejandro Velazquez Juarez ◽  
Cesar Sanchez Cano ◽  
Denise E Costich
Keyword(s):  
Seed Germination ◽  
Plant Genetic Resources ◽  
Seed Viability ◽  
Storage Conditions ◽  
Seed Longevity ◽  
Germplasm Bank ◽  
Significant Difference ◽  
Different Temperatures ◽  
Germination Experiments

Abstract Background and Aims The long-term conservation of seeds of plant genetic resources is of key importance for food security and preservation of agrobiodiversity. Nevertheless, there is scarce information available about seed longevity of many crops under germplasm bank conditions. Methods Through germination experiments as well as the analysis of historical monitoring data, we studied the decline in viability manifested by 1000 maize (Zea mays subsp. mays) seed accessions conserved for an average of 48 years at the CIMMYT germplasm bank, the largest maize seedbank in the world, under two cold storage conditions: an active (–3 °C; intended for seed distribution) and a base conservation chamber (–15 °C; for long-term conservation). Key Results Seed lots stored in the active chamber had a significantly lower and more variable seed germination, averaging 81.4 %, as compared with the seed lots conserved in the base chamber, averaging 92.1 %. The average seed viability detected in this study was higher in comparison with that found in other seed longevity studies on maize conserved under similar conditions. A significant difference was detected in seed germination and longevity estimates (e.g. p85 and p50) among accessions. Correlating seed longevity with seed traits and passport data, grain type showed the strongest correlation, with flint varieties being longer lived than floury and dent types. Conclusions The more rapid loss of seed viability detected in the active chamber suggests that the seed conservation approach, based on the storage of the same seed accessions in two chambers with different temperatures, might be counterproductive for overall long-term conservation and that base conditions should be applied in both. The significant differences detected in seed longevity among accessions underscores that different viability monitoring and regeneration intervals should be applied to groups of accessions showing different longevity profiles.

Temperature Effect on Seed Germination Performance of a Local Variety of Onion in Bangladesh

2021 ◽  
Vol 1 (01) ◽  
pp. 27-30
Author(s):  
IRANI KHATUN ◽  
RIYAD HOSSEN
Keyword(s):  
Seed Germination ◽  
Temperature Effect ◽  
Performance Test ◽  
Germination Rate ◽  
Germination Percentage ◽  
Optimum Range ◽  
Local Variety ◽  
Different Temperatures ◽  
Local Farmers

Seed germination performance test of Taherpuri onion (a local variety of onion) under six different temperatures (15, 20, 25, 30, 35 and 40°C) was the main goal of this experiment. Germination percentage (GP) was calculated at highest 60.25% at 25°C, and the highest germination rate 20.08 was observed in the same temperature condition. The lowest germination performance (13.25 % germi-nation and 3.32 seeds per day as germination rate) was found at 40°C temperature. Finally, the authors mentioned the temperature 20 to 30°C as optimum range, and suggested the temperature 25°C as best suited for obtaining highest results in case of both germination percentage and germination rate of these seeds. To produce maximum seedlings of the local variety of onion, the mentioned temperature should be followed by the local farmers.

scholarly journals Physical characterization of Rhipsalis (Cactaceae) fruits and seeds germination in different temperatures and light regimes

2016 ◽  
Vol 76 (2) ◽  
pp. 367-373 ◽  
Author(s):  
A. B. Lone ◽  
R. C. Colombo ◽  
B. L. G. Andrade ◽  
L. S. A. Takahashi ◽  
R. T. Faria
Keyword(s):  
Seed Germination ◽  
Germination Percentage ◽  
Light Regimes ◽  
Total Absence ◽  
Germination Characteristics ◽  
Different Temperatures ◽  
Medium Time ◽  
Seeds Germination

Abstract The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.

scholarly journals Can Bulk and Nanosized Titanium Dioxide Particles Improve Seed Germination Features of Wheatgrass (Agropyron desertorum)

2013 ◽  
Vol 5 (3) ◽  
pp. 325-331 ◽  
Author(s):  
Reyhaneh AZIMI ◽  
Hassan FEIZI ◽  
Mohammad KHAJEH HOSSEINI
Keyword(s):  
Seed Germination ◽  
Germination Percentage ◽  
Germination Time ◽  
Positive Effects ◽  
Tio2 Particles ◽  
Nanosized Titanium Dioxide ◽  
Mean Germination Time ◽  
Germination Value ◽  
Improve Seed Germination ◽  
Nanosized Tio2

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.

scholarly journals Germination of Dracaena cinnabari Balf.f. Seeds under Controlled Temperature Conditions

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 521
Author(s):  
Lucie Bauerová ◽  
Shiferaw Alem Munie ◽  
Kateřina Houšková ◽  
Hana Habrová
Keyword(s):  
Germination Rate ◽  
Germination Percentage ◽  
T Test ◽  
Test Results ◽  
Optimal Temperature ◽  
Artificial Regeneration ◽  
Seed Collection ◽  
Different Temperatures ◽  
Test Result ◽  
Dracaena Cinnabari

Research highlights: This study is focused on the germination of Dracaena cinnabari seeds in order to discover the possibility of natural and artificial regeneration of this species. Background and Objectives: This study aimed to determine the optimal temperature for D. cinnabari seed germination, e.g., the temperature at which the germination percentage and germination rate (vitality) are the highest. The objectives of this study are to: (1) determine the optimal temperature for the germination of D. cinnabari seeds, (2) compare the suitability of different seed collection methods, and (3) compare the germination parameters of seeds that were collected from different localities. The results of this study will contribute to obtaining the highest number of seedlings from limited seed material for reforestation of the most endangered localities of D. cinnabari species. Materials and methods: Four seed sections were employed. These sections were directly collected from either the fruits of a cut panicle or the ground and were obtained from different localities that differ in altitude. The seeds were tested in a greenhouse while using Petri dishes at three different temperatures—22, 26, and 30 °C—with four replicates of 25 seeds of each section. ANOVA and the t-test were employed for data analysis. Results: The highest germination percentages (GPs) were achieved at 26 °C and 30 °C, which were 84.6% and 82.5%, respectively. The ANOVA and t-test results showed that the germination index (GI) of the species was relatively higher at a temperature of 30 °C relative to that at other temperatures in the study. Although seeds that were collected from the tree achieved a higher GP, the t-test result showed no significant differences in the GI of D. cinnabari seeds that were collected from the ground and from the tree (p > 0.05). Overall, the findings of this study show that temperature has substantial influence on the germination of seeds of D. cinnabari. Therefore, we recommend a temperature of 30 °C to facilitate the germination of D. cinnabari, as it achieved the highest GI at this temperature relative to that at the other temperatures (22 °C, 26 °C) applied in this study.

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
Keyword(s):  
Seed Germination ◽  
Seed Storage ◽  
Germination Percentage ◽  
Cold Season ◽  
Poor Quality ◽  
Northern India ◽  
High Germination ◽  
Monsoon Forest ◽  
Mean Germination Time ◽  
Pre Treatment

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.

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