scholarly journals Improving Germination Rate of Coastal Glehnia by Cold Stratification and Pericarp Removal

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 944
Author(s):  
Moon-Sun Yeom ◽  
Thi Kim Loan Nguyen ◽  
Ju-Sung Cho ◽  
Myung-Min Oh

The medicinal plant, coastal glehnia (Glehnia littoralis F. Schmidt ex Miq.), belongs to the Apiaceae, which is known to exhibit morpho-physiological seed dormancy (MPD). In this study, we aimed to determine the dormancy type of this plant, along with the conditions for breaking dormancy, and how to increase its germination rate for mass production. Initially, the seeds of coastal glehnia had undeveloped embryos, which gradually developed following cold (5 °C) stratification over eight weeks. The embryo to seed (E:S) ratio increased to 66.7%, confirming that the seeds had the MPD type. Coastal glehnia seeds with pericarp did not show inhibited water uptake, and the germination inhibitory chemicals were not detected. However, removal of the pericarp improved the final germination percentage, germination speed, and T50 of coastal glehnia seeds compared with those of seeds with pericarp at 20 °C, which showed the highest value compared with other temperature treatments. Thus, cold stratification at 5 °C for eight weeks and removing the pericarp of germinating seeds maintained at 20 °C is efficient ways to break dormancy and improve the germination rate for the mass production of coastal glehnia.

Botany ◽  
2016 ◽  
Vol 94 (10) ◽  
pp. 967-973 ◽  
Author(s):  
Viheno Iralu ◽  
Krishna Upadhaya

Magnolia punduana Hk. f. & Th. (syn. Michelia punduana) is a threatened tree species restricted to northeastern India. The seeds remain dormant for 6 months after dispersal. Seed development and breaking of dormancy was investigated in the present study. Physical treatments such as water (cold, hot, and boiling) and acid and manual scarification proved ineffective in breaking dormancy. Matured seeds had linear and underdeveloped embryos at the time of dispersal with an embryo to seed length (E:S) ratio of 0.13. Germinating seeds showed a significant increase in the embryo length with an E:S ratio of 0.36. Cold stratification (CS) at 5 °C effectively broke dormancy. The embryo grew significantly after CS, indicating the presence of “non-deep simple” morphophysiological dormancy (MPD). Application of GA3 had a significant effect on germination and the lowest germination time with the shortest T50 was observed in seeds treated with 3000 mg·L−1 GA3. KNO3 did not have an influence on breaking dormancy except in combination with GA3, which increased the germination percentage significantly. CS for 90 days and GA3 (3000 mg·L−1) at 25 °C resulted in optimum germination. In the test for viability, seeds stored at 5 °C showed highest viability of 66.66% after 180 days.


2019 ◽  
Vol 28 (1) ◽  
pp. eSC02 ◽  
Author(s):  
Reinaldo Pire ◽  
Georgina Vargas-Simón

Aim of study: The objective of this study was to present statistical information pertaining to recurrent inconsistencies found in the literature of the last 25 years that involve calculation of the GR and the errors that this may entail when interpreting the seed vigor of different botanical materials.Materiales y métodos: After filtering articles that did not present numerical results or in which the application of Maguire's formula was not clearly indicated, a total of 124 papers were ultimately used in this study.Main results: Germination rate (GR) represents the potential of seeds to germinate and, along with germination percentage (GP), are the two most important measurements when evaluating seed quality. The correct calculation of GR allows the seeds classification according to their vigor and capacity to produce healthy seedlings, so it is very important to rely on the adequate mathematical formula for this purpose. According to the formula developed by Maguire, this parameter is calculated by the sum of values obtained when dividing the GP at different times (i.e. daily) by the total time elapsed since the start of the test. We have found from the relevant literature that different authors have been using different ways of applying the formula, which makes it difficult to directly compare the results.Research highlights: A total of 54.8 % of the papers reviewed, belonging mainly to the theme of forestry, presented objectionable application of the formula. Publication of this warning may help to reduce the occurrence of this situation in the future.Keywords. Germination percentage, germination speed, Maguire’s formula, seed vigor.


2021 ◽  
Vol 27 (4) ◽  
pp. 446-452
Author(s):  
Kássia Barros Ferreira ◽  
Antonio Maricélio Borges de Souza ◽  
Ana Carolina Corrêa Muniz ◽  
Kathia Fernandes Lopes Pivetta

Abstract Palm seeds are indicative of being recalcitrant species. Seeds germination for many species, is slow and uneven, even in favorable conditions, often due to the resistance of the woody endocarp that makes them impermeable to water. Most species also have the characteristic of not tolerating the drying process at low moisture levels, thus losing their viability. In view of these considerations, the objective was to evaluate the effect of different periods of rehydration on the germinative process of seeds of royal palm, dwarf palm and jeriva. Seeds were homogenized and immersed in water containing 3 times their volume, with daily replacement. The experimental design used was completely randomized, with 5 treatments (0, 3, 6, 9, and 12 days of rehydration), with 4 replications of 25 seeds. The seeds were placed in transparent “gerbox” plastic boxes containing medium vermiculite as substrate and placed in BOD with a photoperiod of 16-hour of light and their respective optimum temperatures for each species. The number of germinated seeds was counted every 2 days until germination stabilized. The variables analyzed were germination percentage, germination speed index (GSI), average germination time (AGT) and distribution of germination over the days. Rehydration for 3 days increased the germination rate of royal palm seeds. For dwarf and jeriva species, rehydration did not influence the analyzed variables. The GSI and AGT were negatively influenced by the rehydration periods for royal palm. Rehydration prolonged the peak of germination of the studied species.


2021 ◽  
Vol 43 ◽  
Author(s):  
Nancy Araceli Godínez-Garrido ◽  
Juan Gabriel Ramírez-Pimentel ◽  
Jorge Covarrubias-Prieto ◽  
Francisco Cervantes-Ortiz ◽  
Artemio Pérez-López ◽  
...  

Abstract: Chitosan is a biopolymer obtained from deacetylation of chitin; it has multiple applications in agriculture as an antifungal, soil conditioner, inducer of defense mechanisms, fruits postharvest coating, leaves and seeds, among others. The objective in this research was to evaluate the effect of chitosan coatings mixed with fungicide (dithiocarbamate) on the germination and germination speed of bean and maize seeds in storage and to determine the retention capacity of the fungicide in the coated seeds under different times of imbibition. Two coating treatments at concentrations of 0.1 and 0.5% chitosan in water, two coatings treatments at 0.1 and 0.5% chitosan supplemented with 0.5% fungicide and a coating without chitosan using only 0.5% fungicide in water were used in bean and maize seed; and as control seeds imbibed in distilled water were used; after treatments, germination percentage and germination speed were determined, also fungicide release were determined at 0, 1, 2 and 6 h of imbibition, and the effect of storage time on germination and germination speed was determined at 30, 60, 90, 120, 150 and 180 days of storage at 4 °C and 45% relative humidity. The fungicide release effect was determined by inhibiting Fusarium oxysporum conidia germination. There were no negative effects of coatings on seed germination after storage. The treatment that provided both greater retention of the fungicidal agent and released it gradually, was 0.5% chitosan mixed with fungicide concentration. Chitosan coating seeds mixed with fungicide do not cause negative changes in seed germination or germination rate.


Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 317
Author(s):  
Cássio Do Prado Borges ◽  
Cheila Deisy Ferreira ◽  
Daniela Pereira Dias

Este trabalho objetivou avaliar a germinação e vigor de sementes de Plathymenia reticulata Benth. submetidas a diferentes tratamentos para superação de dormência. Os tratamentos testados foram: controle - sementes intactas (T0), escarificação mecânica com lixa d’água nº 60 (T1), desponte na região lateral do tegumento (T2), imersão em água fervente por 10 min (T3), em hipoclorito de sódio por 15 min (T4) e em solução com detergente por 15 min (T5). Foram determinados: peso de mil sementes, grau de umidade, porcentagem de germinação, índice de velocidade de germinação (IVG), tempo médio de germinação (TMG), curva de embebição, teste da condutividade elétrica e comprimento da radícula. A porcentagem de germinação das sementes submetidas ao T1 e T2 foi estatisticamente igual (respectivamente, 90 e 88%) e superiores aos outros tratamentos testados (12%). As sementes expostas aos T1 e T2 apesentaram porcentagem de absorção de água superiores e em menor tempo, assim como maiores IVG e menores TMG, comparadas aos demais tratamentos. O comprimento das radículas não variou entre os tratamentos testados. A condutividade elétrica da solução com as sementes do T0 foi superior aos outros tratamentos testados. Sementes de P. reticulata expostas ao T1 e T2 apresentam maior germinação e vigor.Palavras-chave: germinação, índice de velocidade de germinação, teste de condutividade elétrica, vigor, vinhático. DORMANCY BREAKING OF Plathymenia reticulata Benth. SEEDS ABSTRACT:This study aimed to evaluate the germination and vigor of Plathymenia reticulata Benth. seeds submitted to different dormancy breaking treatments. Testing treatments were: control - intact seeds (T0); mechanical scarification with sandpaper n. 60 (T1), coating cutting in the lateral side of tegument (T2), immersion in boiling water during 10 min (T3), in sodium hypochlorite solution during 15 min (T4), and in detergent solution during 15 min (T5). Moisture content, 1000-seed weight, germination percentage, germination speed index (GSI), mean germination time (MGT), imbibition curve, electrical conductivity test, and radicle length were determined. Germination percentage to T1 and T2 were statistically equal (90 and 88 %, respectively) and higher than others treatments tested (12%). Seeds exposed to T1 and T2 also presented higher and faster water absorption percentage, when compared to the others treatments, as well as higher GSI, and lower MGT. The rootlets length did not vary among treatments tested. Electrical conductivity of intact seeds was higher than others treatments. P. reticulata seeds expose to T1 e T2 had highest germination percentage and vigor.Keywords: germination, germination speed index, electrical conductivity test, vigor, vinhático.


2018 ◽  
Vol 48 (1) ◽  
pp. 66-74 ◽  
Author(s):  
Rita de Cássia Barbosa da Silva ◽  
Marcelo do Nascimento Araujo ◽  
Fábio Luiz Santos Ornellas ◽  
Bárbara França Dantas

ABSTRACT Given that watermelon is a crop widespread around the world, there is considerable interest in verifying how its seeds physiologically behave under unfavorable temperature conditions. This study aimed to evaluate the biochemical changes mobilization and reserves degradation, as well as the enzyme activity, during seed germination and initial growth of watermelon seedlings subjected to thermal stress, using temperature, germination percentage, germination rate and relative germination frequency over the incubation time as evaluation parameters. The experimental design was completely randomized, in a 5 x 3 factorial scheme, with five temperatures (17 ºC, 20 ºC, 25 ºC, 30 ºC and 35 ºC) and three cultivars (Charleston Gray, Fairfax and Crimson Sweet), with 4 replicates of 50 seeds. Germination, seedling growth, reserve degradation and stress protection system were evaluated. Thermal stress caused deleterious effects on watermelon seeds with germination capacity at well defined temperature limits, being 25 ºC the ideal temperature, with the highest percentage of normal seedlings. Sub- (17 ºC) and supra-optimal (30 ºC) temperatures presented more than 80 % of abnormal seedlings. The α-amylase enzyme activity is intense only at the beginning of germination. Under thermal stress, the proline contents increase mainly in the cotyledons.


Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 319
Author(s):  
Yuhan Tang ◽  
Keliang Zhang ◽  
Yin Zhang ◽  
Jun Tao

Sorbus alnifolia (Siebold & Zucc.) K.Koch (Rosaceae) is an economically important tree in the temperate forests of Eastern China. In recent decades, ever-increasing use and modification of forestlands have resulted in major degeneration of the natural habitat of S. alnifolia. Moreover, S. alnifolia seeds germinate in a complicated way, leading to a high cost of propagation. The current study aimed to determine the requirements for breaking seed dormancy and for germination as well as to characterize the type of seed dormancy present in this species. Moreover, the roles of temperature, cold/warm stratification, and gibberellic acid (GA3) in breaking dormancy were tested combined with a study of the soil seed bank. The results showed that intact seeds of S. alnifolia were dormant, requiring 150 days of cold stratification to achieve the maximum germination percentage at 5/15 °C. Exposure of the seeds to ranges of temperatures at 15/25 °C and 20/30 °C resulted in secondary dormancy. Scarifying seed coat and partial removal of the cotyledon promoted germination. Compared with long-term cold stratification, one month of warm stratification plus cold stratification was superior in breaking dormancy. Application of GA3 did not break the dormancy during two months of incubation. Seeds of S. alnifolia formed a transient seed bank. The viability of freshly matured S. alnifolia seeds was 87.65% ± 11.67%, but this declined to 38.25% after 6-months of storage at room temperature. Seeds of S. alnifolia have a deep physiological dormancy; cold stratification will be useful in propagating this species. The long chilling requirements of S. alnifolia seeds would avoid seedling death in winter.


1994 ◽  
Vol 42 (6) ◽  
pp. 717 ◽  
Author(s):  
MB Lovato ◽  
PS Martins ◽  
Filho JPD Lemos

The germination response to NaCl treatments (0, 67, 134, 201 and 268 mol m-3) was investigated in 6 natural populations of Stylosanthes humilis from 3 ecogeographic regions of Pernambuco State, north-east Brazil. In general, salt tolerance was high, with percentage germination unaltered up to 67 mol m-3 NaCl in 2 populations and unaltered up to 134 mol m-3 NaCl in the remaining 4. The estimated concentration which reduced percentage germination to 50% varied between populations from 200 to 295 mol m-3 NaCl. Salt affected germination rate even more than it did the germination percentage, being altered at 67 mol m-3 NaCl in all populations. The germination rate was reduced to 50% in the range of 131-176 mol m-3 NaCl. There was a significant variation in salt tolerance between these natural populations, and no relation was found between salt tolerance of the populations and the aridity of their provenance.


Botany ◽  
2014 ◽  
Vol 92 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Ali A. El-Keblawy ◽  
Arvind Bhatt ◽  
Sanjay Gairola

Salsola rubescens Franch. is a wind-pollinated halophytic shrub that produces fruits with red and yellow winged perianths. Germinability of seeds from both fruit types was determined under various light, temperature, and salinity treatments. Red seeds, with and without winged perianths, were heavier than yellow seeds. Germination percentage and germination rate index (speed) were significantly affected by the perianth colour, presence of wings, and temperature and light of incubation and most of their interactions. Germination percentage was greater for yellow-winged seeds than for red-winged seeds. Wing removal significantly enhanced the germination percentage and germination speed in the two types. The presence of wings enhanced germination at lower temperatures, but wing absence enhanced germination at higher temperatures. Wing removal enhanced germination to a greater degree in yellow than in red seeds. There was no light requirement during germination of red-winged seeds, but yellow-winged seeds germinated significantly more in light than in darkness. Red-winged and dewinged seeds were more tolerant to salinity than yellow seeds. Removal of wings significantly increased salinity tolerance for seeds of both wing colours. It is concluded that the showy perianth colours have an ecological role in wind-pollinated plants in regulating dormancy and germination behaviour in the heterogeneous unpredictable hyperarid deserts.


2013 ◽  
Vol 5 (1) ◽  
pp. 5-18
Author(s):  
Alireza Pourmohammad ◽  
Fariborz Shekari ◽  
Veeda Soltaniband

Abstract An experiment was concluded to evaluate the effects of priming on germination characteristics and establishment of rapeseed seedlings during three stages. In the first and second stages of experiment, the effects at three factors vis: cultivars (RVS, Hayola), waterdeficit stress (Control,-6 and -12 bar) and cycocel treatment (dry seeds, 300, 600, 900, 1200 and 1500 μM) on germination and seedling growth of plant were assayed. The results showed that priming had positive effects on germination percentage, germination rate index, germination index, and radicle length under water-deficit conditions. RVS had greater efficiency than other cultivars. The third section of experiment revealed that the priming of RVS seeds improved the stem, root and dry weight, total dry weight as well as leaf number and area of seedlings.


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