scholarly journals Effect of Different Temperature Regimes on the Germination of Pseudolysimachion pusanensis (Y. N. Lee) Y. N. Lee Seeds

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 577
Author(s):  
Mi-Hyun Lee ◽  
Jin-Hyun Lim ◽  
Cho-Hee Park ◽  
Jun-Hyeok Kim ◽  
Chae-Sun Na
Keyword(s):  
Native Plants ◽  
Germination Percentage ◽  
Storage Management ◽  
Base Temperature ◽  
Temperature Regimes ◽  
Different Temperatures ◽  
Mean Germination Time ◽  
The Mean ◽  
C 30 ◽  
Gradient Plate

In this study, we determined the germination response in the seeds of the rare plant Pseudolysimachion pusanensis (Y. N. Lee) Y. N. Lee to different temperatures. P. pusanensis seeds were collected from the Baekdudaegan National Arboretum, South Korea, in November 2019, and dried. Dry seeds were placed at constant and alternating temperatures (5 °C, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, and 35 °C) to determine their germination percentage (GP). The seeds were exposed to 59 temperature combinations ranging from 5 °C to 43 °C using a thermal gradient plate. The photoperiod was set at 12:12 h (light:dark) and germination assays were performed five times a week. Subsequently, the seed GP and the number of days required to reach 50% of the germination (T50) were determined. The highest final GP was 94.38%, with a T50 value of 9.26 d at 15 °C. However, the mean germination time was 12.5 d at 15 °C, and linear regression using 1/T50 revealed that the base temperature ranged from 2.69 °C to 4.68 °C. These results for P. pusanensis seeds stored in a seed bank provide useful data for the native plants horticulture industry and can also be utilized for storage management.

scholarly journals Temperatures and substrates for germination and vigor of Erythroxylum pauferrense Plowman seeds

2019 ◽  
Vol 41 ◽  
pp. e46030
Author(s):  
João Everthon da Silva Ribeiro ◽  
Arliston Pereira Leite ◽  
Jackson Silva Nóbrega ◽  
Edna Ursulino Alves ◽  
Riselane de Lucena Alcântara Bruno ◽  
...  
Keyword(s):  
Dry Mass ◽  
Germination Percentage ◽  
Seed Vigor ◽  
Randomized Design ◽  
Temperature Regimes ◽  
Seedling Length ◽  
Physiological Quality ◽  
Mean Germination Time ◽  
Completely Randomized Design ◽  
Understory Plant

Erythroxylum pauferrense is an endemic understory plant species of the Northeast Region of Brazil. The species is of great importance to the region and so ecophysiological studies are needed for its preservation. The objective of the present study was to determine the best substrates and temperatures for testing germination and seed vigor of E. pauferrense. An experiment was performed comprising a completely randomized design in a 5 x 4 factorial scheme, with five temperature regimes (20, 25, 30, 35°C constant and 20-30°C alternating) and four types of substrates (paper, vermiculite, sand and commercial substrate). The following characteristics were evaluated: germination percentage, first germination count, germination speed index, mean germination time, seedling length and dry mass (root and shoot). Paper and vermiculite substrates combined with constant temperatures of 20, 25, 30 and alternated between 20-30°C, provide greater seed germination and vigor while 35°C reduces seed physiological quality.

APHID FECUNDITY, REPRODUCTIVE LONGEVITY, AND PARASITE DEVELOPMENT IN THE SCHIZAPHIS GRAMINUM (RONDANI)(HOMOPTERA: APHIDIDAE) – LYSIPHLEBUS TESTACEIPES (CRESSON) (HYMENOPTERA: BRACONIDAE) SYSTEM

1988 ◽  
Vol 120 (12) ◽  
pp. 1079-1083 ◽  
Author(s):  
T.J. Kring ◽  
J.B. Kring
Keyword(s):  
Schizaphis Graminum ◽  
Parasite Development ◽  
Progeny Production ◽  
Lysiphlebus Testaceipes ◽  
Temperature Regimes ◽  
Reproductive Life ◽  
Different Temperatures ◽  
Total Progeny ◽  
The Mean ◽  
Aphid Fecundity

AbstractThe fecundity and reproductive longevity of Schizaphis graminum (Rondani) parasitized by Lysiphlebus testaceipes (Cresson) were determined in the laboratory under four temperature regimes. Daily reproduction by S. graminum declined rapidly after parasitization except at a relatively low temperature regime (12–16 °C). The mean progeny production by parasitized aphids of 2.75 ± 0.08 nymphs per parasitized adult was not significantly different than that for unparasitized aphids (2.94 ± 0.23 nymphs) during the period of time equal to the reproductive life of parasitized aphids. Reproductive longevity of parasitized aphids was longest at the lowest temperature (5.67 ± 0.25 days at 12–16 °C). No significant differences were observed in total progeny produced at different temperatures. The number of progeny within parasitized nulliparous adults (3.37 ± 0.33) as determined by dissections was not significantly different from the mean total progeny produced by parasitized aphids. Parasitization thus seems to interfere with oogenesis, but not with embryonic development or progeny deposition.

Competition studies in diploid and tetraploid varieties of Lolium perenne: 1. The influence of density and proportion of sowing

1977 ◽  
Vol 88 (2) ◽  
pp. 405-410 ◽  
Author(s):  
J. Norrington-Davies ◽  
J. H. Harries
Keyword(s):  
Binary Mixture ◽  
Lolium Perenne ◽  
Significant Variation ◽  
Germination Percentage ◽  
Pure Stand ◽  
Germination Inhibitors ◽  
Germination Time ◽  
Mean Germination Time ◽  
The Mean ◽  
Seed Coats

SUMMARYTwo varieties of Lolium perenne, the diploid Hora and the tetraploid Terhoy were sown either as a pure stand or as a binary mixture on to the surface of multipots filled with a standard John Innes compost. Density of sowing was varied over the range of 16, 24, 36, 50 and 100 seeds/pot. There were four replicates. The pattern of germination was followed over a period of 14 days when it was found that (i) the varieties did not differ in their germination when grown alone, but in mixtures the diploid was slower to germinate than the tetraploid, (ii) as the density of sowing per pot was increased, the mean germination time (MGT) was increased, and (iii) the final germination of both verities decreased with increasing density.In a second experiment the same procedures were followed as before but seed of each variety was sown either as a pure stand or in a mixture of varying proportion as follows: 100:0, 75:25, 50:50, 25:75, 0:100.The results showed that (i) the diploid had the fastest MGT whilst the mixture values showed no significant variation, and (ii) the final germination percentage of the diploid decreased relative to its pure stand value as its proportion in mixtures decreased, whilst the tetraploid under the same circumstances increased relative to its pure stand value.It is suggested that differences such as those found could be explained by the presence of germination inhibitors in the seed coats of the two ryegrass varieties.

scholarly journals Morphometry and Germination of Passovia pyrifolia, Struthanthus marginatus and Phoradendron mucronatum Diaspores

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
J.M.L. AZEVEDO ◽  
C.G.G. SANTOS ◽  
C.S. CAIRES ◽  
J.C. ARAÚJO NETO ◽  
R.C. SOUZA
Keyword(s):  
Moisture Content ◽  
Germination Rate ◽  
Germination Percentage ◽  
Percentage Germination ◽  
Essential Characteristic ◽  
Germination Time ◽  
Randomized Design ◽  
Different Temperatures ◽  
Mean Germination Time ◽  
Completely Randomized Design

ABSTRACT: The goal of this work was to characterize morphometrically diaspores from three species of mistletoes (Passovia pyrifolia, Struthanthus marginatus e Phoradendron mucronatum), as well as to study its germination behavior according to temperature and luminosity. In germination tests, the completely randomized design was used, in factor scheme 4 x 2, with 4 replications of 15 diaspores. The factors for the first test were different temperatures and two diaspore conditions (intact and without epicarp). In the second test, factors were different light qualities and two diaspore conditions. The analyzed variables were: germination percentage, germination rate index (GRI) and mean germination time (MGT). Mistletoe’s diaspores present an elliptic shape with viscin layer, an essential characteristic for the dispersion of the species. In addition to this, they present a distinction as for the moisture content when compared to the Loranthaceae and Viscaceae, where the latter presents the highest content. Germination is greater at the alternated temperature of 20-30 oC for P. pyrifolia and P. mucronatum diaspores and 20 oC for S. marginatus. Luminosity interfered in the germination of P. mucronatum and S. marginatus but did not influence P. pyrifolia. The diaspore condition influenced the germination of the three studied species, observing a significant increase in their germination when the epicarp was removed. Temperature and luminosity interfere directly in the GRI and MGT of the three mistletoes species.

Relating germination requirements of timber milkvetch to seral stage in the Interior Douglas-fir zone

2014 ◽  
Vol 94 (4) ◽  
pp. 723-726
Author(s):  
D. J. Thompson
Keyword(s):  
Seed Germination ◽  
Germination Rate ◽  
Germination Percentage ◽  
Douglas Fir ◽  
Native Plant ◽  
Temperature Regimes ◽  
The Mean ◽  
Lower Temperature ◽  
Fluctuating Temperatures ◽  
Germination Requirements

Thompson, D. J. 2014. Relating germination requirements of timber milkvetch to seral stage in the Interior Douglas-fir zone. Can. J. Plant Sci. 94: 723–726. Germination of timber milkvetch (Astragalus miser var. serotinus) seeds was studied to determine if it is an early or late seral species. Seeds were collected from a native plant population and those having a dark seed coat were selected. Germination tests were run in the light or dark and under three temperature regimes: low (constant 10°C), high (constant 25°C), and alternating (25°C day and 10°C night). Germination occurred over a protracted period with new germinants up to 90 d at the lowest temperature. Germination was not affected by light. Germination rate was greater at 25°C than 10°C, while fluctuating temperatures (25 and 10°C alternating every 12 h) reduced germination rate to that at the lower temperature. Days to 50% germination was a more sensitive indicator, with the mean for the fluctuating temperatures falling between those continuous to the high and low temperature. Final germination percentage was reduced at 10°C compared with 25°C, but not with fluctuating temperatures. Timber milkvetch seed germination did not respond to light or fluctuating temperatures, adding to a body of evidence that it is a late seral species.

PREHARVEST SPROUTING ASSESSMENT IN WHEAT GENOTYPES INFLUENCED BY TEMPERATURE AND DEGREE DAYS

2017 ◽  
Vol 54 (4) ◽  
pp. 483-490 ◽  
Author(s):  
L. A. OKUYAMA ◽  
N. S. FONSECA JUNIOR ◽  
P. H. CARAMORI ◽  
M. M. KOHLI
Keyword(s):  
Air Temperature ◽  
Germination Percentage ◽  
Preharvest Sprouting ◽  
Vertical Position ◽  
Test Duration ◽  
Base Temperature ◽  
Degree Days ◽  
Simulated Rain ◽  
The Mean ◽  
Testing Condition

SUMMARYThe environmental conditions and test duration in rainfall simulators have been major constraints to find reliable differences in preharvest sprouting (PHS) among wheat cultivars. This study aimed to elucidate the temperature conditions and degree-days (DD) that enable higher discrimination of genotypes in a PHS test. Thirteen genotypes with different degrees of PHS (BR 18, BRS 220, CD 104, CD 105, CD 108, CD 114, CD 116, Frontana, IPR 085, IPR 128, IPR 136, OR1 and Safira) were evaluated in a rainfall simulator, during four years, conducting two trials per year. The tests were carried on 20 spikes per cultivar, kept in a vertical position on Styrofoam plates, spaced 10 cm between rows and 5 cm within the row. The air temperature data were recorded on a thermograph and the DD were calculated from the mean daily air temperature assuming a base temperature of 4 °C. The Falling Number (FN) parameter and germination percentage (GP) data were averaged for each test. The temperatures (minimum, mean and maximum) and the DD were regressed and correlated with FN and GP. Any increase in the minimum and mean air temperature and accumulated DD decreased FN values and increased GP. Higher genotypic discrimination was achieved at an average air temperature of 21.5 °C and 35 DD. These values can be used as reference to set simulated rain testing condition for screening genotype for PHS based on FN or pericarp rupture of grains.

scholarly journals Salinity tolerance at germination of some main cultivated cowpea (Vigna unguiculata) genotypes from Western Cameroon

2017 ◽  
Vol 6 (06) ◽  
pp. 1634
Author(s):  
Ebeny Leonny Tsague ◽  
Eric Bertrand Kouam* ◽  
Christopher Mubeteneh Tankou
Keyword(s):  
Salt Stress ◽  
Vigna Unguiculata ◽  
Germination Percentage ◽  
Randomized Design ◽  
Nacl Concentration ◽  
Mean Germination Time ◽  
The Mean ◽  
Coefficient Of Velocity ◽  
Positive Correlations ◽  
Osmotic Potentials

This study investigates the effect of salt (NaCl) on the germination of seeds of 10 genotypes of cowpea (Vigna unguiculata). The experiment carried out on petri dishes was done using a completely randomized design comprising three replications. The germination of the cultivars was studied using distilled water as control and under osmotic potentials of 50, 100, 150 and 200mM NaCl. The results indicated that the Mean Germination Time (MGT), Time to 50% Germination (T50), Germination Index (GI), Coefficient of Velocity of Germination (CVG), and Germination Percentage (GP), varied between 2.33 and 5.51 days; 2.83 and 14.87 days; 16.66 and 1.63; 0.53 and 0.11; 87.11 and 27.98% respectively. The variables GI, CVG and GP tended to decrease with increasing NaCl concentration while MGT and T50 tended to increase with increasing salt concentrations. For all the germination variables, significant differences at 0.001 probability levels were found among salinity treatments, cowpea genotypes and their interaction. Four genotypes (KEB-CP118, OU59A, OU100 and ICV12) were tolerant to salt stress and performed well under salinity conditions. Four other genotypes were found to be moderately tolerant (ET11, NO1036, MTA22 and KEB-CP009) and two genotypes (KEB-CP098 and NO193) were susceptible to salt stress and were most affected by salinity. At 0.001 probability level, positive correlations were observed between GP and GI (r = 0.792); GP and CVG (r = 0.774); GI and CVG (r = 0.955) and negative correlations were observed between GP and T50 (r = - 0.845); GI and MGT (r = - 0.894); CVG and MGT (r = - 0.895).

scholarly journals Assessing Effects of Temperature Change on Four Limonium Species from Threatened Mediterranean Salt-Affected Habitats

2018 ◽  
Vol 46 (1) ◽  
pp. 286-291 ◽  
Author(s):  
Mariola MONLLOR ◽  
Pilar SORIANO ◽  
Josep V. LLINARES ◽  
Monica BOSCAIU ◽  
Elena ESTRELLES
Keyword(s):  
Seed Germination ◽  
Principal Component ◽  
Fast Response ◽  
Germination Percentage ◽  
Thermal Time ◽  
Eastern Coast ◽  
Soil Parameters ◽  
Base Temperature ◽  
Temperature Regimes ◽  
Saline Habitats

Evaluation of tolerance to temperatures in the germination stage is an important tool to foresee the possible effect of global warming. Moreover, establishing germination protocols for endemic and threatened species is most interesting for restoration and management plans that focus on habitat conservation. Seed germination was analysed in four species of the genus Limonium (L. virgatum, L. narbonense, L. girardianum and L. santapolense) growing in two saline habitats on the eastern coast of the Iberian Peninsula. The study aim was to compare responses of seed germination to different temperature regimes. Seeds were collected in two protected areas, ‘L´ Albufera de Valencia’ (province of Valencia) and ‘Clot de Galvany’ (province of Alicante). Responses to temperature were checked within a constant range, 10-30 °C at 5 °C intervals, by considering the environmental conditions at both sampling sites. The final germination percentage and mean germination time (MGT) were calculated after 30 days. In order to compare thermal responses, base temperature (Tb) and thermal time (S) were determined for each species. The possible correlations of soil parameters with the species´ germination pattern were also analysed. To identify distinct behavioural groups, a non-linear principal component analysis was performed. Significant differences between species were found in the velocity of germination. A fast response as opportunistic germination was observed in all the species. The base temperature and thermal time showed significant differences in competitiveness between species.

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 Temperature and light under the physiological potential of seeds of Handroanthus impetiginosus

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Débora da Rocha Gomes Ferreira ◽  
Edilma Pereira Gonçalves ◽  
Jeandson Silva Viana ◽  
Lidiana Nayara Ralph ◽  
Júlio Cesar de Almeida Silva ◽  
...  
Keyword(s):  
Urban Areas ◽  
Red Light ◽  
Folk Medicine ◽  
Germination Percentage ◽  
Light Regimes ◽  
Economic Exploitation ◽  
Temperature Regimes ◽  
Randomized Experimental Design ◽  
C 30 ◽  
Handroanthus Impetiginosus

H. impetiginosus belongs to the Bignoniaceae family; it has a great potential for economic exploitation and can be used in landscaping of urban areas, reforestation, recovery of degraded areas, and folk medicine. The experiment was carried out to evaluate the effect of light and temperature regimes on the germination and vigor of Handroanthus impetiginosus seeds at the Seed Analysis Laboratory of UFRPE/UAG. The seeds were subjected to light regimes: white, far red, red, and no light at 15°C, 20°C, 25°C, 30°C, 35°C, and 40°C, using a completely randomized experimental design in a factorial scheme (4 × 6), with four repetitions of 25 seeds. The different light regimes did not influence the seed germination of H. impetiginosus. The highest germination percentage (92%) and germination speed index (7.94) were obtained at temperatures 28.2°C and 29.2°C, respectively, both under red light. The longest seedling length was also obtained from the seeds subjected to red light regime at 25°C. The temperatures of 15°C and 40°C inhibited the germination of H. impetiginosus seeds. H. impetiginosus seeds are classified as neutral photoblastics, and constant temperatures of 28.2°C and 29.2°C provided maximum germination.

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