scholarly journals Germination potential and methods for overcoming seed dormancy for domesticated and wild annatto populations after two years of storage

2022 ◽  
Vol 52 (5) ◽  
Author(s):  
Wellington Ferreira do Nascimento ◽  
Fabiana Gonçalves Bastos ◽  
Gabriel Dequigiovanni ◽  
Eliane Gomes Fabri ◽  
Maria Imaculada Zucchi ◽  
...  
Keyword(s):  
Seed Dormancy ◽  
Good Alternative ◽  
Germination Percentage ◽  
Wild Type ◽  
Running Water ◽  
Field Collection ◽  
Germination Potential ◽  
Type Population ◽  
Orthodox Seeds ◽  
Concentrated Sulfuric Acid

ABSTRACT: Annatto (Bixa orellana L.) is an arboreal species domesticated in Amazonia from its wild ancestor (B. orellana var. urucurana). Bixin extracted from its orthodox seeds is a natural dye widely used in the food industry. This study evaluated methods to overcome seed dormancy and determine the germination potential, comparing domesticated and wild annatto populations. Seeds from two domesticated-type populations and two families of a wild-type population, stored for two years after field collection, were submitted to five treatments to overcome dormancy: T1 - control; T2 - mechanical scarification (with sandpaper); T3 - mechanical scarification (with sandpaper) + immersion in water at 36 ºC overnight (12 hours); T4 - immersion in water at room temperature (23 ºC, on average) for 24 h; T5 - immersion in concentrated sulfuric acid (95 - 98%) for 15 min + running water for 3 min. Highly significant differences (P < 0.001) were observed in the germination percentage of annatto seeds between wild and domesticated types, and among the treatments tested. Domesticated types showed higher germination percentage (10 - 58%) over all treatments when compared to the wild type (0 - 44%). The best treatments were those performed with mechanical scarification. Given the simplicity, we concluded that mechanical scarification with sandpaper is a good alternative to overcome dormancy of annatto seeds.

Morphophysiological dormancy and germination ecology in diaspores of the subtropical palm Phoenix canariensis Chabaud

Botany ◽  
2021 ◽  
Author(s):  
Lanlan He ◽  
Ganesh K. Jaganathan ◽  
Baolin Liu
Keyword(s):  
Seed Dormancy ◽  
Seedling Emergence ◽  
Primary Root ◽  
Germination Percentage ◽  
Early Summer ◽  
Germination Ecology ◽  
Phoenix Canariensis ◽  
Morphophysiological Dormancy ◽  
Cotyledonary Petiole ◽  
Seed Dormancy And Germination

The timing of germination is a crucial event in a plant’s life cycle. Seed dormancy and germination mechanisms are important factors regulating seedling emergence. Since detailed experimental evidence for germination pattern of Phoenix canariensis colonizing sub-tropical climate is scarce, we investigated seed dormancy and germination ecology of P. canariensis. We found that the embryo is underdeveloped at the time of dispersal and doubles in size before the cotyledonary petiole (CP) protrudes through the operculum. The primary root and plumule emerge from the elongated CP outside the seed. In light/dark at 30/25°C, the CP emerged from 8% of the diaspores within 30 days and from 76% within 14 weeks. Thus, 8% of the diaspores have MD and the others MPD. Removal of the pericarp and operculum resulted in 100% germination within 5 days in light/dark at 30/25°C. Cold and warm stratification as well as treatment with GA3 significantly increased the germination speed, but the final germination percentage was not significantly increased. Seed germination was synchronized in early summer when seed dormancy was released by cold stratification in the soil over winter. A remote-tubular germination type and intricate root system provide an ecological advantage to the seedling establishment.

scholarly journals Active elimination of intestinal cells drives oncogenic growth in organoids

2020 ◽  
Author(s):  
Ana Krotenberg Garcia ◽  
Arianna Fumagalli ◽  
Huy Quang Le ◽  
Owen J. Sansom ◽  
Jacco van Rheenen ◽  
...  
Keyword(s):  
Quality Control ◽  
Cell Death ◽  
Cancer Cells ◽  
Cell Fate ◽  
Crucial Role ◽  
Intestinal Cells ◽  
Dependent Manner ◽  
Wild Type ◽  
Cell Competition ◽  
Type Population

AbstractCompetitive cell-interactions play a crucial role in quality control during development and homeostasis. Here we show that cancer cells use such interactions to actively eliminate wild-type intestine cells in enteroid monolayers and organoids. This apoptosis-dependent process boosts proliferation of intestinal cancer cells. The remaining wild-type population activates markers of primitive epithelia and transits to a fetal-like state. Prevention of this cell fate transition avoids elimination of wild-type cells and, importantly, limits the proliferation of cancer cells. JNK signalling is activated in competing cells and is required for cell fate change and elimination of wild-type cells. Thus, cell competition drives growth of cancer cells by active out-competition of wild-type cells through forced cell death and cell fate change in a JNK dependent manner.

scholarly journals Epidemiological cutoff values for a 96-well broth microdilution plate for high-throughput research antibiotic susceptibility testing of M. tuberculosis

2021 ◽  
Author(s):  
◽  
Philip W Fowler
Keyword(s):  
Genetic Variants ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Broth Microdilution ◽  
Wild Type ◽  
Genetic Sequencing ◽  
Indicator Tube ◽  
Cutoff Values ◽  
Type Population

AbstractDrug susceptibility testing of M. tuberculosis is rooted in a binary susceptible/resistant paradigm. There are considerable advantages in measuring the minimum inhibitory concentrations (MICs) of a panel of drugs for an isolate, including quantifying the magnitude of effect conferred by genetic variants and being able to identify isolates with elevated MICs that can still be treated with standard therapy. It is necessary, however, to measure the epidemiological cutoff values (ECOFF/ECVs) to permit comparison with qualitative data. Here we present ECOFF/ECVs for 13 anti-TB compounds, including bedaquiline and delamanid, derived from 20,637 clinical isolates collected by 14 laboratories based in 11 countries on five continents. Each isolate was incubated for 14 days on a dry 96-well broth microdilution plate and then read. Resistance to the majority of the drugs due to prior exposure is expected and the MIC distributions for many of the compounds are complex and therefore a phenotypically wild-type population could not be defined. Since a majority of samples also underwent genetic sequencing, we defined a genotypically wild-type population and measured the MIC of the 99th percentile by direct measurement and via fitting a Gaussian using interval regression. The proposed ECOFF/ECV values were then validated by comparing to the MIC distributions of high-confidence genetic variants that confer resistance and to qualitative drug susceptibility tests obtained via Mycobacterial Growth Indicator Tube and the Microscopic-Observation Drug-Susceptibility assay.

Effect of temperature and scarification on germination and emergence of wild safflower, Carthamus oxyacantha Bieb.

1975 ◽  
Vol 84 (2) ◽  
pp. 239-243 ◽  
Author(s):  
A. Bassiri ◽  
I. Rouhani ◽  
S. R. Ghorashy
Keyword(s):  
Seedling Growth ◽  
Room Temperature ◽  
Laboratory Experiments ◽  
Germination Percentage ◽  
Effect Of Temperature ◽  
Silty Clay ◽  
Wild Type ◽  
Different Temperatures ◽  
Wild Safflower ◽  
Wild Seed

SUMMARYSeeds of wild safflower, Carthamus oxyacantha Bieb., collected from the Bajgah area, Iran, were subjected to chilling and/or scarification and their germination and emergence characteristics and seedling growth were studied in two laboratory experiments. Seeds of Arak 2811 variety of cultivated safflower, C. tinctorius L., harvested from the same area at the same time was used for comparison.In the first experiment, the untreated, scarified, chilled at 0 °C for 1 month, and chilled and scarified wild seed and seed of the variety Arak 2811 were incubated at six different temperatures (5, 10, 15, 20, 25 and 30 °C) and their germination percentage and seedling lengths were recorded. In the second experiment, the seeds of the above five treatments were planted in a silty clay loam at room temperature (23 ± 2 °C) and their emergence and seedling heights were noted.In all cases, the cultivated variety, Arak 2811, had higher germination and emergence percentages and seedling heights than the wild type. Germination of both strains was greatly reduced at the two extreme temperatures (5 and 30 °C). The optimum temperatures for germination of the wild and the cultivated strains were between 15 and 20 °C.Scarification of the wild seed did not improve the germination or emergence percentages and chilling of the seed for a month at 0 °C reduced the emergence of the wild seed. Temperature of germination, however, seemed to be an important factor affecting germination and seedling growth of wild safflower.

Physical and physiological components of the graviresponses of wild-type and mutant Paramecium Tetraurelia

2000 ◽  
Vol 203 (6) ◽  
pp. 1059-1070 ◽  
Author(s):  
U. Nagel ◽  
H. Machemer
Keyword(s):  
Swimming Speed ◽  
Sedimentation Rates ◽  
Paramecium Tetraurelia ◽  
Wild Type ◽  
Centre Of Gravity ◽  
In The Wild ◽  
Type Population ◽  
G Value ◽  
Mutant Cells

Wild-type and the morphological mutant kin 241 of Paramecium tetraurelia showed improved orientation away from the centre of gravity (negative gravitaxis) when accelerations were increased from 1 to 7 g. Gravitaxis was more pronounced in the mutant. A correlation between the efficiency of orientation and the applied g value suggests a physical basis for gravitaxis. Transiently enhanced rates of reversal of the swimming direction coincided with transiently enhanced gravitaxis because reversals occurred more often in downward swimmers than in upward swimmers. The results provide evidence of a physiological modulation of gravitaxis by means of the randomizing effect of depolarization-dependent swimming reversals. Gravity bimodally altered propulsion rates of wild-type P. tetraurelia so that sedimentation was partly antagonized in upward and downward swimmers (negative gravikinesis). In the mutant, only increases in propulsion were observed, although the orientation-dependent sensitivity of the gravikinetic response was the same as in the wild-type population. Observed swimming speed and sedimentation rates in the wild-type and mutant cells were linearly related to acceleration, allowing the determination of gravikinesis as a linear (and so far non-saturating) function of gravity.

scholarly journals Dormancy-Breaking and Germination Requirements for Seeds of Sorbus alnifolia (Siebold & Zucc.) K.Koch (Rosaceae), a Mesic Forest Tree with High Ornamental Potential

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 319
Author(s):  
Yuhan Tang ◽  
Keliang Zhang ◽  
Yin Zhang ◽  
Jun Tao
Keyword(s):  
Seed Dormancy ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Natural Habitat ◽  
Eastern China ◽  
Forest Tree ◽  
Germination Percentage ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Breaking Dormancy

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.

scholarly journals Expression of a novel high-affinity purine nucleobase transport function in mutant mammalian T lymphoblasts.

1986 ◽  
Vol 6 (8) ◽  
pp. 2957-2962 ◽  
Author(s):  
B Aronow ◽  
D Toll ◽  
J Patrick ◽  
P Hollingsworth ◽  
K McCartan ◽  
...  
Keyword(s):  
Nucleoside Transport ◽  
Transport Function ◽  
Wild Type ◽  
Purine Bases ◽  
High Affinity ◽  
A Cell ◽  
Type Population ◽  
Guanine And Adenine ◽  
T Lymphoblasts ◽  
Nucleobase Transport

The single nucleoside transport function of mouse S49 lymphoblasts also transports purine bases (B. Aronow and B. Ullman, J. Biol. Chem. 261:2014-2019, 1986). This transport of purine bases by S49 cells is sensitive to inhibition by dipyridamole (DPA) and 4-nitrobenzylthioinosine, two potent inhibitors of nucleoside transport. Therefore, wild-type S49 cells cannot salvage low hypoxanthine concentrations in the presence of 10 microM DPA and 11 microM azaserine; the latter is a potent inhibitor of purine biosynthesis. Among a mutagenized wild-type population, a cell line, JPA2, was isolated which could proliferate in 50 microM hypoxanthine-11 microM azaserine-10 microM DPA. The basis for the survival of JPA2 cells under these selective conditions was expression of a unique, high-affinity purine nucleobase transport function not present in wild-type cells. JPA2 cells could transport 5 microM concentrations of hypoxanthine, guanine, and adenine 15- to 30-fold more efficiently than parental cells did. Kinetic analyses revealed that the affinity of the JPA2 transporter for all three purine bases was much greater than that of the wild-type nucleobase transport system. Moreover, nucleobase transport in JPA2 cells, unlike that in parental cells, was insensitive to inhibition by DPA, 4-nitrobenzylthioinosine, sulfhydryl reagents, and nucleosides. No alterations in nucleoside transport capability, phosphoribosylpyrophosphate levels, or purine phosphoribosyltransferase enzymes were detected in JPA2 cells. Thus, JPA2 cells express a novel nucleobase transport capability which can be distinguished from the nucleoside transport function by multiple biochemical parameters.

Propagation of yellow bells (Geleznowia verrucosa Turcz., Rutaceae) from seed

1991 ◽  
Vol 42 (5) ◽  
pp. 901 ◽  
Author(s):  
BH Paynter ◽  
KW Dixon
Keyword(s):  
Seed Dormancy ◽  
Tap Water ◽  
Germination Percentage ◽  
Percentage Germination ◽  
Untreated Seed ◽  
Factors Influencing ◽  
Germination Temperature ◽  
Commercially Important

Geleznowia verrucosa Turcz. (Rutaceae) is a commercially important, bush-picked wildflower that has no known commercial means of propagation. This study examined factors influencing seed dormancy and likely to restrict germination of the species. Germination of entire, untreated seed was low (less than 2%), but removal of a small portion of the testa at or near the radicle end of the seed improved germination. This response was affected by the temperature under which the seed germinated, but was unaffected by exposure of the seed to light while germinating. The percentage germination of nicked seeds 52 days after sowing increased from 8% to 16-19% by increasing the temperature from 15/10�C to 20/15�C; 55-60% of nicked seed germinated when the germination temperature was increased to 23/15�C. The germination of nicked seed was reduced by leaching in running tap water. Following 1 week of leaching the germination percentage of nicked seed at day 52 in the glasshouse was reduced from 16% to 9%, with a further decrease to 5% after 2 weeks of leaching. There was also no stimulatory effect on the germination of entire seeds by stratifying the seed at 5�C after periods of solarisation. It is concluded that dormancy of fresh seeds of G. verrucosa is caused, in part, by the mechanical restriction of the testa on embryo growth and elongation.

scholarly journals Factors Affecting Seed Dormancy and Germination of Greater Bur-Parsley (Turgenia latifolia)

2018 ◽  
Vol 36 ◽  
Author(s):  
M. REZVANI ◽  
S.A. SADATIAN ◽  
H. NIKKHAHKOUCHAKSARAEI
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Seed Dormancy ◽  
Seedling Emergence ◽  
Potassium Nitrate ◽  
Germination Percentage ◽  
Dormancy Breaking ◽  
Planting Depth ◽  
Factors Affecting ◽  
Drought And Salt Stresses

ABSTRACT: Our knowledge about seed dormancy breaking and environmental factors affecting seed germination of greater bur-parsley (Turgenia latifolia) is restricted. This study has addressed some seed dormancy breaking techniques, including different concentrations of gibberellic acid (GA3) and potassium nitrate (KNO3), leaching duration, physical scarification as well as some environmental factors effective on seed germination such as salt and drought stresses, pH and seed planting depth. Seed germination was promoted with lower concentrations of KNO3 (0.01 to 0.02 g L-1), while higher concentrations reduced germination percentage. Seed dormancy was declined by low concentrations of GA3 up to 100 ppm. Seeds of greater bur-parsley germinated in a range of pH from 3 to 7. With enhancement of drought and salt stresses, seed germination decreased. Also, there was no seed germination in a high level of stresses. Seedling emergence reduced as planting depth increased. Use of GA3, KNO3, leaching and physical scarification had a positive effect on seed dormancy breaking of greater bur-parsley. The information from the study increases our knowledge about seed dormancy breaking techniques, response of germination to drought and salt stresses and also determination of distribution regions of greater bur-parsley in the future.

Variation in Piceaglauca seed germination associated with the year of cone collection

1993 ◽  
Vol 23 (7) ◽  
pp. 1306-1313 ◽  
Author(s):  
G.E. Caron ◽  
B.S.P. Wang ◽  
H.O. Schooley
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Storage Period ◽  
White Spruce ◽  
Germination Percentage ◽  
Degree Days ◽  
Seed Maturity ◽  
Individual Trees ◽  
Collection Time

The effects of cone storage period and pregermination treatment on seed maturity and dormancy were compared for cones of white spruce (Piceaglauca (Moench) Voss) collected from individual trees in 1984 and 1988. Seeds were extracted from cones and germinated after 2 or 6 weeks of cone storage in 1984 and after 2, 4, 6, 10, or 14 weeks in 1988. Based on cumulative degree-days, seeds were more mature at collection time in 1988 than in 1984. Seeds from 1984 cones stored for 6 weeks matured during storage, and both germination percentage (GP) and rate of germination (GR) were significantly improved. In contrast, storage up to 14 weeks in 1988 did not increase GP and GR, as seed had attained maturity prior to cone collection. Seed dormancy was present in both 1984 and 1988. Significant improvements in GP and GR were achieved in 1984 with a pregermination treatment even before seed maturity was attained. Prechilling of seed after 6 weeks of cone storage increased GP from 60 to 95% in 1984 and 64 to 89% in 1988.

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