Effects of osmotic potential on germination of microsclerotia and growth of colonies of Verticillium dahliae

1976 ◽  
Vol 54 (11) ◽  
pp. 1214-1220 ◽  
Author(s):  
Huynh Congly ◽  
Robert Hall
Keyword(s):  
Verticillium Dahliae ◽  
Osmotic Potential ◽  
Aqueous Media ◽  
Germination Percentage ◽  
Maximum Activity ◽  
Percentage Germination ◽  
Sucrose Solutions ◽  
Agar Media ◽  
The Mean ◽  
Germ Tubes

The influence of available water, expressed as osmotic potential (ψs), on germination of microsclerotia (MS) and expansion of colonies of Verticillium dahliae was studied in osmotically adjusted aqueous and agar media. In distilled water (ψs = 0 bar) at 25 °C, 64–70% of MS germinated within 36 h and the mean number of germ tubes per germinated MS (germination vigour) was 4.7. In aqueous solutions of KCl or NaCl percentage germination and germination vigour were increasingly inhibited as ψs was lowered, reaching 50% inhibition at −11 to −14 bar and 100% inhibition at < −98 bar. In aqueous sucrose solutions germination percentage and vigour were significantly higher (P = 0.05) than in salt solutions; maximum activity occurred at −4 bar, 50% inhibition occurred at −40 bar, and 100% inhibition occurred at < −114 bar. On corn meal dextrose agar (CMDA) amended with KCl, percentage germination at 25 °C was maximal at −9 bar, was reduced 50% at −40 bar, and was 0 at −90 bar. For a given ψs, germination percentages at 25 and 30 °C were significantly greater than at 20 and 15 °C. No germination occurred at 4 or 35 °C. Where ψs was adjusted with KCl, agar media were less inhibitory to germination than aqueous media between 0 and −50 bar. On CMDA media amended with KCl, colony expansion was progressively faster as ψs was lowered from −1.1 to −13 bar, then progressively slower as ψs was lowered further. Rates of colony expansion at 20 and 25 °C were significantly greater than at 4, 15 and 30 °C. At 25 °C growth was reduced 50% at −49 bar and was completely suppressed at −119 bar.

Impact of Seed Maturation and Drought on Seed Germination and Early Seedling Growth in White Clover (Trifolium repens L.)

2021 ◽  
Author(s):  
Ruqiang Tong ◽  
Xinyuan Liu ◽  
Bifan Mu ◽  
Junfeng Wang ◽  
Mengxing Liu ◽  
...  
Keyword(s):  
Seedling Growth ◽  
White Clover ◽  
Germination Percentage ◽  
Seed Maturation ◽  
Percentage Germination ◽  
Seedling Vigour ◽  
Early Seedling Growth ◽  
Vigour Index ◽  
Early Seedling ◽  
The Mean

Background: Understanding the drought tolerance of white clover seeds during germination and early seedling growth and how that is linked to seed maturation in legume species, is crucial to developing new stand establishments.Methods: An experiment was conducted in Randomized Block design in two factorial concept to explore how seed maturation and drought tolerance influence seed germination and early seedling growth using the two factors: seed coat color (yellow and brown, two levels as one factor) and drought intensity (control: 0 MPa [distilled water], mild drought: -0.2 MPa, moderate drought: -0.4 MPa and severe drought: -0.6 MPa, four levels as another factor).Result: In contrast to the yellow-coated seeds, the mean germination percentage, germination index, seedling vigour index and radicle length of the brown-coated seeds were lowered by 7.9%, 23.1%, 20.5% and 12.9%, respectively. Compared to the control, introducing drought conditions reduced the mean of germination percentage, germination index, seedling vigour index and radicle length of yellow-coated seeds by 52.4%, 64.1%, 41.9% and 23.2%, respectively. Meanwhile, drought affected brown-coated seeds more than yellow-coated seeds. The results indicating that the seed quality of white clover seed lots with yellow-colored coats higher than the seed lots with brown-coloured coats. In agronomic practice, a larger proportion of yellow-coated seeds should be harvested to improve new stands successful establishment under environment easy to dry.

Effects of melanin-concentrating hormone on licking microstructure and brief-access taste responses

2006 ◽  
Vol 291 (5) ◽  
pp. R1265-R1274 ◽  
Author(s):  
John-Paul Baird ◽  
Catalina Rios ◽  
Nora Elizabeth Gray ◽  
Caroline Elizabeth Walsh ◽  
Shannon Glenora Fischer ◽  
...  
Keyword(s):  
Third Ventricle ◽  
Taste Stimulus ◽  
Water Solutions ◽  
The Third ◽  
Sucrose Solutions ◽  
Quinine Hydrochloride ◽  
Inhibitory Feedback ◽  
Melanin Concentrating Hormone ◽  
Taste Evaluation ◽  
The Mean

The effects of intracerebroventricular application of melanin-concentrating hormone (MCH) on licking for sucrose, quinine hydrochloride (QHCl), and water solutions were evaluated in two experiments. In experiment 1, rats received 90-min access to sucrose and water solutions after MCH or vehicle microinjection to the third ventricle (3V). MCH increased intake largely through increases in the rate of licking early in the meal and in the mean duration of lick bursts, suggesting an effect on gustatory evaluation. Therefore, in experiment 2, brief access tests were used with a series of sucrose and QHCl concentrations to behaviorally isolate the effects of intracerebroventricular MCH on gustatory evaluation. MCH uniformly increased licking for all sucrose solutions, water, and weak concentrations of QHCl; however, it had no effect on licking for the strongest concentrations of QHCl, which were generally avoided under control conditions. Thus MCH did not produce nonspecific increases in oromotor activity, nor did it change the perceived intensity of the tastants. We conclude that MCH enhanced the gain of responses to normally accepted stimuli at a phase of processing after initial gustatory detection and after the decision to accept or reject the taste stimulus. A comparison of 3V NPY and MCH effects on licking microstructure indicated that these two peptides increased intake via dichotomous behavioral processes; although NPY suppressed measures associated with inhibitory feedback from the gut, MCH appeared instead to enhance measures associated with hedonic taste evaluation.

scholarly journals Investigation of pollution level of groundwater in the ALjazaier Area, Babil

2021 ◽  
Vol 877 (1) ◽  
pp. 012004
Author(s):  
N S Hadi ◽  
Z S Jabbur
Keyword(s):  
Risk Index ◽  
Permissible Limit ◽  
Coliform Bacteria ◽  
Pollution Level ◽  
Well Water ◽  
Chemical Contamination ◽  
Total Risk ◽  
Agar Media ◽  
The Mean ◽  
The Difference

Abstract A total with 15 samples was collected from 3 wells in the aljazaier distreet in Babil governorate for the period from January to April 2020, to study the microbial contamination represented by fecal bacteria, while chemical contamination includes a physochemical and the heavy element’s properties. The goal of this study: Study the water of some wells from some microbes and chemical aspects and evaluate this according to Iraqi standards and specifications. Results showed microbial pollution by fecal Coliform bacteria in well water when using Using the agar media. Results showed the difference in the mean of (MPN) of well water. It was found that the EC value (1061) μs/cm was exceeded the permissible limit in W1, Cl values (325, 430)mg/l, pb values (0.43, 0.14) μg/l and Ni values (0.11, 0.11) μg/l and the permissible limit were exceeded in W1, W2 and SO4 values (681, 653, 584) mg / l also the permissible limit was exceeded in W1, W2 and W3 as well as Ag value (0.12) μg/l is in W1 only. The total risk index (HIT) in the groundwater for W1, W2, W3 was acceptable for adult values ΣHI( 0.23, 0.97, 3.8E-4 ) and children values ΣHI ( 2.6E-2, 1.6E-2, 1.3E-3 ) respectively.

scholarly journals SUPERAÇÃO DA DORMÊNCIA EM SEMENTES DE Plathymenia reticulata Benth.

Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 317
Author(s):  
Cássio Do Prado Borges ◽  
Cheila Deisy Ferreira ◽  
Daniela Pereira Dias
Keyword(s):  
Electrical Conductivity ◽  
Germination Percentage ◽  
Lateral Side ◽  
Detergent Solution ◽  
Sodium Hypochlorite Solution ◽  
Percentage Germination ◽  
Dormancy Breaking ◽  
Germination Speed ◽  
Mean Germination Time ◽  
T1 And T2

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.

Effect of heavy metal stress on emerging plants community constructions in wetland

2010 ◽  
Vol 62 (10) ◽  
pp. 2459-2466 ◽  
Author(s):  
Han Peng ◽  
Wu Geng ◽  
Wu Yong-quan ◽  
Li Mao-teng ◽  
Xiang Jun ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Seed Germination ◽  
Seedling Growth ◽  
Heavy Metal Stress ◽  
Germination Percentage ◽  
Percentage Germination ◽  
Wetland Ecosystem ◽  
Ecological Thresholds ◽  
Hongze Lake ◽  
Seedling Length

In this paper, we report the effects of heavy metals (HMs) (cadmium and mercury) on seed germination and seedling growth of Phragmites australis and Triarrhena sacchariflora, which are the two main typical emerging plants in Hongze Lake wetland. The results showed that there was a reduction in germination percentage, germination index and seedling length as HM concentration in the growing media increased for both treatments. The effect of HMs toxicity on seed germination and seedling growth of T. sacchariflora was more obvious than of P. australis. At the stage of seed germination, P. australis and T. sacchariflora were sensitive to Hg2 +  and Cd2 + , respectively, and Hg2 +  was more toxic than Cd2 +  at the stage of seedling growth. The effect of HMs toxicity is not invariable during plant growth. Compared to the stage of seedling growth, P. australis and T. sacchariflora are more susceptible to HMs at the stage of seed germination. In addition, we calculated the ecological thresholds of P. australis to Cd and Hg are 19.32 and 1.08 mg kg−1, and that of T. sacchariflora to Cd is 4.62 mg kg−1 based on the lab simulation. The results also indicated that the species of P. australis is more tolerant than T. sacchariflora to the HMs and is a better candidate for restoration in Hongze Lake wetland ecosystem.

The Germination and Viability of Excreted Common Crupina (Crupina vulgaris) Achenes

Weed Science ◽  
1986 ◽  
Vol 34 (2) ◽  
pp. 237-241 ◽  
Author(s):  
Donald C. Thill ◽  
David L. Zamora ◽  
Donald L. Kambitsch
Keyword(s):  
Bos Taurus ◽  
Odocoileus Hemionus ◽  
Ovis Aries ◽  
Phasianus Colchicus ◽  
Percentage Germination ◽  
Test Species ◽  
Ruminant Animals ◽  
The Mean ◽  
Large Animals

Research was conducted to determine percentage excretion and germination or viability of common crupina (Crupina vulgarisCass. # CJNVU) achenes fed to sheep (Ovis aries), cattle (Bos taurus), deer (Odocoileus hemionus), horses (Equus cabullus), and Chinese pheasants (Phasianus colchicus). No achenes were found in the feces of sheep. Horses (nonruminant), deer, and cows (both ruminant animals) excreted 5, 3, and 25%, respectively, of the achenes consumed. The mean percentage achene excretion for pheasants was 23%; however, excretion was highly variable among individuals. All achenes excreted by any test species were detected within 5 days after consumption. The percentage germination or viability of excreted achenes ranged from 29% (cows) to 81% (deer). The percentage of consumed achenes that were excreted and viable ranged from 2 to 7% for large animals, whereas it was 17% for pheasants.

scholarly journals Thermal stress and physiological changes in watermelon seeds

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
Keyword(s):  
Enzyme Activity ◽  
Thermal Stress ◽  
Germination Rate ◽  
Germination Percentage ◽  
Initial Growth ◽  
Physiological Changes ◽  
Percentage Germination ◽  
Stress Protection ◽  
Evaluation Parameters ◽  
The Ideal

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.

Allelopathic Effects of Lantana (Lantana camara) on Milkweedvine (Morrenia odorata)

Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 757-761 ◽  
Author(s):  
Nagi Reddy Achhireddy ◽  
Megh Singh
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Germination Percentage ◽  
Lantana Camara ◽  
Test Period ◽  
Percentage Germination ◽  
Allelopathic Activity ◽  
Foliar Symptoms ◽  
Allelopathic Effects ◽  
Germination And Growth

Allelopathic effects of lantana (Lantana camaraL. ♯3LANCA) residues (root, shoot), foliar leachates, and the soil (where lantana was grown) on milkweedvine (Morrenia odorataLindl. ♯3MONOD) seed germination and growth over a 30-day period were examined. Foliar leachates or the soil collected from the field where lantana had been growing had no effect on the final germination percentage or the seedling growth of milkweedvine. Incorporation of dried lantana shoot or root material into soil had no effect on the final percentage germination but caused significant reductions in milkweedvine growth over a 30-day test period. Roots were more inhibitory than shoots. Fifty percent of milkweedvine seedlings died within 15 days after germination at 1% (w/w) dried lantana root incorporation into the soil, and higher concentrations increased seedling death. Lantana roots incorporated into the soil produced foliar symptoms such as wilting and desiccation, whereas lantana shoots incorporated into the soil produced yellowing of the foliage of milkweedvine. Allelopathic activity of lantana residues was still strong even after decomposition of lantana residues for 4 weeks prior to the planting of milkweedvine seeds.

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.

Effect of seed size on germination in three species from arid Arabian deserts

Botany ◽  
2020 ◽  
Author(s):  
Sanjay Gairola ◽  
Tamer Mahmoud ◽  
Hatem A. Shabana ◽  
Asma AlKetbi ◽  
Shyam Phartyal
Keyword(s):  
Seed Size ◽  
Low Temperatures ◽  
Germination Percentage ◽  
Light Regime ◽  
Salvadora Persica ◽  
Large Size ◽  
Significant Difference ◽  
Brassica Tournefortii ◽  
The Mean ◽  
Study Species

In many species, seeds with different sizes show diverse responses in their requirements for temperature and light for optimal germination. In this study, the effect of seed size (i.e., small and large) on germination was tested in seeds of Brassica tournefortii Gouan., Lotus garcinii DC., and Salvadora persica L. from arid Arabian Desert habitats. The mean seed size of all three study species differs significantly between small and large-sized seeds. Differences were observed in seed germination between large and small seeds of B. tournefortii and L. garcinii. We found that large-size seeds of B. tournefortii and L. garcinii showed higher germination at all tested temperatures than that displayed by small-sized seeds. However, both small and large seeds of S. persica germinated equally (100%) well under all incubated conditions. Our results show significant differences in germination percentage between small and large-sized seeds of B. tournefortii at 25/35°C under a 12-hour light regime. However, L. garcinii has a significant difference in germination percentage at low temperatures (15/25°C) under a 12-hour light regime.

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