Pollen of Arbutus unedo: Effects of plant growth regulators

Arbutus unedo is a species mainly used for landscaping purposes and lately for honey production. Its antioxidant characteristics have also been a subject of of research interest. The germination of pollen grains freshly collected from flowers was tested in vitro, and 30% sucrose gave the highest pollen germination. Subsequently, three growth regulators belonging to the categories of gibberellins and brassinosteroids [24-epibrassinolide (Ebl) and 22S,23S-homobrassinolide (Hbl)] were added to the growth medium singly or in double combinations (gibberellin + brassinosteroid), and the petri dishes were kept for 24 hours at 26?1?C. The results showed that the highest germination rates were obtained from treatments with 0.01 ppm Hbl (45.47%) and 0.001 ppm Hbl (26.74%). They were followed by treatments with 0.001 ppm Ebl, 25 ppm GA3 and 0.1 ppm Ebl. As the concentration of GA3 increased, the germination rate declined considerably. Statistical analysis of the combined treatments showed that combinations of growth regulators lowered the germination rates compared to their individual application. Moreover, action of the lowest GA3 concentration (25 ppm) best matched the effects of brassinosteroids, and increasing the GA3 concentration in combined treatments did not improve germination. The highest germination was obtained with 0.1 ppm Hbl, followed by all Ebl treatments. Brassinosteroids might be an inducer of pollen germination in plants depending on their type and concentrations. When individually included in the growth medium, the extent of this induction was greater with the homobrassinolide than with the epibrassinolide. Their interactions with gibberellins are shown to be mostly dependent on the concentration of gibberellic acid used. The tested epibrassinolide was more consistent than the homobrassinolide in maintaining higher germination levels. The findings of this study indicate that gathering more information from studies involving other plant species is needed to clarify the role of brassinosteroids in in vitro and in vivo germination.

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Pollen germination of Larix sibirica (Siberian larch) in vitro

Canadian Journal of Botany ◽

10.1139/b70-032 ◽

1970 ◽

Vol 48 (2) ◽

pp. 213-215 ◽

Cited By ~ 3

Author(s):

Ronghui Ho ◽

Glenn E. Rouse

Keyword(s):

Pollen Tube ◽

Pollen Germination ◽

Generative Cell ◽

Siberian Larch ◽

Pollen Grains ◽

The Body ◽

Stalk Cell ◽

Body Cell

Mature pollen grains of Siberian larch were successfully germinated in vitro for the first time. Mature grains, containing two prothallial cells, a generative cell, and a tube cell, were incubated in stock solution B for periods up to 5 days. At the 2-day stage, the generative cell had divided into a stalk cell and body cell. In 5 days, the body nucleus had divided into two male nuclei contained within the body cell. Pollen germination was limited to elongation of the intine towards the distal pole, accompanied by a splitting of the exine, but without any suggestion of the formation of a pollen tube. This supports the suggestion of previous studies in vivo on other species of Larix pollen that a pollen tube does not form before the pollen grain reaches the nucellus of the ovule.

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Germination Characteristics and Dynamic Changes of Antioxidant Enzymes during Storage of Viola dissecta Pollen

International Journal of Agriculture and Biology ◽

10.17957/ijab/15.1736 ◽

2021 ◽

Vol 25 (04) ◽

pp. 838-844

Author(s):

Wenqing Jia

Keyword(s):

Antioxidant Enzymes ◽

Pollen Germination ◽

Room Temperature ◽

Storage Temperature ◽

Germination Rate ◽

Pollen Grains ◽

Suitable Medium ◽

Different Temperatures ◽

Surface Ornamentation

Knowledge about pollen ultra-morphology, storage characteristics and germination rate are essential for directional plant breeding and plant improvement. The objective of this study was to determine a suitable medium for pollen germination in vitro of Viola dissecta and to evaluate the effect of different storage temperatures on its pollen longevity. The pollen ultra-morphology of V. dissecta was observed using scanning electron microscopy (SEM), the suitable medium for pollen germination in vitro was determined by orthogonal test. Dried pollen of V. dissecta was stored at different temperatures (room temperature, 4, -20 and -80°C) and different storage times (24, 40, 72, 120, 184, 264 and 365 d), the germination rate of the stored pollen and the activities of SOD, POD and CAT were investigated. Pollen grains of V. dissecta were medium-sized with three germination ditches. The surface ornamentation was smooth with small grains set on the surface, which was different from Viola spp. pollen. The most suitable medium for V. dissecta was composed of 285 g•L-1 sucrose, 6 g•L-1 agar, 50 mg•L-1 GA3, 250 mg•L-1 boric acid, and 200 mg•L-1 Ca(NO3)2, The best storage temperature of pollen was -80oC, after 365 d of storage, the germination rate was still 57.86%. During storage, the pollen germination rate decreased significantly after the peak of the activities of the three antioxidant enzymes. Correlation analysis showed that SOD was major factor affecting the germination rate of V. dissecta pollen, and it has a significant positive correlation with pollen germination rate, followed by CAT and POD. SOD was a sensitive antioxidant enzyme at room temperature, 4 and -80°C, whereas at -20°C, both SOD and CAT were sensitive antioxidant enzymes. © 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers © 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers©

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Improvised Media for In Vitro Pollen Germination of some Species of Apocynaceae

International Journal of Environment ◽

10.3126/ije.v3i3.11074 ◽

2014 ◽

Vol 3 (3) ◽

pp. 146-153

Author(s):

Reshmi Chatterjee ◽

Satadip Sarkar ◽

GM Narasimha Rao

Keyword(s):

Pollen Germination ◽

Germination Rate ◽

Pollen Viability ◽

Nitrate Solution ◽

Calcium Nitrate ◽

Pollen Grains ◽

In Vitro Pollen Germination ◽

Breeding Programmes ◽

Cultural Media

Pollen germination forms one of the most important stage post pollination prior to fertilization. This is essential for proper seed setting and seed development. In vitro pollen germination test is the most reliable way of assessing the pollen viability. In the present study pollen grains of seven genera under Apocynaceae family namely, Allamanda, Alstonia, Catharanthus, Nerium, Plumeria, Thevetia and Tabernaemontana were tested in some basic cultural media, such as Brewbaker’s media, 6% Glucose solution, 4% Calcium Nitrate solution and 3% Boron solution. Alstonia pollen grains exhibited highest percentage of germination rate in all the cultural media. Glucose and Brewbaker’s media is found to be highly suitable for efficient pollen germination in all the genera. Boron solution is effective for germination of pollen grains of tree species. In vitro pollen germination can be easily carried out in laboratories. These results can be utilised in plant breeding programmes to improve cultivar and varieties. DOI: http://dx.doi.org/10.3126/ije.v3i3.11074 International Journal of Environment Vol.3(3) 2014: 146-153

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Weak Static and Extremely Low Frequency Magnetic Fields AffectIn VitroPollen Germination

The Scientific World JOURNAL ◽

10.1100/tsw.2011.83 ◽

2011 ◽

Vol 11 ◽

pp. 875-890 ◽

Cited By ~ 9

Author(s):

Lucietta Betti ◽

Grazia Trebbi ◽

Fabio Fregola ◽

Michela Zurla ◽

Pietro Mesirca ◽

...

Keyword(s):

Magnetic Field ◽

Growth Medium ◽

Pollen Germination ◽

Copper Wire ◽

Germination Rate ◽

Low Frequency ◽

Biological Marker ◽

Inhibitory Effect ◽

Extremely Low Frequency

This study concerns the effects of a weak static magnetic field (MF) at 10 μT oriented downward, combined with a 16-Hz sinusoidal MF (10 μT), onin vitropollen germination of kiwifruit (Actinidia deliciosa). Extremely low frequency magnetic field (ELF-MF) exposure was carried out by a signal generator unit connected to a copper wire solenoid, inside which samples where placed. Two different kinds of treatment were performed: direct and indirect. In the direct treatment, pollen samples were directly exposed during rehydration, germination, or both. In the indirect treatment, the pollen growth medium was prepared with water aliquots (at standard temperature of 20°C and pH = 6.74) that were exposed before use for 8 or 24 h. The main purpose of our research was to identify a biological marker (in vitropollen germination in a stressing growth medium without Ca2+) susceptible to the effects of direct or indirect ELF-MF exposure. The working variable was the pollen germination rate, as detected blind after 3 h 30 min by an Axioplan microscope. A directionally consistent recovery of germination percentage was observed both for direct exposure (during germination and both rehydration and germination phases) and water-mediated exposure (with water exposed for 24 h and immediately used). Our results suggest that the ELF-MF treatment might partially remove the inhibitory effect caused by the lack of Ca2+in the culture medium, inducing a release of internal Ca2+stored in the secretory vesicles of pollen plasma membrane. Although preliminary, findings seem to indicate thein vitropollen performance as adequate to study the effects of ELF-MFs on living matter.

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Pollen tube growth of Paeonia tenuifolia L. (Paeoniaceae) in vitro and in vivo

Bangladesh Journal of Botany ◽

10.3329/bjb.v40i1.8003 ◽

1970 ◽

Vol 40 (1) ◽

pp. 93-95 ◽

Cited By ~ 1

Author(s):

Feruzan Dane ◽

Nuran Ekici

Keyword(s):

Pollen Tube ◽

Pollen Germination ◽

Pollen Viability ◽

Pollen Grains ◽

Pollen Tubes ◽

In Vivo Studies ◽

In Vivo Growth ◽

Paeonia Tenuifolia

In vitro and in vivo studies on pollen germination of Paeonia tenuifolia L. (Paeoniaceae) revealed that pollen grains are shed at two-celled stage. Normal and abnormal pollens were observed. Pollen viability was recorded between 55 and 75%. In vitro studies revealed 85% germination and usually the germination was monosphonic. Some pollen tubes with swollen tube tip and undulations were found. Styles and stigma were found to contain many pollen tubes 24 hrs after pollination. Key words: Paeonia tenuifolia; Pollen tube; In vitro growth; In vivo growth DOI: http://dx.doi.org/10.3329/bjb.v40i1.8003 Bangladesh J. Bot. 40(1): 93-95, 2011 (June)

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Effect of pH on in vitro Pollen Germination of Fourteen Cultivated and Wild Species of Cucurbit

Journal of Bio-Science ◽

10.3329/jbs.v17i0.7120 ◽

1970 ◽

Vol 17 ◽

pp. 129-133 ◽

Cited By ~ 1

Author(s):

M Rashed Zaman

Keyword(s):

Pollen Germination ◽

Germination Rate ◽

Pollen Grains ◽

Culture Technique ◽

In Vitro Pollen Germination ◽

Effect Of Ph ◽

Germination Medium ◽

Ph Level ◽

Wax Gourd

Context: The pH of the in vitro germination medium is the important factor controlling pollen germination and pollen tube development in different plant speciesObjectives: The aim of the present study was to assess the effect of pH levels of germination medium on the germinability 14 species of cucurbit.Materials and Methods: In vitro pollen germination of 14 cucurbit species was examined at five different levels of pH using Brewbaker and Kwack's medium. The pH of the medium was adjusted to 7.0, 7.5, 8.0, 8.5 and 9.0 by using a digital pH meter with the help of 0.1 N HCl and 0.1 N NaOH. In vitro pollen germination was tested using sitting drop culture technique. Five sitting drop cultures of pollen grains of five different pH for each species were raised on five different microslides. Then the slides were placed in a humidity chamber and incubated at 22 ± 2 °C for 1 to 2 hrs. All the cultures were fixed by adding a drop of a 1-2% acetocarmine before start scoring and the germinated and non-germinated pollen grains were scored using a microscope.Results: The pollen germination rate was higher in increased pH level in most of the cucurbit species studied and at 9.0 pH the maximum germination was observed in pumpkin (98%), snake gourd (98%), ridge gourd (96%), pointed gourd (89%), cucumber (98%), bitter gourd (96%), sweet gourd (98%) and sponge gourd (93%). The highest percentage of germination was observed in bottle gourd (98%) cucumber short (96%), watermelon (98%), muskmelon (97%) and ivy gourd (87%) at 8.5 pH level. The only cucurbit species wax gourd showed highest germination (97%) at the lower pH level of 7.5. Analysis of variance for the 14 cucurbits at five different pH levels showed that the differences between the germination rates of pollen grains of 14 cucurbit species at different pH level were highly significant (F=12.49, P<0.001, at 13/52 df). Conclusion: In most of the investigated cucurbit species pH level 8.5 to 9.0 was found optimum for the highest number of in vitro pollen germination, while wax gourd responded maximum pollen germination at pH 7.5.Key words: cucurbit; pollen; germination; pH.DOI: 10.3329/jbs.v17i0.7120J. bio-sci. 17: 129-133, 2009

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In vivo and in vitro pollen maturation in Lilium: influence of carbohydrates

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1996.014 ◽

2014 ◽

Vol 65 (1-2) ◽

pp. 73-82 ◽

Cited By ~ 3

Author(s):

Christophe Clement ◽

Daniel Al-Awad ◽

Jean C. Audran

Keyword(s):

Germination Rate ◽

Starch Synthesis ◽

Pollen Grains ◽

Second Phase ◽

Flower Buds ◽

Flower Bud ◽

Pollen Maturation ◽

Microspore Stage

The purpose of this study was to develop a protocol for in vitro conform pollen maturation, as a model to study the involvement of carbohydrates on pollen maturation in Lilium. In vivo and in vitro pollen maturations were followed and compared by transmission electron microscopy, and several in vitro parameters were tested in terms of carbohydrate physiology. In vivo, pollen maturation was initiated at the vacuolated microspore stage, and consisted of two successive phases. The first phase was characterized by reactivation of microspore organelles, followed by microspore mitosis, starch synthesis and vacuole breakdown. During the second phase, starch was progressively degraded whereas lipid and phytine reserves accumulated. In vivo, pollen maturation occured within 14 days and pollen germination rate was 73.6 ± 2.2%. We then attempted to realise in vitro pollen maturation starting from the vacuolated microspore stage. The best results were obtained with flower buds cultivated at 26oC, in 100 µmol/m2/s light, with a 16h/8h photoperiod on a modified Heller's medium supplemented with NAA (10-2 mg/l) and sucrose (M/6). In these conditions, pollen maturation occured within 7 days only. In vitro matured pollen is cytologically comparable to in vivo developed pollen grains and the germination rate was 72.4 ± 3.7%. When flower buds were cultivated in the dark, the germination rate decreased, but this could be compensated by providing high sucrose concentrations (1M) in the medium. Further, photosynthesis inhibitors had the same effect on pollen maturation than the darkness, strongly suggesting that photosynthesis occurs in the flower bud and is important for pollen maturation in Lilium.

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Effect of Boron and Calcium on in Vitro and in Vivo Lowbush Blueberry Pollen Germination

HortScience ◽

10.21273/hortsci.30.4.784b ◽

1995 ◽

Vol 30 (4) ◽

pp. 784B-784

Author(s):

Youzhi Chen ◽

John M. Smagula

Keyword(s):

Pollen Germination ◽

Pollen Grains ◽

Germination Percentage ◽

Control Treatment ◽

Water Control ◽

Flower Bud ◽

Lowbush Blueberry ◽

To Receive

Ten clones of lowbush blueberry (Vaccinium angustifolium) having low leaf boron (B) concentrations (<20 ppm) were selected to receive fall foliar B (400 ppm), Ca (4000 ppm), B (400 ppm) + Ca (4000 ppm), or water (control). B concentration was raised in stem and bud tissue 3 months after application, but Ca concentration was unaffected. Two randomly selected 5-inch sod plugs from treatment plots within each clone were transported to cold storage at 2.7C for 1000 h to satisfy flower bud dormancy, then to a growth chamber at 24C to blossom. Pollen from plants receiving B had lower in vitro germination rates on 5% agar with 12% lactose after 20 h compared to control and Ca treatments. For in vivo germination, 10 blossoms were randomly selected on sod plugs of each treatment plot to receive 15 control-treatment pollen grains, which were allowed to germinate for 3 days. With the aid of fluorescence microscopy, a higher pollen germination percentage was observed in blossoms of plants receiving B, Ca, and B + Ca. B and Ca may have more influence on the ability of the stigma to stimulate pollen germination than on the germinability of pollen grains themselves.

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In Vitro Germination of Eucalyptus Pollen: Response to Variation in Boric Acid and Sucrose

Australian Journal of Botany ◽

10.1071/bt9890429 ◽

1989 ◽

Vol 37 (5) ◽

pp. 429 ◽

Cited By ~ 19

Author(s):

BM Potts ◽

JB Marsden-Smedley

Keyword(s):

Pollen Tube ◽

Boric Acid ◽

Pollen Tube Growth ◽

Pollen Germination ◽

Sucrose Concentration ◽

Response Surfaces ◽

Tube Growth ◽

Pollen Competition

The effect of boric acid (0-450 ppm) and sucrose (0-40%) on pollen germination and pollen tube growth in Eucalyptus globulus, E. morrisbyi, E. ovata and E. tirnigera was examined in vitro. Over the con- centrations tested, sucrose had by far the largest effect upon both pollen germination and tube lengths. The optimum sucrose concentration for pollen germination (30%) and pollen tube growth (20%) differed markedly with very little (<lo%) germination occurring in the absence of sucrose. The interaction of sucrose and boric acid was significant. However, in general both pollen germination and pollen tube growth were increased by the addition of up to 100 ppm boric acid, but above this level the response plateauxed. The four species differed significantly in their pattern of response to both boric acid and sucrose and the predicted optima derived from analysis of response surfaces differed between species. The predicted sucrose concentration for optimal germination and growth of E. urnigera pollen was consistently less than the other species and in terms of the optimal level of boric acid for pollen tube growth species can be ranked in the order E. globulus > E. ovata > E. morrisbyi = E. urnigera. Pollen germination and tube growth of all four species on a medium comprising 20% sucrose and 200 ppm boric acid would not differ significantly from the observed maximum response of each species and this could suffice as a generalised medium. However, if only percentage germination is to be assessed 30% sucrose would be preferable. It is argued that subtle interspecific differences in optimal in vitro con- ditions for pollen germination and pollen tube growth are likely to reflect differences in pollen physiology which in vivo may have important implications for the success of hybridisation where pollen competition occurs.

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Biofilm Formation by and Antifungal Susceptibility of Candida Isolates from Urine

Applied and Environmental Microbiology ◽

10.1128/aem.02439-06 ◽

2007 ◽

Vol 73 (6) ◽

pp. 1697-1703 ◽

Cited By ~ 86

Author(s):

N. Jain ◽

R. Kohli ◽

E. Cook ◽

P. Gialanella ◽

T. Chang ◽

...

Keyword(s):

Risk Factors ◽

Growth Medium ◽

Biofilm Formation ◽

Chart Review ◽

Antifungal Susceptibility ◽

Retrospective Chart Review ◽

Urine Samples ◽

Rpmi Medium

ABSTRACT Biofilm formation (BF) in the setting of candiduria has not been well studied. We determined BF and MIC to antifungals in Candida spp. isolates grown from urine samples of patients and performed a retrospective chart review to examine the correlation with risk factors. A total of 67 Candida spp. isolates were grown from urine samples from 55 patients. The species distribution was C. albicans (54%), C. glabrata (36%), and C. tropicalis (10%). BF varied greatly among individual Candida isolates but was stable in sequential isolates during chronic infection. BF also depended on the growth medium and especially in C. albicans was significantly enhanced in artificial urine (AU) compared to RPMI medium. In nine of the C. albicans strains BF was 4- to 10-fold higher in AU, whereas in three of the C. albicans strains and two of the C. glabrata strains higher BF was measured in RPMI medium than in AU. Determination of the MICs showed that planktonic cells of all strains were susceptible to amphotericin B (AMB) and caspofungin (CASPO) and that three of the C. glabrata strains and two of the C. albicans strains were resistant to fluconazole (FLU). In contrast, all biofilm-associated adherent cells were resistant to CASPO and FLU. The biofilms of 14 strains (28%) were sensitive to AMB (MIC50 of <1 μg/ml). Correlation between degree of BF and MIC of AMB was not seen in RPMI grown biofilms but was present when grown in AU. A retrospective chart review demonstrated no correlation of known risk factors of candiduria with BF in AU or RPMI. We conclude that BF is a stable characteristic of Candida strains that varies greatly among clinical strains and is dependent on the growth medium. Resistance to AMB is associated with higher BF in AU, which may represent the more physiologic medium to test BF. Future studies should address whether in vitro BF can predict treatment failure in vivo.

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